<?php

/**
 * Implementation of hook_form_alter.
 */
function opengraph_meta_form_alter(&$form, $form_state, $form_id) {
  // if editing a node
  if ('node_form' == stristr($form_id, 'node_form')) {
    if (!isset($form['metatags'])) {
      return;
    }

    $node = $form['#node'];
    $lang = metatag_entity_get_language('node', $form['#node']);
    $metatags = &$form['metatags'][$lang]['open-graph'];
    $parents = ['metatags', $lang];

    // add meta tags editing for making it easier to share on Facebook
    $form['opengraph_meta'] = array(
      '#type' => 'fieldset',
      '#title' => t('Open Graph meta tags (e.g. for Facebook sharing)'),
      '#description' => $metatags['#description'],
      '#tree' => TRUE,
      '#collapsible' => TRUE,
      '#collapsed' => TRUE,
      // This will be overridden later on in _field_extra_fields_pre_render()
      // and _opengraph_meta_form_reset_weight() but this is what we want to
      // achieve.
      '#weight' => $form['metatags']['#weight'],
    );

    $form['opengraph_meta']['title'] = [
      '#title' => t('Title'),
      '#parents' => array_merge($parents, ['og:title', 'value']),
    ] + $metatags['og:title']['value'];
    unset($metatags['og:title']['value']);

    $form['opengraph_meta']['description'] = [
      '#title' => t('Description'),
      '#parents' => array_merge($parents, ['og:description', 'value']),
    ] + $metatags['og:description']['value'];
    unset($metatags['og:description']['value']);

    $form['opengraph_meta']['type'] = [
      '#parents' => array_merge($parents, ['og:type', 'value']),
    ] + $metatags['og:type']['value'];
    unset($metatags['og:type']['value']);

    // Location stuff
    $form['opengraph_meta']['location'] = array(
      '#type' => 'fieldset',
      '#title' => t('Open Graph Location tags'),
      '#description' => t('Here you can specify the location information.'),
      '#tree' => TRUE,
      '#collapsible' => TRUE,
      '#collapsed' => TRUE,
      '#weight' => 10,
    );
    $fields = array(
      'latitude' => t('Geographical latitude as a decimal number.'),
      'longitude' => t('Geographical longitude as a decimal number.'),
      'street_address' => t('Local street address.'),
      'locality' => t('E.g. town or city.'),
      'region' => t('Region within country, e.g. a county.'),
      'postal_code' => t('Postal code.'),
      'country_name' => t('Full country name.'),
    );
    foreach ($fields as $f => $description) {
      $form['opengraph_meta']['location'][$f] = [
        '#description' => $description,
        '#parents' => array_merge($parents, ["og:$f", 'value']),
      ] + $metatags["og:$f"]['value'];
      unset($metatags["og:$f"]['value']);
    }

    // Contact stuff
    $form['opengraph_meta']['contact'] = array(
      '#type' => 'fieldset',
      '#title' => t('Open Graph Contact tags'),
      '#description' => t('Here you can specify the contact information.'),
      '#tree' => TRUE,
      '#collapsible' => TRUE,
      '#collapsed' => TRUE,
      '#weight' => 9,
    );
    $fields = array(
      'email' => t('Email address.'),
      'phone_number' => t('Phone number.'),
      'fax_number' => t('Fax number.'),
    );
    foreach ($fields as $f => $description) {
      $form['opengraph_meta']['contact'][$f] = [
        '#parents' => array_merge($parents, ["og:$f", 'value']),
      ] + $metatags["og:$f"]['value'];
      unset($metatags["og:$f"]['value']);
    }

    // if we have images in this node then show thumbnail selector
    $images = OpenGraphMeta::instance()->harvestImagesFromNode($node);
    $image_selector_options = [
      '' => t('No image (Facebook will choose one automatically).'),
    ];
    foreach ($images as $url => $image) {
      $image_selector_options[$url] = theme(
        'opengraph_meta_thumbnail',
        ['image' => $image]
      );
    }
    $form['opengraph_meta']['image'] = [
      '#title' => t('Thumbnail image'),
      '#type' => 'select_or_other',
      '#select_type' => 'radios',
      '#default_value' => $metatags['og:image']['value']['#default_value'],
      '#description' => t('The thumbnail image that will get shown in e.g. a Facebook preview. If left unset then then the first available image will be used. If none available then the global fallback image will be used.'),
      '#options' => $image_selector_options,
      '#attributes' => array('class' => array('opengraph-thumbs-wrapper','clearfix')),
      '#other' => t('Provide a URL to a custom preview image.'),
    ];
    unset($metatags['og:image']['value']);

    $form['opengraph_meta']['other'] = array(
      '#type' => 'fieldset',
      '#title' => t('Other'),
      '#description' => t('Additional tags from the specification.'),
      '#tree' => TRUE,
      '#collapsible' => TRUE,
      '#collapsed' => TRUE,
      '#weight' => 11,
    );
    foreach ($metatags as $ogkey => &$fields) {
      if (isset($fields['value'])) {
        $f = substr($ogkey, 3);
        $form['opengraph_meta']['other'][$f] = [
          '#parents' => array_merge($parents, ["og:$f", 'value']),
        ] + $fields['value'];
        unset($fields['value']);
      }
    }
    $metatags['#type'] = 'container';

    // Add our submit handler right before the metatag module's submit handler.
    $submit = [];
    foreach ($form['#submit'] as $func) {
      if ($func == 'metatag_metatags_form_submit') {
        $submit[] = 'opengraph_meta_node_form_submit';
      }
      $submit[] = $func;
    }
    $form['#submit'] = $submit;
    $form['#pre_render'][] = '_opengraph_meta_form_reset_weight';
  }
}

/**
 * Pre-render callback: Set weight of the opengraph_meta wrapper.
 *
 * @see opengraph_meta_form_alter()
 */
function _opengraph_meta_form_reset_weight($element) {
  if (isset($element['opengraph_meta']) && isset($element['metatags'])) {
    $element['opengraph_meta']['#weight'] = $element['metatags']['#weight'];
  }
  return $element;
}

/**
 * Submit callback: Make our values saved via the metatag module.
 *
 * @see opengraph_meta_form_alter()
 */
function opengraph_meta_node_form_submit($form, &$form_state) {
  $lang = metatag_entity_get_language('node', $form['#node']);
  $metatag = &$form_state['values']['metatags'][$lang];
  $opengraph_meta = &$form_state['values']['opengraph_meta'];

  $metatag['og:image']['value'] = $opengraph_meta['image'];
}

/**
 * Implements hook_metatag_info_alter().
 */
function opengraph_meta_metatag_info_alter(&$info) {
  if (isset($info['tags']['og:image'])) {
    $info['tags']['og:image']['class'] = 'OpengraphImageMetaTag';
  }
}

/**
 * Implements hook_theme().
 */
function opengraph_meta_theme() {
  $theme['opengraph_meta_thumbnail'] = [
    'variables' => ['image' => NULL],
  ];
  return $theme;
}

function theme_opengraph_meta_thumbnail($vars) {
  $image = $vars['image'];
  $attributes = array('class' => 'opengraph-thumb');
  $abs_path = url(ltrim($image['url'],'/'));
  return theme('image',
    array(
      'path' => $abs_path,
      'alt' => $image['alt'],
      'height' => '60px',
      'attributes' => array_merge($attributes, array('title' => $image['title']))
    )
  );
}