/*
** SETTING: chat-inline-images    boolean default=on
**
** Specifies whether posted images in /chat should default to being
** displayed inline or as downloadable links. Each chat user can
** change this value for their current chat session in the UI.
*/
/*
** SETTING: chat-poll-timeout    width=10 default=420
**
** On an HTTP request to /chat-poll, if there is no new content available,
** the reply is delayed waiting for new content to arrive.  (This is the
** "long poll" strategy of event delivery to the client.)  This setting
** determines approximately how long /chat-poll will delay before giving
** up and returning an empty reply.  The default value is about 7 minutes,
** which works well for Fossil behind the althttpd web server.  Other
** server environments may choose a longer or shorter delay.
**
** For maximum efficiency, it is best to choose the longest delay that
** does not cause timeouts in intermediate proxies or web server.
*/
/*
** WEBPAGE: chat
**
** 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

    fossil_free(zOut);
  }
}

/*
** WEBPAGE: chat-poll
**
** The chat page generated by /chat using an XHR to this page to
** request new chat content.  A typical invocation is:
**
**     /chat-poll/N
**     /chat-poll?name=N
**
** The "name" argument should begin with an integer which is the largest
** "msgid" that the chat page currently holds. If newer content is
** available, this routine returns that content straight away. If no new
** content is available, this webpage blocks until the new content becomes
** available.  In this way, the system implements "hanging-GET" or "long-poll"
** style event notification. If no new content arrives after a delay of

** approximately chat-poll-timeout seconds (default: 420), then reply is
** sent with an empty "msg": field.
**
** If N is negative, then the return value is the N most recent messages.
** Hence a request like /chat-poll/-100 can be used to initialize a new
** chat session to just the most recent messages.
**
** Some webservers (althttpd) do not allow a term of the URL path to
** begin with "-".  Then /chat-poll/-100 cannot be used.  Instead you

**
** The messages are ordered oldest first unless "before" is provided, in which
** case they are sorted newest first (to facilitate the client-side UI update).
*/
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.*/
  int msgid = atoi(PD("name","0"));
  const int msgBefore = atoi(PD("before","0"));
  int nLimit = msgBefore>0 ? atoi(PD("n","0")) : 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 ) return;
  chat_create_tables();
  cgi_set_content_type("text/json");
  dataVersion = db_int64(0, "PRAGMA data_version");
  blob_append_sql(&sql,
    "SELECT msgid, datetime(mtime), xfrom, xmsg, length(file),"