<?php
// $Id$

/**
 * @file
 * Defines selection, check box and radio button widgets for text and numeric fields.
 */

/**
 * Implementation of hook_form_alter.
 */
function optionwidgets_form_alter(&$form, $form_state, $form_id) {
  // Provide additional help for the field settings form.
  if ($form_id == 'content_field_edit_form' && isset($form['widget'])) {
    $widget_type = $form['#field']['widget']['type'];
    $field_type = $form['#field']['type'];
    $label = $form['#field']['widget']['label'];

    $output = '<p>'. t('Create a list of options as a list in <strong>Allowed values list</strong> or as an array in PHP code. These values will be the same for %field in all content types.', array('%field' => $label)) .'</p>';

    if ($widget_type == 'optionwidgets_onoff') {
      $output .= '<p>'. t("For a 'single on/off checkbox' widget, define the 'off' value first, then the 'on' value in the <strong>Allowed values</strong> section. Note that the checkbox will be labeled with the label of the 'on' value.") .'</p>';
    }
    elseif ($widget_type == 'optionwidgets_buttons') {
      $output .= '<p>'. t("The 'checkboxes/radio buttons' widget will display checkboxes if the multiple values option is selected for this field, otherwise radios will be displayed.") .'</p>';
    }

    if (in_array($field_type, array('text', 'number_integer', 'number_float', 'number_decimal'))
    && in_array($widget_type, array('optionwidgets_onoff', 'optionwidgets_buttons', 'optionwidgets_select'))) {
      $form['field']['allowed_values_fieldset']['#collapsed'] = FALSE;
      $form['field']['allowed_values_fieldset']['#description'] = $output;

      // If no 'allowed values' were set yet, add a remainder in the messages area.
      if (empty($form_state['post'])
      && empty($form['field']['allowed_values_fieldset']['allowed_values']['#default_value'])
      && empty($form['field']['allowed_values_fieldset']['advanced_options']['allowed_values_php']['#default_value'])) {
        drupal_set_message(t("You need to specify the 'allowed values' for this field."), 'warning');
      }
    }
  }
}

/**
 * Implementation of hook_theme().
 */
function optionwidgets_theme() {
  return array(
    'optionwidgets_select' => array(
      'arguments' => array('element' => NULL),
    ),
    'optionwidgets_buttons' => array(
      'arguments' => array('element' => NULL),
    ),
    'optionwidgets_onoff' => array(
      'arguments' => array('element' => NULL),
    ),
    'optionwidgets_none' => array(
      'arguments' => array('widget_type' => NULL, 'field_name' => NULL, 'node_type' => NULL),
      ),
  );
}

/**
 * Implementation of hook_widget_info().
 *
 * We need custom handling of multiple values because we need
 * to combine them into a options list rather than display
 * multiple elements. We will use the content module's default
 * handling for default values.
 *
 * Callbacks can be omitted if default handing is used.
 * They're included here just so this module can be used
 * as an example for custom modules that might do things
 * differently.
 */
function optionwidgets_widget_info() {

  return array(
    'optionwidgets_select' => array(
      'label' => t('Select list'),
      'field types' => array('text', 'number_integer', 'number_decimal', 'number_float'),
      'multiple values' => CONTENT_HANDLE_MODULE,
      'callbacks' => array(
        'default value' => CONTENT_CALLBACK_DEFAULT,
      ),
    ),
    'optionwidgets_buttons' => array(
      'label' => t('Check boxes/radio buttons'),
      'field types' => array('text', 'number_integer', 'number_decimal', 'number_float'),
      'multiple values' => CONTENT_HANDLE_MODULE,
      'callbacks' => array(
        'default value' => CONTENT_CALLBACK_DEFAULT,
      ),
    ),
    'optionwidgets_onoff' => array(
      'label' => t('Single on/off checkbox'),
      'field types' => array('text', 'number_integer', 'number_decimal', 'number_float'),
      'multiple values' => CONTENT_HANDLE_MODULE,
      'callbacks' => array(
        'default value' => CONTENT_CALLBACK_DEFAULT,
      ),
    ),
  );
}

