<?php
// $Id: calendar.module,v 1.102.2.4 2008-02-22 15:14:55 karens Exp $

/**
 * @file
 * Adds calendar filtering and displays to Views.
 */
/**
 * Implementation of hook_help().
 */
function calendar_help($section) {
  switch ($section) {
    case 'admin/help#calendar':
      return t("<p>View complete documentation at !link.</p>", array('!link' => 'http://drupal.org/node/120710'));
  }
}

/**
 *  Implementation of hook_menu().
 */
function calendar_menu($may_cache) {
  $items = array();
  if (!$may_cache) {

    drupal_add_css(drupal_get_path('module', 'calendar') .'/calendar.css');
    define('CALENDAR_EMPTY_ARG', variable_get('calendar_empty_arg', 'all'));

    include_once(drupal_get_path('module', 'calendar') .'/calendar_admin.inc');
    $first = TRUE;
    foreach (calendar_info() as $view_name => $view) {
      if ($first) {
        $items[] = array(
          'path' => 'admin/settings/calendar',
          'title' => t('Calendar Setup'),
          'description' => t('Customize calendar settings options.'),
          'access'   => user_access('administer views'),
          'type' => MENU_NORMAL_ITEM,
          'callback' => 'drupal_get_form',
          'callback arguments' => array('_calendar_setup_form', $view_name),
        );
      }
      $items[] = array(
        'path' => 'admin/settings/calendar/'. $view_name,
        'title' => $view_name,
        'access'   => user_access('administer views'),
        'callback' => 'drupal_get_form',
        'callback arguments' => array('_calendar_setup_form', $view_name),
        'type' => $first ? MENU_DEFAULT_LOCAL_TASK : MENU_LOCAL_TASK,
      );
      $items[] = array(
        'path' => 'admin/settings/calendar/'. $view_name .'/setup',
        'title' => t('Setup'),
        'access'   => user_access('administer views'),
        'callback' => 'drupal_get_form',
        'callback arguments' => array('_calendar_setup_form', $view_name),
        'type' => MENU_DEFAULT_LOCAL_TASK,
      );
      $first = FALSE;
    }
  }
  return $items;
}

/**
 * Find the number of calendar weeks for a year.
 *
 * @param int $year
 * @return int number of calendar weeks in selected year.
 */
function calendar_max_weeks($year) {
  $date = date_make_date(($year+1) . '-01-01 12:00:00', 'UTC');
  date_modify($date, '-1 day');
  return calendar_date_week(date_format($date, 'Y-m-d'));
}

/**
 * Find the calendar week number for a date.
 *
 * @param string $date, in the format Y-m-d
 * @return int calendar week number.
 */
function calendar_date_week($date) {
  $parts = explode('-', $date);

  $date = date_make_date($date . ' 12:00:00', 'UTC');
  $year_date = date_make_date($parts[0] . '-01-01 12:00:00', 'UTC');

  $week = intval(date_format($date, 'W'));
  $year_week = intval(date_format($year_date, 'W'));
  $date_year = intval(date_format($date, 'o'));

  // remove the leap week if it's present
  if ($date_year > intval($parts[0])) {
    $last_date = drupal_clone($date);
    date_modify($last_date, '-7 days');
    $week = date_format($last_date, 'W') + 1;
  } else if ($date_year < intval($parts[0])) {
    $week = 0;
  }
  if ($year_week != 1) $week++;

  // convert to ISO-8601 day number, to match weeks calculated above
  $iso_first_day = 1 + (variable_get('date_first_day', 0) + 6) % 7;

  // if it's before the starting day, it's the previous week
  if (intval(date_format($date, 'N')) < $iso_first_day) $week--;

  // if the year starts before, it's an extra week at the beginning
  if (intval(date_format($year_date, 'N')) < $iso_first_day) $week++;

  return $week;
}

/**
 * Implementation of hook_form_alter().
 * Make sure calendar_info() and calendar_fields() get updated.
 */
function calendar_form_alter($form_id, &$form) {
  if ($form_id == 'views_edit_view') {
    $form['#submit'] = array_merge($form['#submit'], array('calendar_clear_all' => array()));
  }
}

