<?php
// $Id$

/**
 * @file
 */

/**
 * Implementation of hook_init().
 */
function explainfield_init() {
  drupal_add_js(drupal_get_path('module', 'explainfield') . '/explainfield.js');
}

/**
 * Implementation of hook_field_info().
 */
function explainfield_field_info() {
  return array(
    'explainfield' => array(
      'label' => 'Explain Field'
    ),
  );
}

/**
 * Implementation of hook_field_settings().
 */
function explainfield_field_settings($op, $field) {
  switch ($op) {
    case 'form':
      $form = array();
      $form['allowed_values'] = array(
        '#type' => 'textarea',
        '#title' => t('Allowed values list'),
        '#default_value' => isset($field['allowed_values']) ? $field['allowed_values'] : '',
        '#required' => FALSE,
        '#multiple' => FALSE,
        '#rows' => 5,
        '#description' => t('The possible values this field can contain. Enter one value per line, in the format key|label. The key is the value that will be stored in the database and it must match the field storage type, %type. The label is optional and the key will be used as the label if no label is specified.', array('%type' => $field['type'])),
      );
      $form['trigger_value'] = array(
        '#type' => 'textfield',
        '#title' => t('Trigger key'),
        '#default_value' => isset($field['trigger_value']) ? $field['trigger_value'] : '',
        '#required' => FALSE,
        '#description' => t('Select the key on which the explain field will trigger.'),
      );
      $form['explain_options'] = array(
        '#type' => 'fieldset',
        '#title' => t('Explain field options'),
        '#collapsible' => TRUE,
        '#collapsed' => FALSE,
      );
      $form['explain_options']['explain_label'] = array(
        '#type' => 'textfield',
        '#title' => t('Label'),
        '#default_value' => isset($field['explain_label']) ? $field['explain_label'] : '',
        '#required' => FALSE,
        '#description' => t('Label that will appear over the explain field, and when viewing the node.'),
      );
      $form['explain_options']['explain_text'] = array(
        '#type' => 'textarea',
        '#title' => 'Help text for the explain field',
        '#default_value' => isset($field['explain_text']) ? $field['explain_text'] : '',
        '#required' => FALSE,
        '#rows' => 3,
        '#description' => t('Instructions on what to write into the appearing explain field.'),
      );
      $form['explain_options']['max_length'] = array(
        '#type' => 'textfield',
        '#title' => t('Maximum length'),
        '#default_value' => isset($field['max_length']) ? $field['max_length'] : '',
        '#required' => FALSE,
        '#description' => t('The maximum length of the field in characters. Leave blank for an unlimited size.'),
      );
      $form['explain_options']['max_length_notify'] = array(
        '#type' => 'checkbox',
        '#title' => t('Include notification of maximum length'),
        '#default_value' => isset($field['max_length_notify']) ? $field['max_length_notify'] : '',
        '#required' => FALSE,
        '#description' => t('If a maximum length is specified, check here to include a notification on the edit form. If any explain field help text is specified above, this notification would be appended to it.'),
      );
      $form['explain_options']['explain_rows'] = array(
        '#type' => 'textfield',
        '#title' => t('Textfield size'),
        '#default_value' => isset($field['explain_rows']) ? $field['explain_rows'] : '',
        '#required' => FALSE,
        '#description' => t('The height of the explain field. Leave blank for default 3.'),
      );
      return $form;

    case 'save':
      return array(
        'allowed_values',
        'trigger_value',
        'explain_text',
        'explain_label',
        'max_length',
        'max_length_notify',
        'explain_rows',
      );

    case 'database columns':
      $columns = array(
        'value' => array(
          'type' => 'text',
          'not null' => FALSE,
          'sortable' => TRUE,
        ),
        'explainfield' => array(
          'type' => 'text',
          'not null' => FALSE,
          'sortable' => TRUE,
        ),
      );
      return $columns;
  }
}

/**
 * Implementation of hook_content_is_empty().
 */
function explainfield_content_is_empty($item, $field) {
  if (empty($item['value']) && (string)$item['value'] !== '0') {
    return TRUE;
  }
  return FALSE;
}

