<?php
// $Id: skinr.module,v 1.1 2009-06-11 05:34:34 jgirlygirl Exp $

/**
 * Implementation of hook_perm().
 */
function skinr_perm() {
  return array('access skinr', 'access skinr classes', 'administer skinr');
}

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

/**
 * @todo placeholder settings page
 */
function skinr_admin() {
  drupal_set_message(t('Skinr data:'));
  dpm(skinr_get());
  $items = array();
  $items[] = 'Listing of blocks';
  $items[] = 'Listing of node types';
  $items[] = 'Listing of blocks';
  $items[] = 'List of blocks';
  $bullets = theme('item_list', $items);
  $output = '<h2>Future home of bulk editing</h2>';
  $output .= '<p>'. t('Placeholder') .'</p>';
  $output .= $bullets;
  return $output;
}

/**
 * Implementation of hook_help().
 * @todo Integrate w/Advanced Help Module
 */
function skinr_help($path, $arg) {
  switch ($path) {
    case 'admin/help#skinr':
      return 'Need to add some basic description here that points to advanced help.';
      break;
    case 'admin/settings/skinr':
      $items = array();
      $items[] = 'Need to add advanced help module integration';
      $items[] = 'Need to add some basic description here that points to advanced help.';
      $bullets = theme('item_list', $items);
      return $bullets;
      break;
  }
}

/**
 * Implement hook_init().
 */
function skinr_init() {
  skinr_include('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();

  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);
      }

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

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

        $selector_defaults  = $skinr_data;
        $additional_default = isset($skinr_data['_additional']) ? $skinr_data['_additional'] : '';
      }
      else {
        // Handle preview before submit
        $selector_defaults  = $form_state['values']['skinr_'. $module];
        $additional_default = $form_state['values']['skinr_'. $module .'_additional'];
      }

      if (!isset($form['skinr_settings'])) {
        $form['skinr_settings'] = array(
          '#type' => 'fieldset',
          '#title' => $form_settings['skinr_title'],
          '#description' => $form_settings['skinr_description'],
          '#weight' => $form_settings['skinr_weight'],
          '#collapsible' => TRUE,
          '#collapsed' => $form_settings['collapsed'],
        );
      }
      $form['skinr_settings'][$module .'_group'] = array(
        '#type' => 'fieldset',
        '#title' => $form_settings['title'],
        '#description' => $form_settings['description'],
        '#weight' => $form_settings['weight'],
        '#collapsible' => FALSE,
      );
      $form['skinr_settings'][$module .'_group']['skinr_'. $module] = array(
        '#type' => 'checkboxes',
        '#multiple' => TRUE,
        '#title' => t('Select skin(s)'),
        '#options' => $options,
        '#default_value' => $selector_defaults,
      );

      // Check for access
      if (skinr_handler('access_handler', 'access skinr classes', $form_settings['access_handler'], $form, $form_state)) {
        $form['skinr_settings'][$module .'_group']['skinr_'. $module .'_additional'] = array(
          '#type' => 'textfield',
          '#title' => t('Enter additional classes'),
          '#description' => t('Optionally add additional CSS classes. Example: <em>my-first-class my-second-class</em>'),
          '#default_value' => $additional_default,
        );

        // 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';
        }
      }

      // Only add submit handler once
      if (!in_array('skinr_form_submit', $form['#submit'])) {
        $form['#submit'][] = 'skinr_form_submit';
      }
      // Special for views
      if (isset($form['buttons']['submit']['#submit']) && !in_array('skinr_form_submit', $form['buttons']['submit']['#submit'])) {
        $form['buttons']['submit']['#submit'][] = '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'][$form_id]) && isset($form_state['values']['skinr_'. $module .'_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]/', $form_state['values']['skinr_'. $module .'_additional'])) {
        form_set_error('skinr_'. $module .'_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, $hook) {
  //drupal_set_message($hook, 'status', FALSE);

  $skinr_data = skinr_fetch_data();

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

      if (!empty($key)) {
        $style = skinr_get($module, $key);
        $vars['skinr'] = is_array($style) ? implode(' ', $style) : $style;
      }
    }
  }
}

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

/**
 * Include skinr .inc files as necessary.
 */
function skinr_include($file) {
  require_once './'. drupal_get_path('module', 'skinr') ."/includes/$file.inc";
}

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

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

  if (!isset($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($hook, $key, $value) {
  $current_theme = skinr_current_theme();
  $skinr = variable_get('skinr_'. $current_theme, array());

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

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

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

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

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

/**
 * 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_get_skins($hook) {
  static $cache = NULL;

  if (!isset($cache)) {
    $current_theme = skinr_current_theme();
    $themes = system_theme_data();

    $cache = array('all' => array());
    foreach ((array) $themes[$current_theme]->info['skinr'] as $id => $skin) {
      if (!isset($skin['features'])) {
        $skin['features'] = array('*');
      }
      foreach ($skin['features'] as $feature) {
        // Global skins
        if ($feature == '*') {
          $feature = 'all';
        }

        // Initialize array for specified hook
        if (!isset($cache[$feature])) {
          $cache[$feature] = array();
        }

        // Single class per skin syntax
        if (isset($skin['label']) && isset($skin['class'])) {
          $cache[$feature][$skin['class']] = $skin['label'];
        }
        // Multiple classes per skin syntax
        else {
          foreach ($skin as $skin_key => $skin_class) {
            if ($skin_key != 'features') {
              $cache[$feature][$skin_class['class']] = $skin_class['label'];
            }
          }
        }
      }
    }

    // Merge in any elements that are specified to work with any element
    foreach ($cache as $feature => $skins) {
      $cache[$feature] = array_merge($skins, $cache['all']);
    }
  }

  if (isset($cache[$hook])) {
    return $cache[$hook];
  }
  else {
    return $cache['all'];
  }
}

/**
 * Fetch Skinr configuration data from modules
 */
function skinr_fetch_data() {
  static $cache = NULL;

  if (!isset($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',
        'skinr_title' => t('Skinr'),
        'skinr_description' => t('Manage which skins, if any, you want to apply. You can also add additional CSS classes.'),
        'skinr_weight' => 1,
        'title' => '',
        'description' => '',
        'collapsed' => TRUE,
        'weight' => 0,
      );
      return $data;
  }
}

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