<?php

/**
 * @file
 * Defines an "options" form element type for entering select list options.
 */

/**
 * Implements hook_element_info().
 *
 * Defines the #type = 'options' form element type.
 *
 * The 'options' form element type is useful when collecting a series of
 * values in a list. The values within the list may optionally have unique
 * keys, such as that in an array structure. In addition, a default choice
 * (or several default choices) may be selected by the user.
 *
 * @code
 * $element['options'] = array(
 *   '#type' => 'options',
 *   '#limit' => 20,
 *   '#optgroups' => FALSE,
 *   '#multiple' => FALSE,
 *   '#options' => array(
 *     'foo' => 'foo',
 *     'bar' => 'bar',
 *     'baz' => 'baz',
 *   ),
 *   '#default_value' => 'foo'
 *   '#key_type' => 'associative',
 * );
 * @endcode
 *
 * Properties for the 'options' element include:
 * - limit: The maximum number of options that can be added to a list. Defaults
 *   to 100.
 * - optgroups: If nesting of options is supported, up to one level. This is
 *   used when building a select HTML element that uses optgroups. Defaults to
 *   FALSE.
 * - multiple: Affects the number of default values that may be selected.
 * - default_value: The key(s) for the options that are currently selected. If
 *   #multiple is TRUE then, the default value is an array, otherwise it is a
 *   string.
 * - options: An array of options currently within the list.
 * - key_type: The method by which keys are determined for each value in the
 *   option list. Available options include:
 *   - mixed: Each value is not given any ID automatically, but any manually
 *     specified keys will be retained. This most emulates the existing
 *     conventions within Drupal, where keys are optional but allowed.
 *   - numeric: Each value is automatically given a unique numeric ID. This can
 *     be useful when wanting duplicate values in a list and not have to bother
 *     the end-user for keys.
 *   - associative: Keys are automatically mapped from the user-entered values.
 *     This is equivalent to making key|value pairs, but both the key and value
 *     are the same. Each key must be unique.
 *   - custom: Keys are manually entered by the end user. A second set of
 *     textfields are presented to let the user provide keys as well as values.
 *   - none: No keys are specified at all. This effectively creates numeric keys
 *     but unlike numeric keys, the keys are renumbered if the options in the
 *     list are rearranged.
 * - key_type_toggle: If specified, a checkbox will be added that allows the
 *   user to toggle between the current key type and the "custom" key type,
 *   letting them customize the keys as desired. This option has no effect with
 *   the "none" key type.
 * - key_type_toggled: Determine if the toggle checkbox is set or not by
 *   default.
 * - default_value_allowed: Indicates whether the end user should be able to
 *   modify the default value when editing the options list. Defaults to TRUE.
 * - default_value_pattern: If allowing dynamic default value keys, such as a
 *   token, specify a regular expression pattern that will also be allowed as
 *   a default value. Include pattern delimiters. Defaults to an empty string.
 *
 *   @code
 *   $element['options'] = array(
 *     '#type' => 'options',
 *     '#key_type' => 'associative',
 *     '#key_type_toggle' => t('Custom keys'),
 *     '#key_type_toggled' => TRUE,
 *   );
 *   @endcode
 */
function options_element_element_info() {
  $type = array();

  $type['options'] = array(
    '#input' => TRUE,
    '#process' => array('form_options_expand'),
    '#limit' => NULL,
    '#optgroups' => TRUE,
    '#multiple' => FALSE,
    '#options' => array(),
    '#options_readonly' => FALSE,
    '#key_type' => 'mixed',
    '#key_type_toggle' => NULL,
    '#key_type_toggled' => FALSE,
    '#default_value_allowed' => TRUE,
    '#default_value_pattern' => '',
    '#element_validate' => array('form_options_validate'),
    '#theme_wrappers' => array('form_element'),
  );

  return $type;
}

/**
 * Implementation of hook_theme().
 */
function options_element_theme() {
  return array(
    'options' => array(
      'render element' => 'element',
      'file' => 'options_element.inc',
    ),
  );
}

/**
 * Expand the "options" form element type.
 *
 * The "options" type is simply an enhanced textarea that makes it easier to
 * create key|value pairs and put items into optgroups.
 */
function form_options_expand($element) {
  module_load_include('inc', 'options_element');
  return _form_options_expand($element);
}

/**
 * Validate the "options" form element type.
 */
function form_options_validate($element, &$form_state) {
  module_load_include('inc', 'options_element');
  _form_options_validate($element, $form_state);
}

/**
 * This function adjusts the value of the element from a text value to an array.
 */
function form_type_options_value(&$element, $edit = FALSE) {
  module_load_include('inc', 'options_element');
  return _form_type_options_value($element, $edit);
}

/**
 * Create a textual representation of options from an array.
 *
 * @param $options
 *   An array of options used in a select list.
 * @param $key_type
 *   How key/value pairs should be interpreted. Available options:
 *   - mixed
 *   - numeric
 *   - associative
 *   - custom
 *   - none
 */
function form_options_to_text($options, $key_type) {
  module_load_include('inc', 'options_element');
  return _form_options_to_text($options, $key_type);
}