/**
 * Implementation of hook_field_formatter_info().
 */
function explainfield_field_formatter_info() {
  $formatters =  array(
    'default' => array(
      'label' => t('Default'),
      'field types' => array('explainfield'),
      'multiple values' => CONTENT_HANDLE_CORE,
    ),
    'plain' => array(
      'label' => t('Plain Text'),
      'field types' => array('explainfield'),
      'multiple values' => CONTENT_HANDLE_CORE,
    ),
  );
  return $formatters;
}

/**
 * Implementation of hook_theme().
 */
function explainfield_theme() {
  $themes = array(
    'explainfield_formatter_default' => array(
      'arguments' => array('element' => NULL),
    ),
    'explainfield_formatter_plain' => array(
      'arguments' => array('element' => NULL),
    ),
    'explainfield_select' => array(
      'arguments' => array('element' => NULL),
    ),
    'explainfield_buttons' => array(
      'arguments' => array('element' => NULL),
    ),
  );
  return $themes;
}

/**
 * Theme functions for explainfield.
 */
function theme_explainfield_formatter_default($element) {
  $source = $element['#item'];
  $field = content_fields($element['#field_name'], $element['#type_name']);
  if ($allowed = _explainfield_allowed_values($element)) {
    $class = isset($field['']) ? '-inline' : '';
    $output = $allowed;
    if ($source['explainfield'] != '') {
      if ($field['explain_label'] != '') {
        $output .= '<div class="field-label' . $class . '">';
        $output .= $field['explain_label'] . '</div>';
      }
      $output .= '<div class="field-items' . $class . '">';
      $output .= $source['explainfield'] . '</div>';
    }
    return $output;
  }
  else {
    return $element['#item']['safe'];
  }
}

function theme_explainfield_formatter_plain($element) {
  return ($allowed = _explainfield_allowed_values($element)) ? $allowed : strip_tags($element['#item']['safe']);
}

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

function theme_explainfield_buttons($element) {
  $field = content_fields($element['#field_name'], $element['#type_name']);
  if (count(content_allowed_values($field)) == 1) {
    $output = $element['#children'];
    $output = str_replace('type="radio"', 'type="checkbox"', $output);
    return $output;
  }
  else {
    return $element['#children'];
  }
}

/**
 * Local function for allowed values.
 */
function _explainfield_allowed_values($element) {
  $field = content_fields($element['#field_name'], $element['#type_name']);
  if (($allowed_values = content_allowed_values($field))
      && isset($allowed_values[$element['#item']['value']])) {
    return $allowed_values[$element['#item']['value']];
  }
}

/**
 * Implementation of hook_elements().
 */
function explainfield_elements() {
  $elements = array(
    'explainfield_select' => array(
      '#input' => TRUE,
      '#columns' => array('value', 'explainfield'),
      '#delta' => 0,
      '#process' => array('explainfield_select_process'),
    ),
    'explainfield_buttons' => array(
      '#input' => TRUE,
      '#columns' => array('value', 'explainfield'),
      '#delta' => 0,
      '#process' => array('explainfield_buttons_process'),
    ),
  );
  return $elements;
}

/**
 * Implementation of hook_widget_info().
 */
function explainfield_widget_info() {
  $info = array(
    'explainfield_select' => array(
      'label' => 'Explainfield in select list',
      'field types' => array('explainfield'),
      'multiple values' => CONTENT_HANDLE_CORE,
      'callbacks' => array(
        'default value' => CONTENT_CALLBACK_DEFAULT,
      ),
    ),
    'explainfield_buttons' => array(
      'label' => 'Explainfield in list of check boxes/radio buttons',
      'field types' => array('explainfield'),
      'multiple values' => CONTENT_HANDLE_CORE,
      'callbacks' => array(
        'default value' => CONTENT_CALLBACK_DEFAULT,
      ),
    ),
  );
  return $info;
}