/**
 * Implementation of FAPI hook_elements().
 *
 * Any FAPI callbacks needed for individual widgets can be declared here,
 * and the element will be passed to those callbacks for processing.
 *
 * Drupal will automatically theme the element using a theme with
 * the same name as the hook_elements key.
 */
function optionwidgets_elements() {
  return array(
    'optionwidgets_select' => array(
      '#input' => TRUE,
      '#columns' => array('value'), '#delta' => 0,
      '#process' => array('optionwidgets_select_process'),
      ),
    'optionwidgets_buttons' => array(
      '#input' => TRUE,
      '#columns' => array('value'), '#delta' => 0,
      '#process' => array('optionwidgets_buttons_process'),
      ),
    'optionwidgets_onoff' => array(
      '#input' => TRUE,
      '#columns' => array('value'), '#delta' => 0,
      '#process' => array('optionwidgets_onoff_process'),
      ),
    );
}

/**
 * Implementation of hook_widget().
 *
 * Attach a single form element to the form. It will be built out and
 * validated in the callback(s) listed in hook_elements. We build it
 * out in the callbacks rather than here in hook_widget so it can be
 * plugged into any module that can provide it with valid
 * $field information.
 *
 * Content module will set the weight, field name and delta values
 * for each form element. This is a change from earlier CCK versions
 * where the widget managed its own multiple values.
 *
 * If there are multiple values for this field, the content module will
 * call this function as many times as needed.
 *
 * @param $form
 *   the entire form array, $form['#node'] holds node information
 * @param $form_state
 *   the form_state, $form_state['values'][$field['field_name']]
 *   holds the field's form values.
 * @param $field
 *   the field array
 * @param $items
 *   an array of default values for this element
 * @param $delta
 *   the order of this item in the array of subelements (0, 1, 2, etc)
 *
 * @return
 *   the form item for a single element for this field
 */
function optionwidgets_widget(&$form, &$form_state, $field, $items, $delta = NULL) {
  $element = array(
    '#type' => $field['widget']['type'],
    '#default_value' => !empty($items) ? $items : array(),
  );
  return $element;
}

/**
 * Process an individual element.
 *
 * Build the form element. When creating a form using FAPI #process,
 * note that $element['#value'] is already set.
 *
 * The $fields array is in $form['#field_info'][$element['#field_name']].
 */
function optionwidgets_buttons_process($element, $edit, &$form_state, $form) {
  $field_name = $element['#field_name'];
  $field = $form['#field_info'][$field_name];
  $field_key  = $element['#columns'][0];

  // See if this element is in the database format or the transformed format,
  // and transform it if necessary.
  if (is_array($element['#value']) && !array_key_exists($field_key, $element['#value'])) {
    $element['#value'] = optionwidgets_data2form($element, $element['#default_value'], $field);
  }
  $options = optionwidgets_options($field);
  $element[$field_key] = array(
    '#type' => $field['multiple'] ? 'checkboxes' : 'radios',
    '#title' => $element['#title'],
    '#description' => $element['#description'],
    '#required' => isset($element['#required']) ? $element['#required'] : $field['required'],
    '#multiple' => isset($element['#multiple']) ? $element['#multiple'] : $field['multiple'],
    '#options' => $options,
    '#default_value' => isset($element['#value'][$field_key]) ? $element['#value'][$field_key] : NULL,
  );

  // Set #element_validate in a way that it will not wipe out other
  // validation functions already set by other modules.
  if (empty($element['#element_validate'])) {
    $element['#element_validate'] = array();
  }
  array_unshift($element['#element_validate'], 'optionwidgets_validate');

  // Make sure field info will be available to the validator which
  // does not get the values in $form.
  $form_state['#field_info'][$field['field_name']] = $field;
  return $element;
}

/**
 * Process an individual element.
 *
 * Build the form element. When creating a form using FAPI #process,
 * note that $element['#value'] is already set.
 *
 * The $fields array is in $form['#field_info'][$element['#field_name']].
 */
function optionwidgets_select_process($element, $edit, &$form_state, $form) {
  $field_name = $element['#field_name'];
  $field = $form['#field_info'][$field_name];
  $field_key  = $element['#columns'][0];

