(* COCANWIKI - a wiki written in Objective CAML.
 * Written by Richard W.M. Jones <rich@merjis.com>.
 * Copyright (C) 2004 Merjis Ltd.
 * $Id: restore.ml,v 1.17 2005/11/17 10:14:42 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_diff
open Cocanwiki_emailnotify

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

  if q#param_true "yes" then (
    (* 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

    (* Copy the old version of the page to be live. *)
    let sth = dbh#prepare_cached "select title, description, creation_date,
                                         redirect, css
                                    from pages
                                   where hostid = ?
                                     and url_deleted = ? and id = ?" in
    sth#execute [`Int hostid; `String page; `Int version];

    let title, description, creation_date, redirect, css =
      match sth#fetch1 () with
	  [ title; description; creation_date; redirect; css ] ->
	    title, 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, links_from_cn, recently_visited_url_cn
             deferred" in
    sth#execute [];

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

    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; title; description;
		 creation_date; logged_ip; logged_user; redirect; css ];

    let pageid = Int64.to_int (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 version];

    (* Keep the links table in synch. *)
    Cocanwiki_links.update_links_for_page dbh hostid page;

    dbh#commit ();

    (* Email notify. *)
    let subject = "Page " ^ page ^ " has been restored." in
    let body = fun () ->
      (* Prepare the diff between this version and the previous version. *)
      let diff, _ = get_diff dbh hostid page ~version:pageid () in
      "Page: http://" ^ hostname ^ "/" ^ page ^ "\n\n" ^
      diff in

    email_notify ~body ~subject ~user dbh hostid;

    (* Done. *)
    let buttons = [ ok_button ("/" ^ page) ] in
    ok ~title:"Restored" ~buttons
      q "The old page was restored successfully."
  ) else
    q#redirect ("http://" ^ hostname ^ "/" ^ page)

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