<?php
// $Id: skinr.module,v 1.14 2009-11-27 05:44:45 moonray Exp $

/**
 * Implementation of hook_permission().
 */
function skinr_permission() {
  return array(
    'administer skinr' => array(
      'title' => t('Administer Skinr'),
      'description' => t('Administer Skinr\'s settings.'),
    ),
    'access skinr' => array(
      'title' => t('Access Skinr\'s settings'),
      'description' => t('Set Skinr options for individual themes.'),
    ),
    'access skinr classes' => array(
      'title' => t('Access Skinr\'s advanced settings'),
      'description' => t('Set advanced Skinr options, such as custom CSS classes and custom template files.'),
    ),
  );
}

/**
 * Implementation of hook_menu().
 */
function skinr_menu() {
  $items['admin/settings/skinr'] = array(
    'title' => 'Skinr',
    'page callback' => 'skinr_admin',
    'type' => MENU_CALLBACK,
    'access arguments' => array('administer skinr'),
    'file' => 'skinr.admin.inc',
  );
  return $items;
}

/**
 * Implementation of hook_help().
 */
function skinr_help($path, $arg) {
  switch ($path) {
    case 'admin/help#skinr':
      return t('Please refer to <a class="ext" href="http://drupal.org/node/578552">@skinr introduction </a> and <a class="ext" href="http://drupal.org/node/578574">documentation</a>.', array('@skinr' => 'Skinr'));
      break;
    case 'admin/settings/skinr':
      return t('Please refer to <a class="ext" href="http://drupal.org/node/578552">@skinr introduction </a> and <a class="ext" href="http://drupal.org/node/578574">documentation</a>.', array('@skinr' => 'Skinr'));
      break;
  }
}

/**
 * Implement hook_init().
 */
function skinr_init() {
  module_load_include('inc', 'skinr', 'skinr.handlers');
  skinr_module_include('skinr.inc');
}

/**
 * Implementation of hook_form_alter().
 */
function skinr_form_alter(&$form, $form_state, $form_id) {
  $skinr_data = skinr_fetch_data();
  $info = skinr_process_info_files();

  foreach ($skinr_data as $module => $settings) {
    if (isset($settings['form'][$form_id])) {
      $form_settings = array_merge(_skinr_fetch_data_defaults('form'), $settings['form'][$form_id]);

      // Check for access.
      if (!skinr_handler('access_handler', 'access skinr', $form_settings['access_handler'], $form, $form_state)) {
        // Deny access.
        break;
      }

      // Ensure we have the required preprocess_hook or preprocess_hook_callback.
      if (empty($form_settings['preprocess_hook']) && empty($form_settings['preprocess_hook_callback'])) {
        trigger_error(sprintf("No preprocess_hook or preprocess_hook_callback was found for form_id '%s' in module '%s'.", $form_id, $module), E_USER_ERROR);
      }

      $themes = list_themes();
      ksort($themes);

      foreach ($themes as $theme) {
        if (!$theme->status) {
          continue;
        }

        $preprocess_hook = $form_settings['preprocess_hook'] ? $form_settings['preprocess_hook'] : skinr_handler('preprocess_hook_callback', '', $form_settings['preprocess_hook_callback'], $form, $form_state);

        if (!$form_state['submitted']) {
          $skinr_data = skinr_handler('data_handler', 'form', $form_settings['data_handler'], $form, $form_state, $theme->name, $module, $form_settings);

          $defaults  = $skinr_data;
          $additional_default = isset($skinr_data['_additional']) ? $skinr_data['_additional'] : '';
          $template_default = isset($skinr_data['_template']) ? $skinr_data['_template'] : '';
        }
        else {
          // Handle preview before submit.
          $defaults  = $form_state['values']['widgets'];
          $additional_default = $form_state['values']['_additional'];
          $template_default = $form_state['values']['_template'];
        }

        if (!isset($form['skinr_settings'])) {
          $form['skinr_settings'] = array(
            '#tree' => TRUE,
            '#weight' => $form_settings['skinr_weight'],
          );
        }

        if (!isset($form['skinr_settings'][$module . '_group'])) {
          $form['skinr_settings'][$module . '_group'] = array(
            '#type' => 'fieldset',
            '#title' => $form_settings['skinr_title'] . ' ' . $form_settings['title'],
            '#description' => $form_settings['description'] . ' <strong>' . $preprocess_hook . '</strong>.',
            '#weight' => $form_settings['weight'],
            '#collapsible' => TRUE,
            '#collapsed' => $form_settings['collapsed'],
          );
        }

