<?php

/**
 * Implements hook_block_info().
 */
function datepicker_block_block_info() {
  $info = array();
  $info[0] = array(
    'info' => t('Date picker'),
    'cache' => DRUPAL_NO_CACHE,
  );
  return $info;
}

/**
 * Implements hook_block_configure().
 */
function datepicker_block_block_configure($delta = '') {
  $form = array();
  $form['datepicker_block_path'] = array(
    '#title' => t('Form action path'),
    '#type' => 'textfield',
    '#description' => t('Enter the path you want to use as the form action.'),
  );
  $form['datepicker_block_path_current'] = array(
    '#title' => t('Use current path'),
    '#type' => 'checkbox',
    '#description' => t('Use the current path as the form action (overrides "form action path").'),
  );
  $form['datepicker_block_field_type'] = array(
    '#title' => t('Populate date field type'),
    '#type' => 'select',
    '#options' => array(
      'single' => t('Single date'),
      'range' => t('Date range'),
      'multiple' => t('Multiple date fields'),
    ),
  );
  $form['datepicker_block_identifier'] = array(
    '#title' => t('Filter identifier'),
    '#type' => 'textfield',
    '#description' => t('The filter key to populate from this block. If using multiple datefields separate them with a | character, eg date_from|date_to'),
  );
  $form['datepicker_block_format'] = array(
    '#title' => t('Date format'),
    '#type' => 'textfield',
    '#description' => t('The PHP date format that is used in the query string.'),
  );
  foreach (array_keys($form) as $key) {
    $form[$key]['#default_value'] = datepicker_block_defaults(substr($key, strlen('datepicker_block_')));
  }
  return $form;
}

/**
 * Implements hook_block_save().
 */
function datepicker_block_block_save($delta = '', $edit = array()) {
  if ($delta == 0) {
    foreach ($edit as $key => $value) {
      variable_set($key, $value);
    }
  }
}

/**
 * Implements hook_block_view().
 */
function datepicker_block_block_view($delta = '') {
  return array(
    'subject' => t('Date picker'),
    'content' => drupal_get_form('datepicker_block_form'),
  );
}

/**
 * Event finder block form callback.
 */
function datepicker_block_form() {
  $form = array();
  $form['finder'] = array(
    '#type' => 'datepicker',
    '#date_format' => 'd/m/Y',
  );
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Search'),
  );
  return $form;
}

/**
 * Submit handler for the event finder block form.
 */
function datepicker_block_form_submit(&$form, &$form_state) {
  $values =& $form_state['values'];
  $use_current_path = datepicker_block_defaults('path_current');
  if (!empty($use_current_path)) {
    $path = request_path();
  }
  else {
    $path = datepicker_block_defaults('path');
  }
  $identifier = datepicker_block_defaults('identifier');
  $field_type = datepicker_block_defaults('field_type');
  $format = datepicker_block_defaults('format');
  if ($field_type == 'range') {
    $query = array(
      $identifier . '[min][date]' => date($format, strtotime($values['finder'])),
      $identifier . '[max][date]' => date($format, strtotime($values['finder']) + 86400),
    );
  }
  elseif ($field_type == 'single') {
    $query = array(
      $identifier . '[value][date]' => date($format, strtotime($values['finder'])),
    );
  }
  else {
    $ids = explode('|', $identifier);
    $query = array();
    foreach ($ids as $id) {
      $query[$id . '[value][date]'] = date($format, strtotime($values['finder']));
    }
  }
  $form_state['redirect'] = array($path, array('query' => $query));
  $values =& $form_state['values'];
}

/**
 *
 */
function datepicker_block_defaults($key) {
  $defaults = array(
    'format' => 'Y-m-d',
    'identifier' => 'date_filter',
    'path' => '',
    'path_current' => FALSE,
    'range' => 'range',
    'type' => 'textfield',
  );
  $variable_name = 'datepicker_block_' . $key;
  $fallback = (isset($defaults[$key]) ? $defaults[$key] : '');
  return variable_get($variable_name, $fallback);
}