(* COCANWIKI - a wiki written in Objective CAML.
 * Written by Richard W.M. Jones <rich@merjis.com>.
 * Copyright (C) 2004 Merjis Ltd.
 * $Id: cocanwiki_emailnotify.ml,v 1.9 2006/07/31 09:49:45 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 ExtList

open Cocanwiki

(* This is where we coordinate email notification from various
 * scripts which create or update the wiki.
 *)
let email_notify ~subject ~body ?user dbh hostid =
  (* Get own userid, if we have it.  Don't want to send email
   * notification back to the person who changed the page.  If
   * we don't have a userid, set it to 0, because no real user can
   * have userid = 0.
   *
   * Also get the user's email address.
   *)
  let own_userid, from_addr =
    match user with
      | None
      | Some Anonymous -> 0l, None
      | Some (User (userid, _, _, {email = Some email})) ->
	  userid, Some ("", email)
      | Some (User (userid, _, _, _)) ->
	  userid, None in

  (* Send a change email to everyone who hasn't opted out using
   * their preferences.  This behaviour replaces the old
   * 'email_notify' table.  Don't send email to invited accounts
   * who have not yet confirmed.
   *)
  let rows = PGSQL(dbh)
    "select name, email
       from users
      where hostid = $hostid and id <> $own_userid and email_notify
        and email is not null and invite is null" in
  let to_addrs = List.filter_map (
    function
    | (name, Some email) ->
	Some (name, email)
    | (name, None) -> None
  ) rows in

  (* Get the canonical hostname. *)
  let canonical_hostname = List.hd (
    PGSQL(dbh)
      "select canonical_hostname from hosts where id = $hostid"
  ) in

  if to_addrs <> [] then (
    (* Prepare the body of the message.  The assumption is that
     * this takes time and database access, so we defer the creation
     * of the body until we know that someone needs to be notified.
     *)
    let body = body () in

    (* Add the opt-out signature to the body. *)
    let body = body ^ "\n\n-- \n" ^
      "To stop receiving further emails:\n" ^
      "(1) Go to http://" ^ canonical_hostname ^ "/_userprefs\n" ^
      "(2) Uncheck 'Receive email notifications'\n" ^
      "(3) Press 'Update Preferences'\n" in

    let subject = canonical_hostname ^ ": " ^ subject in

    let content_type =
      "text/plain", ["charset", Mimestring.mk_param "UTF-8"] in

    (* Send the email. *)
    let msg =
      Netsendmail.compose ~to_addrs ?from_addr ~content_type ~subject body in
    Netsendmail.sendmail msg
  )