<?php

/**
 * @file
 * This module allows to use different themes than the site default on specific
 * pages.
 */


/**
 * Implementation of hook_help().
 */
function page_theme_help($path, $arg) {

  switch ($path) {

    case 'admin/help#page_theme':
      $output = '<p>'. t('The <em>Page Theme</em> module is a simple and easy module to use which allows you to use different themes than the site default on specific pages.') .'</p>';
      $output .= '<p>'. t('For more information, see the online handbook entry for <a href="@page_theme">Page Theme module</a>.', array('@page_theme' => 'http://drupal.org/project/page_theme')) .'</p>';
      return $output;

    case 'admin/build/page-theme':
      $output = '<p>'. t('If pages are several defined, the first theme in the list will be used.') .'</p>';
      return $output;
  }
}


/**
 * Implementation of hook_perm().
 */
function page_theme_perm() {

  $perm = array();
  $perm[] = 'administer page theme';

  return $perm;
}


/**
 * Implementation of hook_menu().
 */
function page_theme_menu() {

  $menu = array();
  $menu['admin/build/page-theme'] = array(
    'title' => 'Page theme',
    'description' => 'Configure which theme is used on which pages.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('page_theme_admin_overview'),
    'access arguments' => array('administer page theme'),
    'file' => 'page_theme.admin.inc',
  );
  $menu['admin/build/page-theme/overview'] = array(
    'title' => 'Overview',
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'weight' => -10,
  );
  $menu['admin/build/page-theme/add'] = array(
    'title' => 'Add theme',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('page_theme_admin_add'),
    'access callback' => 'page_theme_menu_access_add',
    'access arguments' => array('administer page theme'),
    'type' => MENU_LOCAL_TASK,
    'file' => 'page_theme.admin.inc',
  );
  $menu['admin/build/page-theme/edit/%page_theme'] = array(
    'title' => 'Edit theme',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('page_theme_admin_edit', 4),
    'access arguments' => array('administer page theme'),
    'type' => MENU_CALLBACK,
    'file' => 'page_theme.admin.inc',
  );
  $menu['admin/build/page-theme/delete/%page_theme'] = array(
    'title' => 'Delete theme',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('page_theme_admin_delete', 4),
    'access arguments' => array('administer page theme'),
    'type' => MENU_CALLBACK,
    'file' => 'page_theme.admin.inc',
  );

  return $menu;
}

function page_theme_menu_access_add($perm) {

  $theme_options = page_theme_get_theme_options();
  return user_access($perm) && count($theme_options) > 1;
}

function page_theme_load($theme) {

  $result = db_query('SELECT theme, pages, status, weight FROM {page_theme} WHERE theme = "%s"', $theme);
  return db_fetch_object($result);
}


/**
 * Implementation of hook_theme().
 */
function page_theme_theme() {

  $theme = array();
  $theme['page_theme_admin_overview'] = array(
    'arguments' => array('form' => NULL),
    'file' => 'page_theme.admin.inc',
  );

  return $theme;
}


/**
 * Implementation of hook_init().
 */
function page_theme_init() {

  $path = drupal_get_path_alias($_GET['q']);

  $result = db_query('SELECT theme, pages FROM {page_theme} WHERE status = 1 ORDER BY weight, theme');
  while ($page_theme = db_fetch_object($result)) {

    $page_match = drupal_match_path($path, $page_theme->pages);
    if ($path != $_GET['q']) {
      $page_match = $page_match || drupal_match_path($_GET['q'], $page_theme->pages);
    }

    if ($page_match) {
      global $custom_theme;
      $custom_theme = $page_theme->theme;
      return;
    }
  }
}


/**
 *  Helper functions.
 */
function page_theme_get_theme_options() {

  static $options = array();

  if (!$options) {

    $themes = page_theme_get_themes();

    $result = db_query('SELECT theme FROM {page_theme}');
    while ($page_theme = db_fetch_object($result)) {
      unset($themes[$page_theme->theme]);
    }

    $options['0'] = '- '. t('Select theme') .' -';
    $options += $themes;
  }

  return $options;
}

function page_theme_get_themes($theme = NULL) {

  static $themes = array();

  if (!$themes) {

    foreach (system_theme_data() as $theme_data) {

      $compatible_core = isset($theme_data->info['core']) && $theme_data->info['core'] == DRUPAL_CORE_COMPATIBILITY;
      $compatible_php = version_compare(phpversion(), $theme_data->info['php'], '>=');

      if ($compatible_core && $compatible_php) {
        $themes[$theme_data->name] = $theme_data->info['name'];
      }
    }

    asort($themes);
  }

  return !is_null($theme) ? (isset($themes[$theme]) ? $themes[$theme] : $theme) : $themes;
}

function page_theme_get_theme_name($theme) {

  $themes = page_theme_get_themes();

  return isset($themes[$theme]) ? $themes[$theme] : t('!theme (not available)', array('!theme' => $theme));
}