  // See if this element is in the database format or the transformed format,
  // and transform it if necessary.
  if (is_array($element['#value']) && !array_key_exists($field_key, $element['#value'])) {
    $element['#value'] = optionwidgets_data2form($element, $element['#default_value'], $field);
  }

  $options = optionwidgets_options($field, FALSE);

  // For this specific widget, HTML should be filtered out and entities left unencoded.
  // See content_allowed_values / content_filter_xss / filter_xss.
  content_allowed_values_filter_html($options);

  $element[$field_key] = array(
    '#type' => 'select',
    '#title' => $element['#title'],
    '#description' => $element['#description'],
    '#required' => isset($element['#required']) ? $element['#required'] : $field['required'],
    '#multiple' => isset($element['#multiple']) ? $element['#multiple'] : $field['multiple'],
    '#options' => $options,
    '#default_value' => isset($element['#value'][$field_key]) ? $element['#value'][$field_key] : NULL,
  );

  // Set #element_validate in a way that it will not wipe out other
  // validation functions already set by other modules.
  if (empty($element['#element_validate'])) {
    $element['#element_validate'] = array();
  }
  array_unshift($element['#element_validate'], 'optionwidgets_validate');

  // Make sure field info will be available to the validator which
  // does not get the values in $form.

  // TODO for some reason putting the $field array into $form_state['storage']
  // causes the node's hook_form_alter to be invoked twice, garbling the
  // results. Need to investigate why that is happening (a core bug?), but
  // in the meantime avoid using $form_state['storage'] to store anything.
  $form_state['#field_info'][$field['field_name']] = $field;
  return $element;
}

/**
 * Process an individual element.
 *
 * Build the form element. When creating a form using FAPI #process,
 * note that $element['#value'] is already set.
 *
 * The $fields array is in $form['#field_info'][$element['#field_name']].
 */
function optionwidgets_onoff_process($element, $edit, &$form_state, $form) {
  $field_name = $element['#field_name'];
  $field = $form['#field_info'][$field_name];
  $field_key  = $element['#columns'][0];

  // See if this element is in the database format or the transformed format,
  // and transform it if necessary.
  if (is_array($element['#value']) && !array_key_exists($field_key, $element['#value'])) {
    $element['#value'] = optionwidgets_data2form($element, $element['#default_value'], $field);
  }
  $options = optionwidgets_options($field);
  $keys = array_keys($options);
  $on_value = (!empty($keys) && isset($keys[1])) ? $keys[1] : NULL;
  $element[$field_key] = array(
    '#type' => 'checkbox',
    '#title' => isset($options[$on_value]) ? $options[$on_value] : '',
    '#description' => $element['#description'],
    '#required' => isset($element['#required']) ? $element['#required'] : $field['required'],
    '#default_value' => isset($element['#value'][$field_key][0]) ? $element['#value'][$field_key][0] == $on_value : FALSE,
    '#return_value' => $on_value,
  );

  // Set #element_validate in a way that it will not wipe out other
  // validation functions already set by other modules.
  if (empty($element['#element_validate'])) {
    $element['#element_validate'] = array();
  }
  array_unshift($element['#element_validate'], 'optionwidgets_validate');

  // Make sure field info will be available to the validator which
  // does not get the values in $form.
  $form_state['#field_info'][$field['field_name']] = $field;
  return $element;
}

/**
 * FAPI function to validate optionwidgets element.
 */
function optionwidgets_validate($element, &$form_state) {
  // Transpose selections from field => delta to delta => field,
  // turning multiple selected options into multiple parent elements.
  // Immediate parent is the delta, need to get back to parent's parent
  // to create multiple elements.
  $field = $form_state['#field_info'][$element['#field_name']];
  $items = optionwidgets_form2data($element, $field);
  form_set_value($element, $items, $form_state);

