(* COCANWIKI - a wiki written in Objective CAML.
 * Written by Richard W.M. Jones <rich@merjis.com>.
 * Copyright (C) 2004 Merjis Ltd.
 * $Id: rename_page.ml,v 1.2 2004/11/22 11:11:52 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_pages
open Cocanwiki_strings
open Cocanwiki_emailnotify

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

  (* Cancelled? *)
  if q#param_true "cancel" then (
    q#redirect ("http://" ^ hostname ^ "/" ^ page);
    return ()
  );

  let new_title = trim (q#param "new_title") 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 ()
  );

  (* 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

  (* Generate URL for the new title. *)
  let new_page =
    if page = "index" then page
    else
      match Wikilib.generate_url_of_title dbh hostid new_title with
	| Wikilib.GenURL_OK url | Wikilib.GenURL_Duplicate url -> url
	| Wikilib.GenURL_TooShort | Wikilib.GenURL_BadURL ->
	    error ~title:"Bad title" ~back_button:true
	      q ("The new title for the page isn't valid.  " ^
		 "It may be too short or it may not contain " ^
		 "enough alphabet letters.");
	    return () in

  if page = new_page then (
    (* If it's the same as the old URL, then this is a simple title change. *)
    let model = load_page dbh hostid ~url:page () in
    let model = { model with pt = Title new_title } in
    let url, _ = save_page dbh hostid ~user ~r model in
    assert (url = new_page)
  ) else (
    (* Not the same as the old URL, so set the old page to a redirect and
     * create a new page.
     *)
    let old_model = load_page dbh hostid ~url:page () in
    let new_model = new_page_with_title new_title in
    let new_model = { new_model with description = old_model.description;
			contents = old_model.contents } in
    let old_model = { old_model with redirect = new_page } in
    save_page dbh hostid ~user ~r old_model;

    try
      ignore (save_page dbh hostid ~user ~r new_model)
    with
	SaveURLError ->
	  error ~title:"Page exists"
	    q ("Another page with the same title exists.  " ^
	       "If you tried to rename a page, then rename it back to the " ^
	       "original title, then you may see this error.  This is a bug " ^
	       "which you should raise with the site administrator.");
	  return ()
  );

  (* Finish off XXX *)
  dbh#commit ();

  (* Email notification. *)
  let subject = "Page " ^ page ^ " has been renamed" in

  let body = fun () ->
    "Old title: " ^ old_title ^ "\n" ^
    "New title: " ^ new_title in

  email_notify ~body ~subject ~user dbh hostid;

  let buttons = [ ok_button ("/" ^ new_page) ] in
  ok ~title:"Page renamed" ~buttons
    q "That page was renamed."

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