/**
 * Create an array representation of text option values.
 *
 * If the Key of the option is within < >, treat as an optgroup
 *
 * <Group 1>
 *   creates an optgroup with the label "Group 1"
 *
 * <>
 *   Exits the current group, allowing items to be inserted at the root element.
 */
function form_options_from_text($text, $key_type, $flat = FALSE, &$duplicates = array()) {
  module_load_include('inc', 'options_element');
  return _form_options_from_text($text, $key_type, $flat, $duplicates);
}

/**
 * Implements hook_form_FORM_ID_alter().
 */
function options_element_form_field_ui_field_settings_form_alter(&$form, &$form_state) {
  $type = $form['field']['type']['#value'];

  if (in_array($type, _options_element_supported_field_types())) {
    // Get default value.
    $options = form_options_from_text($form['field']['settings']['allowed_values']['#default_value'], 'mixed');
    // Toggled by default if options already set.
    $key_type_toggled = !empty($options);

    $element_overwrite = array(
      '#options' => $options,
      '#multiple' => FALSE,
      '#key_type_toggled' => $key_type_toggled,
      '#default_value_allowed' => FALSE,
    );
    _options_element_add_allowed_values_element($form, $element_overwrite);
  }
}

/**
 * Implements hook_form_FORM_ID_alter().
 */
function options_element_form_field_ui_field_edit_form_alter(&$form, &$form_state) {
  $field = $form['#field'];

  if (in_array($field['type'], _options_element_supported_field_types())) {

    // Use options_element default widget instead of field widget.
    $form['instance']['default_value_widget']['#access'] = FALSE;
    // Language is hardcoded to 'und' in field_ui_default_value_widget().
    $default_field_value = $form['instance']['default_value_widget'][$field['field_name']][LANGUAGE_NONE]['#default_value'];

    // Overwrite 'allowed_values' element.
    $element_overwrite = array(
      '#options' => $field['settings']['allowed_values'],
      '#multiple' => !($form['field']['cardinality']['#default_value'] == 1),
      '#default_value' => $default_field_value,
    );

    _options_element_add_allowed_values_element($form, $element_overwrite);

    // Add proper default value inside validate callback.
    $form['#validate'][] = 'options_element_field_instance_settings_validate';
  }
}

/**
 * Element #after_build callback for the options list in Field UI.
 */
function options_element_field_settings_after_build($element, &$form_state) {
  // Add original data for validating.
  $element['options_field'] = array_merge($element['options_field'], $element['#original']);
  // Standard validate.
  $element['options_field']['#element_validate'][] = 'list_allowed_values_setting_validate';
  return $element;
}

/**
 * Form #validate callback for Field UI forms that use an options element.
 */
function options_element_field_settings_validate($form, &$form_state) {
  if (!form_get_errors()) {
    // Set allowed values.
    form_set_value(
      $form['field']['settings']['allowed_values'],
      $form['field']['settings']['allowed_values']['#value']['options'],
      $form_state
    );
  }
}

/**
 * Form #validate callback for field_ui_field_edit_form().
 */
function options_element_field_instance_settings_validate($form, &$form_state) {
  $field = $form['#field'];

  if (!form_get_errors()) {
    // Set default values.
    $default_field_value_key = $form['instance']['default_value_widget'][$field['field_name']][LANGUAGE_NONE]['#value_key'];
    // Create transposed array for field storage.
    $default_values = options_array_transpose(array($default_field_value_key => (array)$form['field']['settings']['allowed_values']['#value']['default_value']));

    form_set_value(
      $form['instance']['default_value_widget'][$field['field_name']][LANGUAGE_NONE],
      $default_values,
      $form_state
    );
  }
}

/**
 * Add options_element widget to form.
 */
function _options_element_add_allowed_values_element(&$form, $element) {
  $default_element = array(
    '#type' => 'options',
    '#options' => array(),
    '#key_type' => 'mixed', // Optimal for now.
    '#key_type_toggle' => t('Custom keys'),
    '#key_type_toggled' => TRUE,
    '#after_build' => array('options_element_field_settings_after_build'),
    '#access' => $form['field']['settings']['allowed_values']['#access'],
    '#default_value' => '',
    // Pass original data for validating.
    '#original' => array(
      '#title' => $form['field']['settings']['allowed_values']['#title'],
      '#field_has_data' => $form['field']['settings']['allowed_values']['#field_has_data'],
      '#field' => $form['field']['settings']['allowed_values']['#field'],
      '#field_type' => $form['field']['settings']['allowed_values']['#field_type'],
    )
  );

  $element = drupal_array_merge_deep($default_element, $element);
  $form['field']['settings']['allowed_values'] = $element;

  // Set proper allowed values in $form_state.
  $form['#validate'][] = 'options_element_field_settings_validate';
}

/**
 * Returns supported field types.
 */
function _options_element_supported_field_types() {
  return array('list_integer', 'list_float', 'list_text');
}