/**
 *  TODO need to identify type of timezone handling needed for each date field
 */
function calendar_offset($field_name) {
  $default_offset = variable_get('date_default_timezone', 0);
  $configurable_zones = variable_get('configurable_timezones', 1);
}

/**
 *  Custom views handler for all calendar arguments.
 */
function calendar_handler_arg_type($op, &$query, $argtype, $arg, $field_type) {
  switch ($op) {
    case 'summary':
    case 'link':
      // The query to do summaries when date ranges can include multiple days, months, and years
      // is extremely complex and has been omitted, so summary views with these arguments just will not work.
      // TODO add some kind of validation or warning to keep people from trying to use summary views.
      break;

    case 'filter':
      // Figure out which will be the final calendar argument in this view so we know when to insert the query.
      $view = $GLOBALS['current_view'];
      if ($argtype['type'] == calendar_is_last_arg($view)) {
        $query->calendar_finished = TRUE;
        //calendar_build_filter($query, $view);
      }
      break;

    case 'title':
      // Set titles for each argument.
      $value = intval(str_replace('W', '', $arg ? $arg : $query));
      return theme('calendar_arg_title', $field_type, $value, $query);
  }
  return;
}

/**
 *  Custom views handler for the year argument.
 */
function calendar_handler_arg_year($op, &$query, $argtype, $arg = '') {
  if ($op == 'filter' && !empty($arg) && $arg != CALENDAR_EMPTY_ARG) {
    calendar_filter_year($query, $arg);
  }
  return calendar_handler_arg_type($op, $query, $argtype, $arg, 'YEAR');
}

/**
 * Callback for year filter.
 *   Build year, month, day, min, and max into query object.
 *
 * @param object $query
 * @param integer $arg
 */
function calendar_filter_year(&$query, $arg) {
  $query->calendar_type = 'year';
  $query->year = calendar_part_is_valid($arg, 'year') ? $arg : date_format(date_now(), 'Y');
  $query->month = CALENDAR_EMPTY_ARG;
  $query->day = CALENDAR_EMPTY_ARG;
}

/**
 *  Custom views handler for the month argument.
 */
function calendar_handler_arg_month($op, &$query, $argtype, $arg = '') {
  if ($op == 'filter' && !empty($arg) && $arg != CALENDAR_EMPTY_ARG) {
    calendar_filter_month($query, $arg);
  }
  return calendar_handler_arg_type($op, $query, $argtype, $arg, 'MONTH');
}

/**
 * Callback for month filter.
 *   Build year, month, day, min, and max into query object.
 *
 * @param object $query
 * @param integer $arg
 */
function calendar_filter_month(&$query, $arg) {
  $now = date_now();
  $query->calendar_type = 'month';
  if (!isset($query->year)) {
    calendar_filter_year($query, date_format($now, 'Y'));
  }
  $query->month = calendar_part_is_valid($arg, 'month') ? $arg : date_format($now, 'm');
  $query->day = CALENDAR_EMPTY_ARG;
}

/**
 *  Custom views handler for the day argument.
 */
function calendar_handler_arg_day($op, &$query, $argtype, $arg = '') {
  if ($op == 'filter' && !empty($arg) && $arg != CALENDAR_EMPTY_ARG) {
    calendar_filter_day($query, $arg);
  }
  return calendar_handler_arg_type($op, $query, $argtype, $arg, 'DAY');
}

/**
 * Callback for day filter.
 *   Build year, month, day, min, and max into query object.
 *
 * @param object $query
 * @param integer $arg
 */
function calendar_filter_day(&$query, $arg) {
  $now = date_now();
  if (!isset($query->month)) {
    calendar_filter_month($query, date_format($now, 'm'));
  }
  $query->calendar_type = 'day';
  $query->day = calendar_part_is_valid($arg, 'day') ? $arg : date_format($now, 'j');
}

/**
 *  Custom views handlers for the week argument.
 */
function calendar_handler_arg_week($op, &$query, $argtype, $arg = '') {
  if ($op == 'filter' && !empty($arg) && $arg != CALENDAR_EMPTY_ARG) {
    calendar_filter_week($query, $arg);
  }
  return calendar_handler_arg_type($op, $query, $argtype, $arg, 'WEEK');
}

