<?php
// $Id: linkimagefield.module,v 1.7 2009/08/27 19:50:30 johnfyoung Exp $

/**
 * @file
 * Defines a link image field type.
 *
 * 6.x Port - Mainly wraps the ImageField CCK Type, adding a URL field 
 * The URL is stored (like the image alt and title tags) in the filefield's data element
 * 
 * TODO:
 * - for some reason the display formatter is not being set as the default
 * - 
 */

/**
 * Implementation of hook_init().
 *
 * Load required includes.
 */
function linkimagefield_init() {
  // If Content, FileField, or ImageField is not available, immediately disable Link Image Field.
  $disable = FALSE;
  $message = '';  

  if (!module_exists('content')) {
    $disable = TRUE;
    $message = t('The <a href="http://drupal.org/project/cck">Content Creation Kit</a> needs to be installed for it to work properly.');
  }
  
  if (!module_exists('filefield')) {
    $disable = TRUE;
    $message = (!empty($message) ? '<br />' : '') . t('The <a href="http://drupal.org/project/filefield">FileField module</a> needs to be installed for it to work properly.');
  }
  
  if (!module_exists('imagefield')) {
    $disable = TRUE;
    $message = (!empty($message) ? '<br />' : '') . t('The <a href="http://drupal.org/project/imagefield">ImageField module</a> needs to be installed for it to work properly.');
  }

  if ($disable) {
    module_disable(array('linkimagefield'));
    drupal_set_message(t('The Link Image Field module has been disabled.<br />') . $message);
    return;
  }
  
  // Load include code
  module_load_include('inc', 'linkimagefield', 'linkimagefield_widget');
}


/**
 * Implementation of hook_elements().
 */
function linkimagefield_elements() {
  $elements = array();

  // An LinkImageField is really just a ImageField with a URL.
  $imagefield_elements = imagefield_elements();
  $elements['linkimagefield_widget'] = $imagefield_elements['imagefield_widget'];
  $elements['linkimagefield_widget']['#process'][] = 'linkimagefield_widget_process';
  $elements['linkimagefield_widget']['#element_validate'][] = 'linkimagefield_widget_validate';

  // ImageField needs a separate value callback to save its alt, title and URL texts.
  $elements['linkimagefield_widget']['#value_callback'] = 'linkimagefield_widget_value';

  return $elements;
}

function linkimagefield_theme() {
  $theme =  array(
    'linkimagefield_image' => array(
      'arguments' => array('file' => NULL, 'alt' => '', 'title' => '', 'attributes' => NULL, 'getsize' => TRUE, 'url' => '', 'target' => '_self'),
    ),
    'linkimagefield_justlink' => array(
      'arguments' => array('url' => '', 'target' => '_self', 'title' => '', 'class' => ''),
    ),

    // Theme a Link Image Field field item. It calls linkimagefied_image with the proper
    // item properties as arguments.
    'linkimagefield_item' => array(
      'arguments' => array('item' => NULL),
    ),
    // linkimagefield_widget form element type theme function.
    'linkimagefield_widget' => array(
      'arguments' => array('element' => NULL),
      'file' => 'linkimagefield_widget.inc',
    ),
    // Use to generate a preview (admin view) of an linkimagefield item for use in
    // field item forms and filefield widgets. Invoked by filefield_widget_process.
    'linkimagefield_widget_preview' => array(
      'arguments' => array('item' => NULL),
    ),
    // Theme function for the field item elements. allows you to place children
    // within the context of the parent.
    'linkimagefield_widget_item' => array(
      'arguments' => array('element' => NULL),
    ),
    // Generates and img tag to the admin thumbnail of an LinkImageField upload.
    'linkimagefield_admin_thumbnail' => array(
      'arguments' => array('item' => NULL),
    ),
    'linkimagefield_formatter_linkimage' => array(
      'arguments' => array('element' => NULL),
      'file' => 'linkimagefield_formatter.inc',
    ),
    'linkimagefield_formatter_linkimage_justlink' => array(
      'arguments' => array('element' => NULL),
      'file' => 'linkimagefield_formatter.inc',
    ),
  );
  
  /**
   * to override these themes the function call would look like:
   * 
   * mytheme_linkimagefield_formatter_imagecachepresetname_linkimage
   * 
   * where the imagecachepresetname is the name of the desired imagecache preset
   */
  if(module_exists('imagecache')) {
    $imagecache_presets = module_invoke('imagecache', 'presets');
    foreach ($imagecache_presets as $preset) {
      $theme['linkimagefield_formatter_'. $preset['presetname'] .'_linkimage'] = array(
        'arguments' => array('element' => NULL),
        'function' => 'theme_linkimagefield_imagecache',
      );
    }
  }
  
  return $theme;
}

/**
 * Implementation of hook_views_api().
 */
// TODO: get views data to work
/*
function linkimagefield_views_api() {
  return array(
    'api' => 2.0,
    'path' => drupal_get_path('module', 'linkimagefield') . '/views',
  );
}*/

