<?php

/**
 * @file
 * Allow the administrator to choose which view mode is used to display a node regarding to its content type and the user's roles.
 */

/**
 * Implements hook_entity_view_mode_alter().
 */
function view_mode_per_role_entity_view_mode_alter(&$view_mode, $context) {
  if ($context['entity_type'] == 'node') {
    $view_mode = _view_mode_per_role_get_view_mode($context['entity']);
  }
}

/**
 * Implements hook_theme().
 */
function view_mode_per_role_theme() {
  return array(
    'view_mode_per_role_settings' => array(
      'render element' => 'form',
    ),
  );
}

/**
 * Select view mode according to node type and user roles.
 *
 * @param $node
 *    A node object.
 * @return
 *   A view mode.
 */
function _view_mode_per_role_get_view_mode($node) {
  global $user;

  $settings = variable_get('view_mode_per_role_' . $node->type, array());

  $view_mode = 'full';
  while ($view_mode == 'full' && $setting = current($settings)) {
    if (!empty($user->roles[$setting['role']])) {
      $view_mode = $setting['view_mode'];
    }
    next($settings);
  }

  return $view_mode;
}

/**
 * Implements hook_form_alter() for node_type_form.
 */
function view_mode_per_role_form_node_type_form_alter(&$form, $form_state) {
  // Node type edit form.
  if (isset($form['type'])) {
    drupal_add_js(drupal_get_path('module', 'view_mode_per_role') . '/view_mode_per_role.js');

    // Load old settings
    $settings = variable_get('view_mode_per_role_' . $form['#node_type']->type, array());
    $settings[] = array('role' => NULL, 'view_mode' => NULL);
    // Prepare roles
    $roles    = user_roles();
    $roles = array('_none' => t('Select')) + $roles;
    // Prepare view modes
    $infos    = entity_get_info('node');
    $views_modes = array();
    $views_modes['_none'] = t('Select');
    foreach ($infos['view modes'] as $id => $data) {
      $views_modes[$id] = $data['label'];
    }

    // Build fieldset
    $form['view_mode_per_role'] = array(
      '#title' => t('View mode per role'),
      '#type' => 'fieldset',
      '#group' => 'additional_settings',
      '#tree' => FALSE,
    );
    $form['view_mode_per_role']['vmpr_settings'] = array(
      '#tree' => TRUE,
      '#theme' => 'view_mode_per_role_settings',
    );
    $form['view_mode_per_role']['add_more'] = array(
      '#type' => 'submit',
      '#name' => 'view_mode_per_role_settings_add_more',
      '#value' => t('Add another item'),
      '#attributes' => array('class' => array('field-add-more-submit')),
      '#submit' => array('field_add_more_submit'),
    );
    $form['view_mode_per_role']['help'] = array(
      '#markup' => '<div class="description">'
        . t('This table will allow you to choose which view mode will replace the "@full" for the corresponding roles when viewing a node of this type.', array('@full' => t('Full content')))
        . '<br />'
        . t('For a line to be valid, you have to select the role and the view mode.')
        . '</div>',
    );
    $order = 0;
    foreach ($settings as $setting) {
      $form['view_mode_per_role']['vmpr_settings'][$order] = array();
      $form['view_mode_per_role']['vmpr_settings'][$order]['#weight'] = $order;
      $form['view_mode_per_role']['vmpr_settings'][$order]['weight'] = array(
        '#type' => 'textfield',
        '#title' => t('Weight for @title', array('@title' => !empty($setting['role']) ? $roles[$setting['role']] : '')),
        '#title_display' => 'invisible',
        '#size' => 4,
        '#default_value' => $order,
        '#attributes' => array('class' => array('setting-weight')),
      );
      $form['view_mode_per_role']['vmpr_settings'][$order]['role'] = array(
        '#type' => 'select',
        '#title' => t('Role'),
        '#options' => $roles,
        '#default_value' => $setting['role'],
      );
      $form['view_mode_per_role']['vmpr_settings'][$order]['view_mode'] = array(
        '#type' => 'select',
        '#title' => t('View mode'),
        '#options' => $views_modes,
        '#default_value' => $setting['view_mode'],
      );
      $form['view_mode_per_role']['vmpr_settings'][$order]['deleted'] = array(
        '#type' => 'hidden',
        '#default_value' => 0,
        '#attributes' => array('class' => array('setting-deleted')),
      );
      $form['view_mode_per_role']['vmpr_settings'][$order]['delete'] = array(
        '#type' => 'submit',
        '#name' => 'view_mode_per_role_settings_delete_line',
        '#value' => t('Delete'),
        '#attributes' => array('class' => array('field-delete-submit')),
        '#submit' => array('field_delete_submit'),
      );
      $order++;
    }

    // Add custom submit function
    array_unshift($form['#submit'], 'view_mode_per_role_form_node_type_form_submit');
  }
}

/**
 * Node type form custom submit.
 */
function view_mode_per_role_form_node_type_form_submit($form, &$form_state) {
  $values = $form_state['values'];

  // Delete old settings
  variable_del('view_mode_per_role_' . $values['old_type']);

  // Save new settings
  $settings = array();
  foreach ($values['vmpr_settings'] as $data) {
    if ($data['deleted'] == 0 && $data['role'] != '_none' && $data['view_mode'] != '_none') {
      $settings[] = array('role' => $data['role'], 'view_mode' => $data['view_mode']);
    }
  }
  variable_set('view_mode_per_role_' . $values['type'], $settings);

  // Remove settings to avoid core function to process it
  unset($form_state['values']['vmpr_settings']);
}

/**
 * Returns HTML for the role order and new role form.
 *
 * @param $variables
 *   An associative array containing:
 *   - form: A render element representing the form.
 *
 * @ingroup themeable
 */
function theme_view_mode_per_role_settings($variables) {
  $form = $variables['form'];

  $header = array(t('Roles'), t('Weight'), t('View modes'), t('Operations'));
  $rows = array();
  foreach (element_children($form) as $order) {
    $row = array();
    $row[] = drupal_render($form[$order]['role']);
    $row[] = drupal_render($form[$order]['weight']);
    $row[] = drupal_render($form[$order]['view_mode']);
    $row[] = drupal_render($form[$order]['delete']) . drupal_render($form[$order]['deleted']);
    $rows[] = array('data' => $row, 'class' => array('draggable'), 'id' => 'setting-' . $order);
  }

  drupal_add_tabledrag('view-mode-per-role-settings', 'order', 'sibling', 'setting-weight');

  $output = theme('table', array('header' => $header, 'rows' => $rows, 'attributes' => array('id' => 'view-mode-per-role-settings')));
  $output .= drupal_render_children($form);

  return $output;
}