/*
** Copyright (c) 2007 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the Simplified BSD License (also
** known as the "2-Clause License" or "FreeBSD License".)

** This program is distributed in the hope that it will be useful,
** but without any warranty; without even the implied warranty of
** merchantability or fitness for a particular purpose.
**
** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*******************************************************************************
**
** This file contains code to implement the timeline web page
**
*/
#include "config.h"
#include <string.h>
#include <time.h>
#include "timeline.h"

/*
** The value of one second in julianday notation
*/
#define ONE_SECOND (1.0/86400.0)

/*
** timeline mode options
*/
#define TIMELINE_MODE_NONE      0
#define TIMELINE_MODE_BEFORE    1
#define TIMELINE_MODE_AFTER     2
#define TIMELINE_MODE_CHILDREN  3
#define TIMELINE_MODE_PARENTS   4

/*
** Add an appropriate tag to the output if "rid" is unpublished (private)
*/
#define UNPUB_TAG "<em>(unpublished)</em>"
void tag_private_status(int rid){
  if( content_is_private(rid) ){
    cgi_printf("%s", UNPUB_TAG);
  }
}

/*
** Generate a hyperlink to a version.
*/
void hyperlink_to_uuid(const char *zUuid){
  if( g.perm.Hyperlink ){
    @ %z(chref("timelineHistLink","%R/info/%!S",zUuid))[%S(zUuid)]</a>
  }else{
    @ <span class="timelineHistDsp">[%S(zUuid)]</span>
  }
}

/*
** Generate a hyperlink to a date & time.
*/
void hyperlink_to_date(const char *zDate, const char *zSuffix){
  if( zSuffix==0 ) zSuffix = "";
  if( g.perm.Hyperlink ){
    @ %z(href("%R/timeline?c=%T",zDate))%s(zDate)</a>%s(zSuffix)
  }else{
    @ %s(zDate)%s(zSuffix)
  }
}

/*
** Generate a hyperlink to a user.  This will link to a timeline showing
** events by that user.  If the date+time is specified, then the timeline
** is centered on that date+time.
*/
void hyperlink_to_user(const char *zU, const char *zD, const char *zSuf){
  if( zU==0 || zU[0]==0 ) zU = "anonymous";
  if( zSuf==0 ) zSuf = "";
  if( g.perm.Hyperlink ){
    if( zD && zD[0] ){
      @ %z(href("%R/timeline?c=%T&u=%T&y=a",zD,zU))%h(zU)</a>%s(zSuf)
    }else{
      @ %z(href("%R/timeline?u=%T&y=a",zU))%h(zU)</a>%s(zSuf)
    }
  }else{
    @ %s(zU)
  }
}

/*
** Allowed flags for the tmFlags argument to www_print_timeline
*/
#if INTERFACE
#define TIMELINE_ARTID    0x000001  /* Show artifact IDs on non-check-in lines*/
#define TIMELINE_LEAFONLY 0x000002  /* Show "Leaf" but not "Merge", "Fork" etc*/
#define TIMELINE_BRIEF    0x000004  /* Combine adjacent elements of same obj */
#define TIMELINE_GRAPH    0x000008  /* Compute a graph */
#define TIMELINE_DISJOINT 0x000010  /* Elements are not contiguous */
#define TIMELINE_FCHANGES 0x000020  /* Detail file changes */
#define TIMELINE_BRCOLOR  0x000040  /* Background color by branch name */
#define TIMELINE_UCOLOR   0x000080  /* Background color by user */
#define TIMELINE_FRENAMES 0x000100  /* Detail only file name changes */
#define TIMELINE_UNHIDE   0x000200  /* Unhide check-ins with "hidden" tag */
#define TIMELINE_SHOWRID  0x000400  /* Show RID values in addition to UUIDs */
#define TIMELINE_BISECT   0x000800  /* Show supplimental bisect information */
#define TIMELINE_COMPACT  0x001000  /* Use the "compact" view style */
#define TIMELINE_VERBOSE  0x002000  /* Use the "detailed" view style */
#define TIMELINE_MODERN   0x004000  /* Use the "modern" view style */
#define TIMELINE_COLUMNAR 0x008000  /* Use the "columns" view style */
#define TIMELINE_CLASSIC  0x010000  /* Use the "classic" view style */
#define TIMELINE_VIEWS    0x01f000  /* Mask for all of the view styles */
#define TIMELINE_NOSCROLL 0x100000  /* Don't scroll to the selection */
#define TIMELINE_FILEDIFF 0x200000  /* Show File differences, not ckin diffs */
#define TIMELINE_CHPICK   0x400000  /* Show cherrypick merges */
#endif

/*
** Hash a string and use the hash to determine a background color.
*/
char *hash_color(const char *z){
  int i;                       /* Loop counter */
  unsigned int h = 0;          /* Hash on the branch name */
  int r, g, b;                 /* Values for red, green, and blue */
  int h1, h2, h3, h4;          /* Elements of the hash value */
  int mx, mn;                  /* Components of HSV */
  static char zColor[10];      /* The resulting color */
  static int ix[2] = {0,0};    /* Color chooser parameters */

  if( ix[0]==0 ){
    if( skin_detail_boolean("white-foreground") ){
      ix[0] = 140;
      ix[1] = 40;
    }else{
      ix[0] = 216;
      ix[1] = 16;
    }
  }
  for(i=0; z[i]; i++ ){
    h = (h<<11) ^ (h<<1) ^ (h>>3) ^ z[i];
  }
  h1 = h % 6;  h /= 6;
  h3 = h % 30; h /= 30;
  h4 = h % 40; h /= 40;
  mx = ix[0] - h3;
  mn = mx - h4 - ix[1];
  h2 = (h%(mx - mn)) + mn;
  switch( h1 ){
    case 0:  r = mx; g = h2, b = mn;  break;
    case 1:  r = h2; g = mx, b = mn;  break;
    case 2:  r = mn; g = mx, b = h2;  break;
    case 3:  r = mn; g = h2, b = mx;  break;
    case 4:  r = h2; g = mn, b = mx;  break;
    default: r = mx; g = mn, b = h2;  break;
  }
  sqlite3_snprintf(8, zColor, "#%02x%02x%02x", r,g,b);
  return zColor;
}

/*
** COMMAND: test-hash-color
**
** Usage: %fossil test-hash-color TAG ...
**
** Print out the color names associated with each tag.  Used for
** testing the hash_color() function.
*/
void test_hash_color(void){
  int i;
  for(i=2; i<g.argc; i++){
    fossil_print("%20s: %s\n", g.argv[i], hash_color(g.argv[i]));
  }
}

/*
** WEBPAGE: hash-color-test
**
** Print out the color names associated with each tag.  Used for
** testing the hash_color() function.
*/
void test_hash_color_page(void){
  const char *zBr;
  char zNm[10];
  int i, cnt;
  login_check_credentials();

  style_header("Hash Color Test");
  for(i=cnt=0; i<10; i++){
    sqlite3_snprintf(sizeof(zNm),zNm,"b%d",i);
    zBr = P(zNm);
    if( zBr && zBr[0] ){
      @ <p style='border:1px solid;background-color:%s(hash_color(zBr));'>
      @ %h(zBr) - %s(hash_color(zBr)) -
      @ Omnes nos quasi oves erravimus unusquisque in viam
      @ suam declinavit.</p>
      cnt++;
    }
  }
  if( cnt ){
    @ <hr />
  }
  @ <form method="post" action="%s(g.zTop)/hash-color-test">
  @ <p>Enter candidate branch names below and see them displayed in their
  @ default background colors above.</p>
  for(i=0; i<10; i++){
    sqlite3_snprintf(sizeof(zNm),zNm,"b%d",i);
    zBr = P(zNm);
    @ <input type="text" size="30" name='%s(zNm)' value='%h(PD(zNm,""))'><br />
  }
  @ <input type="submit">
  @ </form>
  style_footer();
}

/*
** Return a new timelineTable id.
*/
int timeline_tableid(void){
  static int id = 0;
  return id++;
}

/*
** Output a timeline in the web format given a query.  The query
** should return these columns:
**
**    0.  rid
**    1.  UUID
**    2.  Date/Time
**    3.  Comment string
**    4.  User
**    5.  True if is a leaf
**    6.  background color
**    7.  type ("ci", "w", "t", "e", "g", "div")
**    8.  list of symbolic tags.
**    9.  tagid for ticket or wiki or event
**   10.  Short comment to user for repeated tickets and wiki
*/
void www_print_timeline(
  Stmt *pQuery,          /* Query to implement the timeline */
  int tmFlags,           /* Flags controlling display behavior */
  const char *zThisUser, /* Suppress links to this user */
  const char *zThisTag,  /* Suppress links to this tag */
  int selectedRid,       /* Highlight the line with this RID value */
  void (*xExtra)(int)    /* Routine to call on each line of display */
){
  int mxWikiLen;
  Blob comment;
  int prevTagid = 0;
  int suppressCnt = 0;
  char zPrevDate[20];
  GraphContext *pGraph = 0;
  int prevWasDivider = 0;     /* True if previous output row was <hr> */
  int fchngQueryInit = 0;     /* True if fchngQuery is initialized */
  Stmt fchngQuery;            /* Query for file changes on check-ins */
  static Stmt qbranch;
  int pendingEndTr = 0;       /* True if a </td></tr> is needed */
  int vid = 0;                /* Current checkout version */
  int dateFormat = 0;         /* 0: HH:MM (default) */
  int bCommentGitStyle = 0;   /* Only show comments through first blank line */
  const char *zStyle;         /* Sub-name for classes for the style */
  const char *zDateFmt;
  int iTableId = timeline_tableid();

  if( cgi_is_loopback(g.zIpAddr) && db_open_local(0) ){
    vid = db_lget_int("checkout", 0);
  }
  zPrevDate[0] = 0;
  mxWikiLen = db_get_int("timeline-max-comment", 0);
  dateFormat = db_get_int("timeline-date-format", 0);
  bCommentGitStyle = db_get_int("timeline-truncate-at-blank", 0);
  if( (tmFlags & TIMELINE_VIEWS)==0 ){
    tmFlags |= timeline_ss_cookie();
  }
  if( tmFlags & TIMELINE_COLUMNAR ){
    zStyle = "Columnar";
  }else if( tmFlags & TIMELINE_COMPACT ){
    zStyle = "Compact";
  }else if( tmFlags & TIMELINE_VERBOSE ){
    zStyle = "Verbose";
  }else if( tmFlags & TIMELINE_CLASSIC ){
    zStyle = "Classic";
  }else{
    zStyle = "Modern";
  }
  zDateFmt = P("datefmt");
  if( zDateFmt ) dateFormat = atoi(zDateFmt);
  if( tmFlags & TIMELINE_GRAPH ){
    pGraph = graph_init();
  }
  db_static_prepare(&qbranch,
    "SELECT value FROM tagxref WHERE tagid=%d AND tagtype>0 AND rid=:rid",
    TAG_BRANCH
  );
  if( (tmFlags & TIMELINE_CHPICK)!=0
   && !db_table_exists("repository","cherrypick")
  ){
    tmFlags &= ~TIMELINE_CHPICK;
  }

  @ <table id="timelineTable%d(iTableId)" class="timelineTable">
  blob_zero(&comment);
  while( db_step(pQuery)==SQLITE_ROW ){
    int rid = db_column_int(pQuery, 0);
    const char *zUuid = db_column_text(pQuery, 1);
    int isLeaf = db_column_int(pQuery, 5);
    const char *zBgClr = db_column_text(pQuery, 6);
    const char *zDate = db_column_text(pQuery, 2);
    const char *zType = db_column_text(pQuery, 7);
    const char *zUser = db_column_text(pQuery, 4);
    const char *zTagList = db_column_text(pQuery, 8);
    int tagid = db_column_int(pQuery, 9);
    const char *zDispUser = zUser && zUser[0] ? zUser : "anonymous";
    const char *zBr = 0;      /* Branch */
    int commentColumn = 3;    /* Column containing comment text */
    int modPending;           /* Pending moderation */
    char *zDateLink;          /* URL for the link on the timestamp */
    int drawDetailEllipsis;   /* True to show ellipsis in place of detail */
    int gidx = 0;             /* Graph row identifier */
    int isSelectedOrCurrent = 0;  /* True if current row is selected */
    char zTime[20];

