(* COCANWIKI - a wiki written in Objective CAML.
 * Written by Richard W.M. Jones <rich@merjis.com>.
 * Copyright (C) 2004 Merjis Ltd.
 * $Id: upload_image.ml,v 1.14 2006/03/28 16:24:08 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 ExtString

open Cocanwiki
open Cocanwiki_ok
open Cocanwiki_emailnotify
open Cocanwiki_images
open Cocanwiki_strings

(* Valid image names. *)
let image_ok_re = Pcre.regexp "^[a-z0-9][-._a-z0-9]*\\.(jpg|jpeg|gif|ico|png)$"

let run r (q : cgi) dbh hostid { hostname = hostname } user=
  let name = q#param "name" in
  let alt = q#param "alt" in
  let title = q#param "title" in
  let longdesc = q#param "longdesc" in
  let clazz = q#param "class" in

  (* See if there was an upload. *)
  let image =
    try
      let upload = q#upload "file" in
      upload.upload_value
    with
	Not_found ->
	  error ~title:"No image" ~back_button:true
	    dbh hostid q "No image was uploaded.";
	  return () in

  (* Check the name is valid. *)
  if not (Pcre.pmatch ~rex:image_ok_re name) then (
    error ~title:"Bad Image Name" ~back_button:true
      dbh hostid q
      ("The Image Name must contain only lowercase English letters, " ^
       "numbers, dots, dashes and underscore.  " ^
       "It must end with .jpg, .gif or .png " ^
       "depending on the image format.");
    return ()
  );

  (* Check the image is an image, and get the size. *)
  let mime_type, width, height =
    try image_identify image
    with
	Invalid_argument _ ->
	  error ~title:"Bad image" ~back_button:true
	    dbh hostid q
	    ("Unknown image type.  Is the file you uploaded really an " ^
	     "image?");
	  return () in

  (* Check the image filename extension matches the MIME type. *)
  let ext_ok =
    match mime_type with
	"image/jpeg" ->
	  String.ends_with name ".jpg" ||
	  String.ends_with name ".jpeg"
      | "image/gif" ->
	  String.ends_with name ".gif"
      | "image/png" ->
	  String.ends_with name ".png"
      | _ -> assert false in
  if not ext_ok then (
    error ~title:"Bad Image Name" ~back_button:true
      dbh hostid q
      ("The Image Name extension has to match the image format.  " ^
       "For example if the image is in JPEG format, the name must " ^
       "be 'something.jpg'.  I detected the following image type " ^
       "in the file you uploaded: " ^ mime_type);
    return ()
  );

  (* Check some ALT text was supplied. *)
  if string_is_whitespace alt then (
    error ~title:"Missing Alt text" ~back_button:true
      dbh hostid q
      ("You must supply Alt text describing the image.  This is required " ^
       "by accessibility laws and to allow search engines to discover the " ^
       "content of images.");
    return ()
  );

  let title = if string_is_whitespace title then None else Some title in
  let longdesc =
    if string_is_whitespace longdesc then None else Some longdesc in
  let clazz = if string_is_whitespace clazz then None else Some clazz in

  (* Make a thumbnail of this image. *)
  let thumbnail, tn_mime_type, tn_width, tn_height =
    image_thumbnail image 120 120 in

  (* Check if something with the same name already exists.  If replace=1
   * then we can replace it, otherwise we must present an error message.
   *)
  let replace = q#param_true "replace" in
  let rows = PGSQL(dbh) "select 1 from images
                          where hostid = $hostid and name = $name" in
  let exists = rows = [Some 1l] in

  if exists then (
    if not replace then (
      error ~title:"Image already exists" ~back_button:true
	dbh hostid q "An image with the same name already exists.";
    return ()
    ) else (
      PGSQL(dbh) "update images
                     set name_deleted = name, name = null
                   where hostid = $hostid and name = $name"
    )
  );

  (* Put the image into the database. *)
  let width = Int32.of_int width in
  let height = Int32.of_int height in
  let tn_width = Int32.of_int tn_width in
  let tn_height = Int32.of_int tn_height in
  PGSQL(dbh)
    "insert into images (hostid, name, image, width, height, alt,
                         title, longdesc, class, thumbnail, tn_width,
                         tn_height, mime_type, tn_mime_type)
     values ($hostid, $name, $image, $width, $height, $alt, $?title,
             $?longdesc, $?clazz, $thumbnail, $tn_width, $tn_height,
             $mime_type, $tn_mime_type)";

  PGOCaml.commit dbh;

  (* Email notify. *)
  let subject = "Image " ^ name ^ " has been uploaded." in
  let body = fun () ->
    "Page: http://" ^ hostname ^ "/_images" in

  email_notify ~body ~subject ~user dbh hostid;

  let buttons = [ ok_button "/_images" ] in
  ok ~title:"Image uploaded" ~buttons
    dbh hostid q "Image was uploaded successfully."

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