<?php
// $Id: geshifilter.module,v 1.4.2.6 2007-08-30 10:41:50 soxofaan Exp $

define('GESHIFILTER_CSS_INLINE', 1);
define('GESHIFILTER_CSS_CLASSES', 2);


/**
 * Implementation of hook_help()
 */
function geshifilter_help($section) {
  switch ($section) {
    case 'admin/modules#description':
      return t("Provides tags for syntax-highlighting code automatically.");
  }
}

/**
 * Implementation of hook_menu()
 */
function geshifilter_menu($may_cache) {
  if (!$may_cache) {
    drupal_add_css(drupal_get_path('module', 'geshifilter') .'/geshifilter.css');
    drupal_add_css(drupal_get_path('module', 'geshifilter') .'/geshi.css');
  }
  else {
    $items[] = array(
      'path' => 'admin/settings/geshifilter',
      'title' => t('GeSHi filter'),
      'description' => t('Configure the general GeSHi filter settings.'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('geshifilter_admin_settings_form'),
      'access' => user_access('administer filters'),
      'type' => MENU_NORMAL_ITEM
    );
    return $items;
  }
}

/**
 * Implementation of hook_filter_tips()
 */
function geshifilter_filter_tips($delta, $format, $long = false) {

  $default_type = variable_get('geshifilter_default_type_'. $format, 0);
  $types = variable_get('geshifilter_types_'. $format, array());
  $start_param = variable_get('geshifilter_start_attribute', FALSE);
  $line_numbers = variable_get('geshifilter_line_numbers', GESHI_NO_LINE_NUMBERS);
  $inline_code=variable_get('geshifilter_inline_code_'. $format, FALSE);

  if ($long) {

    $text=t('<h3>Code:</h3>');

    //some language are allowed, type param is supported
    if (!$types[0]) {
      $text .= t('<p>To post highlighted code, surround it code with &lt;blockcode &#91;type=&quot;<em>language</em>&quot;&#93;&gt;...&lt;/blockcode&gt tags.</p><p>E.g. actionscript block code:<pre>&lt;blockcode type=&quot;<em>actionscript</em>&quot;&gt;<br />...<br />&lt;/blockcode&gt;</pre></p>');
      if ($inline_code) {
        $text .= t('<p>You may also post highlighted inline code surrounding it with &lt;code &#91;type=&quot;<em>language</em>&quot;&#93;&gt;...&lt;/code&gt tags.</p><p>E.g. highlight actionscript inline code:<pre>&lt;code type=&quot;<em>actionscript</em>&quot;&gt;...&lt;/code&gt;</pre></p>');
      }
      if ($default_type) {
        $text .= t('<p>If you don\'t use <em>type=&quot;language&quot;</em> param or specify an unsupported language, the code will be highlighted as %default-code code.</p>', array('%default-code' => theme('placeholder', $default_type)));
      }
      else {
      $text .= t('<p>If you don\'t use <em>type=&quot;language&quot;</em> param or specify an unsupported language, the code will not be highlighted.</p>');
      }
      $supported_types = array_keys($types, TRUE);
      $text .= t('<p>The following languages are supported for highlight:<br />%type_list.</p>', array('%type_list' => theme('item_list', $supported_types)));
    }
    //no languages allowed, type param is not supported
    else {
      $text .= t('<p>To post code, surround it with &lt;blockcode&gt;...&lt;/blockcode&gt tags.</p><p>E.g. <pre>&lt;blockcode&gt;<br />...<br />&lt;/blockcode&gt;</pre></p>');
      if ($inline_code) {
        $text .= t('<p>You may also post inline code surrounding it with &lt;code&gt;...&lt;/code&gt tags.</p><p>E.g.: <pre>&lt;code&gt;...&lt;/code&gt;</pre></p>');
      }
      if ($default_type) {
        $text .= t('<p>By default, the code will be highlighted as %default-code code.</p>', array('%default-code' => theme('placeholder', $default_type)));
      }
      else {
        $text .= t('<p>The code will not be highlighted.</p>');
      }
    }
    if ($line_numbers == GESHI_NORMAL_LINE_NUMBERS || $line_numbers == GESHI_FANCY_LINE_NUMBERS) { //line numbers
      if ($start_param) {
        $text .= ' '. t('<p>The code will be numbered. You can make the line numbers start at any number using <em>start=number</em> param</p><p>E.g. highlight actionscript code and start line number at 5: <pre>&lt;blockcode type=&quot;<em>actionscript</em>&quot; start=&quot;<em>5</em>&quot;&gt;<br />...<br />&lt;/blockcode&gt;</pre></p>');
      }
      else {
        $text .= ' '. t('<p>The code will be numbered.</p>');
      }
    }
    return $text;
  }
  else {
    $text='';
    //some language are allowed, type param is supported
    if (!$types[0]) {
      $text .= t('You may post block code using &lt;blockcode &#91;type=&quot;<em>language</em>&quot;&#93;&gt;...&lt;/blockcode&gt; tags. ');
      if ($inline_code) {
        $text .= t('You may also post inline code using &lt;code &#91;type=&quot;<em>language</em>&quot;&#93;&gt;...&lt;/code&gt; tags.');
      }
    }
    //no languages allowed, type param is not supported
    else {
      $text .= t('You may post block code using &lt;blockcode&gt;...&lt;/blockcode&gt; tags. ');
      if ($inline_code) {
        $text .= t('You may also post inline code using &lt;code&gt;...&lt;/code&gt; tags.');
      }
    }
    return $text;
  }
}