    if( zDate==0 ){
      zDate = "YYYY-MM-DD HH:MM:SS";  /* Something wrong with the repo */
    }
    modPending = moderation_pending(rid);
    if( tagid ){
      if( modPending ) tagid = -tagid;
      if( tagid==prevTagid ){
        if( tmFlags & TIMELINE_BRIEF ){
          suppressCnt++;
          continue;
        }else{
          commentColumn = 10;
        }
      }
    }
    prevTagid = tagid;
    if( suppressCnt ){
      @ <span class="timelineDisabled">... %d(suppressCnt) similar
      @ event%s(suppressCnt>1?"s":"") omitted.</span>
      suppressCnt = 0;
    }
    if( pendingEndTr ){
      @ </td></tr>
      pendingEndTr = 0;
    }
    if( fossil_strcmp(zType,"div")==0 ){
      if( !prevWasDivider ){
        @ <tr><td colspan="3"><hr class="timelineMarker" /></td></tr>
      }
      prevWasDivider = 1;
      continue;
    }
    prevWasDivider = 0;
    /* Date format codes:
    **   (0)  HH:MM
    **   (1)  HH:MM:SS
    **   (2)  YYYY-MM-DD HH:MM
    **   (3)  YYMMDD HH:MM
    **   (4)  (off)
    */
    if( dateFormat<2 ){
      if( fossil_strnicmp(zDate, zPrevDate, 10) ){
        sqlite3_snprintf(sizeof(zPrevDate), zPrevDate, "%.10s", zDate);
        @ <tr class="timelineDateRow"><td>
        @   <div class="divider timelineDate">%s(zPrevDate)</div>
        @ </td><td></td><td></td></tr>
      }
      memcpy(zTime, &zDate[11], 5+dateFormat*3);
      zTime[5+dateFormat*3] = 0;
    }else if( 2==dateFormat ){
      /* YYYY-MM-DD HH:MM */
      sqlite3_snprintf(sizeof(zTime), zTime, "%.16s", zDate);
    }else if( 3==dateFormat ){
      /* YYMMDD HH:MM */
      int pos = 0;
      zTime[pos++] = zDate[2]; zTime[pos++] = zDate[3]; /* YY */
      zTime[pos++] = zDate[5]; zTime[pos++] = zDate[6]; /* MM */
      zTime[pos++] = zDate[8]; zTime[pos++] = zDate[9]; /* DD */
      zTime[pos++] = ' ';
      zTime[pos++] = zDate[11]; zTime[pos++] = zDate[12]; /* HH */
      zTime[pos++] = ':';
      zTime[pos++] = zDate[14]; zTime[pos++] = zDate[15]; /* MM */
      zTime[pos++] = 0;
    }else{
      zTime[0] = 0;
    }
    pendingEndTr = 1;
    if( rid==selectedRid ){
      @ <tr class="timelineSelected">
      isSelectedOrCurrent = 1;
    }else if( rid==vid ){
      @ <tr class="timelineCurrent">
      isSelectedOrCurrent = 1;
    }else {
      @ <tr>
    }
    if( zType[0]=='e' && tagid ){
      char *zId;
      zId = db_text(0, "SELECT substr(tagname, 7) FROM tag WHERE tagid=%d",
                        tagid);
      zDateLink = href("%R/technote/%s",zId);
      free(zId);
    }else if( zUuid ){
      zDateLink = chref("timelineHistLink", "%R/info/%!S", zUuid);
    }else{
      zDateLink = mprintf("<a>");
    }
    @ <td class="timelineTime">%z(zDateLink)%s(zTime)</a></td>
    @ <td class="timelineGraph">
    if( tmFlags & TIMELINE_UCOLOR )  zBgClr = zUser ? hash_color(zUser) : 0;
    if( zType[0]=='c'
    && (pGraph || zBgClr==0 || (tmFlags & TIMELINE_BRCOLOR)!=0)
    ){
      db_reset(&qbranch);
      db_bind_int(&qbranch, ":rid", rid);
      if( db_step(&qbranch)==SQLITE_ROW ){
        zBr = db_column_text(&qbranch, 0);
      }else{
        zBr = "trunk";
      }
      if( zBgClr==0 || (tmFlags & TIMELINE_BRCOLOR)!=0 ){
        if( zBr==0 || strcmp(zBr,"trunk")==0 ){
          zBgClr = 0;
        }else{
          zBgClr = hash_color(zBr);
        }
      }
    }
    if( zType[0]=='c' && pGraph ){
      int nParent = 0;
      int nCherrypick = 0;
      int aParent[GR_MAX_RAIL];
      static Stmt qparent;
      db_static_prepare(&qparent,
        "SELECT pid FROM plink"
        " WHERE cid=:rid AND pid NOT IN phantom"
        " ORDER BY isprim DESC /*sort*/"
      );
      db_bind_int(&qparent, ":rid", rid);
      while( db_step(&qparent)==SQLITE_ROW && nParent<count(aParent) ){
        aParent[nParent++] = db_column_int(&qparent, 0);
      }
      db_reset(&qparent);
      if( (tmFlags & TIMELINE_CHPICK)!=0 && nParent>0 ){
        static Stmt qcherrypick;
        db_static_prepare(&qcherrypick,
          "SELECT parentid FROM cherrypick"
          " WHERE childid=:rid AND parentid NOT IN phantom"
        );
        db_bind_int(&qcherrypick, ":rid", rid);
        while( db_step(&qcherrypick)==SQLITE_ROW && nParent<count(aParent) ){
          aParent[nParent++] = db_column_int(&qcherrypick, 0);
          nCherrypick++;
        }
        db_reset(&qcherrypick);
      }
      gidx = graph_add_row(pGraph, rid, nParent, nCherrypick, aParent,
                           zBr, zBgClr, zUuid, isLeaf);
      db_reset(&qbranch);
      @ <div id="m%d(gidx)" class="tl-nodemark"></div>
    }else if( zType[0]=='e' && pGraph && zBgClr && zBgClr[0] ){
      /* For technotes, make a graph node with nParent==(-1).  This will
      ** not actually draw anything on the graph, but it will set the
      ** background color of the timeline entry */
      gidx = graph_add_row(pGraph, rid, -1, 0, 0, zBr, zBgClr, zUuid, 0);
      @ <div id="m%d(gidx)" class="tl-nodemark"></div>
    }
    @</td>
    if( !isSelectedOrCurrent ){
      @ <td class="timeline%s(zStyle)Cell" id='mc%d(gidx)'>
    }else{
      @ <td class="timeline%s(zStyle)Cell">
    }
    if( pGraph && zType[0]!='c' ){
      @ &bull;
    }
    if( modPending ){
      @ <span class="modpending">(Awaiting Moderator Approval)</span>
    }
    if( (tmFlags & TIMELINE_BISECT)!=0 && zType[0]=='c' ){
      static Stmt bisectQuery;
      db_static_prepare(&bisectQuery,
          "SELECT seq, stat FROM bilog WHERE rid=:rid");
      db_bind_int(&bisectQuery, ":rid", rid);
      if( db_step(&bisectQuery)==SQLITE_ROW ){
        @ <b>%s(db_column_text(&bisectQuery,1))</b>
        @ (%d(db_column_int(&bisectQuery,0)))
      }
      db_reset(&bisectQuery);
    }
    drawDetailEllipsis = (tmFlags & (TIMELINE_COMPACT))!=0;
    db_column_blob(pQuery, commentColumn, &comment);
    if( tmFlags & TIMELINE_COMPACT ){
      @ <span class='timelineCompactComment' data-id='%d(rid)'>
    }else{
      @ <span class='timeline%s(zStyle)Comment'>
    }
    if( (tmFlags & TIMELINE_CLASSIC)!=0 ){
      if( zType[0]=='c' ){
        hyperlink_to_uuid(zUuid);
        if( isLeaf ){
          if( db_exists("SELECT 1 FROM tagxref"
                        " WHERE rid=%d AND tagid=%d AND tagtype>0",
                        rid, TAG_CLOSED) ){
            @ <span class="timelineLeaf">Closed-Leaf:</span>
          }else{
            @ <span class="timelineLeaf">Leaf:</span>
          }
        }
      }else if( zType[0]=='e' && tagid ){
        hyperlink_to_event_tagid(tagid<0?-tagid:tagid);
      }else if( (tmFlags & TIMELINE_ARTID)!=0 ){
        hyperlink_to_uuid(zUuid);
      }
      if( tmFlags & TIMELINE_SHOWRID ){
        int srcId = delta_source_rid(rid);
        if( srcId ){
          @ (%d(rid)&larr;%d(srcId))
        }else{
          @ (%d(rid))
        }
      }
    }
    if( zType[0]!='c' ){
      /* Comments for anything other than a check-in are generated by
      ** "fossil rebuild" and expect to be rendered as text/x-fossil-wiki */
      if( zType[0]=='w' ) wiki_hyperlink_override(zUuid);
      wiki_convert(&comment, 0, WIKI_INLINE);
      wiki_hyperlink_override(0);
    }else{
      if( bCommentGitStyle ){
        /* Truncate comment at first blank line */
        int ii, jj;
        int n = blob_size(&comment);
        char *z = blob_str(&comment);
        for(ii=0; ii<n; ii++){
          if( z[ii]=='\n' ){
            for(jj=ii+1; jj<n && z[jj]!='\n' && fossil_isspace(z[jj]); jj++){}
            if( z[jj]=='\n' ) break;
          }
        }
        z[ii] = 0;
        cgi_printf("%W",z);
      }else if( mxWikiLen>0 && blob_size(&comment)>mxWikiLen ){
        Blob truncated;
        blob_zero(&truncated);
        blob_append(&truncated, blob_buffer(&comment), mxWikiLen);
        blob_append(&truncated, "...", 3);
        @ %W(blob_str(&truncated))
        blob_reset(&truncated);
        drawDetailEllipsis = 0;
      }else{
        cgi_printf("%W",blob_str(&comment));
      }
    }
    @ </span>
    blob_reset(&comment);

    /* Generate extra information and hyperlinks to follow the comment.
    ** Example:  "(check-in: [abcdefg], user: drh, tags: trunk)"
    */
    if( drawDetailEllipsis ){
      @ <span class='timelineEllipsis' id='ellipsis-%d(rid)' \
      @ data-id='%d(rid)'>...</span>
    }
    if( tmFlags & TIMELINE_COLUMNAR ){
      if( !isSelectedOrCurrent ){
        @ <td class="timelineDetailCell" id='md%d(gidx)'>
      }else{
        @ <td class="timelineDetailCell">
      }
    }
    if( tmFlags & TIMELINE_COMPACT ){
      cgi_printf("<span class='clutter' id='detail-%d'>",rid);
    }
    cgi_printf("<span class='timeline%sDetail'>", zStyle);
    if( (tmFlags & (TIMELINE_CLASSIC|TIMELINE_VERBOSE|TIMELINE_COMPACT))!=0 ){
      cgi_printf("(");
    }

    if( (tmFlags & TIMELINE_CLASSIC)==0 ){
      if( zType[0]=='c' ){
        if( isLeaf ){
          if( db_exists("SELECT 1 FROM tagxref"
                        " WHERE rid=%d AND tagid=%d AND tagtype>0",
                        rid, TAG_CLOSED) ){
            @ <span class='timelineLeaf'>Closed-Leaf</span>
          }else{
            @ <span class='timelineLeaf'>Leaf</span>
          }
        }
        cgi_printf("check-in:&nbsp;%z%S</a> ",href("%R/info/%!S",zUuid),zUuid);
      }else if( zType[0]=='e' && tagid ){
        cgi_printf("technote:&nbsp;");
        hyperlink_to_event_tagid(tagid<0?-tagid:tagid);
      }else{
        cgi_printf("artifact:&nbsp;%z%S</a> ",href("%R/info/%!S",zUuid),zUuid);
      }
    }else if( zType[0]=='g' || zType[0]=='w' || zType[0]=='t' || zType[0]=='f'){
      cgi_printf("artifact:&nbsp;%z%S</a> ",href("%R/info/%!S",zUuid),zUuid);
    }

    if( g.perm.Hyperlink && fossil_strcmp(zDispUser, zThisUser)!=0 ){
      char *zLink = mprintf("%R/timeline?u=%h&c=%t&y=a", zDispUser, zDate);
      cgi_printf("user:&nbsp;%z%h</a>", href("%z",zLink), zDispUser);
    }else{
      cgi_printf("user:&nbsp;%h", zDispUser);
    }

    /* Generate the "tags: TAGLIST" at the end of the comment, together
    ** with hyperlinks to the tag list.
    */
    if( zTagList && zTagList[0]==0 ) zTagList = 0;
    if( zTagList ){
      if( g.perm.Hyperlink ){
        int i;
        const char *z = zTagList;
        Blob links;
        blob_zero(&links);
        while( z && z[0] ){
          for(i=0; z[i] && (z[i]!=',' || z[i+1]!=' '); i++){}
          if( zThisTag==0 || memcmp(z, zThisTag, i)!=0 || zThisTag[i]!=0 ){
            blob_appendf(&links,
                  "%z%#h</a>%.2s",
                  href("%R/timeline?r=%#t&c=%t",i,z,zDate), i,z, &z[i]
            );
          }else{
            blob_appendf(&links, "%#h", i+2, z);
          }
          if( z[i]==0 ) break;
          z += i+2;
        }
        cgi_printf(" tags:&nbsp;%s", blob_str(&links));
        blob_reset(&links);
      }else{
        cgi_printf(" tags:&nbsp;%h", zTagList);
      }
    }

    if( tmFlags & TIMELINE_SHOWRID ){
      int srcId = delta_source_rid(rid);
      if( srcId ){
        cgi_printf(" id:&nbsp;%d&larr;%d", rid, srcId);
      }else{
        cgi_printf(" id:&nbsp;%d", rid);
      }
    }
    tag_private_status(rid);
    if( xExtra ){
      xExtra(rid);
    }
    /* End timelineDetail */
    if( (tmFlags & (TIMELINE_CLASSIC|TIMELINE_VERBOSE|TIMELINE_COMPACT))!=0 ){
      cgi_printf(")");
    }
    if( tmFlags & TIMELINE_COMPACT ){
      @ </span></span>
    }else{
      @ </span>
    }

    /* Generate the file-change list if requested */
    if( (tmFlags & (TIMELINE_FCHANGES|TIMELINE_FRENAMES))!=0
     && zType[0]=='c' && g.perm.Hyperlink
    ){
      int inUl = 0;
      if( !fchngQueryInit ){
        db_prepare(&fchngQuery,
          "SELECT pid,"
          "       fid,"
          "       (SELECT name FROM filename WHERE fnid=mlink.fnid) AS name,"
          "       (SELECT uuid FROM blob WHERE rid=fid),"
          "       (SELECT uuid FROM blob WHERE rid=pid),"
          "       (SELECT name FROM filename WHERE fnid=mlink.pfnid) AS oldnm"
          "  FROM mlink"
          " WHERE mid=:mid AND (pid!=fid OR pfnid>0)"
          "   AND (fid>0 OR"
               "   fnid NOT IN (SELECT pfnid FROM mlink WHERE mid=:mid))"
          "   AND NOT mlink.isaux"
          " ORDER BY 3 /*sort*/"
        );
        fchngQueryInit = 1;
      }
      db_bind_int(&fchngQuery, ":mid", rid);
      while( db_step(&fchngQuery)==SQLITE_ROW ){
        const char *zFilename = db_column_text(&fchngQuery, 2);
        int isNew = db_column_int(&fchngQuery, 0)<=0;
        int isMergeNew = db_column_int(&fchngQuery, 0)<0;
        int fid = db_column_int(&fchngQuery, 1);
        int isDel = fid==0;
        const char *zOldName = db_column_text(&fchngQuery, 5);
        const char *zOld = db_column_text(&fchngQuery, 4);
        const char *zNew = db_column_text(&fchngQuery, 3);
        const char *zUnpub = "";
        char *zA;
        char zId[40];
        if( !inUl ){
          @ <ul class="filelist">
          inUl = 1;
        }
        if( tmFlags & TIMELINE_SHOWRID ){
          int srcId = delta_source_rid(fid);
          if( srcId ){
            sqlite3_snprintf(sizeof(zId), zId, " (%d&larr;%d) ", fid, srcId);
          }else{
            sqlite3_snprintf(sizeof(zId), zId, " (%d) ", fid);
          }
        }else{
          zId[0] = 0;
        }
        if( (tmFlags & TIMELINE_FRENAMES)!=0 ){
          if( !isNew && !isDel && zOldName!=0 ){
            @ <li> %h(zOldName) &rarr; %h(zFilename)%s(zId)
          }
          continue;
        }
        zA = href("%R/artifact/%!S",fid?zNew:zOld);
        if( content_is_private(fid) ){
          zUnpub = UNPUB_TAG;
        }
        if( isNew ){
          @ <li> %s(zA)%h(zFilename)</a>%s(zId) %s(zUnpub)
          if( isMergeNew ){
            @ (added by merge)
          }else{
            @ (new file)
          }
          @ &nbsp; %z(href("%R/artifact/%!S",zNew))[view]</a></li>
        }else if( isDel ){
          @ <li> %s(zA)%h(zFilename)</a> (deleted)</li>
        }else if( fossil_strcmp(zOld,zNew)==0 && zOldName!=0 ){
          @ <li> %h(zOldName) &rarr; %s(zA)%h(zFilename)</a>%s(zId)
          @ %s(zUnpub) %z(href("%R/artifact/%!S",zNew))[view]</a></li>
        }else{
          if( zOldName!=0 ){
            @ <li>%h(zOldName) &rarr; %s(zA)%h(zFilename)%s(zId)</a> %s(zUnpub)
          }else{
            @ <li>%s(zA)%h(zFilename)</a>%s(zId) &nbsp; %s(zUnpub)
          }
          @ %z(href("%R/fdiff?v1=%!S&v2=%!S",zOld,zNew))[diff]</a></li>
        }
        fossil_free(zA);
      }
      db_reset(&fchngQuery);
      if( inUl ){
        @ </ul>
      }
    }
  }
  if( suppressCnt ){
    @ <span class="timelineDisabled">... %d(suppressCnt) similar
    @ event%s(suppressCnt>1?"s":"") omitted.</span>
    suppressCnt = 0;
  }
  if( pendingEndTr ){
    @ </td></tr>
  }
  if( pGraph ){
    graph_finish(pGraph, (tmFlags & TIMELINE_DISJOINT)!=0);
    if( pGraph->nErr ){
      graph_free(pGraph);
      pGraph = 0;
    }else{
      @ <tr class="timelineBottom" id="btm-%d(iTableId)">\
      @ <td></td><td></td><td></td></tr>
    }
  }
  @ </table>
  if( fchngQueryInit ) db_finalize(&fchngQuery);
  timeline_output_graph_javascript(pGraph, tmFlags, iTableId);
}