        $form['skinr_settings'][$module . '_group'][$theme->name] = array(
          '#type' => 'fieldset',
          '#title' => $theme->info['name'] . ($theme->name == skinr_current_theme() ? ' (' . t('enabled + default') . ')' : ''),
          '#collapsible' => TRUE,
          '#collapsed' => $theme->name == skinr_current_theme() ? FALSE : TRUE,
        );
        if ($theme->name == skinr_current_theme()) {
          $form['skinr_settings'][$module . '_group'][$theme->name]['#weight'] = -10;
        }

        // Create individual widgets for each skin.
        $template_options = array();
        foreach ($info[$theme->name]['skins'] as $skin_id => $skin) {
          // Check if this skin applies to this hook.
          if (!in_array('*', $skin['features']) && !in_array($preprocess_hook, $skin['features'])) {
            continue;
          }

          // Create widget.
          switch ($skin['type']) {
            case 'checkboxes':
              $form['skinr_settings'][$module . '_group'][$theme->name]['widgets'][$skin_id] = array(
                '#type' => 'checkboxes',
                '#multiple' => TRUE,
                '#title' => $skin['title'],
                '#options' => skinr_info_options_to_form_options($skin['options']),
                '#default_value' => isset($defaults[$skin_id]) ? $defaults[$skin_id] : array(),
                '#description' => $skin['description'],
              );
              break;
            case 'radios':
              $form['skinr_settings'][$module . '_group'][$theme->name]['widgets'][$skin_id] = array(
                '#type' => 'radios',
                '#title' => $skin['title'],
                '#options' => array_merge(array('' => '&lt;none&gt;'), skinr_info_options_to_form_options($skin['options'])),
                '#default_value' => isset($defaults[$skin_id]) ? $defaults[$skin_id] : '',
                '#description' => $skin['description'],
              );
              break;
            case 'select':
              $form['skinr_settings'][$module . '_group'][$theme->name]['widgets'][$skin_id] = array(
                '#type' => 'select',
                '#title' => $skin['title'],
                '#options' => array_merge(array('' => '<none>'), skinr_info_options_to_form_options($skin['options'])),
                '#default_value' => isset($defaults[$skin_id]) ? $defaults[$skin_id] : '',
                '#description' => $skin['description'],
              );
              break;
          }

          // Prepare templates.
          $templates = skinr_info_templates_filter($skin['templates'], $preprocess_hook);
          $template_options = array_merge($template_options, skinr_info_templates_to_form_options($templates));
        }

        // Check for access.
        if (skinr_handler('access_handler', 'access skinr classes', $form_settings['access_handler'], $form, $form_state)) {
          $form['skinr_settings'][$module . '_group'][$theme->name]['advanced'] = array(
            '#type' => 'fieldset',
            '#title' => t('Advanced options'),
            '#collapsible' => TRUE,
            '#collapsed' => empty($additional_default),
          );
          $form['skinr_settings'][$module . '_group'][$theme->name]['advanced']['_additional'] = array(
            '#type' => 'textfield',
            '#title' => t('Apply additional CSS classes'),
            '#description' => t('Optionally add additional CSS classes. Example: <em>my-first-class my-second-class</em>'),
            '#default_value' => $additional_default,
          );
          $form['skinr_settings'][$module . '_group'][$theme->name]['advanced']['_template'] = array(
            '#type' => 'select',
            '#title' => t('Template file'),
            '#options' => array_merge(array('' => 'Default'), $template_options),
            '#default_value' => $template_default,
            '#description' => t('Optionally, select a template file to associate with this <strong>!hook</strong>. Selecting "Default" will let Drupal handle this.', array('!hook' => $preprocess_hook)),
          );

          // Only add validation handler once.
          if (!in_array('skinr_form_validate', $form['#validate'])) {
            $form['#validate'][] = 'skinr_form_validate';
          }
          // Special for views.
          if (isset($form['buttons']['submit']['#validate']) && !in_array('skinr_form_validate', $form['buttons']['submit']['#validate'])) {
            $form['buttons']['submit']['#validate'][] = 'skinr_form_validate';
          }
        }
      }
      