/**
 * Implementation of hook_file_download.
 *
 * @param string $filepath
 */
function linkimagefield_file_download($filepath) {
  // Delegate to ImageField
  imagefield_file_download($filepath);
}

/**
 * Implementation of CCK's hook_widget_info().
 *
 * @return array
 */
function linkimagefield_widget_info() {
  $module_path = drupal_get_path('module', 'linkimagefield');
  return array(
    'linkimagefield_widget' => array(
      'label' => t('Link Image'),
      'field types' => array('filefield'),
      'multiple values' => CONTENT_HANDLE_CORE,
      'callbacks' => array('default value' => CONTENT_CALLBACK_CUSTOM),
      'description' => t('An edit widget for image files that display as a link, including a preview of the image.'),
    ),
  );
}

/**
 * Implementation of CCK's hook_widget_settings().
 *
 * @param string $op
 * @param array $widget
 * @return array
 */
function linkimagefield_widget_settings($op, $widget) {
  switch ($op) {
    case 'form':
      return linkimagefield_widget_settings_form($widget);
    case 'validate':
      return linkimagefield_widget_settings_validate($widget);
    case 'save':
      return linkimagefield_widget_settings_save($widget);
  }
}

/**
 * Implementation of CCK's hook_widget
 *
 * @param array $form
 * @param array $form_state
 * @param array $field
 * @param array $items
 * @param integer $delta
 * @return array
 */
function linkimagefield_widget(&$form, &$form_state, $field, $items, $delta = 0) {
  if (empty($items[$delta])) {
    $items[$delta] = array('url' => '');
  }
  
  // Delegate to ImageField
  $element = imagefield_widget($form, $form_state, $field, $items, $delta);

  return $element;
}

/**
 * Implementation of hook_field_formatter_info
 *
 * @return array
 */
function linkimagefield_field_formatter_info() {
  $formatters['linkimage'] = array(
      'label' => t('Link Image'),
      'field types' => array('filefield'),
      'description' => t('Displays image files as link to provided URL.'),
  );
  
  $formatters['linkimage_justlink'] = array(
      'label' => t('Link Image - Just Link'),
      'field types' => array('filefield'),
      'description' => t('Displays just the link supplied for a Link Image Field.'),
  );
  
  if(module_exists('imagecache')) {
    $imagecache_presets = module_invoke('imagecache', 'presets');
    
    foreach ($imagecache_presets as $preset) {
      $formatters[$preset['presetname'] .'_linkimage'] = array(
        'label' => t('@preset Link Image', array('@preset' => $preset['presetname'])),
        'field types' => array('image', 'filefield'),
      );
    }
  }

  return $formatters;
}

/**
 * Implementation of hook_form_[form_id]_alter().
 *
 * Modify the add new field form to make "LinkImage" the default formatter.
 */
function linkimagefield_form_content_field_overview_form_alter(&$form, &$form_state) {
  $form['#submit'][] = 'linkimagefield_form_content_field_overview_submit';
}

/**
 * Submit handler to set a new field's formatter to "linkimage_urllink".
 */
function linkimagefield_form_content_field_overview_submit(&$form, &$form_state) {
  if (isset($form_state['fields_added']['_add_new_field']) && isset($form['#type_name'])) {
    $new_field = $form_state['fields_added']['_add_new_field'];
    $node_type = $form['#type_name'];
    $field = content_fields($new_field, $node_type);
    if ($field['widget']['module'] == 'linkimagefield') {
      foreach ($field['display_settings'] as $display_type => $display_settings) {
        if ($field['display_settings'][$display_type]['format'] == 'default') {
          $field['display_settings'][$display_type]['format'] = 'linkimage_urllink';
        }
      }
      content_field_instance_update($field);
    }
  }
}

/**
 * Implementation of CCK's hook_default_value().
 */
function linkimagefield_default_value(&$form, &$form_state, $field, $delta) {
  return imagefield_default_value($form, $form_state, $field, $delta);
}

/**
 * determine whether an attribute for the link should be the default or the custom
 * 
 * works for a url, alt or title attribute
 *
 * @param string $attr
 * @param array $item
 * @param array $field
 * @return string
 */
function _linkimagefield_format_set_attribute($attr, $item, $field) {
  $attr_value = '';
  