/**
 * Implementation of hook_widget().
 */
function explainfield_widget(&$form, &$form_state, $field, $items, $delta = 0) {
  switch ($field['widget']['type']) {
    case 'explainfield_select':
      $element = array(
        '#type' => 'explainfield_select',
        '#default_value' => isset($items[$delta]) ? $items[$delta] : array(),
      );
      break;
    case 'explainfield_buttons':
      $element = array(
        '#type' => 'explainfield_buttons',
        '#default_value' => isset($items[$delta]) ? $items[$delta] : array(),
      );
      break;
  }
  return $element;
}

function explainfield_select_process($element, $edit, $form_state, $form) {
  $defaults = $element['#value'];
  $field = content_fields($element['#field_name'], $element['#type_name']);
  $max_length = 0;
  if ($field['max_length'] && is_numeric($field['max_length'])) {
    $max_length = $field['max_length'];
  }
  $explain_rows = 3;
  if ($field['explain_rows'] && is_numeric($field['explain_rows'])) {
    $explain_rows = $field['explain_rows'];
  }

  static $pointer = 0;
  $pointer++;

  $field_key = $element['#columns'][0];

  $prefix = "\n" . '<div class="explainfield-select">' . "\n";
  $prefix .= '<span class="keys-' . $element['#field_name'] . '">';
  $prefix .= '<input class="trigger" type="hidden" value="' . $field['trigger_value'] . '"/>';
  $prefix .= '<input class="pointer" type="hidden" value="' . $pointer . '"/>';
  $prefix .= '</span>' . "\n";

  $options = content_allowed_values($field);
  $element[$field_key] = array(
    '#type' => 'select',
    '#default_value' => isset($defaults[$field_key]) ? $defaults[$field_key] : '',
    '#title' => $element['#title'],
    '#required' => $element['#required'],
    '#description' => $element['#description'],
    '#field_name' => $element['#field_name'],
    '#type_name' => $element['#type_name'],
    '#delta' => $element['#delta'],
    '#columns' => $element['#columns'],
    '#prefix' =>  $prefix,
    '#options' => $options,
    '#element_validate' => array('explainfield_select_validate'),
  );

  $field_key  = $element['#columns'][1];
  $element[$field_key] = array(
    '#title' => $field['explain_label'],
    '#type' => $explain_rows == 1 ? 'textfield' : 'textarea',
    '#default_value' => isset($defaults[$field_key]) ? $defaults[$field_key] : '',
    '#rows' => $explain_rows,
    '#prefix' => '<div class="explainfield-text-' . $element['#field_name'] . '-' . $pointer . '">',
    '#suffix' => '</div></div>',
  );
  if ($field['explain_text']) {
    $element[$field_key]['#description'] = $field['explain_text'];
    if ($max_length > 0 && $field['max_length_notify']) {
      $element[$field_key]['#description'] .= t(' You can enter a maximum of %max characters for this field.', array('%max' => $max_length));
    }
  }
  else if ($max_length > 0 && $field['max_length_notify']) {
    $element[$field_key]['#description'] = t('You can enter a maximum of %max characters for this field.', array('%max' => $max_length));
  }

  return $element;
}

function explainfield_buttons_process($element, $edit, $form_state, $form) {
  $defaults = $element['#value'];
  $field = content_fields($element['#field_name'], $element['#type_name']);
  $max_length = 0;
  if ($field['max_length'] && is_numeric($field['max_length'])) {
    $max_length = $field['max_length'];
  }
  $explain_rows = 3;
  if ($field['explain_rows'] && is_numeric($field['explain_rows'])) {
    $explain_rows = $field['explain_rows'];
  }

  static $pointer = 0;
  $pointer++;

  $field_key = $element['#columns'][0];

  $prefix = "\n" . '<div class="explainfield-buttons">' . "\n";
  $prefix .= '<span class="keys-' . $element['#field_name'] . '">';
  $prefix .= '<input class="trigger" type="hidden" value="' . $field['trigger_value'] . '"/>';
  $prefix .= '<input class="pointer" type="hidden" value="' . $pointer . '"/>';
  $prefix .= '</span>' . "\n";

  $options = content_allowed_values($field);
  $element[$field_key] = array(
    '#type' => 'radios',
    '#default_value' => isset($defaults[$field_key]) ? $defaults[$field_key] : '',
    '#title' => $element['#title'],
    '#required' => $element['#required'],
    '#description' => $element['#description'],
    '#field_name' => $element['#field_name'],
    '#type_name' => $element['#type_name'],
    '#delta' => $element['#delta'],
    '#prefix' =>  $prefix,
    '#options' => $options,
    '#columns' => $element['#columns'],
    '#element_validate' => array('explainfield_buttons_validate'),
  );

