<?php

/*********************************************************************************************
 *
 * CORE HOOKS
 *
 ********************************************************************************************/
/**
 * Implements hook_permission().
 */
function scratchpads_front_permission(){
  return array(
    'administer front page' => array(
      'title' => t('Administer front page')
    )
  );
}

/**
 * Implements hook_scratchpads_default_permissions().
 */
function scratchpads_front_scratchpads_default_permissions(){
  return array(
    'maintainer' => array(
      'administer front page'
    )
  );
}

/**
 * Implements hook_menu().
 */
function scratchpads_front_menu(){
  $items['scratchpads-front'] = array(
    // The page callback also invokes drupal_set_title() in case
    // the menu router's title is overridden by a menu link.
    'page callback' => 'scratchpads_front_page_view',
    'access arguments' => array(
      'access content'
    )
  );
  $items['scratchpads-front/view'] = array(
    'title' => 'View',
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'weight' => -10
  );
  $items['scratchpads-front/edit'] = array(
    'title' => 'Edit',
    'page callback' => 'drupal_get_form',
    'page arguments' => array(
      'scratchpads_front_page_edit'
    ),
    'access arguments' => array(
      'administer front page'
    ),
    'weight' => 0,
    'type' => MENU_LOCAL_TASK,
    'context' => MENU_CONTEXT_PAGE | MENU_CONTEXT_INLINE
  );
  return $items;
}

/**
 * Implements hook_block_view_alter
 */
function scratchpads_front_block_view_alter(&$data, $block){
  // We need to set the block title for the "Custom" views blocks.
  if(isset($block->context) && substr($block->bid, 0, -1) == 'views-front_page_blocks-block_'){
    // if the form has passed in the argument of custom
    if(@isset($data['content']['#views_contextual_links_info']['views_ui']['view']->args[0]) && $data['content']['#views_contextual_links_info']['views_ui']['view']->args[0] == 'custom'){
      $custom_block = scratchpads_front_get_custom_block('front_page_' . $data['content']['#views_contextual_links_info']['views_ui']['view_display_id'] . '_node_type');
      if($custom_block->module == 'views'){
        // title too long so it is md5 hashed by views
        if(strlen($custom_block->delta) == 32){
          $hashes = variable_get('views_block_hashes', array());
          if(!empty($hashes[$custom_block->delta])){
            $custom_block->delta = $hashes[$custom_block->delta];
          }
        }
        $view_and_display = explode('-', $custom_block->delta);
        $view = views_get_view($view_and_display[0]);
        $data['title'] = $view->display[$view_and_display[1]]->display_options['title'];
      }elseif(isset($custom_block->title)){
        $data['title'] = $custom_block->title;
      }
    }
    // Check to see whether or not the block has content.
    $content = $data['content'];
    $content = trim(str_replace("\n", '', strip_tags(drupal_render($content))));
    if(!$content){
      unset($data['content']);
      unset($data['subject']);
    }
  }
  if(isset($block->context) && substr($block->bid, 0, -1) == 'views-front_page_blocks-block_' && isset($data['subject']) && substr($data['subject'], -3) == 'rys'){
    $data['subject'] = substr($data['subject'], 0, -2) . 'ies';
  }
  if(isset($block->context) && (!user_access('administer front page'))){
    if($block->context == 'scratchpads_front_page'){
      if(isset($data['content']) && substr_count($data['content']['#markup'], 'class="view-empty"') > 1){
        unset($data['content']);
        unset($data['subject']);
      }
    }
  }
}

function scratchpads_front_menu_contextual_links_alter(&$links, $router_item, $root_path){
  if($root_path == 'scratchpads-front/edit'){
    $links['block-']['title'] = t("Edit front page");
  }
}

/**
 * Implements hook_admin_paths().
 */
function scratchpads_front_admin_paths(){
  $paths = array(
    'scratchpads-front/edit' => true
  );
  return $paths;
}