/*
** Change the RGB background color given in the argument in a foreground
** color with the same hue.
*/
static const char *bg_to_fg(const char *zIn){
  int i;
  unsigned int x[3];
  unsigned int mx = 0;
  static int whiteFg = -1;
  static char zRes[10];
  if( strlen(zIn)!=7 || zIn[0]!='#' ) return zIn;
  zIn++;
  for(i=0; i<3; i++){
    x[i] = hex_digit_value(zIn[0])*16 + hex_digit_value(zIn[1]);
    zIn += 2;
    if( x[i]>mx ) mx = x[i];
  }
  if( whiteFg<0 ) whiteFg = skin_detail_boolean("white-foreground");
  if( whiteFg ){
    /* Make the color lighter */
    static const unsigned int t = 215;
    if( mx<t ) for(i=0; i<3; i++) x[i] += t - mx;
  }else{
    /* Make the color darker */
    static const unsigned int t = 128;
    if( mx>t ){
      for(i=0; i<3; i++){
        x[i] = x[i]>=mx-t ? x[i] - (mx-t) : 0;
      }
    }
  }
  sqlite3_snprintf(sizeof(zRes),zRes,"#%02x%02x%02x",x[0],x[1],x[2]);
  return zRes;
}

/*
** Generate all of the necessary javascript to generate a timeline
** graph.
*/
void timeline_output_graph_javascript(
  GraphContext *pGraph,     /* The graph to be displayed */
  int tmFlags,              /* Flags that control rendering */
  int iTableId              /* Which graph is this for */
){
  if( pGraph && pGraph->nErr==0 ){
    GraphRow *pRow;
    int i;
    char cSep;
    int iRailPitch;      /* Pixels between consecutive rails */
    int showArrowheads;  /* True to draw arrowheads.  False to omit. */
    int circleNodes;     /* True for circle nodes.  False for square nodes */
    int colorGraph;      /* Use colors for graph lines */
    int iTopRow;         /* Index of the top row of the graph */
    int fileDiff;        /* True for file diff.  False for check-in diff */
    int omitDescenders;  /* True to omit descenders */
    int scrollToSelect;  /* True to scroll to the selection */

    iRailPitch = atoi(PD("railpitch","0"));
    showArrowheads = skin_detail_boolean("timeline-arrowheads");
    circleNodes = skin_detail_boolean("timeline-circle-nodes");
    colorGraph = skin_detail_boolean("timeline-color-graph-lines");
    iTopRow = pGraph->pFirst ? pGraph->pFirst->idx : 0;
    omitDescenders = (tmFlags & TIMELINE_DISJOINT)!=0;
    fileDiff = (tmFlags & TIMELINE_FILEDIFF)!=0;
    scrollToSelect = (tmFlags & TIMELINE_NOSCROLL)==0;
    @ <script id='timeline-data-%d(iTableId)' type='application/json'>{
    @   "iTableId": %d(iTableId),
    @   "circleNodes": %d(circleNodes),
    @   "showArrowheads": %d(showArrowheads),
    @   "iRailPitch": %d(iRailPitch),
    @   "colorGraph": %d(colorGraph),
    @   "nomo": %d(PB("nomo")),
    @   "iTopRow": %d(iTopRow),
    @   "omitDescenders": %d(omitDescenders),
    @   "fileDiff": %d(fileDiff),
    @   "scrollToSelect": %d(scrollToSelect),
    @   "nrail": %d(pGraph->mxRail+1),
    @   "baseUrl": "%R",
    @   "bottomRowId": "btm-%d(iTableId)",
    if( pGraph->nRow==0 ){
      @   "rowinfo": null
    }else{
      @   "rowinfo": [
    }

    /* the rowinfo[] array contains all the information needed to generate
    ** the graph.  Each entry contains information for a single row:
    **
    **   id:  The id of the <div> element for the row. This is an integer.
    **        to get an actual id, prepend "m" to the integer.  The top node
    **        is iTopRow and numbers increase moving down the timeline.
    **   bg:  The background color for this row
    **    r:  The "rail" that the node for this row sits on.  The left-most
    **        rail is 0 and the number increases to the right.
    **    d:  If exists and true then there is a "descender" - an arrow
    **        coming from the bottom of the page straight up to this node.
    **   mo:  "merge-out".  If it exists, this is the rail position
    **        for the upward portion of a merge arrow.  The merge arrow goes as
    **        a solid normal merge line up to the row identified by "mu" and
    **        then as a dashed cherrypick merge line up further to "cu".
    **        If this value is omitted if there are no merge children.
    **   mu:  The id of the row which is the top of the merge-out arrow.
    **        Only exists if "mo" exists.
    **   cu:  Extend the mu merge arrow up to this row as a cherrypick
    **        merge line, if this value exists.
    **    u:  Draw a thick child-line out of the top of this node and up to
    **        the node with an id equal to this value.  0 if it is straight to
    **        the top of the page, -1 if there is no thick-line riser.
    **   sb:  Draw a dotted child-line out of the top of this node up to the
    **        node with the id equal to the value.  This is like "u" except
    **        that the line is dotted instead of solid and has no arrow.
    **        Mnemonic: "Same Branch".
    **    f:  0x01: a leaf node.
    **   au:  An array of integers that define thick-line risers for branches.
    **        The integers are in pairs.  For each pair, the first integer is
    **        is the rail on which the riser should run and the second integer
    **        is the id of the node upto which the riser should run. If there
    **        are no risers, this array does not exist.
    **   mi:  "merge-in".  An array of integer rail positions from which
    **        merge arrows should be drawn into this node.  If the value is
    **        negative, then the rail position is the absolute value of mi[]
    **        and a thin merge-arrow descender is drawn to the bottom of
    **        the screen. This array is omitted if there are no inbound
    **        merges.
    **   ci:  "cherrypick-in". Like "mi" except for cherrypick merges.
    **        omitted if there are no cherrypick merges.
    **    h:  The artifact hash of the object being graphed
    */
    for(pRow=pGraph->pFirst; pRow; pRow=pRow->pNext){
      int k = 0;
      cgi_printf("{\"id\":%d,",     pRow->idx);
      cgi_printf("\"bg\":\"%s\",",  pRow->zBgClr);
      cgi_printf("\"r\":%d,",       pRow->iRail);
      if( pRow->bDescender ){
        cgi_printf("\"d\":%d,",       pRow->bDescender);
      }
      if( pRow->mergeOut>=0 ){
        cgi_printf("\"mo\":%d,",      pRow->mergeOut);
        if( pRow->mergeUpto==0 ) pRow->mergeUpto = pRow->idx;
        cgi_printf("\"mu\":%d,",      pRow->mergeUpto);
        if( pRow->cherrypickUpto>0 && pRow->cherrypickUpto<pRow->mergeUpto ){
          cgi_printf("\"cu\":%d,",    pRow->cherrypickUpto);
        }
      }
      if( pRow->isStepParent ){
        cgi_printf("\"sb\":%d,",      pRow->aiRiser[pRow->iRail]);
      }else{
        cgi_printf("\"u\":%d,",       pRow->aiRiser[pRow->iRail]);
      }
      k = 0;
      if( pRow->isLeaf ) k |= 1;
      cgi_printf("\"f\":%d,",k);
      for(i=k=0; i<GR_MAX_RAIL; i++){
        if( i==pRow->iRail ) continue;
        if( pRow->aiRiser[i]>0 ){
          if( k==0 ){
            cgi_printf("\"au\":");
            cSep = '[';
          }
          k++;
          cgi_printf("%c%d,%d", cSep, i, pRow->aiRiser[i]);
          cSep = ',';
        }
      }
      if( k ){
        cgi_printf("],");
      }
      if( colorGraph && pRow->zBgClr[0]=='#' ){
        cgi_printf("\"fg\":\"%s\",", bg_to_fg(pRow->zBgClr));
      }
      /* mi */
      for(i=k=0; i<GR_MAX_RAIL; i++){
        if( pRow->mergeIn[i]==1 ){
          int mi = i;
          if( (pRow->mergeDown >> i) & 1 ) mi = -mi;
          if( k==0 ){
            cgi_printf("\"mi\":");
            cSep = '[';
          }
          k++;
          cgi_printf("%c%d", cSep, mi);
          cSep = ',';
        }
      }
      if( k ) cgi_printf("],");
      /* ci */
      for(i=k=0; i<GR_MAX_RAIL; i++){
        if( pRow->mergeIn[i]==2 ){
          int mi = i;
          if( (pRow->cherrypickDown >> i) & 1 ) mi = -mi;
          if( k==0 ){
            cgi_printf("\"ci\":");
            cSep = '[';
          }
          k++;
          cgi_printf("%c%d", cSep, mi);
          cSep = ',';
        }
      }
      if( k ) cgi_printf("],");
      cgi_printf("\"h\":\"%!S\"}%s",
                 pRow->zUuid, pRow->pNext ? ",\n" : "]\n");
    }
    @ }</script>
    style_graph_generator();
    graph_free(pGraph);
  }
}

/*
** Create a temporary table suitable for storing timeline data.
*/
static void timeline_temp_table(void){
  static const char zSql[] =
    @ CREATE TEMP TABLE IF NOT EXISTS timeline(
    @   rid INTEGER PRIMARY KEY,
    @   uuid TEXT,
    @   timestamp TEXT,
    @   comment TEXT,
    @   user TEXT,
    @   isleaf BOOLEAN,
    @   bgcolor TEXT,
    @   etype TEXT,
    @   taglist TEXT,
    @   tagid INTEGER,
    @   short TEXT,
    @   sortby REAL
    @ )
  ;
  db_multi_exec("%s", zSql/*safe-for-%s*/);
}

/*
** Return a pointer to a constant string that forms the basis
** for a timeline query for the WWW interface.
*/
const char *timeline_query_for_www(void){
  static const char zBase[] =
    @ SELECT
    @   blob.rid AS blobRid,
    @   uuid AS uuid,
    @   datetime(event.mtime,toLocal()) AS timestamp,
    @   coalesce(ecomment, comment) AS comment,
    @   coalesce(euser, user) AS user,
    @   blob.rid IN leaf AS leaf,
    @   bgcolor AS bgColor,
    @   event.type AS eventType,
    @   (SELECT group_concat(substr(tagname,5), ', ') FROM tag, tagxref
    @     WHERE tagname GLOB 'sym-*' AND tag.tagid=tagxref.tagid
    @       AND tagxref.rid=blob.rid AND tagxref.tagtype>0) AS tags,
    @   tagid AS tagid,
    @   brief AS brief,
    @   event.mtime AS mtime
    @  FROM event CROSS JOIN blob
    @ WHERE blob.rid=event.objid
  ;
  return zBase;
}

/*
** Convert a symbolic name used as an argument to the a=, b=, or c=
** query parameters of timeline into a julianday mtime value.
*/
double symbolic_name_to_mtime(const char *z, const char **pzDisplay){
  double mtime;
  int rid;
  const char *zDate;
  if( z==0 ) return -1.0;
  if( fossil_isdate(z) ){
    mtime = db_double(0.0, "SELECT julianday(%Q,fromLocal())", z);
    if( mtime>0.0 ) return mtime;
  }
  zDate = fossil_expand_datetime(z, 1);
  if( zDate!=0
   && (mtime = db_double(0.0, "SELECT julianday(%Q,fromLocal())", zDate))>0.0
  ){
    if( pzDisplay ) *pzDisplay = fossil_strdup(zDate);
    return mtime;
  }
  rid = symbolic_name_to_rid(z, "*");
  if( rid ){
    mtime = db_double(0.0, "SELECT mtime FROM event WHERE objid=%d", rid);
  }else{
    mtime = db_double(-1.0,
        "SELECT max(event.mtime) FROM event, tag, tagxref"
        " WHERE tag.tagname GLOB 'event-%q*'"
        "   AND tagxref.tagid=tag.tagid AND tagxref.tagtype"
        "   AND event.objid=tagxref.rid",
        z
    );
  }
  return mtime;
}

/*
** zDate is a localtime date.  Insert records into the
** "timeline" table to cause <hr> to be inserted on zDate.
*/
static int timeline_add_divider(double rDate){
  int rid = db_int(-1,
    "SELECT rid FROM timeline ORDER BY abs(sortby-%.16g) LIMIT 1", rDate
  );
  if( rid>0 ) return rid;
  db_multi_exec(
    "INSERT INTO timeline(rid,sortby,etype) VALUES(-1,%.16g,'div')",
    rDate
  );
  return -1;
}

/*
** Return all possible names for file zUuid.
*/
char *names_of_file(const char *zUuid){
  Stmt q;
  Blob out;
  const char *zSep = "";
  db_prepare(&q,
    "SELECT DISTINCT filename.name FROM mlink, filename"
    " WHERE mlink.fid=(SELECT rid FROM blob WHERE uuid=%Q)"
    "   AND filename.fnid=mlink.fnid",
    zUuid
  );
  blob_zero(&out);
  while( db_step(&q)==SQLITE_ROW ){
    const char *zFN = db_column_text(&q, 0);
    blob_appendf(&out, "%s%z%h</a>", zSep,
          href("%R/finfo?name=%t&m=%!S", zFN, zUuid), zFN);
    zSep = " or ";
  }
  db_finalize(&q);
  return blob_str(&out);
}


/*
** Add the select/option box to the timeline submenu that is used to
** set the y= parameter that determines which elements to display
** on the timeline.
*/
static void timeline_y_submenu(int isDisabled){
  static int i = 0;
  static const char *az[14];
  if( i==0 ){
    az[0] = "all";
    az[1] = "Any Type";
    i = 2;
    if( g.perm.Read ){
      az[i++] = "ci";
      az[i++] = "Check-ins";
      az[i++] = "g";
      az[i++] = "Tags";
    }
    if( g.perm.RdWiki ){
      az[i++] = "e";
      az[i++] = "Tech Notes";
    }
    if( g.perm.RdTkt ){
      az[i++] = "t";
      az[i++] = "Tickets";
    }
    if( g.perm.RdWiki ){
      az[i++] = "w";
      az[i++] = "Wiki";
    }
    if( g.perm.RdForum ){
      az[i++] = "f";
      az[i++] = "Forum";
    }
    assert( i<=count(az) );
  }
  if( i>2 ){
    style_submenu_multichoice("y", i/2, az, isDisabled);
  }
}

