"ALTER TABLE repository.pending_alert"
    " ADD COLUMN sentMod BOOLEAN DEFAULT false;"
  );
}

/*
** Enable triggers that automatically populate the pending_alert
** table. (Later:) Also add triggers that automatically relay timeline
** events to chat, if chat is configured for that.
*/
void alert_create_trigger(void){
  if( db_table_exists("repository","pending_alert") ){
    db_multi_exec(
      "DROP TRIGGER IF EXISTS repository.alert_trigger1;\n" /* Purge legacy */

      "CREATE TRIGGER temp.alert_trigger1\n"
      "AFTER INSERT ON repository.event BEGIN\n"
      "  INSERT INTO pending_alert(eventid)\n"
      "    SELECT printf('%%.1c%%d',new.type,new.objid) WHERE true\n"
      "    ON CONFLICT(eventId) DO NOTHING;\n"
      "END;"
    );
  }
  if( db_table_exists("repository","chat") ){
    const char *zChatUser = db_get("chat-timeline-user", 0);
    char *zChatCaps;
    if( zChatUser==0 || zChatUser[0]==0 ) return;
    zChatCaps = db_text(0, "SELECT cap FROM user WHERE login=%Q", zChatUser);
    if( zChatCaps && strchr(zChatCaps,'C')!=0 ){
      db_multi_exec(
         "CREATE TRIGGER temp.chat_trigger1\n"
         "AFTER INSERT ON repository.event BEGIN\n"
         "  INSERT INTO chat(mtime,xfrom,xmsg)"
         "  SELECT julianday(), %Q,"
                 " format('[%%.12s]: %%s', blob.uuid, new.comment)"
         "  FROM blob WHERE rid=new.objid;\n"
         "END;\n",
         zChatUser
      );
    }
    fossil_free(zChatCaps);
  }
}

/*
** Disable triggers the event_pending and chat triggers.
**
** This must be called before rebuilding the EVENT table, for example
** via the "fossil rebuild" command.
*/
void alert_drop_trigger(void){
  db_multi_exec(
    "DROP TRIGGER IF EXISTS temp.alert_trigger1;\n"
    "DROP TRIGGER IF EXISTS repository.alert_trigger1;\n" /* Purge legacy */
    "DROP TRIGGER IF EXISTS temp.chat_trigger1;\n"
  );
}

/*
** Return true if email alerts are active.
*/
int alert_enabled(void){

*/
/*
** SETTING: chat-alert-sound     width=10
**
** This is the name of the builtin sound file to use for the alert tone.
** The value must be the name of a builtin WAV file.
*/
/*
** SETTING: chat-timeline-user    width=10
**
** If this setting is defined and is not an empty string and its value is
** the name of a user that hash chat privilege (privilege letter "C"), then
** timeline events are posted to the chat as they arrive. The synthesized
** chat messages appear to come from the user identified by this setting,
** not the user on the timeline event.
**
** All chat messages that come from the chat-timeline-user are interpreted
** as text/x-fossil-wiki instead of as text/markdown.  For this reason,
** the chat-timeline-user name should probably not be a real user.
*/
/*
** WEBPAGE: chat loadavg-exempt
**
** Start up a browser-based chat session.
**
** This is the main page that humans use to access the chatroom.  Simply
** point a web-browser at /chat and the screen fills with the latest

** it into HTML that is safe to insert using innerHTML. As of 2021-09-19,
** it does so by using markdown_to_html() to convert markdown-formatted
** zMsg to HTML.
**
** Space to hold the returned string is obtained from fossil_malloc()
** and must be freed by the caller.
*/
static char *chat_format_to_html(const char *zMsg, int isWiki){
  Blob out;
  blob_init(&out, "", 0);
  if( zMsg==0 || zMsg[0]==0 ){
    /* No-op */
  }else if( isWiki ){
    /* Used for chat-timeline-user.  The zMsg is text/x-fossil-wiki. */
    Blob bIn;
    blob_init(&bIn, zMsg, (int)strlen(zMsg));
    wiki_convert(&bIn, &out, WIKI_INLINE);
  }else{
    /* The common case:  zMsg is text/markdown */
    Blob bIn;
    blob_init(&bIn, zMsg, (int)strlen(zMsg));
    markdown_to_html(&bIn, NULL, &out);
  }
  return blob_str(&out);
}

*/
void chat_test_formatter_cmd(void){
  int i;
  char *zOut;
  db_find_and_open_repository(0,0);
  g.perm.Hyperlink = 1;
  for(i=0; i<g.argc; i++){
    zOut = chat_format_to_html(g.argv[i], 0);
    fossil_print("[%d]: %s\n", i, zOut);
    fossil_free(zOut);
  }
}

/*
** WEBPAGE: chat-poll hidden loadavg-exempt

** in a prominent manner and then stop polling for new messages.
*/
void chat_poll_webpage(void){
  Blob json;                  /* The json to be constructed and returned */
  sqlite3_int64 dataVersion;  /* Data version.  Used for polling. */
  const int iDelay = 1000;    /* Delay until next poll (milliseconds) */
  int nDelay;                 /* Maximum delay.*/
  const char *zChatUser;      /* chat-timeline-user */
  int isWiki = 0;             /* True if chat message is x-fossil-wiki */
  int msgid = atoi(PD("name","0"));
  const int msgBefore = atoi(PD("before","0"));
  int nLimit = msgBefore>0 ? atoi(PD("n","0")) : 0;
  const int bRaw = P("raw")!=0;
  