/**
 * Callback for week filter.
 *   Build year, month, day, min, and max into query object.
 *
 * @param object $query
 * @param integer $arg
 */
function calendar_filter_week(&$query, $arg) {
  $now = date_now();
  if (!isset($query->year)) {
    calendar_filter_year($query, date_format($now, 'Y'));
  }
  $arg = str_replace('W', '', $arg);
  $query->calendar_type = 'week';
  $query->week = calendar_part_is_valid($arg, 'week') ? $arg : NULL;
  $range = calendar_week_range($query);
  $query->month = date_format($range[0], 'n');
  $query->day = date_format($range[0], 'j');
}

/**
 *  Implementation of hook_views_query()
 *    Insert filters into the query based on the current calendar view and the selected fields
 *    Used when the actual view arguments don't provide enough info to construct the query.
 *    i.e. on a view with no arguments or one with partial arguments like year or year/month.
 *
 *  @param object $query
 *  @param object $view
 */
function calendar_views_query_alter(&$query, &$view) {
  if (!calendar_has_calendar_args($view) ||
    (empty($view->args) && !calendar_is_calendar_arg($view)
    && $view->argument[0]['argdefault'] != 2)) {
    return;
  }

  // Check if a new date has been selected and if so redirect.
  if (isset($_POST['calendar_goto'])) {
    $parts = explode('/', $_POST['calendar_goto']['date']);
    $type = $_POST['calendar_type'];
    if ($type == 'year') {
      unset($parts[1], $parts[2]);
    }
    elseif ($type == 'month') {
      unset($parts[2]);
    }
    elseif ($type == 'week') {
      $date = implode('-', $parts);
      $parts[1] = 'W'. calendar_date_week($date);
      unset($parts[2]);
    }
    drupal_goto($view->url .'/'. implode('/', $parts));
    drupal_exit();
  }

  include_once('./'. drupal_get_path('module', 'calendar') .'/calendar.inc');
  include_once('./'. drupal_get_path('module', 'calendar') .'/calendar.theme');
  return _calendar_views_query_alter($query, $view);
}

/**
 *  Implementation of hook_views_pre_view()
 */
function calendar_views_pre_view(&$view, &$items) {
  include_once('./'. drupal_get_path('module', 'calendar') .'/calendar.theme');

  // If no part of this view has calendar elements, exit.
  if ((!calendar_is_calendar($view) || !calendar_has_calendar_args($view))) {
    return;
  }
  if (!calendar_is_calendar_arg($view)) {
    return;
  }

  include_once('./'. drupal_get_path('module', 'calendar') .'/calendar.inc');

  // Massage the resulting items into formatted calendar items.
  $items = calendar_build_nodes($view, $items);

  // Merge in items from other sources.
  foreach (module_implements('calendar_add_items') as $module) {
    $function = $module .'_calendar_add_items';
    if (function_exists($function)) {
      if ($feeds = $function($view)) {
        foreach ($feeds as $feed) {
          $items[] = $feed;
        }
      }
    }
  }

  if ($view->build_type == 'block' || $view->calendar_type == 'year') $view->mini = TRUE;

  // Construct a formatted title for the view from the last calendar
  // argument encountered.
  $view->subtitle = theme('calendar_nav_title', $view->calendar_type, $view);

  // If this is a view with calendar arguments but not a calendar view,
  // add navigation to the top of the view and return.
  if (!calendar_is_calendar($view) && calendar_has_calendar_args($view)) {
    return theme('calendar_show_nav', $view,  $view->build_type == 'block', calendar_is_calendar($view));
  }