/*
** Convert the current "ss" display preferences cookie into an
** appropriate TIMELINE_* flag
*/
int timeline_ss_cookie(void){
  int tmFlags;
  switch( cookie_value("ss","m")[0] ){
    case 'c':  tmFlags = TIMELINE_COMPACT;  break;
    case 'v':  tmFlags = TIMELINE_VERBOSE;  break;
    case 'j':  tmFlags = TIMELINE_COLUMNAR; break;
    case 'x':  tmFlags = TIMELINE_CLASSIC;  break;
    default:   tmFlags = TIMELINE_MODERN;   break;
  }    
  return tmFlags;
}

/*
** Add the select/option box to the timeline submenu that is used to
** set the ss= parameter that determines the viewing mode.
**
** Return the TIMELINE_* value appropriate for the view-style.
*/
int timeline_ss_submenu(void){
  static const char *azViewStyles[] = {
     "m", "Modern View",
     "j", "Columnar View",
     "c", "Compact View",
     "v", "Verbose View",
     "x", "Classic View",
  };
  cookie_link_parameter("ss","ss","m");
  style_submenu_multichoice("ss", sizeof(azViewStyles)/(2*sizeof(azViewStyles[0])),
                            azViewStyles, 0);
  return timeline_ss_cookie();
}

/*
** If the zChng string is not NULL, then it should be a comma-separated
** list of glob patterns for filenames.  Add an term to the WHERE clause
** for the SQL statement under construction that excludes any check-in that
** does not modify one or more files matching the globs.
*/
static void addFileGlobExclusion(
  const char *zChng,        /* The filename GLOB list */
  Blob *pSql                /* The SELECT statement under construction */
){
  if( zChng==0 || zChng[0]==0 ) return;
  blob_append_sql(pSql," AND event.objid IN ("
      "SELECT mlink.mid FROM mlink, filename"
      " WHERE mlink.fnid=filename.fnid AND %s)",
      glob_expr("filename.name", zChng));
}
static void addFileGlobDescription(
  const char *zChng,        /* The filename GLOB list */
  Blob *pDescription        /* Result description */
){
  if( zChng==0 || zChng[0]==0 ) return;
  blob_appendf(pDescription, " that include changes to files matching '%h'",
               zChng);
}

/*
** Tag match expression type code.
*/
typedef enum {
  MS_EXACT,   /* Matches a single tag by exact string comparison. */
  MS_GLOB,    /* Matches tags against a list of GLOB patterns. */
  MS_LIKE,    /* Matches tags against a list of LIKE patterns. */
  MS_REGEXP   /* Matches tags against a list of regular expressions. */
} MatchStyle;

/*
** Quote a tag string by surrounding it with double quotes and preceding
** internal double quotes and backslashes with backslashes.
*/
static const char *tagQuote(
   int len,         /* Maximum length of zTag, or negative for unlimited */
   const char *zTag /* Tag string */
){
  Blob blob = BLOB_INITIALIZER;
  int i, j;
  blob_zero(&blob);
  blob_append(&blob, "\"", 1);
  for( i=j=0; zTag[j] && (len<0 || j<len); ++j ){
    if( zTag[j]=='\"' || zTag[j]=='\\' ){
      if( j>i ){
        blob_append(&blob, zTag+i, j-i);
      }
      blob_append(&blob, "\\", 1);
      i = j;
    }
  }
  if( j>i ){
    blob_append(&blob, zTag+i, j-i);
  }
  blob_append(&blob, "\"", 1);
  return blob_str(&blob);
}

/*
** Construct the tag match SQL expression.
**
** This function is adapted from glob_expr() to support the MS_EXACT, MS_GLOB,
** MS_LIKE, and MS_REGEXP match styles.  For MS_EXACT, the returned expression
** checks for integer match against the tag ID which is looked up directly by
** this function.  For the other modes, the returned SQL expression performs
** string comparisons against the tag names, so it is necessary to join against
** the tag table to access the "tagname" column.
**
** Each pattern is adjusted to to start with "sym-" and be anchored at end.
**
** In MS_REGEXP mode, backslash can be used to protect delimiter characters.
** The backslashes are not removed from the regular expression.
**
** In addition to assembling and returning an SQL expression, this function
** makes an English-language description of the patterns being matched, suitable
** for display in the web interface.
**
** If any errors arise during processing, *zError is set to an error message.
** Otherwise it is set to NULL.
*/
static const char *tagMatchExpression(
  MatchStyle matchStyle,        /* Match style code */
  const char *zTag,             /* Tag name, match pattern, or pattern list */
  const char **zDesc,           /* Output expression description string */
  const char **zError           /* Output error string */
){
  Blob expr = BLOB_INITIALIZER; /* SQL expression string assembly buffer */
  Blob desc = BLOB_INITIALIZER; /* English description of match patterns */
  Blob err = BLOB_INITIALIZER;  /* Error text assembly buffer */
  const char *zStart;           /* Text at start of expression */
  const char *zDelimiter;       /* Text between expression terms */
  const char *zEnd;             /* Text at end of expression */
  const char *zPrefix;          /* Text before each match pattern */
  const char *zSuffix;          /* Text after each match pattern */
  const char *zIntro;           /* Text introducing pattern description */
  const char *zPattern = 0;     /* Previous quoted pattern */
  const char *zFail = 0;        /* Current failure message or NULL if okay */
  const char *zOr = " or ";     /* Text before final quoted pattern */
  char cDel;                    /* Input delimiter character */
  int i;                        /* Input match pattern length counter */

  /* Optimize exact matches by looking up the ID in advance to create a simple
   * numeric comparison.  Bypass the remainder of this function. */
  if( matchStyle==MS_EXACT ){
    *zDesc = tagQuote(-1, zTag);
    return mprintf("(tagid=%d)", db_int(-1,
        "SELECT tagid FROM tag WHERE tagname='sym-%q'", zTag));
  }

  /* Decide pattern prefix and suffix strings according to match style. */
  if( matchStyle==MS_GLOB ){
    zStart = "(";
    zDelimiter = " OR ";
    zEnd = ")";
    zPrefix = "tagname GLOB 'sym-";
    zSuffix = "'";
    zIntro = "glob pattern ";
  }else if( matchStyle==MS_LIKE ){
    zStart = "(";
    zDelimiter = " OR ";
    zEnd = ")";
    zPrefix = "tagname LIKE 'sym-";
    zSuffix = "'";
    zIntro = "SQL LIKE pattern ";
  }else/* if( matchStyle==MS_REGEXP )*/{
    zStart = "(tagname REGEXP '^sym-(";
    zDelimiter = "|";
    zEnd = ")$')";
    zPrefix = "";
    zSuffix = "";
    zIntro = "regular expression ";
  }

  /* Convert the list of matches into an SQL expression and text description. */
  blob_zero(&expr);
  blob_zero(&desc);
  blob_zero(&err);
  while( 1 ){
    /* Skip leading delimiters. */
    for( ; fossil_isspace(*zTag) || *zTag==','; ++zTag );

    /* Next non-delimiter character determines quoting. */
    if( !*zTag ){
      /* Terminate loop at end of string. */
      break;
    }else if( *zTag=='\'' || *zTag=='"' ){
      /* If word is quoted, prepare to stop at end quote. */
      cDel = *zTag;
      ++zTag;
    }else{
      /* If word is not quoted, prepare to stop at delimiter. */
      cDel = ',';
    }

    /* Find the next delimiter character or end of string. */
    for( i=0; zTag[i] && zTag[i]!=cDel; ++i ){
      /* If delimiter is comma, also recognize spaces as delimiters. */
      if( cDel==',' && fossil_isspace(zTag[i]) ){
        break;
      }

      /* In regexp mode, ignore delimiters following backslashes. */
      if( matchStyle==MS_REGEXP && zTag[i]=='\\' && zTag[i+1] ){
        ++i;
      }
    }

    /* Check for regular expression syntax errors. */
    if( matchStyle==MS_REGEXP ){
      ReCompiled *regexp;
      char *zTagDup = fossil_strndup(zTag, i);
      zFail = re_compile(&regexp, zTagDup, 0);
      re_free(regexp);
      fossil_free(zTagDup);
    }

    /* Process success and error results. */
    if( !zFail ){
      /* Incorporate the match word into the output expression.  %q is used to
       * protect against SQL injection attacks by replacing ' with ''. */
      blob_appendf(&expr, "%s%s%#q%s", blob_size(&expr) ? zDelimiter : zStart,
          zPrefix, i, zTag, zSuffix);

      /* Build up the description string. */
      if( !blob_size(&desc) ){
        /* First tag: start with intro followed by first quoted tag. */
        blob_append(&desc, zIntro, -1);
        blob_append(&desc, tagQuote(i, zTag), -1);
      }else{
        if( zPattern ){
          /* Third and subsequent tags: append comma then previous tag. */
          blob_append(&desc, ", ", 2);
          blob_append(&desc, zPattern, -1);
          zOr = ", or ";
        }

        /* Second and subsequent tags: store quoted tag for next iteration. */
        zPattern = tagQuote(i, zTag);
      }
    }else{
      /* On error, skip the match word and build up the error message buffer. */
      if( !blob_size(&err) ){
        blob_append(&err, "Error: ", 7);
      }else{
        blob_append(&err, ", ", 2);
      }
      blob_appendf(&err, "(%s%s: %s)", zIntro, tagQuote(i, zTag), zFail);
    }

    /* Advance past all consumed input characters. */
    zTag += i;
    if( cDel!=',' && *zTag==cDel ){
      ++zTag;
    }
  }

  /* Finalize and extract the pattern description. */
  if( zPattern ){
    blob_append(&desc, zOr, -1);
    blob_append(&desc, zPattern, -1);
  }
  *zDesc = blob_str(&desc);

  /* Finalize and extract the error text. */
  *zError = blob_size(&err) ? blob_str(&err) : 0;

  /* Finalize and extract the SQL expression. */
  if( blob_size(&expr) ){
    blob_append(&expr, zEnd, -1);
    return blob_str(&expr);
  }

  /* If execution reaches this point, the pattern was empty.  Return NULL. */
  return 0;
}

/*
** Similar to fossil_expand_datetime()
**
** Add missing "-" characters into a date/time.  Examples:
**
**       20190419  =>  2019-04-19
**       201904    =>  2019-04
*/
const char *timeline_expand_datetime(const char *zIn){
  static char zEDate[20];
  static const char aPunct[] = { 0, 0, '-', '-', ' ', ':', ':' };
  int n = (int)strlen(zIn);
  int i, j;

  /* Only three forms allowed:
  **   (1)  YYYYMMDD
  **   (2)  YYYYMM
  **   (3)  YYYYWW
  */
  if( n!=8 && n!=6 ) return zIn;

  /* Every character must be a digit */
  for(i=0; fossil_isdigit(zIn[i]); i++){}
  if( i!=n ) return zIn;

  /* Expand the date */
  for(i=j=0; zIn[i]; i++){
    if( i>=4 && (i%2)==0 ){
      zEDate[j++] = aPunct[i/2];
    }
    zEDate[j++] = zIn[i];
  }
  zEDate[j] = 0;

  /* It looks like this may be a date.  Return it with punctuation added. */
  return zEDate;
}


/*
** WEBPAGE: timeline
**
** Query parameters:
**
**    a=TIMEORTAG     After this event
**    b=TIMEORTAG     Before this event
**    c=TIMEORTAG     "Circa" this event
**    m=TIMEORTAG     Mark this event
**    n=COUNT         Maximum number of events.  "all" for no limit
**    p=CHECKIN       Parents and ancestors of CHECKIN
**    d=CHECKIN       Children and descendants of CHECKIN
**    dp=CHECKIN      The same as d=CHECKIN&p=CHECKIN
**    t=TAG           Show only check-ins with the given TAG
**    r=TAG           Show check-ins related to TAG, equivalent to t=TAG&rel
**    rel             Show related check-ins as well as those matching t=TAG
**    mionly          Limit rel to show ancestors but not descendants
**    nowiki          Do not show wiki associated with branch or tag
**    ms=MATCHSTYLE   Set tag match style to EXACT, GLOB, LIKE, REGEXP
**    u=USER          Only show items associated with USER
**    y=TYPE          'ci', 'w', 't', 'e', 'f', or 'all'.
**    ss=VIEWSTYLE    c: "Compact"  v: "Verbose"   m: "Modern"  j: "Columnar"
**    advm            Use the "Advanced" or "Busy" menu design.
**    ng              No Graph.
**    ncp             Omit cherrypick merges
**    nd              Do not highlight the focus check-in
**    v               Show details of files changed
**    f=CHECKIN       Show family (immediate parents and children) of CHECKIN
**    from=CHECKIN    Path from...
**      to=CHECKIN      ... to this
**      shorest         ... show only the shortest path
**      rel             ... also show related checkins
**    uf=FILE_HASH    Show only check-ins that contain the given file version
**    chng=GLOBLIST   Show only check-ins that involve changes to a file whose
**                      name matches one of the comma-separate GLOBLIST
**    brbg            Background color from branch name
**    ubg             Background color from user
**    namechng        Show only check-ins that have filename changes
**    forks           Show only forks and their children
**    cherrypicks     Show all cherrypicks
**    ym=YYYY-MM      Show only events for the given year/month
**    yw=YYYY-WW      Show only events for the given week of the given year
**    yw=YYYY-MM-DD   Show events for the week that includes the given day
**    ymd=YYYY-MM-DD  Show only events on the given day
**    days=N          Show events over the previous N days
**    datefmt=N       Override the date format
**    bisect          Show the check-ins that are in the current bisect
**    showid          Show RIDs
**    showsql         Show the SQL text
**
** p= and d= can appear individually or together.  If either p= or d=
** appear, then u=, y=, a=, and b= are ignored.
**
** If both a= and b= appear then both upper and lower bounds are honored.
**
** CHECKIN or TIMEORTAG can be a check-in hash prefix, or a tag, or the
** name of a branch.
*/
void page_timeline(void){
  Stmt q;                            /* Query used to generate the timeline */
  Blob sql;                          /* text of SQL used to generate timeline */
  Blob desc;                         /* Description of the timeline */
  int nEntry;                        /* Max number of entries on timeline */
  int p_rid = name_to_typed_rid(P("p"),"ci");  /* artifact p and its parents */
  int d_rid = name_to_typed_rid(P("d"),"ci");  /* artifact d and descendants */
  int f_rid = name_to_typed_rid(P("f"),"ci");  /* artifact f and close family */
  const char *zUser = P("u");        /* All entries by this user if not NULL */
  const char *zType;                 /* Type of events to display */
  const char *zAfter = P("a");       /* Events after this time */
  const char *zBefore = P("b");      /* Events before this time */
  const char *zCirca = P("c");       /* Events near this time */
  const char *zMark = P("m");        /* Mark this event or an event this time */
  const char *zTagName = P("t");     /* Show events with this tag */
  const char *zBrName = P("r");      /* Equivalent to t=TAG&rel */
  int related = PB("rel");           /* Show events related to zTagName */
  const char *zMatchStyle = P("ms"); /* Tag/branch match style string */
  MatchStyle matchStyle = MS_EXACT;  /* Match style code */
  const char *zMatchDesc = 0;        /* Tag match expression description text */
  const char *zError = 0;            /* Tag match error string */
  const char *zTagSql = 0;           /* Tag/branch match SQL expression */
  const char *zSearch = P("s");      /* Search string */
  const char *zUses = P("uf");       /* Only show check-ins hold this file */
  const char *zYearMonth = P("ym");  /* Show check-ins for the given YYYY-MM */
  const char *zYearWeek = P("yw");   /* Check-ins for YYYY-WW (week-of-year) */
  char *zYearWeekStart = 0;          /* YYYY-MM-DD for start of YYYY-WW */
  const char *zDay = P("ymd");       /* Check-ins for the day YYYY-MM-DD */
  const char *zNDays = P("days");    /* Show events over the previous N days */
  int nDays = 0;                     /* Numeric value for zNDays */
  const char *zChng = P("chng");     /* List of GLOBs for files that changed */
  int useDividers = P("nd")==0;      /* Show dividers if "nd" is missing */
  int renameOnly = P("namechng")!=0; /* Show only check-ins that rename files */
  int forkOnly = PB("forks");        /* Show only forks and their children */
  int bisectLocal = PB("bisect");    /* Show the check-ins of the bisect */
  const char *zBisect = P("bid");    /* Bisect description */
  int cpOnly = PB("cherrypicks");    /* Show all cherrypick checkins */
  int tmFlags = 0;                   /* Timeline flags */
  const char *zThisTag = 0;          /* Suppress links to this tag */
  const char *zThisUser = 0;         /* Suppress links to this user */
  HQuery url;                        /* URL for various branch links */
  int from_rid = name_to_typed_rid(P("from"),"ci"); /* from= for paths */
  int to_rid = name_to_typed_rid(P("to"),"ci");    /* to= for path timelines */
  int noMerge = P("shortest")==0;           /* Follow merge links if shorter */
  int me_rid = name_to_typed_rid(P("me"),"ci");  /* me= for common ancestory */
  int you_rid = name_to_typed_rid(P("you"),"ci");/* you= for common ancst */
  int pd_rid;
  double rBefore, rAfter, rCirca;     /* Boundary times */
  const char *z;
  char *zOlderButton = 0;             /* URL for Older button at the bottom */
  char *zNewerButton = 0;             /* URL for Newer button at the top */
  int selectedRid = -9999999;         /* Show a highlight on this RID */
  int disableY = 0;                   /* Disable type selector on submenu */
  int advancedMenu = 0;               /* Use the advanced menu design */
  char *zPlural;                      /* Ending for plural forms */
  int showCherrypicks = 1;            /* True to show cherrypick merges */