/**
 * Implements hook_form_FORM_ID_alter().
 */
function scratchpads_front_form_system_site_information_settings_alter(&$form, $form_state, $form_id){
  unset($form['front_page']['default_nodes_main']);
  $welcome_message = variable_get('front_page_welcome_message', array(
    'value' => ''
  ));
  $form['front_page']['front_page_welcome_message'] = array(
    '#title' => t('Welcome message'),
    '#type' => 'textarea',
    '#default_value' => $welcome_message['value'],
    '#required' => true
  );
}

/*********************************************************************************************
 *
 * VIEWS
 *
 ********************************************************************************************/
/**
 * Implementation of hook_views_api
 */
function scratchpads_front_views_api(){
  $path = drupal_get_path('module', 'scratchpads_front');
  return array(
    'api' => '3',
    'path' => $path . '/views'
  );
}

/**
 * Implements hook_views_pre_view().
 * Pass the view front page settings as arguments
 */
function scratchpads_front_views_pre_view(&$view, &$display_id, &$args){
  $var = 'front_page_' . $display_id . '_node_type';
  switch($view->name){
    case 'front_page_blocks':
      if(scratchpads_front_variable_get($var) == 'custom' && $view->current_display == $display_id){
        $custom_block = scratchpads_front_get_custom_block($var);
        $render_array = _block_get_renderable_array(_block_render_blocks(array(
          $custom_block
        )));
        $render_block_id = $custom_block->module . '_' . $custom_block->delta;
        $custom_view_block_css = '';
        if(!empty($render_array[$render_block_id]['#views_contextual_links_info']['views_ui']['view']->display['block']->display_options['css_class'])){
          $custom_view_block_css = $render_array[$render_block_id]['#views_contextual_links_info']['views_ui']['view']->display['block']->display_options['css_class'];
        }
        $markup = '<div class="view view-front-page-blocks view-id-front_page_blocks view-display-id-' . $display_id . '">
        <div class="view-content' . $custom_view_block_css . '">' . (isset($render_array[$render_block_id]['#markup']) ? $render_array[$render_block_id]['#markup'] : '') . '</div>
      </div>';
        $empty_area_options = array(
          'area' => array(
            'id' => 'area',
            'table' => 'views',
            'field' => 'area',
            'format' => 'filtered_html',
            'content' => $markup
          )
        );
        $view->display_handler->set_option('empty', $empty_area_options);
      }
      if (isset($custom_block->subject) && $custom_block->subject != ''){
        $view->title = $custom_block->subject;
      }
      $view->args[] = scratchpads_front_variable_get($var);
      break;
    case 'front_page_slideshow':
      $view->args[] = scratchpads_front_variable_get($var);
      if(!user_access('administer front page')){
        $view->display_handler->default_display->options['empty'] = array();
        $view->display_handler->options['empty'] = array();
      }
      break;
  }
}

/*********************************************************************************************
 *
 * MENU CALLBACKS
 *
 ********************************************************************************************/
/**
 * Menu callback
 * Display the home page
 */
function scratchpads_front_page_view(){
  $page = array();
  $path = drupal_get_path('module', 'scratchpads_front');
  $welcome_message = '<h1 id="front-page-title" class="title"> ';
  $default_welcome_message = t('Welcome to @site-name', array(
    '@site-name' => variable_get('site_name', 'Drupal')
  ));
  if(variable_get('front_page_override_welcome_title', 0)){
    $welcome_message .= variable_get('front_page_welcome_title', $default_welcome_message);
  }else{
    $welcome_message .= $default_welcome_message;
  }
  $welcome_message .= '</h1>';
  if(($set_message = variable_get('front_page_welcome_message', FALSE)) !== FALSE){
    $welcome_message .= check_markup($set_message['value'], 'filtered_html');
  }else{
    if(user_access('administer front page')){
      $welcome_message .= '<p>' . t('Click <em>Edit</em> above to customise the "Welcome message" for your site or, complete your site setup by clicking <em>Dashboard</em>, and then <em>Finish setting up the site</em>.') . '</p>';
    }
  }
  switch(scratchpads_front_variable_get('front_page_main_block_type')){
    case 'images':
      $view_name = 'front_page_slideshow';
      $args = array();
      break;
    case 'content':
      $view_name = 'front_page_content';
      $args = array(
        scratchpads_front_variable_get('front_page_main_block_node_type')
      );
      break;
  }
  // Load the view and render it.
  if($view = views_get_view($view_name)){
    $block = $view->execute_display(NULL, $args);
  }
  // Add an alternate link to the RSS feed.
  drupal_add_html_head_link(array(
    'rel' => 'alternate',
    'title' => variable_get('site_name', ''),
    'href' => url('rss.xml', array(
      'absolute' => TRUE
    )),
    'type' => 'application/rss+xml'
  ));
  return array(
    'welcome' => array(
      '#prefix' => '<div class="grid-4 alpha">',
      '#markup' => $welcome_message,
      '#suffix' => '</div>'
    ),
    'block' => array(
      '#prefix' => '<div class="grid-8 omega">',
      '#markup' => $block,
      '#suffix' => '</div>'
    ),
    '#attached' => array(
      'css' => array(
        $path . '/css/scratchpads_front.css'
      )
    )
  );
}