  // If this is a calendar plugin theme view, make sure empty results
  // will produce blank calendar page
  if (array_key_exists($view->page_type, calendar_view_types())) {
    if (!$items && $view->build_type == 'page' && $view->year) {
      $view->page_empty = check_markup($view->page_header, $view->page_header_format) . check_markup($view->page_empty, $view->page_empty_format) . theme('calendar_display', $view, array(), 'page') . check_markup($view->page_footer, $view->page_footer_format);
      $view->page_empty_format = 3;
    }
  }
  if (array_key_exists($view->block_type, calendar_view_types())) {
    if (!$items && $view->build_type == 'block' && $view->year) {
      $view->block_empty = check_markup($view->block_header, $view->block_header_format) . check_markup($view->block_empty, $view->block_empty_format) . theme('calendar_display', $view, array(), 'block') . check_markup($view->block_footer, $view->block_footer_format);
      $view->block_empty_format = 3;
    }
  }
}

/**
 * Implementation of hook_views_post_view().
 *
 * Views automatically sets the page title to the value of the last argument.
 * The calendar module has already created a proper title within the
 * calendar, so override Views to set the page title to match the View title.
 */
function calendar_views_post_view(&$view, $items, $output) {
  // If no part of this view has calendar elements, exit.
  if ($view->build_type != 'page' || !calendar_is_calendar($view) || !calendar_has_calendar_args($view)) {
    return;
  }
  include_once('./'. drupal_get_path('module', 'calendar') .'/calendar.inc');
  $title = theme('calendar_page_title', $view, $items, $output);
  drupal_set_title($title);
}

/**
 *  A function to test the validity of various date parts
 */
function calendar_part_is_valid($value, $type) {
  if ( !preg_match('/^[0-9]*$/', $value) ) {
    return false;
  }
  $value = intval($value);
  if ($value <= 0) return false;
  switch ($type) {
    case 'year':
      if ($value < DATE_MIN_YEAR) return false;
      break;
    case 'month':
      if ($value < 0 || $value > 12) return false;
      break;
    case 'day':
      if ($value < 0 || $value > 31) return false;
      break;
    case 'week':
      if ($value < 0 || $value > 53) return false;
  }
  return true;
}

/**
 *  implementation of hook_block()
 */
function calendar_block($op = 'list', $delta = 0) {
  switch ($op) {
    case 'list' :
      $blocks[0]['info'] = t('Calendar Legend.');
      $blocks[1]['info'] = t('Switch Calendar.');
      return $blocks;
      break;
    case 'view' :
      switch ($delta) {
      case 0:
        $block['subject'] = t('Calendar Legend');
        $block['content'] = $GLOBALS['calendar_stripe_labels'] ? '<div class="calendar legend">'. theme('calendar_stripe_legend', $GLOBALS['calendar_stripe_labels']) .'</div>' : '';
        return $block;
      case 1:
        $block['subject'] = t('Switch Calendar');
        $block['content'] = $GLOBALS['calendar_is_calendar'] ? drupal_get_form('calendar_switch_view') : '';
        return $block;
      }
  }
}

/**
 * A block with a drop-down list that allows the user to switch between
 * views of the current period
 */
function calendar_switch_view() {

  $options[''] = t('Calendar');
  $options['list'] = t('List');
  $options['teasers'] = t('Teasers');
  $options['nodes'] = t('Nodes');
  $options['table'] = t('Table');

  $form = array(
    '#method' => 'GET',
    'view' => array(
      '#type' => 'select',
      '#default_value' => $_GET['view'],
      '#options' => $options,
      ),
    'q' => array(
      '#type' => 'hidden',
      '#value' => $_GET['q'],
      ),
    'submit' => array('#type' => 'submit', '#value' => t('Switch')),
    );
  return $form;
}

/**
 * Valid calendar arguments.
 */
function calendar_args() {
  return array('calendar_year', 'calendar_week', 'calendar_month', 'calendar_day');
}

/**
 * Figure out what the URL of the calendar view we're currently looking at is.
 */
function calendar_real_url($view, $args) {
  // Add non-calendar arguments to the base url.
  $parts = explode('/', $view->url);
  $bump = 0;
  foreach ($parts as $delta => $part) {
    // If one of the args is buried in the url, add it here and adjust
    // the delta values we'll compare the calendar arg positions to.
    if (in_array($part, array('$arg', '$node', '$user', '$group'))) {
      $parts[$delta] = array_shift($args);
      $bump++;
    }
  }
  foreach ($args as $delta => $arg) {
    if (!in_array($delta + $bump, calendar_arg_positions($view)) && !empty($arg)) {
      array_push($parts, $arg);
    }
  }
  return implode('/', $parts);
}