  /* Set number of rows to display */
  cookie_read_parameter("n","n");
  z = P("n");
  if( z==0 ) z = db_get("timeline-default-length",0);
  if( z ){
    if( fossil_strcmp(z,"all")==0 ){
      nEntry = 0;
    }else{
      nEntry = atoi(z);
      if( nEntry<=0 ){
        z = "10";
        nEntry = 10;
      }
    }
  }else{
    z = "50";
    nEntry = 50;
  }
  cgi_replace_query_parameter("n",z);
  cookie_write_parameter("n","n",0);
  tmFlags |= timeline_ss_submenu();  
  cookie_link_parameter("advm","advm","0");
  advancedMenu = atoi(PD("advm","0"));

  /* Omit all cherry-pick merge lines if the "ncp" query parameter is
  ** present or if this repository lacks a "cherrypick" table. */
  if( PB("ncp") || !db_table_exists("repository","cherrypick") ){
    showCherrypicks = 0;
  }

  /* To view the timeline, must have permission to read project data.
  */
  pd_rid = name_to_typed_rid(P("dp"),"ci");
  if( pd_rid ){
    p_rid = d_rid = pd_rid;
  }
  login_check_credentials();
  if( (!g.perm.Read && !g.perm.RdTkt && !g.perm.RdWiki && !g.perm.RdForum)
   || (bisectLocal && !g.perm.Setup)
  ){
    login_needed(g.anon.Read && g.anon.RdTkt && g.anon.RdWiki);
    return;
  }
  cookie_read_parameter("y","y");
  zType = P("y");
  if( zType==0 ){
    zType = g.perm.Read ? "ci" : "all";
    cgi_set_parameter("y", zType);
  }
  if( zType[0]=='a' || zType[0]=='c' ){
    cookie_write_parameter("y","y",zType);
  }
  cookie_render();
  url_initialize(&url, "timeline");
  cgi_query_parameters_to_url(&url);

  /* Convert r=TAG to t=TAG&rel. */
  if( zBrName && !related ){
    cgi_delete_query_parameter("r");
    cgi_set_query_parameter("t", zBrName);
    cgi_set_query_parameter("rel", "1");
    zTagName = zBrName;
    related = 1;
    zType = "ci";
  }

  /* Ignore empty tag query strings. */
  if( zTagName && !*zTagName ){
    zTagName = 0;
  }

  /* Finish preliminary processing of tag match queries. */
  if( zTagName ){
    zType = "ci";
    /* Interpet the tag style string. */
    if( fossil_stricmp(zMatchStyle, "glob")==0 ){
      matchStyle = MS_GLOB;
    }else if( fossil_stricmp(zMatchStyle, "like")==0 ){
      matchStyle = MS_LIKE;
    }else if( fossil_stricmp(zMatchStyle, "regexp")==0 ){
      matchStyle = MS_REGEXP;
    }else{
      /* For exact maching, inhibit links to the selected tag. */
      zThisTag = zTagName;
    }

    /* Display a checkbox to enable/disable display of related check-ins. */
    if( advancedMenu ){
      style_submenu_checkbox("rel", "Related", 0, 0);
    }

    /* Construct the tag match expression. */
    zTagSql = tagMatchExpression(matchStyle, zTagName, &zMatchDesc, &zError);
  }

  if( zMark && zMark[0]==0 ){
    if( zAfter ) zMark = zAfter;
    if( zBefore ) zMark = zBefore;
    if( zCirca ) zMark = zCirca;
  }
  if( (zTagSql && db_int(0,"SELECT count(*) "
      "FROM tagxref NATURAL JOIN tag WHERE %s",zTagSql/*safe-for-%s*/)<=nEntry)
  ){
    nEntry = -1;
    zCirca = 0;
  }
  if( zType[0]=='a' ){
    tmFlags |= TIMELINE_BRIEF | TIMELINE_GRAPH | TIMELINE_CHPICK;
  }else{
    tmFlags |= TIMELINE_GRAPH | TIMELINE_CHPICK;
  }
  if( PB("ncp") ){
    tmFlags &= ~TIMELINE_CHPICK;
  }
  if( PB("ng") || zSearch!=0 ){
    tmFlags &= ~(TIMELINE_GRAPH|TIMELINE_CHPICK);
  }
  if( PB("brbg") ){
    tmFlags |= TIMELINE_BRCOLOR;
  }
  if( PB("unhide") ){
    tmFlags |= TIMELINE_UNHIDE;
  }
  if( PB("ubg") ){
    tmFlags |= TIMELINE_UCOLOR;
  }
  if( zUses!=0 ){
    int ufid = db_int(0, "SELECT rid FROM blob WHERE uuid GLOB '%q*'", zUses);
    if( ufid ){
      zUses = db_text(0, "SELECT uuid FROM blob WHERE rid=%d", ufid);
      db_multi_exec("CREATE TEMP TABLE usesfile(rid INTEGER PRIMARY KEY)");
      compute_uses_file("usesfile", ufid, 0);
      zType = "ci";
      disableY = 1;
    }else{
      zUses = 0;
    }
  }
  if( renameOnly ){
    db_multi_exec(
      "CREATE TEMP TABLE rnfile(rid INTEGER PRIMARY KEY);"
      "INSERT OR IGNORE INTO rnfile"
      "  SELECT mid FROM mlink WHERE pfnid>0 AND pfnid!=fnid;"
    );
    disableY = 1;
  }
  if( forkOnly ){
    db_multi_exec(
      "CREATE TEMP TABLE rnfork(rid INTEGER PRIMARY KEY);\n"
      "INSERT OR IGNORE INTO rnfork(rid)\n"
      "  SELECT pid FROM plink\n"
      "   WHERE (SELECT value FROM tagxref WHERE tagid=%d AND rid=cid)=="
      "           (SELECT value FROM tagxref WHERE tagid=%d AND rid=pid)\n"
      "   GROUP BY pid"
      "   HAVING count(*)>1;\n"
      "INSERT OR IGNORE INTO rnfork(rid)"
      "  SELECT cid FROM plink\n"
      "   WHERE (SELECT value FROM tagxref WHERE tagid=%d AND rid=cid)=="
      "           (SELECT value FROM tagxref WHERE tagid=%d AND rid=pid)\n"
      "     AND pid IN rnfork;",
      TAG_BRANCH, TAG_BRANCH, TAG_BRANCH, TAG_BRANCH
    );
    tmFlags |= TIMELINE_UNHIDE;
    zType = "ci";
    disableY = 1;
  }
  if( bisectLocal
   && fossil_strcmp(g.zIpAddr,"127.0.0.1")==0
   && db_open_local(0)
  ){
    int iCurrent = db_lget_int("checkout",0);
    char *zPerm = bisect_permalink();
    bisect_create_bilog_table(iCurrent, 0);
    tmFlags |= TIMELINE_UNHIDE | TIMELINE_BISECT;
    zType = "ci";
    disableY = 1;
    style_submenu_element("Permalink", "%R/timeline?bid=%z", zPerm);
  }else{
    bisectLocal = 0;
  }
  if( zBisect!=0 && bisect_create_bilog_table(0, zBisect) ){
    tmFlags |= TIMELINE_UNHIDE | TIMELINE_BISECT;
    zType = "ci";
    disableY = 1;
  }else{
    zBisect = 0;
  }

  style_header("Timeline");
  if( advancedMenu ){
    style_submenu_element("Help", "%R/help?cmd=/timeline");
  }
  login_anonymous_available();
  timeline_temp_table();
  blob_zero(&sql);
  blob_zero(&desc);
  blob_append(&sql, "INSERT OR IGNORE INTO timeline ", -1);
  blob_append(&sql, timeline_query_for_www(), -1);
  if( PB("fc") || PB("v") || PB("detail") ){
    tmFlags |= TIMELINE_FCHANGES;
  }
  if( (tmFlags & TIMELINE_UNHIDE)==0 ){
    blob_append_sql(&sql,
      " AND NOT EXISTS(SELECT 1 FROM tagxref"
      " WHERE tagid=%d AND tagtype>0 AND rid=blob.rid)\n",
      TAG_HIDDEN
    );
  }
  if( ((from_rid && to_rid) || (me_rid && you_rid)) && g.perm.Read ){
    /* If from= and to= are present, display all nodes on a path connecting
    ** the two */
    PathNode *p = 0;
    const char *zFrom = 0;
    const char *zTo = 0;
    Blob ins;
    int nNodeOnPath = 0;

    if( from_rid && to_rid ){
      p = path_shortest(from_rid, to_rid, noMerge, 0);
      zFrom = P("from");
      zTo = P("to");
    }else{
      if( path_common_ancestor(me_rid, you_rid) ){
        p = path_first();
      }
      zFrom = P("me");
      zTo = P("you");
    }
    blob_init(&ins, 0, 0);
    db_multi_exec(
      "CREATE TABLE IF NOT EXISTS temp.pathnode(x INTEGER PRIMARY KEY);"
    );
    if( p ){
      blob_init(&ins, 0, 0);
      blob_append_sql(&ins, "INSERT INTO pathnode(x) VALUES(%d)", p->rid);
      p = p->u.pTo;
      nNodeOnPath = 1;
      while( p ){
        blob_append_sql(&ins, ",(%d)", p->rid);
        p = p->u.pTo;
        nNodeOnPath++;
      }
    }
    path_reset();
    db_multi_exec("%s", blob_str(&ins)/*safe-for-%s*/);
    blob_reset(&ins);
    if( related ){
      db_multi_exec(
        "CREATE TABLE IF NOT EXISTS temp.related(x INTEGER PRIMARY KEY);"
        "INSERT OR IGNORE INTO related(x)"
        "  SELECT pid FROM plink WHERE cid IN pathnode AND NOT isprim;"
      );
      if( P("mionly")==0 ){
        db_multi_exec(
          "INSERT OR IGNORE INTO related(x)"
          "  SELECT cid FROM plink WHERE pid IN pathnode;"
        );
      }
      if( showCherrypicks ){
        db_multi_exec(
          "INSERT OR IGNORE INTO related(x)"
          "  SELECT parentid FROM cherrypick WHERE childid IN pathnode;"
        );
        if( P("mionly")==0 ){
          db_multi_exec(
            "INSERT OR IGNORE INTO related(x)"
            "  SELECT childid FROM cherrypick WHERE parentid IN pathnode;"
          );
        }
      }
      db_multi_exec("INSERT OR IGNORE INTO pathnode SELECT x FROM related");
    }
    blob_append_sql(&sql, " AND event.objid IN pathnode");
    addFileGlobExclusion(zChng, &sql);
    tmFlags |= TIMELINE_DISJOINT;
    db_multi_exec("%s", blob_sql_text(&sql));
    if( advancedMenu ){
      style_submenu_checkbox("v", "Files", (zType[0]!='a' && zType[0]!='c'),0);
    }
    blob_appendf(&desc, "%d check-ins going from ", nNodeOnPath);
    blob_appendf(&desc, "%z[%h]</a>", href("%R/info/%h", zFrom), zFrom);
    blob_append(&desc, " to ", -1);
    blob_appendf(&desc, "%z[%h]</a>", href("%R/info/%h",zTo), zTo);
    if( related ){
      int nRelated = db_int(0, "SELECT count(*) FROM timeline") - nNodeOnPath;
      if( nRelated>0 ){
        blob_appendf(&desc, " and %d related check-in%s", nRelated,
                     nRelated>1 ? "s" : "");
      }
    }
    addFileGlobDescription(zChng, &desc);
  }else if( (p_rid || d_rid) && g.perm.Read && zTagSql==0 ){
    /* If p= or d= is present, ignore all other parameters other than n= */
    char *zUuid;
    int np, nd;

