<?php
// $Id: print.module,v 1.25.2.34 2008-08-07 08:14:08 jcnventura Exp $

/**
 * @file
 * Displays Printer-friendly versions of Drupal pages.
 *
 * This is the core module of the PF package, with the Drupal hooks
 * and other administrative functions.
 */

define('PRINT_PATH', 'print');

define('PRINT_LOGO_OPTIONS_DEFAULT', 1);
define('PRINT_LOGO_URL_DEFAULT', '');
define('PRINT_CSS_DEFAULT', '');
define('PRINT_URLS_DEFAULT', 1);
define('PRINT_COMMENTS_DEFAULT', 0);
define('PRINT_NEWWINDOW_DEFAULT', 1);

define('PRINT_HTML_LINK_POS_DEFAULT', 'link');
define('PRINT_HTML_SHOW_LINK_DEFAULT', 1);
define('PRINT_HTML_NODE_LINK_VISIBILITY_DEFAULT', 0);
define('PRINT_HTML_NODE_LINK_PAGES_DEFAULT', '');
define('PRINT_HTML_LINK_CLASS_DEFAULT', 'print-page');
define('PRINT_HTML_SYS_LINK_VISIBILITY_DEFAULT', 1);
define('PRINT_HTML_SYS_LINK_PAGES_DEFAULT', '<front>');
define('PRINT_HTML_BOOK_LINK_DEFAULT', 1);
define('PRINT_HTML_NEW_WINDOW_DEFAULT', 0);
define('PRINT_HTML_SENDTOPRINTER_DEFAULT', 0);

define('PRINT_SOURCEURL_ENABLED_DEFAULT', 1);
define('PRINT_SOURCEURL_DATE_DEFAULT', 0);
define('PRINT_SOURCEURL_FORCENODE_DEFAULT', 0);

define('PRINT_ROBOTS_NOINDEX_DEFAULT', 1);
define('PRINT_ROBOTS_NOFOLLOW_DEFAULT', 1);
define('PRINT_ROBOTS_NOARCHIVE_DEFAULT', 0);

define('PRINT_TYPE_SHOW_LINK_DEFAULT', 1);
define('PRINT_TYPE_COMMENT_LINK_DEFAULT', 0);

define('PRINT_ALLOW_NORMAL_LINK', 1);
define('PRINT_ALLOW_BOOK_LINK', 2);

/**
 * Implementation of hook_perm().
 */
function print_perm() {
  return array('access print', 'administer print');
}

/**
 * Implementation of hook_theme().
 */
function print_theme() {
  return array(
    'print_format_link' => array(
      'arguments' => array(),
    ),
    'print_text' => array(
      'arguments' => array(),
    ),
  );
}

/**
 * Implementation of hook_menu().
 */
function print_menu() {
  $items = array();

  $items[PRINT_PATH] = array(
    'title' => 'Printer-friendly',
    'page callback' => 'print_controller_html',
    'access arguments' => array('access print'),
    'type' => MENU_CALLBACK,
    'file' => 'print.pages.inc',
  );
  $items['admin/settings/print'] = array(
    'title' => 'Printer-friendly pages',
    'description' => 'Adds a printer-friendly version link to content and administrative pages.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('print_html_settings'),
    'access arguments'  => array('administer print'),
    'file' => 'print.admin.inc',
  );
  $items['admin/settings/print/html'] = array(
    'title' => 'Web page',
    'weight' => 1,
    'type' => MENU_DEFAULT_LOCAL_TASK,
  );
  $items['admin/settings/print/common'] = array(
    'title' => 'Settings',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('print_main_settings'),
    'access arguments'  => array('administer print'),
    'weight' => 10,
    'type' => MENU_LOCAL_TASK,
    'file' => 'print.admin.inc',
  );

  return $items;
}

/**
 * Implementation of hook_link().
 */
function print_link($type, $node = NULL, $teaser = FALSE) {
  $print_html_link_pos = variable_get('print_html_link_pos', array(PRINT_HTML_LINK_POS_DEFAULT => PRINT_HTML_LINK_POS_DEFAULT));
  $allowed_type = print_link_allowed(array('type' => $type, 'node' => $node, 'teaser' => $teaser));
  if (($allowed_type === PRINT_ALLOW_NORMAL_LINK) && !empty($print_html_link_pos['link'])) {
    drupal_add_css(drupal_get_path('module', 'print') .'/printlinks.css');
    $links = array();
    $format = theme('print_format_link');