/**
 * Admin page linked from menu
 */
function geshifilter_admin_settings_form() {
  $form = array();

  // GeSHi library
  $form['geshi_library'] = array(
    '#type' => 'fieldset',
    '#title' => t('GeSHi library'),
    '#collapsible' => true,
  );
  $form['geshi_library']['geshifilter_geshi_dir'] = array(
    '#type' => 'textfield',
    '#title' => t('GeSHi Directory'),
    '#default_value' => variable_get('geshifilter_geshi_dir', drupal_get_path('module', 'geshifilter') .'/geshi'),
    '#description' => t('Location of directory where geshi.php is. i.e: "modules/geshifilter/geshi" (without quotes).'),
    '#required' => TRUE
  );

  $form['geshi_library']['geshifilter_lang_dir'] = array(
    '#type' => 'textfield',
    '#title' => t('Languages directory'),
    '#default_value' => variable_get('geshifilter_lang_dir', drupal_get_path('module', 'geshifilter') .'/geshi/geshi'),
    '#description' => t('Location where GeSHi languages files reside. Languages files are files with the names of languages, ended with .php extension. i.e: "modules/geshifilter/geshi/geshi" (without quotes).'),
    '#required' => TRUE
  );

  // load GeSHi library for defined constants and present the
  // GeSHi filter settings if successful
  if (_geshifilter_load_geshi()) {

    $form['geshi_theming'] = array(
      '#type' => 'fieldset',
      '#title' => t('Theming, styling and CSS'),
    );
    // Code container
    $form['geshi_theming']['geshifilter_code_container'] = array(
      '#type' => 'radios',
      '#title' => t('Code Container'),
      '#default_value' => variable_get('geshifilter_code_container', GESHI_HEADER_PRE),
      '#options' => array(
        GESHI_HEADER_PRE => t('Use &lt;pre&gt; container'),
        GESHI_HEADER_DIV => t('Use &lt;div&gt; container'),
        GESHI_HEADER_NONE => t('No container')
      ),
      '#description' => t('Define the container element to put the highlighted source code in. (GeSHi documentation: !link).',
        array('!link' => l('The Code Container', 'http://qbnz.com/highlighter/geshi-doc.html#the-code-container'))),
    );
    // CSS mode
    $form['geshi_theming']['geshifilter_css_mode'] = array(
      '#type' => 'radios',
      '#title' => t('CSS mode'),
      '#default_value' => variable_get('geshifilter_css_mode', GESHIFILTER_CSS_INLINE),
      '#options' =>  array(
        GESHIFILTER_CSS_INLINE => t('Use in-line styles'),
        GESHIFILTER_CSS_CLASSES => t('Use CSS classes')
      ),
      '#description' => t('Using CSS classes to highlight your code instead of in-lining the styles is more compliant (the style attribute is deprecating in XHTML 2.0) and results in far less outputted code (GeSHi documentation: !link).',
        array('!link' => l('Using CSS Classes', 'http://qbnz.com/highlighter/geshi-doc.html#using-css-classes'))),
    );
    // Line numbers
    $form['geshi_theming']['geshifilter_line_numbers'] = array(
      '#type' => 'radios',
      '#title' => t('Line Numbers'),
      '#default_value' => variable_get('geshifilter_line_numbers', GESHI_NO_LINE_NUMBERS),
      '#options' => array(
        GESHI_NO_LINE_NUMBERS => t('Disable line numbers'),
        GESHI_NORMAL_LINE_NUMBERS => t('Use normal line numbering'),
        GESHI_FANCY_LINE_NUMBERS => t('Use fancy line numbering')
      ),
      '#description' => t('Add line numbers to code. Fancy line numbers means that you can specify a different style for each n<sup>th</sup> line number (GeSHi documentation: !link).',
        array('!link' => l('Line Numbers', 'http://qbnz.com/highlighter/geshi-doc.html#line-numbers'))),
    );