/**
 * Pick up filter and sort info from url.
 */
function calendar_url_append($view) {
  if ($view->build_type == 'page') {
    foreach ($_GET as $key => $val) {
      if ($key != 'q' && $key != 'view') {
        if (!is_array($val)) {
          $url .= '&'. $key .'='. $val;
        }
        else {
          foreach ($val as $v) {
            $url .= '&'. $key .'[]='. $v;
          }
        }
      }
    }
  }
  return $url;
}

/**
 *  Function to test whether this is a view that uses the calendar plugin theme.
 */
function calendar_is_calendar($view) {
  $calendar_info = calendar_info();
  return $calendar_info[$view->name][$view->build_type];
}

/**
 * Function to test whether any calendar args are used in this view.
 */
function calendar_has_calendar_args($view, $reset = FALSE) {
  $calendar_info = calendar_info();
  if (count($calendar_info[$view->name]['args']) > 0) {
    return TRUE;
  }
  else {
    return FALSE;
  }
}

/**
 * The positions in the view that hold calendar arguments.
 */
function calendar_arg_positions($view) {
  $calendar_info = calendar_info();
  if (array_key_exists($view->name, $calendar_info)) {
    return array_keys($calendar_info[$view->name]['args']);
  }
  else {
    return array();
  }
}

/**
 * Is the current argument a calendar argument.
 * Used to sort out whether or not to display the calendar at each point.
 */
function calendar_is_calendar_arg($view) {
  if (empty($view->real_args)) {
    $delta = 0;
  }
  else {
    $delta = max(array_keys($view->real_args));
  }
  if (in_array($delta, calendar_arg_positions($view))) {
    return TRUE;
  }
  return FALSE;
}

/**
 * Identify the final calendar argument in this view.
 *   Needed because we can't construct a query until we know all the calendar elements.
 *   Used to tell when to add the filter to the query object.
 *
 * @param object $view
 * @return string $argtype
 */
function calendar_is_last_arg($view, $reset = FALSE) {
  foreach ($view->argument as $argument) {
    if (in_array($argument['id'], calendar_args())) {
      $calendar_arg = $argument['id'];
    }
    $max = $argument['id'];
  }
  return $max < $calendar_arg;
}

/**
 * Helper function to find the display formats
 * for each part of this view.
 */
function calendar_get_formats($view) {
  return variable_get('calendar_display_format_'. $view->name, array(
    'year' => 'calendar',
    'month' => 'calendar',
    'week' => 'calendar',
    'day' => 'calendar',
    'block' => 'calendar'));
}

/**
 * create a stripe id from a combination of the field and content types
 * and store value for legend
 * formula tries to create a unique id for each possible combination
 *
 * @param $node - the node object
 * @param $query_name - the views queryname for this date field
 * @param $delta - the delta for this field, used to distinguish fields that appear more than once in the calendar
 * @param $label - the label to give this stripe.
 */
function calendar_node_stripe($view, $node, $query_name, $delta, $stripe = NULL, $label = '') {
  $type_names = node_get_types('names');
  if (!$label) {
    $label = $type_names[$node->type]  .' '. $view->field[$delta]['label'];
  }
  if (!$stripe) {
    $i = 1;
    foreach ($type_names as $k => $v) {
      if ($k == $node->type) {
        break;
      }
      $i++;
    }
    $stripe = intval((20 * $delta) + $i);
  }
  $GLOBALS['calendar_stripe_labels'][$stripe] = $label;
  return $stripe;
}

/**
 * Moved the following infrequently-used functions to separate file
 * so the code is not parsed on every page.
 */

/**
 *  Implementation of hook_views_style_plugins()
 */
function calendar_views_style_plugins() {
  include_once('./'. drupal_get_path('module', 'calendar') .'/calendar_admin.inc');
  return _calendar_views_style_plugins();
}

/**
 * Implementation of hook_views_default_views()
 */
function calendar_views_default_views() {
  include_once('./'. drupal_get_path('module', 'calendar') .'/calendar_admin.inc');
  return _calendar_views_default_views();
}