      // Add weight to additional settings and submit form elements.
      $form['additional_settings']['#weight'] = 39;
      $form['submit']['#weight'] = 40;

      // Only add submit handler once.
      eval('$element =& $form' . $form_settings['submit_handler_attach_to'] . ';');
      if (!empty($element) && !in_array('skinr_form_submit', $element)) {
        $string = $element[] = 'skinr_form_submit';
      }

      // Keep looping, there might be other modules that implement the same form_id.
    }
  }
}

/**
 * Validation handler.
 */
function skinr_form_validate(&$form, &$form_state) {
  $form_id = $form_state['values']['form_id'];
  $skinr_data = skinr_fetch_data();

  foreach ($skinr_data as $module => $settings) {
    if (isset($settings['form'][$form_id])) {
      foreach ($form_state['values']['skinr_settings'][$module . '_group'] as $theme_name => $theme) {
        if (isset($theme['advanced']['_additional'])) {
          $form_settings = array_merge(_skinr_fetch_data_defaults('form'), $settings['form'][$form_id]);

          // Validate additional classes field
          if (preg_match('/[^a-zA-Z0-9\-\_\s]/', $theme['advanced']['_additional'])) {
            form_set_error('skinr_settings][' . $module . '_group][' . $theme_name . '][advanced][_additional', t('Additional classes for Skinr may only contain alphanumeric characters, spaces, - and _.'));
          }

          // Keep looping, there might be other modules that implement the same form_id.
        }
      }
    }
  }
}

/**
 * Submit handler.
 */
function skinr_form_submit(&$form, &$form_state) {
  $form_id = $form_state['values']['form_id'];
  $skinr_data = skinr_fetch_data();

  foreach ($skinr_data as $module => $settings) {
    if (isset($settings['form'][$form_id])) {
      $form_settings = array_merge(_skinr_fetch_data_defaults('form'), $settings['form'][$form_id]);
      skinr_handler('submit_handler', '', $form_settings['submit_handler'], $form, $form_state, $module, $form_settings);

      // Keep looping, there might be other modules that implement the same form_id.
    }
  }
}

/**
 * Implementation of hook_preprocess().
 */
function skinr_preprocess(&$vars, $hook) {
  $skinr_data = skinr_fetch_data();
  $info = skinr_process_info_files();
  $current_theme = skinr_current_theme();
  $theme_registry = theme_get_registry();

  $themes = array($current_theme);

  $original_hook = $hook;
  if (isset($theme_registry[$hook]['original hook'])) {
    $original_hook = $theme_registry[$hook]['original hook'];
  }

  foreach ($skinr_data as $module => $settings) {
    if (!empty($settings['preprocess'][$original_hook])) {
      $preprocess_settings = $settings['preprocess'][$original_hook];
      $key = skinr_handler('preprocess_index_handler', 'preprocess', $preprocess_settings['index_handler'], $vars);

      if (!empty($key)) {
        $style = skinr_get(NULL, $module, $key);

        foreach ($style as $skin => $classes) {
          // Add custom CSS files.
          if (!empty($info[$current_theme]['skins'][$skin]['stylesheets'])) {
            foreach ($info[$current_theme]['skins'][$skin]['stylesheets'] as $media => $stylesheets) {
              foreach ($stylesheets as $stylesheet) {
                _skinr_add_file($stylesheet, $themes, 'css', $media);
              }
            }
          }

          // Add custom JS files.
          if (isset($info[$current_theme]['skins'][$skin]['scripts'])) {
            foreach ($info[$current_theme]['skins'][$skin]['scripts'] as $script) {
              _skinr_add_file($script, $themes, 'js');
            }
          }
        }

        if (!empty($style['_template'])) {
          $vars['template_files'][] = $style['_template'];
          unset($style['_template']);
        }

        $vars['skinr'] = skinr_style_flatten_array($style);
        $vars['classes_array'] = array_merge($vars['classes_array'], $vars['skinr']);
      }
    }
  }
}

/**
 * Helper fuction to add CSS and JS files.
 *
 * The function checks an array of paths for the existence of the file to account for base themes.
 */
function _skinr_add_file($filename, $themes, $type, $media = NULL) {
  if (!is_array($themes)) {
    $themes = array($themes);
  }
  
  foreach ($themes as $theme) {
    $filename = drupal_get_path('theme', $theme) . '/' . $filename;
    if (file_exists($filename)) {
      if ($type == 'css') {
        drupal_add_css($filename, array('weight' => CSS_THEME, 'media' => $media));
      }
      else {
        drupal_add_js($filename, array('weight' => JS_THEME));
      }
      break;
    }
  }
}

