/*
** Format help text for TTY display.
*/
static void help_to_text(const char *zHelp, Blob *pText){
  int i, x;
  char c;
  if( zHelp[0]=='>' ){
    blob_appendf(pText, "Usage:");
    zHelp++;
  }
  for(i=0; (c = zHelp[i])!=0; i++){
    if( c=='%' && strncmp(zHelp+i,"%fossil",7)==0 ){
      if( i>0 ) blob_append(pText, zHelp, i);
      blob_append(pText, "fossil", 6);
      zHelp += i+7;
      i = -1;
      continue;

      occHelp[aCommand[i].iHelp] = 0;
    }
  }
  @ </dl>
  blob_reset(&buf);
  style_finish_page();
}

/*
** Input z[] is help text for zTopic.  If zTopic has sub-command zSub,
** then cut out all portions of the original help text that do not
** directly pertain to zSub and write the zSub-relevant parts into
** pOut.
**
** Return the number of lines of z[] written into pOut.  A return of
** zero means no simplification occurred.
*/
static int simplify_to_subtopic(
  const char *z,            /* Full original help text */
  Blob *pOut,               /* Write simplified help text here */
  const char *zTopic,       /* TOPIC */
  const char *zSubtopic     /* SUBTOPIC */
){
  Blob in, line;
  int n = 0;
  char *zGlob = mprintf("> fossil %s *%s*", zTopic, zSubtopic);

  blob_init(&in, z, -1);
  while( blob_line(&in, &line) ){
    if( sqlite3_strglob(zGlob, blob_str(&line))==0 ){
      blob_appendb(pOut, &line);
      n++;
      while( blob_line(&in, &line) && blob_str(&line)[0]!='>' ){
        blob_appendb(pOut, &line);
        n++;
      }
      break;
    }
  }
  fossil_free(zGlob);
  if( n ) blob_trim(pOut);
  return n;
  return 0;
}

/*
** Input z[] is help text for a command zTopic.  Write into pOut all lines of
** z[] that show the command-line syntax for that command.  Lines written
** to pOut are lines that begin with out of:
**
**     Usage:
**     or:
**     > fossil TOPIC
**
** Return the number of lines written into pOut.
*/
static int simplify_to_usage(
  const char *z,            /* Full original help text */
  Blob *pOut,               /* Write simplified help text here */
  const char *zTopic        /* The command for which z[] is full help text */
){
  ReCompiled *pRe = 0;
  Blob in, line;
  int n = 0;

  re_compile(&pRe, "^(Usage: | *[Oo]r: +%fossi |> fossil )", 0);
  blob_init(&in, z, -1);
  while( blob_line(&in, &line) ){
    if( re_match(pRe, (unsigned char*)blob_str(&line), blob_strlen(&line)) ){
      blob_appendb(pOut, &line);
      n++;
    }
  }
  re_free(pRe);
  if( n ) blob_trim(pOut);
  return n;
}

static void multi_column_list(const char **azWord, int nWord){
  int i, j, len;
  int mxLen = 0;
  int nCol;
  int nRow;
  for(i=0; i<nWord; i++){

@   --sshtrace              Trace SSH activity
@   --ssl-identity NAME     Set the SSL identity to NAME
@   --systemtrace           Trace calls to system()
@   -U|--user USER          Make the default user be USER
@   --utc                   Display times using UTC
@   --vfs NAME              Cause SQLite to use the NAME VFS
;

/*
** COMMAND: usage
**
** Usage: %fossil usage COMMAND [SUBCOMMAND]
**
** Show succinct usage instruction for a Fossil command.  Shorthand 
** for "fossil help --usage COMMAND [SUBCOMMAND]"
*/
void usage_cmd(void){
  help_cmd();
}

/*
** COMMAND: help
**
** Usage: %fossil help [OPTIONS] [TOPIC] [SUBCOMMAND]
**
** Display information on how to use TOPIC, which may be a command, webpage, or
** setting.  Webpage names begin with "/".  If TOPIC is omitted, a list of
** topics is returned.
**
** The following options can be used when TOPIC is omitted:
**
**    -a|--all          List both common and auxiliary commands
**    -e|--everything   List all help on all topics
**    -f|--full         List full set of commands (including auxiliary
**                      and unsupported "test" commands), options,
**                      settings, and web pages
**    -o|--options      List command-line options common to all commands
**    -s|--setting      List setting names
**    -t|--test         List unsupported "test" commands
**    -v|--verbose      List both names and help text
**    -x|--aux          List only auxiliary commands
**    -w|--www          List all web pages




