<?php
/**
 * @file
 * Code for the Farm Quick module.
 */

/**
 * Implements hook_hook_info().
 */
function farm_quick_hook_info() {
  $hooks['farm_quick_forms'] = array(
    'group' => 'farm_quick',
  );
  return $hooks;
}

/**
 * Implements hook_permission().
 */
function farm_quick_permission() {
  return array(
    'configure farm quick forms' => array(
      'title' => t('Configure quick forms'),
      'description' => t('Allow access to the quick forms configuration.'),
    ),
  );
}

/**
 * Implements hook_farm_access_perms().
 */
function farm_quick_farm_access_perms($role) {
  $perms = array();

  // Load the list of farm roles.
  $roles = farm_access_roles();

  // If this role has 'config' access, allow them to configure quick forms.
  if (!empty($roles[$role]['access']['config'])) {
    $perms[] = 'configure farm quick forms';
  }

  return $perms;
}

/**
 * Load information about all quick forms provided by other modules.
 */
function farm_quick_forms() {

  // Ask modules for quick forms.
  $forms = array();
  $modules = module_implements('farm_quick_forms');
  foreach ($modules as $module) {
    $module_forms = module_invoke($module, 'farm_quick_forms');
    foreach ($module_forms as &$form) {
      $form['module'] = $module;
    }
    $forms = array_merge($forms, $module_forms);
  }

  // Sort the quick forms.
  uasort($forms, 'farm_quick_forms_sort');

  // Return the array of quick forms.
  return $forms;
}

/**
 * Sort function for quick form definitions.
 */
function farm_quick_forms_sort($a, $b) {

  // Sort alphabetically by the 'label' property.
  return strcasecmp($a['label'], $b['label']);
}

/**
 * Implements hook_menu().
 */
function farm_quick_menu() {

  // Start with an empty menu items array.
  $items = array();

  // Ask for quick forms from modules.
  $forms = farm_quick_forms();

  // Get a list of enabled quick forms from saved variable.
  $enabled_quick_forms = variable_get('farm_quick_forms_enabled', array());

  // Filter out disabled forms.
  foreach ($forms as $name => $info) {
    if (empty($enabled_quick_forms[$name])) {
      unset($forms[$name]);
    }
  }

  // Add a menu item for each form.
  foreach ($forms as $name => $form) {

    // Get access permissions for the quick form.
    // Convert it to an array if it isn't already.
    $permissions = array();
    if (isset($form['permission'])) {
      if (!is_array($form['permission'])) {
        $form['permission'] = array($form['permission']);
      }
      $permissions = $form['permission'];
    }

    // Build a menu item definition.
    $menu_item = array(
      'title' => $form['label'],
      'page callback' => 'farm_quick_form_page',
      'page arguments' => array($form['label'], $form['form']),
      'access callback' => 'farm_quick_access',
      'access arguments' => array($permissions),
      'type' => MENU_LOCAL_TASK,
    );

    // If the quick form code is in a separate file, add that information
    // to the menu item so Drupal knows where to look.
    if (!empty($form['file']) && !empty($form['module'])) {
      $menu_item['file'] = $form['file'];
      $menu_item['file path'] = drupal_get_path('module', $form['module']);
    }

    // Add a menu item.
    $items['farm/quick/' . $name] = $menu_item;
  }

  // Add a tab for configuring quick forms.
  $items['farm/quick/configure'] = array(
    'title' => t('Configure'),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('farm_quick_configure_form'),
    'access arguments' => array('configure farm quick forms'),
    'type' => MENU_LOCAL_TASK,
    'weight' => 100,
  );

  // Make the first item into the default tab.
  reset($items);
  $first = key($items);
  $items['farm/quick'] = $items[$first];
  $items['farm/quick']['title'] = 'Quick forms';
  $items['farm/quick']['type'] = MENU_LOCAL_TASK;
  $items[$first] = array(
    'title' => $items[$first]['title'],
    'type' => MENU_DEFAULT_LOCAL_TASK,
  );

  // Return menu items.
  return $items;
}

/**
 * Quick form access callback.
 *
 * @param $permissions
 *   An array of permissions, such as "administer nodes", being checked for.
 * @param $account
 *   (optional) The account to check, if not given use currently logged in user.
 *
 * @return bool
 *   Boolean TRUE if the user has ALL the requested permissions.
 */
function farm_quick_access($permissions, $account = NULL) {
  $grant = TRUE;
  foreach ($permissions as $permission) {
    if (!user_access($permission, $account)) {
      $grant = FALSE;
      break;
    }
  }
  return $grant;
}

/**
 * Quick form page callback.
 */
function farm_quick_form_page($title, $form_id) {
  drupal_set_title(t('Quick form') . ': ' . $title);
  return drupal_get_form($form_id);
}

/**
 * Form for configuring quick forms.
 */
function farm_quick_configure_form($form, &$form_state) {

  // Load the list of quick forms.
  $quick_forms = farm_quick_forms();

  // If there are no forms, bail.
  if (empty($quick_forms)) {
    $form['empty'] = array(
      '#type' => 'markup',
      '#markup' => 'There are no quick forms available.',
    );
    return $form;
  }

  // Create a set of checkbox options for the forms.
  $options = array();
  foreach ($quick_forms as $name => $info) {
    if (!empty($info['label'])) {
      $options[$name] = $info['label'];
    }
  }

  // Load the list of enabled quick forms from a variable.
  $enabled_quick_forms = variable_get('farm_quick_forms_enabled', array());

  // Display as a list of checkboxes.
  $form['farm_quick_forms_enabled'] = array(
    '#type' => 'checkboxes',
    '#title' => t('Enable or disable quick forms'),
    '#options' => $options,
    '#default_value' => $enabled_quick_forms,
  );

  // Wrap it in a system settings form.
  $form = system_settings_form($form);

  // Add a submit function that will rebuild the menu tabs (to run after the
  // system_settings_form() submit function.
  $form['#submit'][] = 'farm_quick_configure_form_submit';

  // Return the form.
  return $form;
}

/**
 * Submit function for rebuilding the menu tabs after configuring quick forms.
 */
function farm_quick_configure_form_submit(&$form, &$form_state) {
  menu_rebuild();
}

/**
 * Link an entity to a quick form.
 *
 * @param string $quick_form_id
 *   The quick form ID.
 * @param string $entity_type
 *   The entity type.
 * @param $entity
 *   The entity.
 */
function farm_quick_entity_link($quick_form_id, $entity_type, $entity) {

  // If no quick form ID is provided, bail.
  if (empty($quick_form_id)) {
    return;
  }

  // Get the entity ID.
  $id = entity_id($entity_type, $entity);

  // If the ID could not be found, bail.
  if (empty($id)) {
    return;
  }

  // Save it to the {farm_quick_entity} table.
  $record = array(
    'entity_type' => $entity_type,
    'entity_id' => $id,
    'quick_form_id' => $quick_form_id
  );
  drupal_write_record('farm_quick_entity', $record);
}

/**
 * Implements hook_entity_delete().
 */
function farm_quick_entity_delete($entity, $type) {

  // When an entity is deleted, delete associated records in
  // {farm_quick_entity}.
  $id = entity_id($type, $entity);
  if (!empty($id) && is_numeric($id)) {
    db_query('DELETE FROM {farm_quick_entity} WHERE entity_type = :entity_type AND entity_id = :entity_id', array(':entity_type' => $type, ':entity_id' => $id));
  }
}