/**
 * Helper function to convert an array of classes settings into a string, usable in HTML.
 */
function skinr_style_flatten_array($style) {
  $return = array();
  foreach ($style as $entry) {
    if (is_array($entry)) {
      foreach ($entry as $subentry) {
        if (!empty($subentry)) {
          $return[] = $subentry;
        }
      }
    }
    elseif (!empty($entry)) {
      $return[] = $entry;
    }
  }

  return $return;
}

// ------------------------------------------------------------------
// Include file helpers

/**
 * Load views files on behalf of modules.
 */
function skinr_module_include($file) {
  foreach (skinr_get_module_apis() as $module => $info) {
    $filepath = DRUPAL_ROOT . "/$info[path]/$module.$file";
    if (is_file($filepath)) {
      require_once $filepath;
    }
  }
}

/**
 * Get a list of modules that support skinr.
 */
function skinr_get_module_apis() {
  $cache = &drupal_static(__FUNCTION__, NULL);

  if (is_null($cache)) {
    $cache = array();
    foreach (module_implements('skinr_api') as $module) {
      $function = $module . '_skinr_api';
      $info = $function();
      if (isset($info['api']) && $info['api'] == 1.000) {
        if (!isset($info['path'])) {
          $info['path'] = drupal_get_path('module', $module);
        }
        $cache[$module] = $info;
      }
    }
  }

  return $cache;
}

// -----------------------------------------------------------------------
// Skinr data handling functions

/**
 * Save an entry to Skinr.
 */
function skinr_set($theme, $module, $key, $value) {
  $skinr = variable_get('skinr_' . $theme, array());

  // Make sure we're getting valid data.
  if (empty($module) || empty($key)) {
    return;
  }

  if (!$value && isset($skinr[$module][$key])) {
    unset($skinr[$module][$key]);
  }
  else {
    if (!isset($skinr[$module])) {
      $skinr[$module] = array();
    }
    $skinr[$module][$key] = $value;
  }

  variable_set('skinr_' . $theme, $skinr);
}

/**
 * Retrieves the desired classes.
 *
 * If no hook or key is specified, it will return all skinr classes.
 * @return An array
 *
 * @todo Account for admin theme.
 */
function skinr_get($theme = NULL, $module = NULL, $key = NULL) {
  if (is_null($theme)) {
    $theme = skinr_current_theme();
  }
  $skinr = variable_get('skinr_' . $theme, array());

  if (is_null($module) || is_null($key)) {
    return $skinr;
  }
  elseif (isset($skinr[$module][$key])) {
    return $skinr[$module][$key];
  }
  else {
    return array();
  }
}

/**
 * Helper function to retrieve the current theme.
 * The global variable $theme_key doesn't work for out purposes when an admin
 * theme is enabled.
 */
function skinr_current_theme() {
  global $user;

  if ($user->theme) {
    $current_theme = $user->theme;
  }
  else {
    $current_theme = variable_get('theme_default', 'garland');
  }
  return $current_theme;
}

/**
 * Retrieves all the Skinr skins from theme parents. Theme skins
 * will override any skins of the same name from its parents.
 */
function skinr_inherited_skins($theme, $themes) {
  $all_skins = $skins = array();
  $base_theme = (!empty($themes[$theme]->info['base theme'])) ? $themes[$theme]->info['base theme'] : '';
  while ($base_theme) {
    $all_skins[] = (!empty($themes[$base_theme]->info['skinr'])) ? (array)$themes[$base_theme]->info['skinr'] : array();
    $base_theme = (!empty($themes[$base_theme]->info['base theme'])) ? $themes[$base_theme]->info['base theme'] : '';
  }
  array_reverse($all_skins);
  foreach ($all_skins as $new_skin) {
    $skins = array_merge($skins, $new_skin);
  }
  return $skins;
}

/**
 * Themes are allowed to set Skinr styles in their .info files.
 *
 * @todo Do we want to allow manual addition of styles?
 * @todo Use DB caching. No need to keep processing things every page load.
 */
function skinr_process_info_files() {
  $cache = &drupal_static(__FUNCTION__, NULL);

  if (is_null($cache)) {
    $themes = system_get_info('theme');

    foreach ($themes as $theme_idx => $theme) {
      $cache[$theme_idx] = array(
        'options' => array(),
        'skins' => array(),
      );

      if (!empty($theme['skinr'])) {
        $info = (array)$theme['skinr'];