  // Check we don't exceed the allowed number of values.
  if ($field['multiple'] >= 2) {
    // Filter out 'none' value (if present, will always be in key 0)
    $field_key = $element['#columns'][0];
    if (isset($items[0][$field_key]) && $items[0][$field_key] === '') {
      unset($items[0]);
    }
    if (count($items) > $field['multiple']) {
      $field_key  = $element['#columns'][0];
      form_error($element[$field_key], t('%name: this field cannot hold more than @count values.', array('%name' => t($field['widget']['label']), '@count' => $field['multiple'])));
    }
  }
}

/**
 * Helper function to transpose the values as stored in the database
 * to the format the widget needs. Can be called anywhere this
 * transformation is needed.
 */
function optionwidgets_data2form($element, $items, $field) {
  $field_key  = $element['#columns'][0];
  $options    = optionwidgets_options($field);

  $items_transposed = content_transpose_array_rows_cols($items);
  $values = (isset($items_transposed[$field_key]) && is_array($items_transposed[$field_key])) ? $items_transposed[$field_key] : array();
  $keys = array();
  foreach ($values as $value) {
    $key = array_search($value, array_keys($options));
    if (isset($key)) {
      $keys[] = $value;
    }
  }
  if ($field['multiple'] || $element['#type'] == 'optionwidgets_onoff') {
    return array($field_key => $keys);
  }
  else {
    return !empty($keys) ? array($field_key => $value) : array();
  }
}

/**
 * Helper function to transpose the values returned by submitting the widget
 * to the format to be stored in the field. Can be called anywhere this
 * transformation is needed.
 */
function optionwidgets_form2data($element, $field) {
  $field_key = $element['#columns'][0];
  $items = (array) $element[$field_key]['#value'];
  $options = optionwidgets_options($field);

  $values = array_values($items);

  if ($element['#type'] == 'optionwidgets_onoff' && ($values[0] === 0)) {
    $keys = array_keys($options);
    $values = array(array_key_exists(0, $keys) ? $keys[0] : NULL);
  }

  if (empty($values)) {
    $values[] = NULL;
  }
  $result = content_transpose_array_rows_cols(array($field_key => $values));
  return $result;
}

/**
 * Helper function for finding the allowed values list for a field.
 *
 * See if there is a module hook for the option values.
 * Otherwise, try content_allowed_values() for an options list.
 *
 * @param $field
 *   The field whose allowed values are requested.
 * @param $flatten
 *   Optional. Use TRUE to return a flattened array (default).
 *   FALSE can be used to support optgroups for select widgets
 *   when allowed values list is generated using PHP code.
 */
function optionwidgets_options($field, $flatten = TRUE) {
  $function = $field['module'] .'_allowed_values';
  $options = function_exists($function) ? $function($field) : (array) content_allowed_values($field, $flatten);
  // Add an empty choice for :
  // - non required radios
  // - non required selects
  if (!$field['required']) {
    if ((in_array($field['widget']['type'], array('optionwidgets_buttons', 'nodereference_buttons', 'userreference_buttons')) && !$field['multiple'])
      || (in_array($field['widget']['type'], array('optionwidgets_select', 'nodereference_select', 'userreference_select')))) {
      $options = array('' => theme('optionwidgets_none', $field)) + $options;
    }
  }
  return $options;
}

/**
 *  Theme the label for the empty value for options that are not required.
 *  The default theme will display N/A for a radio list and blank for a select.
 */
function theme_optionwidgets_none($field) {
  switch ($field['widget']['type']) {
    case 'optionwidgets_buttons':
    case 'nodereference_buttons':
    case 'userreference_buttons':
      return t('N/A');
    case 'optionwidgets_select':
    case 'nodereference_select':
    case 'userreference_select':
      return t('- None -');
    default :
      return '';
  }
}

/**
 * FAPI themes for optionwidgets.
 *
 * The select, checkboxes or radios are already rendered by the
 * select, checkboxes, or radios themes and the HTML output
 * lives in $element['#children']. Override this theme to
 * make custom changes to the output.
 *
 * $element['#field_name'] contains the field name
 * $element['#delta]  is the position of this element in the group
 */
function theme_optionwidgets_select($element) {
  return $element['#children'];
}

function theme_optionwidgets_onoff($element) {
  return $element['#children'];
}

function theme_optionwidgets_buttons($element) {
  return $element['#children'];
}