    $form['geshi_theming']['geshifilter_fancy_number'] = array(
      '#type' => 'textfield',
      '#size' => 2,
      '#maxlength' => 2,
      '#title' => t('Fancy number each'),
      '#default_value' => variable_get('geshifilter_fancy_number', 5),
      '#description' => t('Line numbers will be styled with a different style every n line numbers. (GeSHi documentation: !link).',
        array('!link' => l('Line Numbers', 'http://qbnz.com/highlighter/geshi-doc.html#line-numbers'))),
    );

    $form['geshi_theming']['geshifilter_start_attribute'] = array(
      '#type' => 'checkbox',
      '#title' => t('Allow <em>start</em> attribute'),
      '#default_value' => variable_get('geshifilter_start_attribute', FALSE),
      '#description' => t('Allow users to make the line numbers start at any number using the <em>start=number</em> attribute. This feature will break XHTML strict compliancy (GeSHi documentation: !link).',
        array('!link' => l('Choosing a Start Number', 'http://qbnz.com/highlighter/geshi-doc.html#starting-line-numbers'))),
    );

    // inline styles
    $form['inline'] = array(
      '#type' => 'fieldset',
      '#title' => t('In-line styles'),
      '#collapsible' => true,
      '#collapsed' => true,
    );
    $form['inline']['geshifilter_overall_style'] = array(
      '#type' => 'textfield',
      '#maxlength' => 255,
      '#title' => t('Overall code block style'),
      '#default_value' => variable_get('geshifilter_overall_style', ''),
      '#description' => t('Style the overall code block. For example, you can set the border style/colour, any margins and padding etc. (GeSHi documentation: !link).',
        array('!link' => l('The Overall Styles', 'http://qbnz.com/highlighter/geshi-doc.html#the-overall-styles'))),
    );
    $form['inline']['geshifilter_number_style'] = array(
      '#type' => 'textfield',
      '#maxlength' => 255,
      '#title' => t('Line number style'),
      '#default_value' => variable_get('geshifilter_number_style', ''),
      '#description' => t('(GeSHi documentation: !link).',
        array('!link' => l('Line Number Styles', 'http://qbnz.com/highlighter/geshi-doc.html#line-number-styles'))),
    );
    $form['inline']['geshifilter_fancy_number_style'] = array(
      '#type' => 'textfield',
      '#maxlength' => 255,
      '#title' => t('Fancy line number style'),
      '#default_value' => variable_get('geshifilter_fancy_number_style', 'font-weight: bold;'),
      '#description' => t('(GeSHi documentation: !link).',
        array('!link' => l('Line Number Styles', 'http://qbnz.com/highlighter/geshi-doc.html#line-number-styles'))),
    );
    $form['inline']['geshifilter_code_style'] = array(
      '#type' => 'textfield',
      '#maxlength' => 255,
      '#title' => t('Code style'),
      '#default_value' => variable_get('geshifilter_code_style', 'font-weight: normal;'),
      '#description' => t('Explicitly override the styles you set for line numbers (GeSHi documentation: !link).',
        array('!link' => l('Styling Line Numbers', 'http://qbnz.com/highlighter/geshi-doc.html#styling-line-numbers'))),
    );
  }
  return system_settings_form($form);
}

/*
 * Validate the settings form
 */
function geshifilter_admin_settings_form_validate($form_id, $form_values) {

  // Check if geshi directory exists.
  if (!is_dir($form_values['geshifilter_geshi_dir'])) {
    form_set_error('geshifilter_geshi_dir', t('The directory "%geshi-directory" does not exist.',
      array('%geshi-directory' => $form_values['geshifilter_geshi_dir'])));
  }

