(* COCANWIKI - a wiki written in Objective CAML.
 * Written by Richard W.M. Jones <rich@merjis.com>.
 * Copyright (C) 2004 Merjis Ltd.
 * $Id: edit_page_title.ml,v 1.1 2004/09/25 16:05:03 rich Exp $
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *)

open Apache
open Registry
open Cgi
open Printf

open Cocanwiki
open Cocanwiki_ok
open Cocanwiki_emailnotify
open Cocanwiki_strings

let run r (q : cgi) (dbh : Dbi.connection) hostid {hostname = hostname} user =
  let page = q#param "page" in
  let new_title = trim (q#param "title") in

  (* Get the old title. *)
  let sth = dbh#prepare_cached "select title from pages
                                 where hostid = ? and url = ?" in
  sth#execute [`Int hostid; `String page];

  let old_title = sth#fetch1string () in

  (* New title mustn't be empty string. *)
  if new_title = "" then (
    error ~back_button:true ~title:"Empty title not allowed"
      q "The new title cannot be empty.";
    return ()
  );

  (* If it's the index page, then they can change the title however
   * they want.  On other pages, however, you are only allowed limited
   * edits which preserve the title -> url mapping.
   *)
  if page <> "index" then (
    let new_page =
      match Wikilib.generate_url_of_title dbh hostid new_title with
	  Wikilib.GenURL_OK url -> url
	| Wikilib.GenURL_TooShort
	| Wikilib.GenURL_BadURL -> ""
	| Wikilib.GenURL_Duplicate url -> url in

    if new_page <> page then (
      error ~back_button:true ~title:"Title altered too much"
        q ("The new title is too different from the old one.  You can only " ^
	   "make limited changes to the title of a page.  The manual " ^
	   "describes why, and how to copy pages instead.");
      return ()
    )
  );

  (* Get the IP address of the user, if available. *)
  let logged_ip =
    try `String (Connection.remote_ip (Request.connection r))
    with Not_found -> `Null in

  let logged_user =
    match user with
      | User (id, _, _) -> `Int id
      | _ -> `Null in

  (* Changing the title creates a new version of the page.  This enables
   * us to revert changes.
   *)
  let sth = dbh#prepare_cached "select id, description, creation_date,
                                       redirect, css
                                  from pages
                                 where hostid = ? and url = ?" in
  sth#execute [`Int hostid; `String page];

  let oldpageid, description, creation_date, redirect, css =
    match sth#fetch1 () with
	[ `Int id; description; creation_date; redirect; css ] ->
	  id, description, creation_date, redirect, css
      | _ -> assert false in

  let sth = dbh#prepare_cached
	      "set constraints pages_redirect_cn, sitemenu_url_cn,
                   page_emails_url_cn deferred" in
  sth#execute [];

  let sth = dbh#prepare_cached "update pages set url_deleted = url,
                                                 url = null
                                 where hostid = ? and id = ?" in
  sth#execute [`Int hostid; `Int oldpageid];

  let sth = dbh#prepare_cached "insert into pages (hostid, url, title,
                                   description, creation_date, logged_ip,
                                   logged_user, redirect, css)
                                values (?, ?, ?, ?, ?, ?, ?, ?, ?)" in
  sth#execute [`Int hostid; `String page; `String new_title; description;
	       creation_date; logged_ip; logged_user; redirect; css ];

  let pageid = sth#serial "pages_id_seq" in

  let sth = dbh#prepare_cached "insert into contents (pageid, ordering,
                                       sectionname, content, divname)
                                select ? as pageid, ordering, sectionname,
                                            content, divname
                                  from contents
                                 where pageid = ?" in
  sth#execute [`Int pageid; `Int oldpageid];

  dbh#commit ();

  (* Email notification. *)
  let subject = "Title of page " ^ page ^ " has been modified" in
  let body = fun () ->
    "Page: http://" ^ hostname ^ "/" ^ page ^ "\n\n" ^
    "Old title: " ^ old_title ^ "\n" ^
    "New title: " ^ new_title ^ "\n" in

  email_notify ~subject ~body dbh hostid;

  let buttons = [ ok_button ("/" ^ page) ] in
  ok ~title:"Title changed" ~buttons
    q "The page title was changed successfully."

let () =
  register_script ~restrict:[CanEdit] run