  // if custom values are allowed, use the user supplied value or default if one's not supplied
  // else since no custom values are allowed, just use the default if supplied
  // (URL is a special case - doesn't have a check for use custom value) 
  if(($field['widget']['custom_'.$attr]) || $attr == 'url' || $attr == 'target') {
    if($attr == 'target' && $item['data'][$attr] == 'default') {
      $item['data'][$attr] = $field['widget'][$attr];
    }
    $attr_value = !empty($item['data'][$attr]) ? $item['data'][$attr] : (!empty($field['widget'][$attr]) ? $field['widget'][$attr] : '');      
  } else {
    $attr_value = !empty($field['widget'][$attr]) ? $field['widget'][$attr] : ($attr == 'target' ? '_self' : '');
  }
  
  return $attr_value;
}

function theme_linkimagefield_formatter($element) {
  if (isset($element['#item']['nid']) && $node = node_load($element['#item']['nid'])) {
    return linkimagefield_field_formatter($element['#field_name'], $element['#item'], $element['#formatter'], $node);
  }
}

function theme_linkimagefield_image($file, $alt = '', $title = '', $attributes = NULL, $getsize = TRUE, $url = '', $target = '_self', $nofollow = FALSE) {
  $url_attributes = array('title' => $title);
  if($target != '_self') {
    $url_attributes['target'] = $target;
  }
  if($nofollow) {
    $url_attributes['rel'] = 'nofollow';
  }
  $imagetag = theme('imagefield_image', $file, $alt, $title, $attributes, $getsize);
  if(empty($url)) {
    return $imagetag;
  }
  return l($imagetag, $url, array('attributes' => $url_attributes, 'html' => TRUE));
}

function theme_linkimagefield_justlink($url = '', $target = '_self', $title = '', $class = '', $nofollow = FALSE) {
  $url_attributes = array('class' => $class, 'title' => $title);
  if($target != '_self') {
    $url_attributes['target'] = $target;
  }
  if($nofollow) {
    $url_attributes['rel'] = 'nofollow';
  }
  return l($url, $url, array('attributes' => $url_attributes, 'html' => TRUE));
}

function theme_linkimagefield_imagecache($element) {
  $field = content_fields($element['#field_name']);
  $item = $element['#item'];
  $formatter = $element['#formatter'];
  
  if (empty($item['fid']) && $field['use_default_image']) {
    $item = $field['default_image'];
  } else if (empty($item['fid'])) {  // mod by eric
    return '';
  }
  // Views does not load the file for us, while CCK display fields does.
  if (empty($item['filepath'])) {
    $item = array_merge($item, field_file_load($item['fid']));
  }
  if (is_string($item['data'])) {
    $item['data'] = unserialize($item['data']);
  }
  
  $alt = _linkimagefield_format_set_attribute('alt', $item, $field);
  $title = _linkimagefield_format_set_attribute('title', $item, $field);
  $url = _linkimagefield_format_set_attribute('url', $item, $field);
  $target = _linkimagefield_format_set_attribute('target', $item, $field);
  $nofollow = $item['data']['nofollow'];
  $parts =  explode('_', $formatter);
  $style = array_pop($parts);
  $presetname = implode('_', $parts);

  $class = "linkimagefield imagecache imagecache-$presetname imagecache-$style imagecache-$formatter";
  if ($preset = imagecache_preset_by_name($presetname)) {
    $item['filepath'] = $item['fid'] == 'upload' ? $item['preview'] : $item['filepath'];
    $imagetag = theme('imagecache', $presetname, $item['filepath'], $alt, $title);
    $attributes = array('class' => $class, 'title' => $title);
    if($target != '_self') {
      $attributes['target'] = $target;
    }
    if($nofollow) {
      $attributes['rel'] = 'nofollow';
    }
    if(empty($url)) {
      return $imagetag;
    }
    return l($imagetag, $url, array('attributes' => $attributes, 'html' => TRUE));
  }
  return '<!-- linkimagefield formatter imagecache preset('. $presetname .') not found! -->';
}

function theme_linkimagefield_item($item) {
  return theme('linkimagefield_image', $item, $item['alt'], $item['title'], TRUE, $item[$url], $item[$target]);
}

function theme_linkimagefield_widget_item($element) {
  return theme('imagefield_widget_item', $element);
}

function theme_linkimagefield_widget_preview($item = NULL) {
  return '<div class="imagefield-preview">'. theme('imagefield_admin_thumbnail', $item) .'</div>';
}

function theme_linkimagefield_admin_thumbnail($item = NULL) {
  return theme_imagefield_admin_thumbnail($item);
}