/**
 *  Implementation of hook_views_arguments()
 */
function calendar_views_arguments() {
  include_once('./'. drupal_get_path('module', 'calendar') .'/calendar_admin.inc');
  return _calendar_views_arguments();
}

/**
 *  Function to return all possible calendar views page display types.
 */
function calendar_view_types($reset = FALSE) {
  include_once('./'. drupal_get_path('module', 'calendar') .'/calendar_admin.inc');
  return _calendar_view_types($reset);
}

/**
 * Function to get information about all views that have calendar components.
 */
function calendar_info($reset = FALSE) {
  static $calendar_views;
  if (empty($calendar_views) || $reset) {
    $cid = 'calendar_views';
    if (!$reset && $cached = cache_get($cid, 'cache_views')) {
      $calendar_views = unserialize($cached->data);
    }
    else {
     include_once('./'. drupal_get_path('module', 'calendar') .'/calendar_admin.inc');
     $calendar_views = _calendar_info();
    }
  }
  return $calendar_views;
}

/**
 *  Identify all potential date/timestamp fields
 */
function calendar_fields($reset = FALSE) {
  static $fields;
  if (empty($fields) || $reset) {
    $cid = 'calendar_fields';
    if (!$reset && $cached = cache_get($cid, 'cache_views')) {
      $fields = unserialize($cached->data);
    }
    else {
      include_once('./'. drupal_get_path('module', 'calendar') .'/calendar_admin.inc');
      $fields = _calendar_fields();
    }
  }
  return $fields;
}

/**
 * Validate a view during Views administration.
 */
function calendar_views_validate($type, $view, $form) {
  include_once('./'. drupal_get_path('module', 'calendar') .'/calendar_admin.inc');
  return _calendar_views_validate($type, $view, $form);
}

/**
 * Setup Calendar parameters in the Setup Tab.
 */
function calendar_setup_form($view_name) {
  include_once('./'. drupal_get_path('module', 'calendar') .'/calendar_admin.inc');
  return _calendar_setup_form($view_name);
}

/**
 * Save Setup values.
 */
function calendar_setup_form_submit($form_id, $form_values) {
  include_once('./'. drupal_get_path('module', 'calendar') .'/calendar_admin.inc');
  return _calendar_setup_form_submit($form_id, $form_values);
}

/**
 * Empty or reset cached values.
 *
 * @param $remove
 *   whether or not to completely remove the caches.
 */
function calendar_clear_all($remove = FALSE) {
  if ($remove) {
    cache_clear_all('calendar_views', 'cache_views');
    cache_clear_all('calendar_fields', 'cache_views');
  }
  else {
    calendar_fields(TRUE);
    calendar_info(TRUE);
  }
}

/**
 * Helper function to figure out a group gid to use in blocks.
 *
 * @return an array of group nodes that are relevant.
 * @todo this may need more work.
 */
function calendar_og_groups($view) {
  if (!$groupnode = og_get_group_context()) {
    global $user;
    $groupnodes = array_keys($user->og_groups);
  }
  else {
    $groupnodes = array($groupnode->nid);
  }
  return $groupnodes;
}

/**
 * A selector to jump to a new date in the calendar.
 *
 * @param unknown_type $view
 * @return unknown
 */
function calendar_date_select($view) {
  return '<div class="calendar-date-select">'. drupal_get_form('calendar_date_select_form', $view) .'</div>';
}

/**
 * The date selector form.
 *
 * @param object $view
 * @return the form element
 *
 * @TODO is the title desired here or does it take up too much space??
 */
function calendar_date_select_form($view) {
  $format = 'Y/m/d';
  $form['calendar_goto'] = array(
    //'#title' => t('Calendar date'),
    '#type' => 'date_popup',
    '#default_value' => date_format($view->min_date, 'Y-m-d'),
    '#date_timezone' => date_default_timezone_name(),
    '#date_format' => $format,
    );
  $form['calendar_type'] = array(
    '#type' => 'hidden',
    '#value' => $view->calendar_type,
    );
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Change date'),
    );
  return $form;
}