/**
 * Implements hook_entity_view
 *
 * REMOVE links from the species slideshow, and ADD links to the front page
 * slideshow. This is a thoroughly shit way of doing this, but the styles and
 * file entity code is so messed up that I'm reluctant to spend time trying to
 * do this correctly.
 */
function scratchpads_front_entity_view_alter(&$build, $type){
  if($type == 'file' && isset($build['#view_mode']) && $build['#view_mode'] == 'file_styles_slideshow_large'){
    $matches = FALSE;
    preg_match('/<img [^>]*>/', $build['file']['#markup'], $matches);
    if($matches){
      $build['file']['#markup'] = str_replace($matches[0], l($matches[0], 'file/' . $build['file']['#file']->fid, array(
        'html' => TRUE
      )), $build['file']['#markup']);
    }
  } elseif($type == 'file' && isset($build['#view_mode']) && $build['#view_mode'] == 'file_styles_species_slideshow_thumbnail'){
    $matches = FALSE;
    preg_match('|(<a href[^>]*>)<img [^>]*>(</a>)|', $build['file']['#markup'], $matches);
    for($i = 1; $i <= 2; $i++){
      $build['file']['#markup'] = str_replace($matches[$i], '', $build['file']['#markup']);
    }
  }
}

/**
 * Menu callback
 * Edit the home page
 */
function scratchpads_front_page_edit($form, &$form_state){
  // Switch the realm if we need to.
  if(module_exists('variable_realm')){
    if(($params = variable_realm_params()) != FALSE){
      foreach($params as $realm_name => $realm_key){
        variable_realm_switch($realm_name, $realm_key, FALSE);
      }
      variable_realm_rebuild();
    }
  }
  $node_types = scratchpads_front_node_types();
  $form['site_information'] = array(
    '#type' => 'fieldset',
    '#title' => t('Site details')
  );
  $form['site_information']['site_name'] = array(
    '#type' => 'textfield',
    '#title' => t('Site name'),
    '#default_value' => variable_get('site_name', 'Drupal'),
    '#required' => TRUE
  );
  $form['site_information']['site_slogan'] = array(
    '#type' => 'textfield',
    '#title' => t('Slogan'),
    '#default_value' => variable_get('site_slogan', ''),
    '#description' => t("How this is used depends on your site's theme.")
  );
  $form['site_information']['site_mail'] = array(
    '#type' => 'textfield',
    '#title' => t('E-mail address'),
    '#default_value' => variable_get('site_mail', ini_get('sendmail_from')),
    '#description' => t("The <em>From</em> address in automated e-mails sent during registration and new password requests, and other notifications. (Use an address ending in your site's domain to help prevent this e-mail being flagged as spam.)"),
    '#required' => TRUE
  );
  $form['front_page_welcome'] = array(
    '#type' => 'fieldset',
    '#title' => 'Welcome'
  );
  $form['front_page_welcome']['front_page_override_welcome_title'] = array(
    '#title' => t('Override welcome title'),
    '#type' => 'checkbox',
    '#default_value' => variable_get('front_page_override_welcome_title', 0)
  );
  $form['front_page_welcome']['front_page_welcome_title'] = array(
    '#title' => t('Welcome title'),
    '#type' => 'textfield',
    '#default_value' => variable_get('front_page_welcome_title', t('Welcome to @site-name', array(
      '@site-name' => variable_get('site_name', 'Drupal')
    ))),
    '#description' => t('Setting the welcome title will prevent it from being translated on multi-lingual sites.'),
    '#states' => array(
      'visible' => array(
        ':input[name="front_page_override_welcome_title"]' => array(
          'checked' => TRUE
        )
      )
    )
  );
  $default_welcome_message = variable_get('front_page_welcome_message', array(
    'value' => ''
  ));
  $form['front_page_welcome']['front_page_welcome_message'] = array(
    '#title' => t('Welcome message'),
    '#type' => 'text_format',
    '#format' => null,
    '#default_value' => $default_welcome_message['value'],
    '#required' => true
  );
  $form['main_block'] = array(
    '#type' => 'fieldset',
    '#title' => t('Main block'),
    '#collapsible' => TRUE,
    '#collapsed' => FALSE
  );
  $form['main_block']['front_page_main_block_type'] = array(
    '#type' => 'radios',
    '#title' => t('Main block'),
    '#default_value' => scratchpads_front_variable_get('front_page_main_block_type'),