  // Check if geshi.php exists
  if (!is_file($form_values['geshifilter_geshi_dir'] .'/geshi.php')) {
    form_set_error('geshifilter_geshi_dir', t('Unable to find the GeSHi library (geshi.php) in %geshi-directory.',
      array('%geshi-directory' => $form_values['geshifilter_geshi_dir'])));
  }

  // Check if languages directory exists.
  if (!is_dir($form_values['geshifilter_lang_dir'])) {
    form_set_error('geshifilter_lang_dir', t('The GeSHi languages directory %directory does not exist.',
      array('%directory' => $form_values['geshifilter_lang_dir'])));
  }

  // Check if there are some language files in the directory
  $files = file_scan_directory($form_values['geshifilter_lang_dir'], '\.php$', array('.', '..', 'CVS', 'geshi.php'), 0, FALSE, 'name');
  if (count($files) == 0) {
    drupal_set_message(t('No language pattern files found. Are you sure to have correctly installed the GeShi package?'));
  }
}

/**
 * Implementation of hook_filter()
 */
function geshifilter_filter($op, $delta = 0, $format = -1, $text = '') {

  //disable cache for developpement cause nocache doesn't work
  switch ($op) {

    case 'list':
      return array(0 => t('GeSHi filter'));

    case 'description':
      return t('Allows users to post hightlighted code verbatim using &lt;blockcode type=&quot;<em>language</em>&quot;&gt; tag.');

    case 'settings':
      $lang_dir = variable_get('geshifilter_lang_dir', drupal_get_path('module', 'geshifilter') .'/geshi/geshi');

      // Find languages in the directory, we get a table where key == value
      $files = file_scan_directory($lang_dir, '\.php$', array('.', '..', 'CVS', 'geshi.php'), 0, FALSE, 'name');

      //produce an associative array whit keys equal to values
      $languages = drupal_map_assoc(array_keys($files));
      uasort($languages, 'strnatcasecmp');
      $languages_select = $languages;
      $languages_select[0] = t('- DO NOT HIGHLIGHT -');

      $form['geshifilter'] = array(
        '#type' => 'fieldset',
        '#title' => t('GeSHi filter'),
      );

      $form['geshifilter']['geshifilter_inline_code_'. $format] = array(
        '#type' => 'checkbox',
        '#title' => t('Highlight inline code'),
        '#default_value' => variable_get('geshifilter_inline_code_'. $format, FALSE),
        '#description' => t('Enable highligthing for code surrounded by &lt;code&gt;...&lt;/code&gt; tags.'),
      );

      $form['geshifilter']['geshifilter_default_type_'. $format] = array(
        '#type' => 'select',
        '#title' => t('Default language'),
        '#default_value' => variable_get('geshifilter_default_type_'. $format, 0),
        '#options' => $languages_select,
        '#description' => t('Default language pattern used to highlight posted code where type=&quot;<em>language</em>&quot; param is omitted.'),
      );

      $form['geshifilter']['geshifilter_types_'. $format] = array(
        '#type' => 'checkboxes',
        '#title' => t('Allowed Languages'),
        '#default_value' => variable_get('geshifilter_types_'. $format, array()),
        '#options' => $languages,
        '#description' => t('Check every languages you want to be allowed for highlighting (i.e. usable in <em>lang</em> param).'),
      );

      //pass the format value, so filter_admin_configure_validate can know which format is being processed
      $form['geshifilter']['format'] = array(
        '#type' => 'hidden',
        '#default_value' => $format,
      );

      return $form;

    case 'prepare':
      return $text;

    case 'process':
      return _geshifilter_process_code($format, $text);

    default:
      return $text;
  }
}

/**
 * Helper function for loading the GeSHi library
 */
function _geshifilter_load_geshi() {
  $geshi_lib = variable_get('geshifilter_geshi_dir', drupal_get_path('module', 'geshifilter') .'/geshi') .'/geshi.php';
  if (file_exists($geshi_lib)) {
    require_once($geshi_lib);
    return TRUE;
  }
  else {
    drupal_set_message(t('GeSHi library not found'), 'error');
    return FALSE;
  }
}

/**
 *
 */
function _geshifilter_process_code($format, $text, $flags = '') {
  // load the GeSHi library and just return text if not successful
  if (!_geshifilter_load_geshi()) {
    return $text;
  }