    $query_arr = $_GET;
    if ($type == 'comment') {
      $query_arr['comment'] = $node->cid;
    }
    $query = print_query_string_encode($query_arr, array('q'));
    if (empty($query)) $query = NULL;

    $links['print'] = array('href' => PRINT_PATH .'/'. $node->nid,
                            'title' => $format['text'],
                            'attributes' => $format['attributes'],
                            'html' => $format['html'],
                            'query' => $query,
                      );

    return $links;
  }
  else {
    return;
  }
}

/**
 * Implementation of hook_link_alter().
 */
function print_link_alter(&$links, $node) {
  foreach ($links as $module => $link) {
    if (strpos($module, 'book_printer') !== FALSE) {
      $print_html_book_link = variable_get('print_html_book_link', PRINT_HTML_BOOK_LINK_DEFAULT);

      if ($print_html_book_link) {
        $format = theme('print_format_link');
        $format['attributes']['title'] = $link['attributes']['title'];

        $links[$module]['href'] = PRINT_PATH .'/'. $link['href'];
        $links[$module]['attributes'] = $format['attributes'];
      }
    }
  }
}

/**
 * Implementation of hook_help().
 */
function print_help($path, $arg) {
  switch ($path) {
    case 'admin/help#print':
      // Return a line-break version of the module README
      return filter_filter('process', 1, NULL, file_get_contents(drupal_get_path('module', 'print') .'/README.txt') );
  }

  $print_html_link_pos = variable_get('print_html_link_pos', array(PRINT_HTML_LINK_POS_DEFAULT => PRINT_HTML_LINK_POS_DEFAULT));
  if (print_link_allowed(array('path' => $path)) && (preg_match('!^node/!i', $path) == 0) &&
      !(empty($print_html_link_pos['link']) && empty($print_html_link_pos['corner']))) {
    static $output = FALSE;

    if ($output === FALSE) {
      drupal_add_css(drupal_get_path('module', 'print') .'/printlinks.css');
      $output = TRUE;

      return '<span class="print-syslink">'. print_insert_link() .'</span>';
    }
  }
}

/**
 * Implementation of hook_nodeapi().
 */
function print_nodeapi(&$node, $op = 'view', $teaser, $page) {
  switch ($op) {
    case 'view':
      $print_html_link_pos = variable_get('print_html_link_pos', array(PRINT_HTML_LINK_POS_DEFAULT => PRINT_HTML_LINK_POS_DEFAULT));
      $allowed_type = print_link_allowed(array('node' => $node, 'teaser' => $teaser));
      if (($allowed_type != FALSE) && !empty($print_html_link_pos['corner']) &&
          (preg_match('!^print!i', $_GET['q']) == 0)) {
        drupal_add_css(drupal_get_path('module', 'print') .'/printlinks.css');
        if ($allowed_type === PRINT_ALLOW_BOOK_LINK) {
          $path = PRINT_PATH .'/book/export/html/'. $node->nid;
        }
        $link = print_insert_link($path);
        $node->content['print_link'] = array(
          '#value' => "<span class='print-link'>$link</span>",
          '#weight' => -1,
        );
      }
  }
}

/**
 * Implementation of hook_form_alter().
 */
function print_form_alter(&$form, $form_state, $form_id) {
  // Add the node-type settings option to activate the printer-friendly version link
  if ($form_id == 'node_type_form') {
    $form['print'] = array(
      '#type' => 'fieldset',
      '#title' => t('Printer-friendly pages'),
      '#collapsible' => TRUE,
      '#collapsed' => TRUE,
    );

    $form['print']['print_display'] = array(
      '#type' => 'checkbox',
      '#title' => t('Show printer-friendly version link'),
      '#default_value' => variable_get('print_display_'. $form['#node_type']->type, PRINT_TYPE_SHOW_LINK_DEFAULT),
      '#description' => t('Displays the link to a printer-friendly version of the content. Further configuration is available on the !settings.', array('!settings' => l(t('settings page'), 'admin/settings/print' ))),
    );
    $form['print']['print_display_comment'] = array(
      '#type' => 'checkbox',
      '#title' => t('Show printer-friendly version link in individual comments'),
      '#default_value' => variable_get('print_display_comment_'. $form['#node_type']->type, PRINT_TYPE_COMMENT_LINK_DEFAULT),
      '#description' => t('Displays the link to a printer-friendly version of the comment. Further configuration is available on the !settings.', array('!settings' => l(t('settings page'), 'admin/settings/print' ))),
    );
  }
}