    '#options' => array(
      'images' => t('Images'),
      'content' => t('Content')
    ),
    '#description' => t('Please select what content type to display in the main front page block.'),
    '#required' => true
  );
  $form['main_block']['front_page_main_block_node_type'] = array(
    '#type' => 'select',
    '#title' => t('Content type'),
    '#options' => array(
      'all' => 'All content types'
    ) + $node_types,
    '#default_value' => scratchpads_front_variable_get('front_page_main_block_node_type'),
    '#required' => true,
    '#states' => array(
      'invisible' => array(
        'input[name="front_page_main_block_type"]' => array(
          'value' => 'images'
        )
      )
    )
  );
  // if the view has been edited we don't add the option to edit the view via this form
  if(strlen(views_get_view('front_page_slideshow')->vid) == 0){
    $form['main_block']['front_page_main_block_slideshow_text_creator'] = array(
      '#type' => 'checkbox',
      '#title' => t('Display Image Creator'),
      '#description' => t('Do you want the image creators to be displayed in the slideshow?'),
      '#default_value' => scratchpads_front_variable_get('front_page_main_block_slideshow_text_creator'),
      '#required' => false,
      '#states' => array(
        'visible' => array(
          'input[name="front_page_main_block_type"]' => array(
            'value' => 'images'
          )
        )
      )
    );
    $form['main_block']['front_page_main_block_slideshow_text_licence'] = array(
      '#type' => 'checkbox',
      '#title' => t('Display Image Licence'),
      '#description' => t('Do you want the image licences to be displayed in the slideshow?'),
      '#default_value' => scratchpads_front_variable_get('front_page_main_block_slideshow_text_licence'),
      '#required' => false,
      '#states' => array(
        'visible' => array(
          'input[name="front_page_main_block_type"]' => array(
            'value' => 'images'
          )
        )
      )
    );
  }
  $form['small_blocks'] = array(
    '#type' => 'fieldset',
    '#title' => t('Small blocks'),
    '#collapsible' => TRUE,
    '#collapsed' => FALSE
  );
  $view = views_get_view('front_page_blocks');
  $count = 1;
  $form_state['vars'] = array();
  foreach(array_keys($view->display) as $display_id){
    if($display_id === 'default'){
      continue;
    }
    $var = 'front_page_' . $display_id . '_node_type';
    $form_state['vars'][] = $var;
    $form['small_blocks']['small_block_' . $count] = array(
      '#type' => 'fieldset',
      '#title' => t('Block ' . $count),
      '#collapsible' => TRUE,
      '#collapsed' => FALSE
    );
    $form['small_blocks']['small_block_' . $count][$var] = array(
      '#type' => 'select',
      '#title' => t('Block ' . $count),
      '#options' => $node_types + array(   /* add custom as an option. If user selects this, a list of blocks is returned to choose from */
        'custom' => 'Custom'
      ),
      '#default_value' => scratchpads_front_variable_get($var),
      '#description' => t('Select which node type to display in the home page block.'),
      '#required' => true
    );
    $form['small_blocks']['small_block_' . $count]['custom_block_' . $count] = array(
      '#type' => 'fieldset',
      '#title' => t('Custom block ' . $count),
      '#collapsible' => FALSE,
      '#collapsed' => FALSE,
      // This #states rule says that the "custom block" fieldset should only be shown if the "nodetype (var)" form element is set to "custom".
      '#states' => array(
        'visible' => array(
          ':input[name="' . $var . '"]' => array(
            'value' => 'custom'
          )
        )
      )
    );
    $form['small_blocks']['small_block_' . $count]['custom_block_' . $count][$var . '_custom'] = array(
      '#type' => 'select',
      '#title' => t('Block ' . $count . ' custom'),
      '#options' => scratchpads_front_blocks_as_options(),
      '#default_value' => scratchpads_front_variable_get($var . '_custom'),
      '#empty_option' => '- SELECT -',
      '#empty_value' => 0
    );
    $count++;
  }
  $form = system_settings_form($form);
  $form['#submit'][] = 'scratchpads_front_page_edit_submit';
  return $form;
}