    tmFlags |= TIMELINE_DISJOINT;
    if( p_rid && d_rid ){
      if( p_rid!=d_rid ) p_rid = d_rid;
      if( P("n")==0 ) nEntry = 10;
    }
    db_multi_exec(
       "CREATE TEMP TABLE IF NOT EXISTS ok(rid INTEGER PRIMARY KEY)"
    );
    zUuid = db_text("", "SELECT uuid FROM blob WHERE rid=%d",
                         p_rid ? p_rid : d_rid);
    blob_append_sql(&sql, " AND event.objid IN ok");
    nd = 0;
    if( d_rid ){
      compute_descendants(d_rid, nEntry==0 ? 0 : nEntry+1);
      nd = db_int(0, "SELECT count(*)-1 FROM ok");
      if( nd>=0 ) db_multi_exec("%s", blob_sql_text(&sql));
      if( nd>0 ) blob_appendf(&desc, "%d descendant%s", nd,(1==nd)?"":"s");
      if( useDividers ) selectedRid = d_rid;
      db_multi_exec("DELETE FROM ok");
    }
    if( p_rid ){
      compute_ancestors(p_rid, nEntry==0 ? 0 : nEntry+1, 0);
      np = db_int(0, "SELECT count(*)-1 FROM ok");
      if( np>0 ){
        if( nd>0 ) blob_appendf(&desc, " and ");
        blob_appendf(&desc, "%d ancestors", np);
        db_multi_exec("%s", blob_sql_text(&sql));
      }
      if( useDividers ) selectedRid = p_rid;
    }
    blob_appendf(&desc, " of %z[%S]</a>",
                   href("%R/info/%!S", zUuid), zUuid);
    if( d_rid ){
      if( p_rid ){
        /* If both p= and d= are set, we don't have the uuid of d yet. */
        zUuid = db_text("", "SELECT uuid FROM blob WHERE rid=%d", d_rid);
      }
    }
    if( advancedMenu ){
      style_submenu_checkbox("v", "Files", (zType[0]!='a' && zType[0]!='c'),0);
    }
    style_submenu_entry("n","Max:",4,0);
    timeline_y_submenu(1);
  }else if( f_rid && g.perm.Read ){
    /* If f= is present, ignore all other parameters other than n= */
    char *zUuid;
    db_multi_exec(
       "CREATE TEMP TABLE IF NOT EXISTS ok(rid INTEGER PRIMARY KEY);"
       "INSERT INTO ok VALUES(%d);"
       "INSERT OR IGNORE INTO ok SELECT pid FROM plink WHERE cid=%d;"
       "INSERT OR IGNORE INTO ok SELECT cid FROM plink WHERE pid=%d;",
       f_rid, f_rid, f_rid
    );
    if( showCherrypicks ){
      db_multi_exec(
         "INSERT OR IGNORE INTO ok SELECT parentid FROM cherrypick"
         " WHERE childid=%d;"
         "INSERT OR IGNORE INTO ok SELECT childid FROM cherrypick"
         " WHERE parentid=%d;",
         f_rid, f_rid
      );
    }
    blob_append_sql(&sql, " AND event.objid IN ok");
    db_multi_exec("%s", blob_sql_text(&sql));
    if( useDividers ) selectedRid = f_rid;
    blob_appendf(&desc, "Parents and children of check-in ");
    zUuid = db_text("", "SELECT uuid FROM blob WHERE rid=%d", f_rid);
    blob_appendf(&desc, "%z[%S]</a>", href("%R/info/%!S", zUuid), zUuid);
    tmFlags |= TIMELINE_DISJOINT;
    if( advancedMenu ){
      style_submenu_checkbox("unhide", "Unhide", 0, 0);
      style_submenu_checkbox("v", "Files", (zType[0]!='a' && zType[0]!='c'),0);
    }
  }else{
    /* Otherwise, a timeline based on a span of time */
    int n;
    const char *zEType = "event";
    char *zDate;
    Blob cond;
    blob_zero(&cond);
    if( zChng && *zChng ){
      addFileGlobExclusion(zChng, &cond);
      tmFlags |= TIMELINE_DISJOINT;
    }
    if( zUses ){
      blob_append_sql(&cond, " AND event.objid IN usesfile ");
    }
    if( renameOnly ){
      blob_append_sql(&cond, " AND event.objid IN rnfile ");
    }
    if( forkOnly ){
      blob_append_sql(&cond, " AND event.objid IN rnfork ");
    }
    if( cpOnly && showCherrypicks ){
      db_multi_exec(
        "CREATE TABLE IF NOT EXISTS cpnodes(rid INTEGER PRIMARY KEY);"
        "INSERT OR IGNORE INTO cpnodes SELECT childid FROM cherrypick;"
        "INSERT OR IGNORE INTO cpnodes SELECT parentid FROM cherrypick;"
      );
      blob_append_sql(&cond, " AND event.objid IN cpnodes ");
    }
    if( bisectLocal || zBisect!=0 ){
      blob_append_sql(&cond, " AND event.objid IN (SELECT rid FROM bilog) ");
    }
    if( zYearMonth ){
      zYearMonth = timeline_expand_datetime(zYearMonth);
      blob_append_sql(&cond, " AND %Q=strftime('%%Y-%%m',event.mtime) ",
                      zYearMonth);
    }
    else if( zYearWeek ){
      zYearWeek = timeline_expand_datetime(zYearWeek);
      char *z = db_text(0, "SELECT strftime('%%Y-%%W',%Q)", zYearWeek);
      if( z && z[0] ){
        zYearWeekStart = db_text(0, "SELECT date(%Q,'-6 days','weekday 1')",
                                 zYearWeek);
        zYearWeek = z;
      }else{
        if( strlen(zYearWeek)==7 ){       
          zYearWeekStart = db_text(0,
             "SELECT date('%.4q-01-01','+%d days','weekday 1')",
             zYearWeek, atoi(zYearWeek+5)*7);
        }else{
          zYearWeekStart = 0;
        }
        if( zYearWeekStart==0 || zYearWeekStart[0]==0 ){
          zYearWeekStart = db_text(0,
             "SELECT date('now','-6 days','weekday 1');");
          zYearWeek = db_text(0,
             "SELECT strftime('%%Y-%%W','now','-6 days','weekday 1')");
        }
      }
      blob_append_sql(&cond, " AND %Q=strftime('%%Y-%%W',event.mtime) ",
                   zYearWeek);
      nEntry = -1;
    }
    else if( zDay ){
      zDay = timeline_expand_datetime(zDay);
      zDay = db_text(0, "SELECT date(%Q)", zDay);
      if( zDay==0 || zDay[0]==0 ){
        zDay = db_text(0, "SELECT date('now')");
      }
      blob_append_sql(&cond, " AND %Q=date(event.mtime) ",
                   zDay);
      nEntry = -1;
    }
    else if( zNDays ){
      nDays = atoi(zNDays);
      if( nDays<1 ) nDays = 1;
      blob_append_sql(&cond, " AND event.mtime>=julianday('now','-%d days') ",
                      nDays);
      nEntry = -1;
    }
    if( zTagSql ){
      db_multi_exec(
        "CREATE TEMP TABLE selected_nodes(rid INTEGER PRIMARY KEY);"
        "INSERT OR IGNORE INTO selected_nodes"
        " SELECT tagxref.rid FROM tagxref NATURAL JOIN tag"
        " WHERE %s AND tagtype>0", zTagSql/*safe-for-%s*/
      );
      if( !related ){
        blob_append_sql(&cond, " AND blob.rid IN selected_nodes");
      }else{
        db_multi_exec(
          "CREATE TEMP TABLE related_nodes(rid INTEGER PRIMARY KEY);"
          "INSERT INTO related_nodes SELECT rid FROM selected_nodes;"
        );
        blob_append_sql(&cond, " AND blob.rid IN related_nodes");
        /* The next two blob_appendf() calls add SQL that causes check-ins that
        ** are not part of the branch which are parents or children of the
        ** branch to be included in the report.  These related check-ins are
        ** useful in helping to visualize what has happened on a quiescent
        ** branch that is infrequently merged with a much more activate branch.
        */
        db_multi_exec(
          "INSERT OR IGNORE INTO related_nodes"
          " SELECT pid FROM selected_nodes CROSS JOIN plink"
          " WHERE selected_nodes.rid=plink.cid;"
        );
        if( P("mionly")==0 ){
          db_multi_exec(
            "INSERT OR IGNORE INTO related_nodes"
            " SELECT cid FROM selected_nodes CROSS JOIN plink"
            " WHERE selected_nodes.rid=plink.pid;"
          );
          if( showCherrypicks ){
            db_multi_exec(
              "INSERT OR IGNORE INTO related_nodes"
              " SELECT childid FROM selected_nodes CROSS JOIN cherrypick"
              " WHERE selected_nodes.rid=cherrypick.parentid;"
            );
          }
        }
        if( showCherrypicks ){
          db_multi_exec(
            "INSERT OR IGNORE INTO related_nodes"
            " SELECT parentid FROM selected_nodes CROSS JOIN cherrypick"
            " WHERE selected_nodes.rid=cherrypick.childid;"
          );
        }
        if( (tmFlags & TIMELINE_UNHIDE)==0 ){
          db_multi_exec(
            "DELETE FROM related_nodes WHERE rid IN "
            " (SELECT related_nodes.rid FROM related_nodes, tagxref"
            " WHERE tagid=%d AND tagtype>0 AND tagxref.rid=related_nodes.rid)",
            TAG_HIDDEN
          );
        }
      }
    }
    if( (zType[0]=='w' && !g.perm.RdWiki)
     || (zType[0]=='t' && !g.perm.RdTkt)
     || (zType[0]=='e' && !g.perm.RdWiki)
     || (zType[0]=='c' && !g.perm.Read)
     || (zType[0]=='g' && !g.perm.Read)
     || (zType[0]=='f' && !g.perm.RdForum)
    ){
      zType = "all";
    }
    if( zType[0]=='a' ){
      if( !g.perm.Read || !g.perm.RdWiki || !g.perm.RdTkt ){
        char cSep = '(';
        blob_append_sql(&cond, " AND event.type IN ");
        if( g.perm.Read ){
          blob_append_sql(&cond, "%c'ci','g'", cSep);
          cSep = ',';
        }
        if( g.perm.RdWiki ){
          blob_append_sql(&cond, "%c'w','e'", cSep);
          cSep = ',';
        }
        if( g.perm.RdTkt ){
          blob_append_sql(&cond, "%c't'", cSep);
          cSep = ',';
        }
        if( g.perm.RdForum ){
          blob_append_sql(&cond, "%c'f'", cSep);
          cSep = ',';
        }
        blob_append_sql(&cond, ")");
      }
    }else{ /* zType!="all" */
      blob_append_sql(&cond, " AND event.type=%Q", zType);
      if( zType[0]=='c' ){
        zEType = "check-in";
      }else if( zType[0]=='w' ){
        zEType = "wiki";
      }else if( zType[0]=='t' ){
        zEType = "ticket change";
      }else if( zType[0]=='e' ){
        zEType = "technical note";
      }else if( zType[0]=='g' ){
        zEType = "tag";
      }else if( zType[0]=='f' ){
        zEType = "forum post";
      }
    }
    if( zUser ){
      int n = db_int(0,"SELECT count(*) FROM event"
                       " WHERE user=%Q OR euser=%Q", zUser, zUser);
      if( n<=nEntry ){
        zCirca = zBefore = zAfter = 0;
        nEntry = -1;
      }
      blob_append_sql(&cond, " AND (event.user=%Q OR event.euser=%Q)",
                   zUser, zUser);
      zThisUser = zUser;
    }
    if( zSearch ){
      blob_append_sql(&cond,
        " AND (event.comment LIKE '%%%q%%' OR event.brief LIKE '%%%q%%')",
        zSearch, zSearch);
    }
    rBefore = symbolic_name_to_mtime(zBefore, &zBefore);
    rAfter = symbolic_name_to_mtime(zAfter, &zAfter);
    rCirca = symbolic_name_to_mtime(zCirca, &zCirca);
    blob_append_sql(&sql, "%s", blob_sql_text(&cond));
    if( rAfter>0.0 ){
      if( rBefore>0.0 ){
        blob_append_sql(&sql,
           " AND event.mtime>=%.17g AND event.mtime<=%.17g"
           " ORDER BY event.mtime ASC", rAfter-ONE_SECOND, rBefore+ONE_SECOND);
        nEntry = -1;
      }else{
        blob_append_sql(&sql,
           " AND event.mtime>=%.17g  ORDER BY event.mtime ASC",
           rAfter-ONE_SECOND);
      }
      zCirca = 0;
      url_add_parameter(&url, "c", 0);
    }else if( rBefore>0.0 ){
      blob_append_sql(&sql,
         " AND event.mtime<=%.17g ORDER BY event.mtime DESC",
         rBefore+ONE_SECOND);
      zCirca = 0;
      url_add_parameter(&url, "c", 0);
    }else if( rCirca>0.0 ){
      Blob sql2;
      blob_init(&sql2, blob_sql_text(&sql), -1);
      blob_append_sql(&sql2,
          " AND event.mtime<=%f ORDER BY event.mtime DESC", rCirca);
      if( nEntry>0 ){
        blob_append_sql(&sql2," LIMIT %d", (nEntry+1)/2);
        nEntry -= (nEntry+1)/2;
      }
      if( PB("showsql") ){
         @ <pre>%h(blob_sql_text(&sql2))</pre>
      }
      db_multi_exec("%s", blob_sql_text(&sql2));
      blob_reset(&sql2);
      blob_append_sql(&sql,
          " AND event.mtime>=%f ORDER BY event.mtime ASC",
          rCirca
      );
      if( zMark==0 ) zMark = zCirca;
    }else{
      blob_append_sql(&sql, " ORDER BY event.mtime DESC");
    }
    if( nEntry>0 ) blob_append_sql(&sql, " LIMIT %d", nEntry);
    db_multi_exec("%s", blob_sql_text(&sql));