/**
 * Auxiliary function to fill the Printer-friendly link attributes
 *
 * @param $title
 *   text to displayed by the link when hovering over it with the mouse
 * @param $class
 *   class attribute to be used in the link
 * @param $new_window
 *   if TRUE opens the target page in a new window
 * @return
 *   array of formatted attributes
 */
function print_fill_attributes($title = '', $class = '', $new_window = FALSE) {
  $print_newwindow = variable_get('print_newwindow', PRINT_NEWWINDOW_DEFAULT);
  $print_robots_noindex = variable_get('print_robots_noindex', PRINT_ROBOTS_NOINDEX_DEFAULT);

  $attributes = array();
  $attributes['title'] = $title;
  if (!empty($class)) {
    $attributes['class'] = $class;
  }

  if ($new_window) {
    switch ($print_newwindow) {
    case 0:
      $attributes['target'] = '_blank';
      break;
    case 1:
      $attributes['onclick'] = 'window.open(this.href); return false';
      break;
    }
  }
  if (!empty($print_robots_noindex)) {
    $attributes['rel'] = 'nofollow';
  }
  return $attributes;
}

/**
 * Auxiliary function to set the link text and html flag
 *
 * @param $type
 *   type of link: 0 or 1 for a text-only link, 2 for icon-only and 3 for
 *   both text and icon
 * @param $text
 *   text to be displayed on the link to the printer-friendly page
 * @param $img
 *   path to the icon file
 * @return
 *   array with the link text and html flag
 */
function _print_format_link_aux($type = 0, $text = '', $img = '') {
  if ($type >= 2) {
    $html = TRUE;
    switch ($type) {
    case 2:
      $text = theme('image', $img, $text, '', array('class' => 'print-icon'));
      break;
    case 3:
      $text = theme('image', $img, $text, '', array('class' => 'print-icon print-icon-margin')) . $text;
      break;
    }
  }
  else {
    $html = FALSE;
  }

  return array('text' => $text,
               'html' => $html,
              );
}

/**
 * Format the Printer-friendly link
 *
 * @return
 *   array of formatted attributes
 * @ingroup themeable
 */
function theme_print_format_link() {
  $print_html_link_class = variable_get('print_html_link_class', PRINT_HTML_LINK_CLASS_DEFAULT);
  $print_html_new_window = variable_get('print_html_new_window', PRINT_HTML_NEW_WINDOW_DEFAULT);
  $print_html_show_link = variable_get('print_html_show_link', PRINT_HTML_SHOW_LINK_DEFAULT);

  $text = t('Printer-friendly version');
  $img = drupal_get_path('module', 'print') .'/icons/print_icon.gif';
  $title = t('Display a printer-friendly version of this page.');
  $class = strip_tags($print_html_link_class);
  $new_window = $print_html_new_window;
  $format = _print_format_link_aux($print_html_show_link, $text, $img);

  return array('text' => $format['text'],
               'html' => $format['html'],
               'attributes' => print_fill_attributes($title, $class, $new_window),
              );
}

/**
 * Define the strings displayed by the module in the printer-friendly template
 *
 * @return
 *   array with the used text strings
 * @ingroup themeable
 */
function theme_print_text() {
  return array('retrieved' => '',
               'sourceURL' => '',
               'published' => '',
               'by' => '',
               'created' => '',
               'links' => '',
              );
}

/**
 * Auxiliary function to display a formatted Printer-friendly link
 *
 * Function made available so that developers may call this function from
 * their defined pages/blocks.
 *
 * @param $path
 *   path of the original page (optional). If not specified, the current URL
 *   is used
 * @return
 *   string with the HTML link to the printer-friendly page
 */
function print_insert_link($path = NULL) {
  if (user_access('access print')) {
    if ($path === NULL) {
      $path = PRINT_PATH .'/'. preg_replace('!^node/!', '', $_GET['q']);
      $query = print_query_string_encode($_GET, array('q'));
      if (empty($query)) {
        $query = NULL;
      }
    }
    $format = theme('print_format_link');
    return '<span class="print">'. l($format['text'], $path, array('attributes' => $format['attributes'], 'query' => $query, 'absolute' => TRUE, 'html' => $format['html'])) .'</span>';
  }
}

