/*
** Maximum length of a line in a text file, in bytes.  (2**15 = 32768 bytes)
*/
#define LENGTH_MASK_SZ  15
#define LENGTH_MASK     ((1<<LENGTH_MASK_SZ)-1)

/*
** An instance of this object describes the formatting and processing
** details desired of a "diff" operation.
**
** Conceptually, this object is as an encoding of the command-line options
** for the "fossil diff" command.  That is not a precise description, though,
** because not all diff operations are started from the command-line.  But
** the idea is sound.
**
** Information encoded by this object includes but is not limited to:
**
**    *   The desired output format (unified vs. side-by-side, 
**        TCL, JSON, HTML vs. plain-text).
**
**    *   Number of lines of context surrounding each difference block
**
**    *   Width of output columns for text side-by-side diffop          
*/
struct DiffConfig {
  u64 diffFlags;       /* Legacy diff flags */
};

#endif /* INTERFACE */

    free(c.aFrom);
    free(c.aTo);
    return c.aEdit;
  }
}

/*
** Initialize the DiffConfig object using command-line options.
**
** Process diff-related command-line options and return an appropriate
** "diffFlags" integer.
**
**   --brief                    Show filenames only    DIFF_BRIEF
**   -c|--context N             N lines of context.    DIFF_CONTEXT_MASK
**   --html                     Format for HTML        DIFF_HTML
**   --invert                   Invert the diff        DIFF_INVERT
**   -n|--linenum               Show line numbers      DIFF_LINENO
**   --noopt                    Disable optimization   DIFF_NOOPT
**   --numstat                  Show change counts     DIFF_NUMSTAT
**   --strip-trailing-cr        Strip trailing CR      DIFF_STRIP_EOLCR
**   --unified                  Unified diff.          ~DIFF_SIDEBYSIDE
**   -w|--ignore-all-space      Ignore all whitespaces DIFF_IGNORE_ALLWS
**   -W|--width N               N character lines.     DIFF_WIDTH_MASK
**   -y|--side-by-side          Side-by-side diff.     DIFF_SIDEBYSIDE
**   -Z|--ignore-trailing-space Ignore eol-whitespaces DIFF_IGNORE_EOLWS
*/
void diff_options(DiffConfig *pCfg, int isGDiff){
  u64 diffFlags = 0;
  const char *z;
  int f;

  memset(pCfg, 0, sizeof(*pCfg));

  if( find_option("ignore-trailing-space","Z",0)!=0 ){
    diffFlags = DIFF_IGNORE_EOLWS;
  }
  if( find_option("ignore-all-space","w",0)!=0 ){
    diffFlags = DIFF_IGNORE_ALLWS; /* stronger than DIFF_IGNORE_EOLWS */
  }
  if( find_option("strip-trailing-cr",0,0)!=0 ){

    diffFlags |= DIFF_TCL;
  }

  /* Undocumented and unsupported flags used for development
  ** debugging and analysis: */
  if( find_option("debug",0,0)!=0 ) diffFlags |= DIFF_DEBUG;
  if( find_option("raw",0,0)!=0 )   diffFlags |= DIFF_RAW;

  pCfg->diffFlags = diffFlags;


}

/*
** COMMAND: test-diff
** COMMAND: xdiff
**
** Usage: %fossil xdiff [options] FILE1 FILE2

** See the "diff" command for a full list of command-line options.
**
** This command used to be called "test-diff".  The older "test-diff" spelling
** still works, for compatibility.
*/
void test_diff_cmd(void){
  Blob a, b, out;

  const char *zRe;           /* Regex filter for diff output */
  ReCompiled *pRe = 0;       /* Regex filter for diff output */
  DiffConfig DCfg;

  if( find_option("tk",0,0)!=0 ){
    diff_tk("test-diff", 2);
    return;
  }
  find_option("i",0,0);
  find_option("v",0,0);
  zRe = find_option("regexp","e",1);
  if( zRe ){
    const char *zErr = re_compile(&pRe, zRe, 0);
    if( zErr ) fossil_fatal("regex error: %s", zErr);
  }
  diff_options(&DCfg, 0);
  verify_all_options();
  if( g.argc!=4 ) usage("FILE1 FILE2");
  blob_zero(&out);
  diff_begin(DCfg.diffFlags);
  diff_print_filenames(g.argv[2], g.argv[3], DCfg.diffFlags, &out);
  blob_read_from_file(&a, g.argv[2], ExtFILE);
  blob_read_from_file(&b, g.argv[3], ExtFILE);
  text_diff(&a, &b, &out, pRe, &DCfg);
  blob_write_to_file(&out, "-");
  diff_end(DCfg.diffFlags, 0);
  re_free(pRe);
}

/**************************************************************************
** The basic difference engine is above.  What follows is the annotation
** engine.  Both are in the same file since they share many components.
*/