    n = db_int(0, "SELECT count(*) FROM timeline WHERE etype!='div' /*scan*/");
    zPlural = n==1 ? "" : "s";
    if( zYearMonth ){
      blob_appendf(&desc, "%d %s%s for %h", n, zEType, zPlural, zYearMonth);
    }else if( zYearWeek ){
      blob_appendf(&desc, "%d %s%s for week %h beginning on %h", 
                   n, zEType, zPlural, zYearWeek, zYearWeekStart);
    }else if( zDay ){
      blob_appendf(&desc, "%d %s%s occurring on %h", n, zEType, zPlural, zDay);
    }else if( zNDays ){
      blob_appendf(&desc, "%d %s%s within the past %d day%s",
                          n, zEType, zPlural, nDays, nDays>1 ? "s" : "");
    }else if( zBefore==0 && zCirca==0 && n>=nEntry && nEntry>0 ){
      blob_appendf(&desc, "%d most recent %s%s", n, zEType, zPlural);
    }else{
      blob_appendf(&desc, "%d %s%s", n, zEType, zPlural);
    }
    if( zUses ){
      char *zFilenames = names_of_file(zUses);
      blob_appendf(&desc, " using file %s version %z%S</a>", zFilenames,
                   href("%R/artifact/%!S",zUses), zUses);
      tmFlags |= TIMELINE_DISJOINT;
    }
    if( renameOnly ){
      blob_appendf(&desc, " that contain filename changes");
      tmFlags |= TIMELINE_DISJOINT|TIMELINE_FRENAMES;
    }
    if( forkOnly ){
      blob_appendf(&desc, " associated with forks");
      tmFlags |= TIMELINE_DISJOINT;
    }
    if( bisectLocal || zBisect!=0 ){
      blob_appendf(&desc, " in a bisect");
      tmFlags |= TIMELINE_DISJOINT;
    }
    if( cpOnly && showCherrypicks ){
      blob_appendf(&desc, " that participate in a cherrypick merge");
      tmFlags |= TIMELINE_CHPICK|TIMELINE_DISJOINT;
    }
    if( zUser ){
      blob_appendf(&desc, " by user %h", zUser);
      tmFlags |= TIMELINE_DISJOINT;
    }
    if( zTagSql ){
      if( matchStyle==MS_EXACT ){
        if( related ){
          blob_appendf(&desc, " related to %h", zMatchDesc);
        }else{
          blob_appendf(&desc, " tagged with %h", zMatchDesc);
        }
      }else{
        if( related ){
          blob_appendf(&desc, " related to tags matching %h", zMatchDesc);
        }else{
          blob_appendf(&desc, " with tags matching %h", zMatchDesc);
        }
      }
      tmFlags |= TIMELINE_DISJOINT;
    }
    addFileGlobDescription(zChng, &desc);
    if( rAfter>0.0 ){
      if( rBefore>0.0 ){
        blob_appendf(&desc, " occurring between %h and %h.<br />",
                     zAfter, zBefore);
      }else{
        blob_appendf(&desc, " occurring on or after %h.<br />", zAfter);
      }
    }else if( rBefore>0.0 ){
      blob_appendf(&desc, " occurring on or before %h.<br />", zBefore);
    }else if( rCirca>0.0 ){
      blob_appendf(&desc, " occurring around %h.<br />", zCirca);
    }
    if( zSearch ){
      blob_appendf(&desc, " matching \"%h\"", zSearch);
    }
    if( g.perm.Hyperlink ){
      static const char *const azMatchStyles[] = {
        "exact", "Exact", "glob", "Glob", "like", "Like", "regexp", "Regexp"
      };
      double rDate;
      zDate = db_text(0, "SELECT min(timestamp) FROM timeline /*scan*/");
      if( (!zDate || !zDate[0]) && ( zAfter || zBefore ) ){
        zDate = mprintf("%s", (zAfter ? zAfter : zBefore));
      }
      if( zDate ){
        rDate = symbolic_name_to_mtime(zDate, 0);
        if( db_int(0,
            "SELECT EXISTS (SELECT 1 FROM event CROSS JOIN blob"
            " WHERE blob.rid=event.objid AND mtime<=%.17g%s)",
            rDate-ONE_SECOND, blob_sql_text(&cond))
        ){
          zOlderButton = fossil_strdup(url_render(&url, "b", zDate, "a", 0));
        }
        free(zDate);
      }
      zDate = db_text(0, "SELECT max(timestamp) FROM timeline /*scan*/");
      if( (!zDate || !zDate[0]) && ( zAfter || zBefore ) ){
        zDate = mprintf("%s", (zBefore ? zBefore : zAfter));
      }
      if( zDate ){
        rDate = symbolic_name_to_mtime(zDate, 0);
        if( db_int(0,
            "SELECT EXISTS (SELECT 1 FROM event CROSS JOIN blob"
            " WHERE blob.rid=event.objid AND mtime>=%.17g%s)",
            rDate+ONE_SECOND, blob_sql_text(&cond))
        ){
          zNewerButton = fossil_strdup(url_render(&url, "a", zDate, "b", 0));
        }
        free(zDate);
      }
      if( advancedMenu ){
        if( zType[0]=='a' || zType[0]=='c' ){
          style_submenu_checkbox("unhide", "Unhide", 0, 0);
        }
        style_submenu_checkbox("v", "Files",(zType[0]!='a' && zType[0]!='c'),0);
      }
      style_submenu_entry("n","Max:",4,0);
      timeline_y_submenu(disableY);
      if( advancedMenu ){
        style_submenu_entry("t", "Tag Filter:", -8, 0);
        style_submenu_multichoice("ms", count(azMatchStyles)/2,azMatchStyles,0);
      }
    }
    blob_zero(&cond);
  }
  if( PB("showsql") ){
    @ <pre>%h(blob_sql_text(&sql))</pre>
  }
  if( search_restrict(SRCH_CKIN)!=0 ){
    style_submenu_element("Search", "%R/search?y=c");
  }
  if( advancedMenu ){
    style_submenu_element("Basic", "%s", 
        url_render(&url, "advm", "0", "udc", "1"));
  }else{
    style_submenu_element("Advanced", "%s",
        url_render(&url, "advm", "1", "udc", "1"));
  }
  if( PB("showid") ) tmFlags |= TIMELINE_SHOWRID;
  if( useDividers && zMark && zMark[0] ){
    double r = symbolic_name_to_mtime(zMark, 0);
    if( r>0.0 ) selectedRid = timeline_add_divider(r);
  }
  blob_zero(&sql);
  db_prepare(&q, "SELECT * FROM timeline ORDER BY sortby DESC /*scan*/");
  if( fossil_islower(desc.aData[0]) ){
    desc.aData[0] = fossil_toupper(desc.aData[0]);
  }
  if( zBrName
   && !PB("nowiki")
   && wiki_render_associated("branch", zBrName, WIKIASSOC_ALL)
  ){
    @ <div class="section">%b(&desc)</div>
  }else
  if( zTagName
   && matchStyle==MS_EXACT
   && zBrName==0
   && !PB("nowiki")
   && wiki_render_associated("tag", zTagName, WIKIASSOC_ALL)
  ){
    @ <div class="section">%b(&desc)</div>
  } else{
    @ <h2>%b(&desc)</h2>
  }
  blob_reset(&desc);

  /* Report any errors. */
  if( zError ){
    @ <p class="generalError">%h(zError)</p>
  }

  if( zNewerButton ){
    @ %z(chref("button","%z",zNewerButton))More&nbsp;&uarr;</a>
  }
  www_print_timeline(&q, tmFlags, zThisUser, zThisTag, selectedRid, 0);
  db_finalize(&q);
  if( zOlderButton ){
    @ %z(chref("button","%z",zOlderButton))More&nbsp;&darr;</a>
  }
  style_footer();
}

/*
** The input query q selects various records.  Print a human-readable
** summary of those records.
**
** Limit number of lines or entries printed to nLimit.  If nLimit is zero
** there is no limit.  If nLimit is greater than zero, limit the number of
** complete entries printed.  If nLimit is less than zero, attempt to limit
** the number of lines printed (this is basically the legacy behavior).
** The line limit, if used, is approximate because it is only checked on a
** per-entry basis.  If verbose mode, the file name details are considered
** to be part of the entry.
**
** The query should return these columns:
**
**    0.  rid
**    1.  uuid
**    2.  Date/Time
**    3.  Comment string and user
**    4.  Number of non-merge children
**    5.  Number of parents
**    6.  mtime
**    7.  branch
*/
void print_timeline(Stmt *q, int nLimit, int width, int verboseFlag){
  int nAbsLimit = (nLimit >= 0) ? nLimit : -nLimit;
  int nLine = 0;
  int nEntry = 0;
  char zPrevDate[20];
  const char *zCurrentUuid = 0;
  int fchngQueryInit = 0;     /* True if fchngQuery is initialized */
  Stmt fchngQuery;            /* Query for file changes on check-ins */
  int rc;

  zPrevDate[0] = 0;
  if( g.localOpen ){
    int rid = db_lget_int("checkout", 0);
    zCurrentUuid = db_text(0, "SELECT uuid FROM blob WHERE rid=%d", rid);
  }

  while( (rc=db_step(q))==SQLITE_ROW ){
    int rid = db_column_int(q, 0);
    const char *zId = db_column_text(q, 1);
    const char *zDate = db_column_text(q, 2);
    const char *zCom = db_column_text(q, 3);
    int nChild = db_column_int(q, 4);
    int nParent = db_column_int(q, 5);
    char *zFree = 0;
    int n = 0;
    char zPrefix[80];

    if( nAbsLimit!=0 ){
      if( nLimit<0 && nLine>=nAbsLimit ){
        fossil_print("--- line limit (%d) reached ---\n", nAbsLimit);
        break; /* line count limit hit, stop. */
      }else if( nEntry>=nAbsLimit ){
        fossil_print("--- entry limit (%d) reached ---\n", nAbsLimit);
        break; /* entry count limit hit, stop. */
      }
    }
    if( fossil_strnicmp(zDate, zPrevDate, 10) ){
      fossil_print("=== %.10s ===\n", zDate);
      memcpy(zPrevDate, zDate, 10);
      nLine++; /* record another line */
    }
    if( zCom==0 ) zCom = "";
    fossil_print("%.8s ", &zDate[11]);
    zPrefix[0] = 0;
    if( nParent>1 ){
      sqlite3_snprintf(sizeof(zPrefix), zPrefix, "*MERGE* ");
      n = strlen(zPrefix);
    }
    if( nChild>1 ){
      const char *zBrType;
      if( count_nonbranch_children(rid)>1 ){
        zBrType = "*FORK* ";
      }else{
        zBrType = "*BRANCH* ";
      }
      sqlite3_snprintf(sizeof(zPrefix)-n, &zPrefix[n], zBrType);
      n = strlen(zPrefix);
    }
    if( fossil_strcmp(zCurrentUuid,zId)==0 ){
      sqlite3_snprintf(sizeof(zPrefix)-n, &zPrefix[n], "*CURRENT* ");
      n += strlen(zPrefix+n);
    }
    if( content_is_private(rid) ){
      sqlite3_snprintf(sizeof(zPrefix)-n, &zPrefix[n], "*UNPUBLISHED* ");
      n += strlen(zPrefix+n);
    }
    zFree = mprintf("[%S] %s%s", zId, zPrefix, zCom);
    /* record another X lines */
    nLine += comment_print(zFree, zCom, 9, width, get_comment_format());
    fossil_free(zFree);

    if(verboseFlag){
      if( !fchngQueryInit ){
        db_prepare(&fchngQuery,
           "SELECT (pid<=0) AS isnew,"
           "       (fid==0) AS isdel,"
           "       (SELECT name FROM filename WHERE fnid=mlink.fnid) AS name,"
           "       (SELECT uuid FROM blob WHERE rid=fid),"
           "       (SELECT uuid FROM blob WHERE rid=pid)"
           "  FROM mlink"
           " WHERE mid=:mid AND pid!=fid AND NOT mlink.isaux"
           " ORDER BY 3 /*sort*/"
        );
        fchngQueryInit = 1;
      }
      db_bind_int(&fchngQuery, ":mid", rid);
      while( db_step(&fchngQuery)==SQLITE_ROW ){
        const char *zFilename = db_column_text(&fchngQuery, 2);
        int isNew = db_column_int(&fchngQuery, 0);
        int isDel = db_column_int(&fchngQuery, 1);
        if( isNew ){
          fossil_print("   ADDED %s\n",zFilename);
        }else if( isDel ){
          fossil_print("   DELETED %s\n",zFilename);
        }else{
          fossil_print("   EDITED %s\n", zFilename);
        }
        nLine++; /* record another line */
      }
      db_reset(&fchngQuery);
    }
    nEntry++; /* record another complete entry */
  }
  if( rc==SQLITE_DONE ){
    /* Did the underlying query actually have all entries? */
    if( nAbsLimit==0 ){
      fossil_print("+++ end of timeline (%d) +++\n", nEntry);
    }else{
      fossil_print("+++ no more data (%d) +++\n", nEntry);
    }
  }
  if( fchngQueryInit ) db_finalize(&fchngQuery);
}

/*
** Return a pointer to a static string that forms the basis for
** a timeline query for display on a TTY.
*/
const char *timeline_query_for_tty(void){
  static const char zBaseSql[] =
    @ SELECT
    @   blob.rid AS rid,
    @   uuid,
    @   datetime(event.mtime,toLocal()) AS mDateTime,
    @   coalesce(ecomment,comment)
    @     || ' (user: ' || coalesce(euser,user,'?')
    @     || (SELECT case when length(x)>0 then ' tags: ' || x else '' end
    @           FROM (SELECT group_concat(substr(tagname,5), ', ') AS x
    @                   FROM tag, tagxref
    @                  WHERE tagname GLOB 'sym-*' AND tag.tagid=tagxref.tagid
    @                    AND tagxref.rid=blob.rid AND tagxref.tagtype>0))
    @     || ')' as comment,
    @   (SELECT count(*) FROM plink WHERE pid=blob.rid AND isprim)
    @        AS primPlinkCount,
    @   (SELECT count(*) FROM plink WHERE cid=blob.rid) AS plinkCount,
    @   event.mtime AS mtime,
    @   tagxref.value AS branch
    @ FROM tag CROSS JOIN event CROSS JOIN blob
    @      LEFT JOIN tagxref ON tagxref.tagid=tag.tagid
    @   AND tagxref.tagtype>0
    @   AND tagxref.rid=blob.rid
    @ WHERE blob.rid=event.objid
    @   AND tag.tagname='branch'
  ;
  return zBaseSql;
}

/*
** Return true if the input string is a date in the ISO 8601 format:
** YYYY-MM-DD.
*/
static int isIsoDate(const char *z){
  return strlen(z)==10
      && z[4]=='-'
      && z[7]=='-'
      && fossil_isdigit(z[0])
      && fossil_isdigit(z[5]);
}

/*
** Return true if the input string can be converted to a julianday.
*/
static int fossil_is_julianday(const char *zDate){
  return db_int(0, "SELECT EXISTS (SELECT julianday(%Q) AS jd"
                   " WHERE jd IS NOT NULL)", zDate);
}