        // Store skinr options
        if (!empty($info['options'])) {
          $cache[$theme_idx]['options'] = $info['options'];
          unset($info['options']);
        }

        // Inherit skins from parent theme, if inherit_skins is set to true.
        if (!empty($cache[$theme_idx]['options']['inherit_skins'])) {
          $info = array_merge(skinr_inherited_skins($theme_idx, $themes), $info);
        }

        foreach ($info as $id => $skin) {
          $processed_skin = array(
            'title' => isset($skin['title']) ? $skin['title'] : '',
            'type' => isset($skin['type']) ? $skin['type'] : 'checkboxes',
            'description' => isset($skin['description']) ? $skin['description'] : '',
            'features' => isset($skin['features']) ? $skin['features'] : array('*'),
            'templates' => isset($skin['templates']) ? $skin['templates'] : array(),
            'options' => isset($skin['options']) ? $skin['options'] : array(),
            'stylesheets' => isset($skin['stylesheets']) ? $skin['stylesheets'] : array(),
            'scripts' => isset($skin['scripts']) ? $skin['scripts'] : array(),
          );

          $cache[$theme_idx]['skins'][$id] = $processed_skin;
        }
      }
    }
  }

  return $cache;
}

/**
 * Helper function to convert an array of options, as specified in the info
 * file, into an array usable by form api.
 */
function skinr_info_options_to_form_options($options) {
  $form_options = array();
  foreach ($options as $option) {
    $form_options[$option['class']] = $option['label'];
  }
  return $form_options;
}

/**
 * Helper function to convert an array of template filenames, as specified in
 * the info file, into an array usable by form api.
 */
function skinr_info_templates_to_form_options($templates) {
  $form_options = array();
  foreach ($templates as $template) {
    // If it exists, strip .tpl.php from template
    $template = str_replace('.tpl.php', '', $template);
    $form_options[$template] = $template . '.tpl.php';
  }
  return $form_options;
}

/**
 * Helper function to filter templates by preprocess_hook.
 */
function skinr_info_templates_filter($templates, $preprocess_hook) {
  $filtered_templates = array();
  foreach ($templates as $template) {
    // If it exists, strip .tpl.php from template
    $template = str_replace('.tpl.php', '', $template);
    if (drupal_substr($template, (drupal_strlen($preprocess_hook) * -1)) == $preprocess_hook) {
      $filtered_templates[] = $template;
    }
  }
  return $filtered_templates;
}

/**
 * Fetch Skinr configuration data from modules.
 */
function skinr_fetch_data() {
  $cache = &drupal_static(__FUNCTION__, NULL);

  if (is_null($cache)) {
    $cache = module_invoke_all('skinr_data');
    foreach (module_implements('skinr_data_alter') as $module) {
      $function = $module . '_skinr_data_alter';
      $function($cache);
    }
  }

  return $cache;
}

/**
 * Fetch default configuration data for modules.
 */
function _skinr_fetch_data_defaults($setting) {
  switch ($setting) {
    case 'form':
      $data = array(
        'access_handler' => 'skinr_access_handler',
        'data_handler' => 'skinr_data_handler',
        'submit_handler' => 'skinr_submit_handler',
        'submit_handler_attach_to' => "['#submit']",
        'skinr_title' => t('Skinr'),
        'skinr_weight' => 1,
        'title' => '',
        'description' => t('Manage which skins you want to apply to this'),
        'collapsed' => TRUE,
        'weight' => 0,
      );
      return $data;
  }
}

/**
 * Execute a module's data handler.
 */
function skinr_handler($type, $op, $handler, &$a3, $a4 = NULL, $a5 = NULL, $a6 = NULL, $a7 = NULL) {
  if (is_callable($handler)) {
    switch ($type) {
      case 'preprocess_index_handler':
        return $handler($a3);
      case 'preprocess_hook_callback':
        return $handler($a3, $a4);
      case 'data_handler':
      case 'submit_handler':
        return $handler($a3, $a4, $a5, $a6, $a7);
      default:
        return $handler($op, $a3, $a4);
    }
  }
}