  $field_key = $element['#columns'][1];
  $element[$field_key] = array(
    '#title' => $field['explain_label'],
    '#type' => $explain_rows == 1 ? 'textfield' : 'textarea',
    '#default_value' => isset($defaults[$field_key]) ? $defaults[$field_key] : '',
    '#rows' => $explain_rows,
    '#prefix' => '<div class="explainfield-text-' . $element['#field_name'] . '-' . $pointer . '">',
    '#suffix' => '</div></div>' . "\n",
  );
  if ($field['explain_text']) {
    $element[$field_key]['#description'] = $field['explain_text'];
    if ($max_length > 0 && $field['max_length_notify']) {
      $element[$field_key]['#description'] .= t(' You can enter a maximum of %max characters for this field.', array('%max' => $max_length));
    }
  }
  else if ($max_length > 0 && $field['max_length_notify']) {
    $element[$field_key]['#description'] = t('You can enter a maximum of %max characters for this field.', array('%max' => $max_length));
  }

  return $element;
}

function explainfield_select_validate($element, &$form_state) {
  $field_name = $element['#field_name'];
  $multiples_count = count($form_state['values'][$field_name]);
  $field = content_fields($element['#field_name'], $element['#type_name']);
  for ($i = 0; $i < $multiples_count; $i++) {
    // If the select/button/check value is not equal to the trigger value, there is
    // no reason to save any lingering value for the explain field itself.
    if ($form_state['values'][$field_name][$i]['value'] != $field['trigger_value']) {
      $form_state['values'][$field_name][$i]['explainfield'] = '';
    }
    else {
      // Now make sure it *is* filled out and correctly so if it's supposed to be.
      if (trim($form_state['values'][$field_name][$i]['explainfield']) == '') {
        $error_field = $field_name . '][' . $i . '][explainfield';
        form_set_error($error_field, t('Please fill the optional form in %label if you select this option.', array('%label' => t($field['widget']['label']))));
      }
      else {
        if ($field['max_length'] > 0) {
          $error_field = $field['field_name'] .']['. $i .'][explainfield';
          $data = $form_state['values'][$field_name][$i];
          if (strlen($data['explainfield']) > $field['max_length']) {
            form_set_error($error_field, t('There is a limit of %max characters on %label; your current entry contains %used characters.', array('%max' => $field['max_length'], '%label' => $field['widget']['label'], '%used' => strlen($data['explainfield']))));
          }
        }
      }
    }
  }
}

function explainfield_buttons_validate($element, &$form_state) {
  $field_name = $element['#field_name'];
  $multiples_count = count($form_state['values'][$field_name]);
  $field = content_fields($element['#field_name'], $element['#type_name']);
  for ($i = 0; $i < $multiples_count; $i++) {
    // If the select/button/check value is not equal to the trigger value, there is
    // no reason to save any lingering value for the explain field itself.
    if ($form_state['values'][$field_name][$i]['value'] != $field['trigger_value']) {
      $form_state['values'][$field_name][$i]['explainfield'] = '';
    }
    else {
      // Now make sure it *is* filled out and correctly so if it's supposed to be.
      if (trim($form_state['values'][$field_name][$i]['explainfield']) == '') {
        $error_field = $field_name . '][' . $i . '][explainfield';
        form_set_error($error_field, t('Please fill the optional form in %label if you select this option.', array('%label' => t($field['widget']['label']))));
      }
      else {
        if ($field['max_length'] > 0) {
          $error_field = $field['field_name'] .']['. $i .'][explainfield';
          $data = $form_state['values'][$field_name][$i];
          if (strlen($data['explainfield']) > $field['max_length']) {
            form_set_error($error_field, t('There is a limit of %max characters on %label; your current entry contains %used characters.', array('%max' => $field['max_length'], '%label' => $field['widget']['label'], '%used' => strlen($data['explainfield']))));
          }
        }
      }
    }
  }
}