/*
** COMMAND: timeline
**
** Usage: %fossil timeline ?WHEN? ?CHECKIN|DATETIME? ?OPTIONS?
**
** Print a summary of activity going backwards in date and time
** specified or from the current date and time if no arguments
** are given.  The WHEN argument can be any unique abbreviation
** of one of these keywords:
**
**     before
**     after
**     descendants | children
**     ancestors | parents
**
** The CHECKIN can be any unique prefix of 4 characters or more. You
** can also say "current" for the current version.
**
** DATETIME may be "now" or "YYYY-MM-DDTHH:MM:SS.SSS". If in
** year-month-day form, it may be truncated, the "T" may be replaced by
** a space, and it may also name a timezone offset from UTC as "-HH:MM"
** (westward) or "+HH:MM" (eastward). Either no timezone suffix or "Z"
** means UTC.
**
**
** Options:
**   -n|--limit N         If N is positive, output the first N entries.  If
**                        N is negative, output the first -N lines.  If N is
**                        zero, no limit.  Default is -20 meaning 20 lines.
**   -p|--path PATH       Output items affecting PATH only.
**                        PATH can be a file or a sub directory.
**   --offset P           skip P changes
**   --sql                Show the SQL used to generate the timeline
**   -t|--type TYPE       Output items from the given types only, such as:
**                            ci = file commits only
**                            e  = technical notes only
**                            t  = tickets only
**                            w  = wiki commits only
**   -v|--verbose         Output the list of files changed by each commit
**                        and the type of each change (edited, deleted,
**                        etc.) after the check-in comment.
**   -W|--width <num>     Width of lines (default is to auto-detect). Must be
**                        >20 or 0 (= no limit, resulting in a single line per
**                        entry).
**   -R REPO_FILE         Specifies the repository db to use. Default is
**                        the current checkout's repository.
*/
void timeline_cmd(void){
  Stmt q;
  int n, k, width;
  const char *zLimit;
  const char *zWidth;
  const char *zOffset;
  const char *zType;
  char *zOrigin;
  char *zDate;
  Blob sql;
  int objid = 0;
  Blob uuid;
  int mode = TIMELINE_MODE_NONE;
  int verboseFlag = 0 ;
  int iOffset;
  const char *zFilePattern = 0;
  Blob treeName;
  int showSql = 0;

  verboseFlag = find_option("verbose","v", 0)!=0;
  if( !verboseFlag){
    verboseFlag = find_option("showfiles","f", 0)!=0; /* deprecated */
  }
  db_find_and_open_repository(0, 0);
  zLimit = find_option("limit","n",1);
  zWidth = find_option("width","W",1);
  zType = find_option("type","t",1);
  zFilePattern = find_option("path","p",1);
  showSql = find_option("sql",0,0)!=0;

  if( !zLimit ){
    zLimit = find_option("count",0,1);
  }
  if( zLimit ){
    n = atoi(zLimit);
  }else{
    n = -20;
  }
  if( zWidth ){
    width = atoi(zWidth);
    if( (width!=0) && (width<=20) ){
      fossil_fatal("-W|--width value must be >20 or 0");
    }
  }else{
    width = -1;
  }
  zOffset = find_option("offset",0,1);
  iOffset = zOffset ? atoi(zOffset) : 0;

  /* We should be done with options.. */
  verify_all_options();

  if( g.argc>=4 ){
    k = strlen(g.argv[2]);
    if( strncmp(g.argv[2],"before",k)==0 ){
      mode = TIMELINE_MODE_BEFORE;
    }else if( strncmp(g.argv[2],"after",k)==0 && k>1 ){
      mode = TIMELINE_MODE_AFTER;
    }else if( strncmp(g.argv[2],"descendants",k)==0 ){
      mode = TIMELINE_MODE_CHILDREN;
    }else if( strncmp(g.argv[2],"children",k)==0 ){
      mode = TIMELINE_MODE_CHILDREN;
    }else if( strncmp(g.argv[2],"ancestors",k)==0 && k>1 ){
      mode = TIMELINE_MODE_PARENTS;
    }else if( strncmp(g.argv[2],"parents",k)==0 ){
      mode = TIMELINE_MODE_PARENTS;
    }else if(!zType && !zLimit){
      usage("?WHEN? ?CHECKIN|DATETIME? ?-n|--limit #? ?-t|--type TYPE? "
            "?-W|--width WIDTH? ?-p|--path PATH");
    }
    if( '-' != *g.argv[3] ){
      zOrigin = g.argv[3];
    }else{
      zOrigin = "now";
    }
  }else if( g.argc==3 ){
    zOrigin = g.argv[2];
  }else{
    zOrigin = "now";
  }
  k = strlen(zOrigin);
  blob_zero(&uuid);
  blob_append(&uuid, zOrigin, -1);
  if( fossil_strcmp(zOrigin, "now")==0 ){
    if( mode==TIMELINE_MODE_CHILDREN || mode==TIMELINE_MODE_PARENTS ){
      fossil_fatal("cannot compute descendants or ancestors of a date");
    }
    zDate = mprintf("(SELECT datetime('now'))");
  }else if( strncmp(zOrigin, "current", k)==0 ){
    if( !g.localOpen ){
      fossil_fatal("must be within a local checkout to use 'current'");
    }
    objid = db_lget_int("checkout",0);
    zDate = mprintf("(SELECT mtime FROM plink WHERE cid=%d)", objid);
  }else if( fossil_is_julianday(zOrigin) ){
    const char *zShift = "";
    if( mode==TIMELINE_MODE_CHILDREN || mode==TIMELINE_MODE_PARENTS ){
      fossil_fatal("cannot compute descendants or ancestors of a date");
    }
    if( mode==TIMELINE_MODE_NONE ){
      if( isIsoDate(zOrigin) ) zShift = ",'+1 day'";
    }
    zDate = mprintf("(SELECT julianday(%Q%s, fromLocal()))", zOrigin, zShift);
  }else if( name_to_uuid(&uuid, 0, "*")==0 ){
    objid = db_int(0, "SELECT rid FROM blob WHERE uuid=%B", &uuid);
    zDate = mprintf("(SELECT mtime FROM event WHERE objid=%d)", objid);
  }else{
    fossil_fatal("unknown check-in or invalid date: %s", zOrigin);
  }

  if( zFilePattern ){
    if( zType==0 ){
      /* When zFilePattern is specified and type is not specified, only show
       * file check-ins */
      zType="ci";
    }
    file_tree_name(zFilePattern, &treeName, 0, 1);
    if( fossil_strcmp(blob_str(&treeName), ".")==0 ){
      /* When zTreeName refers to g.zLocalRoot, it's like not specifying
       * zFilePattern. */
      zFilePattern = 0;
    }
  }

  if( mode==TIMELINE_MODE_NONE ) mode = TIMELINE_MODE_BEFORE;
  blob_zero(&sql);
  blob_append(&sql, timeline_query_for_tty(), -1);
  blob_append_sql(&sql, "\n  AND event.mtime %s %s",
     ( mode==TIMELINE_MODE_BEFORE ||
       mode==TIMELINE_MODE_PARENTS ) ? "<=" : ">=", zDate /*safe-for-%s*/
  );

  /* When zFilePattern is specified, compute complete ancestry;
   * limit later at print_timeline() */
  if( mode==TIMELINE_MODE_CHILDREN || mode==TIMELINE_MODE_PARENTS ){
    db_multi_exec("CREATE TEMP TABLE ok(rid INTEGER PRIMARY KEY)");
    if( mode==TIMELINE_MODE_CHILDREN ){
      compute_descendants(objid, (zFilePattern ? 0 : n));
    }else{
      compute_ancestors(objid, (zFilePattern ? 0 : n), 0);
    }
    blob_append_sql(&sql, "\n  AND blob.rid IN ok");
  }
  if( zType && (zType[0]!='a') ){
    blob_append_sql(&sql, "\n  AND event.type=%Q ", zType);
  }
  if( zFilePattern ){
    blob_append(&sql,
       "\n  AND EXISTS(SELECT 1 FROM mlink\n"
         "              WHERE mlink.mid=event.objid\n"
         "                AND mlink.fnid IN ", -1);
    if( filenames_are_case_sensitive() ){
      blob_append_sql(&sql,
        "(SELECT fnid FROM filename"
        " WHERE name=%Q"
        " OR name GLOB '%q/*')",
        blob_str(&treeName), blob_str(&treeName));
    }else{
      blob_append_sql(&sql,
        "(SELECT fnid FROM filename"
        " WHERE name=%Q COLLATE nocase"
        " OR lower(name) GLOB lower('%q/*'))",
        blob_str(&treeName), blob_str(&treeName));
    }
    blob_append(&sql, ")", -1);
  }
  blob_append_sql(&sql, "\nORDER BY event.mtime DESC");
  if( iOffset>0 ){
    /* Don't handle LIMIT here, otherwise print_timeline()
     * will not determine the end-marker correctly! */
    blob_append_sql(&sql, "\n LIMIT -1 OFFSET %d", iOffset);
  }
  if( showSql ){
    fossil_print("%s\n", blob_str(&sql));
  }
  db_prepare_blob(&q, &sql);
  blob_reset(&sql);
  print_timeline(&q, n, width, verboseFlag);
  db_finalize(&q);
}

/*
** WEBPAGE: thisdayinhistory
**
** Generate a vanity page that shows project activity for the current
** day of the year for various years in the history of the project.
**
** Query parameters:
**
**    today=DATE             Use DATE as today's date
*/
void thisdayinhistory_page(void){
  static int aYearsAgo[] = { 1, 2, 3, 4, 5, 10, 15, 20, 30, 40, 50, 75, 100 };
  const char *zToday;
  char *zStartOfProject;
  int i;
  Stmt q;
  char *z;

  login_check_credentials();
  if( (!g.perm.Read && !g.perm.RdTkt && !g.perm.RdWiki && !g.perm.RdForum) ){
    login_needed(g.anon.Read && g.anon.RdTkt && g.anon.RdWiki);
    return;
  }
  style_header("Today In History");
  zToday = (char*)P("today");
  if( zToday ){
    zToday = timeline_expand_datetime(zToday);
    if( !fossil_isdate(zToday) ) zToday = 0;
  }
  if( zToday==0 ){
    zToday = db_text(0, "SELECT date('now',toLocal())");
  }
  @ <h1>This Day In History For %h(zToday)</h1>
  z = db_text(0, "SELECT date(%Q,'-1 day')", zToday);
  style_submenu_element("Yesterday", "%R/thisdayinhistory?today=%t", z);
  z = db_text(0, "SELECT date(%Q,'+1 day')", zToday);
  style_submenu_element("Tomorrow", "%R/thisdayinhistory?today=%t", z);
  zStartOfProject = db_text(0,
      "SELECT datetime(min(mtime),toLocal()) FROM event;"
  );
  timeline_temp_table();
  db_prepare(&q, "SELECT * FROM timeline ORDER BY sortby DESC /*scan*/");
  for(i=0; i<sizeof(aYearsAgo)/sizeof(aYearsAgo[0]); i++){
    int iAgo = aYearsAgo[i];
    char *zThis = db_text(0, "SELECT date(%Q,'-%d years')", zToday, iAgo);
    Blob sql;
    char *zId;
    if( strcmp(zThis, zStartOfProject)<0 ) break;
    blob_init(&sql, 0, 0);
    blob_append(&sql, "INSERT OR IGNORE INTO timeline ", -1);
    blob_append(&sql, timeline_query_for_www(), -1);
    blob_append_sql(&sql,
       " AND %Q=date(event.mtime,toLocal()) "
       " AND event.mtime BETWEEN julianday(%Q,'-1 day')"
             " AND julianday(%Q,'+2 days')",
       zThis, zThis, zThis
    );
    db_multi_exec("DELETE FROM timeline; %s;", blob_sql_text(&sql));
    blob_reset(&sql);
    if( db_int(0, "SELECT count(*) FROM timeline")==0 ){
      continue;
    }
    zId = db_text(0, "SELECT timestamp FROM timeline"
                     " ORDER BY sortby DESC LIMIT 1");
    @ <h2>%d(iAgo) Year%s(iAgo>1?"s":"") Ago
    @ <small>%z(href("%R/timeline?c=%t",zId))(more context)</a>\
    @ </small></h2>
    www_print_timeline(&q, TIMELINE_GRAPH, 0, 0, 0, 0);
  }
  db_finalize(&q);
  style_footer();
}


/*
** COMMAND: test-timewarp-list
**
** Usage: %fossil test-timewarp-list ?-v|---verbose?
**
** Display all instances of child check-ins that appear earlier in time
** than their parent.  If the -v|--verbose option is provided, both the
** parent and child check-ins and their times are shown.
*/
void test_timewarp_cmd(void){
  Stmt q;
  int verboseFlag;

  db_find_and_open_repository(0, 0);
  verboseFlag = find_option("verbose", "v", 0)!=0;
  if( !verboseFlag ){
    verboseFlag = find_option("detail", 0, 0)!=0; /* deprecated */
  }
  db_prepare(&q,
     "SELECT (SELECT uuid FROM blob WHERE rid=p.cid),"
     "       (SELECT uuid FROM blob WHERE rid=c.cid),"
     "       datetime(p.mtime), datetime(c.mtime)"
     "  FROM plink p, plink c"
     " WHERE p.cid=c.pid  AND p.mtime>c.mtime"
  );
  while( db_step(&q)==SQLITE_ROW ){
    if( !verboseFlag ){
      fossil_print("%s\n", db_column_text(&q, 1));
    }else{
      fossil_print("%.14s -> %.14s   %s -> %s\n",
         db_column_text(&q, 0),
         db_column_text(&q, 1),
         db_column_text(&q, 2),
         db_column_text(&q, 3));
    }
  }
  db_finalize(&q);
}

/*
** WEBPAGE: timewarps
**
** Show all check-ins that are "timewarps".  A timewarp is a
** check-in that occurs before its parent, according to the
** timestamp information on the check-in.  This can only actually
** happen, of course, if a users system clock is set incorrectly.
*/
void test_timewarp_page(void){
  Stmt q;
  int cnt = 0;

  login_check_credentials();
  if( !g.perm.Read || !g.perm.Hyperlink ){
    login_needed(g.anon.Read && g.anon.Hyperlink);
    return;
  }
  style_header("Instances of timewarp");
  db_prepare(&q,
     "SELECT blob.uuid, "
     "       date(ce.mtime),"
     "       pe.mtime>ce.mtime,"
     "       coalesce(ce.euser,ce.user)"
     "  FROM plink p, plink c, blob, event pe, event ce"
     " WHERE p.cid=c.pid  AND p.mtime>c.mtime"
     "   AND blob.rid=c.cid"
     "   AND pe.objid=p.cid"
     "   AND ce.objid=c.cid"
     " ORDER BY 2 DESC"
  );
  while( db_step(&q)==SQLITE_ROW ){
    const char *zCkin = db_column_text(&q, 0);
    const char *zDate = db_column_text(&q, 1);
    const char *zStatus = db_column_int(&q,2) ? "Open"
                                 : "Resolved by editing date";
    const char *zUser = db_column_text(&q, 3);
    char *zHref = href("%R/timeline?c=%S", zCkin);
    if( cnt==0 ){
      style_table_sorter();
      @ <div class="brlist">
      @ <table class='sortable' data-column-types='tttt' data-init-sort='2'>
      @ <thead><tr>
      @ <th>Check-in</th>
      @ <th>Date</th>
      @ <th>User</th>
      @ <th>Status</th>
      @ </tr></thead><tbody>
    }
    @ <tr>
    @ <td>%s(zHref)%S(zCkin)</a></td>
    @ <td>%s(zHref)%s(zDate)</a></td>
    @ <td>%h(zUser)</td>
    @ <td>%s(zStatus)</td>
    @ </tr>
    fossil_free(zHref);
    cnt++;
  }
  db_finalize(&q);
  if( cnt==0 ){
    @ <p>No timewarps in this repository</p>
  }else{
    @ </tbody></table></div>
  }
  style_footer();
}