  Blob sql = empty_blob;
  Stmt q1;
  nDelay = db_get_int("chat-poll-timeout",420);  /* Default about 7 minutes */
  login_check_credentials();
  if( !g.perm.Chat ) {
    chat_emit_permissions_error(1);
    return;
  }
  zChatUser = db_get("chat-timeline-user",0);
  chat_create_tables();
  cgi_set_content_type("application/json");
  dataVersion = db_int64(0, "PRAGMA data_version");
  blob_append_sql(&sql,
    "SELECT msgid, datetime(mtime), xfrom, xmsg, length(file),"
    "       fname, fmime, %s, lmtime"
    "  FROM chat ",

      blob_appendf(&json, "\"mtime\":\"%.10sT%sZ\",", zDate, zDate+11);
      if( zLMtime && zLMtime[0] ){
        blob_appendf(&json, "\"lmtime\":%!j,", zLMtime);
      }
      blob_append(&json, "\"xfrom\":", -1);
      if(zFrom){
        blob_appendf(&json, "%!j,", zFrom);
        isWiki = fossil_strcmp(zFrom,zChatUser)==0;
      }else{
        /* see https://fossil-scm.org/forum/forumpost/e0be0eeb4c */
        blob_appendf(&json, "null,");
        isWiki = 0;
      }
      blob_appendf(&json, "\"uclr\":%!j,",
                   user_color(zFrom ? zFrom : "nobody"));

      if(bRaw){
        blob_appendf(&json, "\"xmsg\":%!j,", zRawMsg);
      }else{
        zMsg = chat_format_to_html(zRawMsg ? zRawMsg : "", isWiki);
        blob_appendf(&json, "\"xmsg\":%!j,", zMsg);
        fossil_free(zMsg);
      }

      if( nByte==0 ){
        blob_appendf(&json, "\"fsize\":0");
      }else{

** /chat-poll (without the wrapper array) or a JSON-format error
** response, as documented for ajax_route_error().
*/
void chat_fetch_one(void){
  Blob json = empty_blob;   /* The json to be constructed and returned */
  const int fRaw = PD("raw",0)!=0;
  const int msgid = atoi(PD("name","0"));
  const char *zChatUser;
  int isWiki;
  Stmt q;
  login_check_credentials();
  if( !g.perm.Chat ) {
    chat_emit_permissions_error(0);
    return;
  }
  zChatUser = db_get("chat-timeline-user",0);
  chat_create_tables();
  cgi_set_content_type("application/json");
  db_prepare(&q, 
    "SELECT datetime(mtime), xfrom, xmsg, length(file),"
    "       fname, fmime, lmtime"
    "  FROM chat WHERE msgid=%d AND mdel IS NULL",
    msgid);

    blob_appendf(&json, "\"mtime\":\"%.10sT%sZ\",", zDate, zDate+11);
    if( zLMtime && zLMtime[0] ){
      blob_appendf(&json, "\"lmtime\":%!j,", zLMtime);
    }
    blob_append(&json, "\"xfrom\":", -1);
    if(zFrom){
      blob_appendf(&json, "%!j,", zFrom);
      isWiki = fossil_strcmp(zFrom, zChatUser);
    }else{
      /* see https://fossil-scm.org/forum/forumpost/e0be0eeb4c */
      blob_appendf(&json, "null,");
      isWiki = 0;
    }
    blob_appendf(&json, "\"uclr\":%!j,",
                 user_color(zFrom ? zFrom : "nobody"));
    blob_append(&json,"\"xmsg\":", 7);
    if(fRaw){
      blob_appendf(&json, "%!j,", zRawMsg);
    }else{
      char * zMsg = chat_format_to_html(zRawMsg ? zRawMsg : "", isWiki);
      blob_appendf(&json, "%!j,", zMsg);
      fossil_free(zMsg);
    }
    if( nByte==0 ){
      blob_appendf(&json, "\"fsize\":0");
    }else{
      blob_appendf(&json, "\"fsize\":%d,\"fname\":%!j,\"fmime\":%!j",

  @ eventual must give up and return an empty message set.  This setting
  @ determines how long /chat-poll will wait before giving up.  The
  @ default setting of approximately 7 minutes works well on many systems.
  @ Shorter delays might be required on installations that use proxies
  @ or web-servers with short timeouts.  For best efficiency, this value
  @ should be larger rather than smaller.
  @ (Property: "chat-poll-timeout")</p>
  @ <hr />
  entry_attribute("Chat Timeline Robot Username", 15,
                  "chat-timeout-user", "chatrobot", "", 0);
  @ <p>If this setting is the name of a user that has "C" privilege, then
  @ all changes to the timeline will result in a new chat message from this
  @ user.  Leave this blank to omit notifications of check-ins and other
  @ timeline events from appearing in chat.
  @ (Property: "chat-timeout-user")</p>
  @ <hr />

  multiple_choice_attribute("Alert sound",
     "chat-alert-sound", "snd", azAlerts[0],
     count(azAlerts)/2, azAlerts);
  @ <p>The sound used in the client-side chat to indicate that a new
  @ chat message has arrived.