/**
 * Form submit
 * Edit the home page
 */
function scratchpads_front_page_edit_submit($form, &$form_state){
  /*
   * $form_state['vars'][2] = front_page_block_3_node_type
   * $form_state['values']['front_page_block_3_node_type'] = 'custom'
   * $form_state['values']['front_page_block_3_node_type_custom'] = views:custom_twitter_block-block' (module:delta)
   *
   * unset custom variable if custom is not selected as a node type
   */
  foreach($form_state['vars'] as $var){
    if($form_state['values'][$var] && $form_state['values'][$var] != 'custom'){
      variable_del($var . '_custom');
    }
    variable_set($var, $form_state['values'][$var]);
  }
  $form_state['redirect'] = '<front>';
  // Clear the views cache, as the slideshow view is dynamic
  views_invalidate_cache();
  // clear the other caches so the blocks update
  drupal_flush_all_caches();
}

/*********************************************************************************************
 *
 * MODULE FUNCTIONS
 *
 ********************************************************************************************/
/**
 *
 * Helper function for variable_get
 * @param string $name
 */
function scratchpads_front_variable_get($name){
  $default = scratchpads_front_variable_default($name);
  return variable_get($name, $default);
}

/**
 *
 * Helper function for variable defaults
 * @param string $name
 */
function scratchpads_front_variable_default($name = NULL){
  static $defaults;
  if(!isset($defaults)){
    $defaults = array(
      'front_page_main_block_type' => 'images',
      'front_page_main_block_node_type' => 'all'
    );
    $view = views_get_view('front_page_blocks');
    foreach(array_keys($view->display) as $display_id){
      if($display_id === 'default'){
        continue;
      }
      $var = 'front_page_' . $display_id . '_node_type';
      switch($display_id){
        case 'block_1':
          $defaults[$var] = 'page';
          $defaults[$var . '_custom'] = 0;
          break;
        case 'block_2':
          $defaults[$var] = 'biblio';
          $defaults[$var . '_custom'] = 0;
          break;
        case 'block_3':
          $defaults[$var] = 'spm';
          $defaults[$var . '_custom'] = 0;
          break;
      }
    }
  }
  if(!isset($name)){return $defaults;}
  if(isset($defaults[$name])){return $defaults[$name];}
}

/**
 *
 * Get a list of node types
 */
function scratchpads_front_node_types(){
  static $node_types;
  if(!isset($node_types)){
    foreach(node_type_get_types() as $node_type => $node_info){
      $node_types[$node_type] = $node_info->name;
    }
  }
  return $node_types;
}