**
** These options can be used when TOPIC is present:
**
**    -c|--commands     Restrict TOPIC search to commands
**    -h|--html         Format output as HTML rather than plain text
**    --raw             Output raw, unformatted help text
**    -u|--usage        Show a succinct usage summary, not full help text
*/
void help_cmd(void){
  int rc;
  int mask = CMDFLAG_ANY;        /* Mask of help topic types */
  int isPage = 0;                /* True if TOPIC is a page */
  int verboseFlag = 0;           /* -v option */
  int commandsFlag = 0;          /* -c option */
  const char *z;                 /* Original, untranslated help text */
  const char *zCmdOrPage;        /* "command" or "page" or "setting" */
  const CmdOrPage *pCmd = 0;     /* ptr to aCommand[] entry for TOPIC */
  int useHtml = 0;               /* -h option */
  int bUsage = g.zCmdName[0]=='u';  /* --usage or "fossil usage TOPIC" */
  int bRaw;                      /* --raw option */
  const char *zTopic;            /* TOPIC argument */
  const char *zSubtopic = 0;     /* SUBTOPIC argument */
  Blob subtext1, subtext2;       /* Subsets of z[] containing subtopic/usage */
  Blob txt;                      /* Text after rendering */

  verboseFlag = find_option("verbose","v",0)!=0;
  commandsFlag = find_option("commands","c",0)!=0;
  useHtml = find_option("html","h",0)!=0;
  bRaw = find_option("raw",0,0)!=0;
  if( find_option("usage","u",0)!=0 ) bUsage = 1;
  if( find_option("options","o",0) ){
    fossil_print("%s", zOptions);
    return;
  }
  else if( find_option("all","a",0) ){
    command_list(CMDFLAG_1ST_TIER | CMDFLAG_2ND_TIER, verboseFlag, useHtml);
    return;

      "Frequently used commands:\n",
      z, z, z);
    command_list(CMDFLAG_1ST_TIER,verboseFlag,useHtml);
    if( !verboseFlag ) version_cmd();
    return;
  }
  zTopic = g.argv[2];
  zSubtopic = g.argc>=4 ? g.argv[3] : 0;
  isPage = ('/' == zTopic[0]) ? 1 : 0;
  if(isPage){
    zCmdOrPage = "page";
  }else if( commandsFlag ){
    mask = CMDFLAG_COMMAND;
    zCmdOrPage = "command";
  }else{

                 zCmdOrPage, g.argv[2]);
    }
    fossil_print("Did you mean one of these TOPICs:\n");
    n = dispatch_approx_match(g.argv[2], 5, az);
    for(i=0; i<n; i++){
      fossil_print("  *  %s\n", az[i]);
    }
    fossil_print("Other commands to try:\n");
    fossil_print("   fossil search -h PATTERN  ;# search all help text\n");
    fossil_print("   fossil help -a            ;# show all commands\n");
    fossil_print("   fossil help -w            ;# show all web-pages\n");
    fossil_print("   fossil help -s            ;# show all settings\n");
    fossil_print("   fossil help -o            ;# show global options\n");
    return;
  }
  blob_init(&subtext1, 0, 0);
  blob_init(&subtext2, 0, 0);
  z = pCmd->zHelp;
  if( z==0 ){
    fossil_fatal("no help available for the %s %s",
                 pCmd->zName, zCmdOrPage);
  }
  if( zSubtopic!=0 ){
    if( simplify_to_subtopic(z, &subtext1, zTopic, zSubtopic) ){
      z = blob_str(&subtext1);
    }else{
      fossil_print("No subtopic \"%s\" for \"%s\".\n", zTopic, zSubtopic);
      if( strstr(z, "Usage:")!=0 || strstr(z, "\n> fossil")!=0 ){
        bUsage = 1;
      }
    }
  }
  if( bUsage && simplify_to_usage(z, &subtext2, zTopic) ){
    z = blob_str(&subtext2);
  }
  if( pCmd->eCmdFlags & CMDFLAG_SETTING ){
    const Setting *pSetting = db_find_setting(pCmd->zName, 0);
    char *zDflt = 0;
    if( pSetting!=0 && pSetting->def!=0 && *pSetting->def!=0 ){
      zDflt = mprintf(" (default: %s)", pSetting->def);
    }
    fossil_print("Setting: \"%s\"%s%s\n\n",
         pCmd->zName, zDflt!=0 ? zDflt : "",
         (pCmd->eCmdFlags & CMDFLAG_VERSIONABLE)!=0 ? " (versionable)" : ""
    );
    fossil_free(zDflt);
  }
  blob_init(&txt, 0, 0);
  if( bRaw ){
    blob_append(&txt, z, -1);
  }else if( useHtml ){
    help_to_html(z, &txt);
  }else{
    help_to_text(z, &txt);
  }
  fossil_print("%s\n", blob_str(&txt));
  blob_reset(&txt);
  blob_reset(&subtext1);
  blob_reset(&subtext2);
}

/*
** Return a pointer to the setting information array.
**
** This routine provides access to the aSetting[] array which is created
** by the mkindex utility program and included with <page_index.h>.