/**
 * Determine if the current page is enabled according to the visibility settings
 *
 * @param $visibility
 *   current visibility settings:
 *    0 for show on every page except the listed pages
 *    1 for show on only the listed pages
 * @param $pages
 *   list of pages
 * @return
 *   TRUE if it is enabled, FALSE otherwise
 */
function _print_page_match($visibility, $pages) {
  if ($pages) {
    $path = drupal_get_path_alias($_GET['q']);
    $page_match = drupal_match_path($path, $pages);
    if ($path != $_GET['q']) {
      $page_match = $page_match || drupal_match_path($_GET['q'], $pages);
    }

    return !($visibility xor $page_match);
  }
  else {
    return !$visibility;
  }
}

/**
 * Determine a the link to the PF version is allowed depending on all possible settings
 *
 * @param $args
 *   array containing the possible parameters:
 *    teaser, node, type, path
 * @return
 *   FALSE if not allowed
 *   PRINT_ALLOW_NORMAL_LINK if a normal link is allowed
 *   PRINT_ALLOW_BOOK_LINK if a link is allowed in a book node
 */
function print_link_allowed($args) {
  if ($args['teaser'] || !user_access('access print')) {
    // If showing only the teaser or the user is not allowed or link is disabled
    return FALSE;
  }
  $node = $args['node'];
  if (isset($node) && $node) {
    static $node_type = FALSE;
    if (($node_type === FALSE) && isset($node->type)) {
      $node_type = $node->type;
    }
    else {
      $node_type = '';
    }
    // Node
    $print_html_node_link_visibility = variable_get('print_html_node_link_visibility', PRINT_HTML_NODE_LINK_VISIBILITY_DEFAULT);
    $print_html_node_link_pages = variable_get('print_html_node_link_pages', PRINT_HTML_NODE_LINK_PAGES_DEFAULT);

    if ($node->printing ||
        !_print_page_match($print_html_node_link_visibility, $print_html_node_link_pages)) {
      // Page not in visibility list or we are working!
      return FALSE;
    }
    elseif (($args['type'] == 'comment') && isset($node_type)) {
      // Link is for a comment, return the configured setting
      return variable_get('print_display_comment_'. $node_type, PRINT_TYPE_COMMENT_LINK_DEFAULT);
    }
    else {
      // Node link
      if (isset($node_type) &&
          !variable_get('print_display_'. $node_type, PRINT_TYPE_SHOW_LINK_DEFAULT)) {
        // Link for this node type is disabled
        return FALSE;
      }
      elseif (($node_type == 'book') || isset($node->book)) {
        // Node is a book;
        $print_html_book_link = variable_get('print_html_book_link', PRINT_HTML_BOOK_LINK_DEFAULT);
        if (!$print_html_book_link || !user_access('access printer-friendly version')) {
          // Book link is disabled
          return FALSE;
        }
        else {
          return PRINT_ALLOW_BOOK_LINK;
        }
      }
      else {
        return PRINT_ALLOW_NORMAL_LINK;
      }
    }
  }
  else {
    // 'System' page
    $print_html_sys_link_visibility = variable_get('print_html_sys_link_visibility', PRINT_HTML_SYS_LINK_VISIBILITY_DEFAULT);
    $print_html_sys_link_pages = variable_get('print_html_sys_link_pages', PRINT_HTML_SYS_LINK_PAGES_DEFAULT);

    return _print_page_match($print_html_sys_link_visibility, $print_html_sys_link_pages);
  }
}

/**
 * Parse an array into a valid urlencoded query string.
 * Modified from drupal_query_string_encode to prevent re-encoding of
 * encoded original.
 *
 * @param $query
 *   The array to be processed e.g. $_GET
 * @param $exclude
 *   The array filled with keys to be excluded.
 * @return
 *   urlencoded string which can be appended to/as the URL query string
 */
function print_query_string_encode($query, $exclude = array()) {
  $params = array();
  foreach ($query as $key => $value) {
    if (in_array($key, $exclude)) {
      continue;
    }
    $params[] = $key .'='. rawurlencode($value);
  }
  return implode('&', $params);
}