/*********************************************************************************************
 *
 * PREPROCESSORS
 *
 ********************************************************************************************/
/**
 * Preprocessor for theme('block').
 */
function scratchpads_front_preprocess_block(&$vars){
  $block = $vars['block'];
  if(isset($block->context) && $block->context == 'scratchpads_front_page'){
    $display_id = substr(strrchr($block->bid, "-"), 1); // this is the block into which we are placing the custom block
    $custom_block_selected = variable_get('front_page_' . $display_id . '_node_type_custom');
    if($custom_block_selected){
      list($module, $delta) = explode(':', $custom_block_selected, 2);
      $vars['title_suffix']['contextual_links']['#contextual_links']['block'] = array(
        'admin/structure/block/manage',
        array(
          $module,
          $delta
        )
      );
    }else{
      // Change the contextual links
      $vars['title_suffix']['contextual_links']['#contextual_links']['block'] = array(
        'scratchpads-front/edit',
        array()
      );
    }
  }
}

/*********************************************************************************************
 *
 * CTOOLS
 *
 ********************************************************************************************/
/**
 * Implementation of hook_ctools_plugin_api().
 */
function scratchpads_front_ctools_plugin_api(){
  list($module, $api) = func_get_args();
  if($module == "context" && $api == "context"){return array(
      "version" => "3"
    );}
}

/*********************************************************************************************
 *
 * IMAGE STYLES
 *
 ********************************************************************************************/
/**
 * Implementation of hook_styles_default_styles().
 */
function scratchpads_front_styles_default_styles(){
  $styles = array();
  // Exported style: slideshow_large
  $styles['file']['styles']['slideshow_large'] = array(
    'label' => 'slideshow_large',
    'description' => '',
    'preset_info' => array(
      'image' => array(
        'slideshow_large' => array(
          'default preset' => 'original',
          'preset' => 'slideshow_large'
        )
      ),
      'audio' => array(
        'slideshow_large' => array(
          'default preset' => 'original'
        )
      ),
      'video' => array(
        'slideshow_large' => array(
          'default preset' => 'original'
        )
      ),
      'default' => array(
        'slideshow_large' => array(
          'default preset' => 'original'
        )
      )
    )
  );
  // Exported style: slideshow_thumbnail
  $styles['file']['styles']['slideshow_thumbnail'] = array(
    'label' => 'slideshow_thumbnail',
    'description' => '',
    'preset_info' => array(
      'image' => array(
        'slideshow_thumbnail' => array(
          'default preset' => 'original',
          'preset' => 'slideshow_thumbnail'
        )
      ),
      'audio' => array(
        'slideshow_thumbnail' => array(
          'default preset' => 'original'
        )
      ),
      'video' => array(
        'slideshow_thumbnail' => array(
          'default preset' => 'original'
        )
      ),
      'default' => array(
        'slideshow_thumbnail' => array(
          'default preset' => 'original'
        )
      )
    )
  );
  return $styles;
}

/**
 * Implements hook_styles_default_presets_alter().
 */
function scratchpads_front_styles_default_presets_alter(&$presets){
  $styles = styles_default_styles();
  if($styles['file']['styles']['slideshow_large']['storage'] == STYLES_STORAGE_DEFAULT){
    $presets['file']['containers']['image']['styles']['slideshow_large'] = array(
      'default preset' => 'original',
      'preset' => 'slideshow_large'
    );
    $presets['file']['containers']['audio']['styles']['slideshow_large'] = array(
      'default preset' => 'original'
    );
    $presets['file']['containers']['video']['styles']['slideshow_large'] = array(
      'default preset' => 'original'
    );
    $presets['file']['containers']['default']['styles']['slideshow_large'] = array(
      'default preset' => 'original'
    );
  }
  if($styles['file']['styles']['slideshow_thumbnail']['storage'] == STYLES_STORAGE_DEFAULT){
    $presets['file']['containers']['image']['styles']['slideshow_thumbnail'] = array(
      'default preset' => 'original',
      'preset' => 'slideshow_thumbnail'
    );
    $presets['file']['containers']['audio']['styles']['slideshow_thumbnail'] = array(
      'default preset' => 'original'
    );
    $presets['file']['containers']['video']['styles']['slideshow_thumbnail'] = array(
      'default preset' => 'original'
    );
    $presets['file']['containers']['default']['styles']['slideshow_thumbnail'] = array(
      'default preset' => 'original'
    );
  }
}