  $lang_dir = variable_get('geshifilter_lang_dir', drupal_get_path('module', 'geshifilter') .'/geshi/geshi');
  $types = variable_get('geshifilter_types_'. $format, array());
  $code_container = variable_get('geshifilter_code_container', GESHI_HEADER_PRE);
  $line_numbers = variable_get('geshifilter_line_numbers', GESHI_NO_LINE_NUMBERS);
  $fancy_number = variable_get('geshifilter_fancy_number', 5);
  $start_param = variable_get('geshifilter_start_attribute', FALSE);
  $overall_style = variable_get('geshifilter_overall_style', '');
  $number_style = variable_get('geshifilter_number_style', '');
  $fancy_number_style = variable_get('geshifilter_fancy_number_style', 'font-weight: bold;');
  $code_style = variable_get('geshifilter_code_style', 'font-weight: normal;');
  $inline_code = variable_get('geshifilter_inline_code_'. $format, FALSE);

  $tags = 'blockcode'. ($inline_code?'|code':'');
  if (preg_match_all('/<('. $tags .')((?:\s(?:.|\s|\z)*?)*)\s*>((?:.|\s|\z)*?)<\/\1\s*>/i', $text, $match)) {
    // $match[0][xx] .... fully matched string <blockcode type="language">...</blockcode>
    // $match[1][xx] .... tag
    // $match[2][xx] .... full params string type="language"...
    // $match[3][xx] .... code to highlight

    foreach ($match[3] as $key => $value) {

      preg_match_all('/(type|start)\s*=\s*[\"]((?:.|\s|\z)*?)[\"]/i', $match[2][$key], $param);      //let lang and language tags for backward compatibility
      // $param[0][xx] .... fully matched string type="language"
      // $param[1][xx] .... param name
      // $param[2][xx] .... param value

      //default values
      $lang = variable_get('geshifilter_default_type_'. $format, 0);
      $start = 1;

      foreach ($param[2] as $p_key => $p_value) {
        //if lang is known, allowed and found
        if ($param[1][$p_key] == 'type' && in_array($p_value, $types)  && $types[$p_value]) {
          $lang = $p_value;
        }
        //if start param has been allowed
        if (($line_numbers == GESHI_NORMAL_LINE_NUMBERS ||$line_numbers == GESHI_FANCY_LINE_NUMBERS) && $start_param) {
          //if start param is found
          if ($param[1][$p_key] == 'start' && $p_value) {
            $start = $p_value;
          }
        }
      }

      // geshi will reencode these
      $matched = decode_entities($value);

      // undo nl and p formatting
      $matched = preg_replace("@<br />@", "", $matched);
      $matched = preg_replace("@<p>|</p>@", "", $matched);

      $geshi = new GeSHi($matched, $lang, $lang_dir);

      // enable usage of CSS classes instead of inline styles
      // (should be the first method of the GeSHi object to call according to
      // http://qbnz.com/highlighter/geshi-doc.html#enabling-css-classes)
      if (variable_get('geshifilter_css_mode', GESHIFILTER_CSS_INLINE) == GESHIFILTER_CSS_CLASSES) {
        $geshi->enable_classes(TRUE);
      }

      if ($match[1][$key] =='code') {
        $geshi->set_header_type(GESHI_HEADER_NONE);
      }
      else {
        $geshi->set_header_type($code_container);
      }

      if ($match[1][$key] != 'code') {
        $geshi->set_overall_class('geshifilter');
      }

      //line numbers
      if ($line_numbers != GESHI_NO_LINE_NUMBERS && $match[1][$key] != 'code') {
        $geshi->enable_line_numbers($line_numbers, ($line_numbers == GESHI_FANCY_LINE_NUMBERS)?$fancy_number:null);

        if ($start_param) {
          $geshi->start_line_numbers_at($start);
        }
      }

      //styles
      $geshi->set_overall_style($overall_style) ;
      $geshi->set_line_style($number_style, $fancy_number_style);
      $geshi->set_code_style($code_style);

      if ($match[1][$key] == 'code') {
        $text = str_replace($match[0][$key], '<code class="geshifilter'. ($lang?' '. $lang:'') .'">'. $geshi->parse_code() .'</code>', $text);
      }
      else {
        $text = str_replace($match[0][$key], $geshi->parse_code(), $text);
      }
    }
  }

  return $text;
}