/**
 * Implementation of hook_image_default_styles().
 */
function scratchpads_front_image_default_styles(){
  return array(
    'slideshow_large' => array(
      'name' => 'slideshow_large',
      'effects' => array(
        array(
          'name' => 'image_scale_and_crop',
          'data' => array(
            'width' => '619',
            'height' => '463'
          ),
          'weight' => '1'
        ),
        array(
          'name' => 'convert_image_format',
          'data' => array(
            'format' => 'image/jpeg',
            'quality' => '80'
          ),
          'weight' => '1'
        )
      )
    ),
    'slideshow_thumbnail' => array(
      'name' => 'slideshow_thumbnail',
      'effects' => array(
        array(
          'name' => 'image_scale_and_crop',
          'data' => array(
            'width' => '154',
            'height' => '115'
          ),
          'weight' => '1'
        ),
        array(
          'name' => 'convert_image_format',
          'data' => array(
            'format' => 'image/jpeg',
            'quality' => '80'
          ),
          'weight' => '1'
        )
      )
    )
  );
}

/**
 * Hook for defining extra blocks are allowed
 * in scratchpads_front
 */
function hook_scratchpads_front_blocks(){
  return [
    'block_module_name' => 'block_delta'
  ];
}

/* adding custom blocks */
function scratchpads_front_blocks_as_options(){
  $query = db_select('block', 'b');
  $or_cond = db_or()->condition('b.module', 'views', '=')->condition('b.module', 'block', '=');
  $block_info = $query->fields('b')->orderBy('b.title')->orderBy('b.module')->condition($or_cond)->condition('b.theme', 'scratchpads')->condition('b.delta', array(
    'front_page_blocks-block_1',
    'front_page_blocks-block_2',
    'front_page_blocks-block_3',
    'front_page_slideshow-block_1',
    'front_page_content-block'
  ), 'NOT IN')->addTag('block_load')->addTag('translatable')->execute()->fetchAllAssoc('bid');
  $options = array();
  $hidden_views = _scratchpads_hands_off_hidden_views();

  // Invoke hook to see if any other modules provide blocks for the front page
  $contrib_blocks = module_invoke_all('scratchpads_front_blocks');

  foreach($contrib_blocks as $module => $deltas) {
    // Block delta is basically its machine name or id (not database id though)
    // May or may not be an array
    if(!is_array($deltas)) {
      $deltas = [$deltas];
    }

    foreach($deltas as $delta) {
      // Load the block record from the database
      $block = block_load($module, $delta);
      // Need to get the title from the block_info hook since it's not kept in DB
      $block->title = module_invoke($module, "block_info")[$delta]['info'];
      // Add to the block lists
      $block_info[$block->bid] = $block;
    }
  }

  foreach($block_info as $block){
    $blockTitle = strip_tags($block->title);
    if($blockTitle){
      $options['Block']["{$block->module}:{$block->delta}"] = "{$blockTitle}";
    }elseif($block->module == 'views'){
      // title too long so it is md5 hashed by views
      if(strlen($block->delta) == 32){
        $hashes = variable_get('views_block_hashes', array());
        if(!empty($hashes[$block->delta])){
          $block->delta = $hashes[$block->delta];
        }
      }
      $view_and_display = explode('-', $block->delta);
      if(!in_array($view_and_display[0], $hidden_views)){
        $view = views_get_view($view_and_display[0]);
        if($view){
          $arguments = $view->get_items('argument', $view_and_display[1]);
          if(!$arguments){
            $options[$view->get_human_name()]["{$block->module}:{$block->delta}"] = $view->display[$view_and_display[1]]->display_title;
          }
        }
      }
    }
  }
  return $options;
}

function scratchpads_front_get_custom_block($var){
  $custom_block_selected = variable_get($var . '_custom');
  if($custom_block_selected){
    list($module, $delta) = explode(':', $custom_block_selected);
    $custom_block = block_load($module, $delta);
    return $custom_block;
  }
}