<?php
// $Id: date_facets.module,v 1.10 2009-05-01 22:12:33 davidlesieur Exp $

/**
 * @file
 * Exposes CCK Date fields as facets.
 */

module_load_include('inc', 'cck_facets');

// TODO: Support 'todate' column.
// TODO: Timezone handling.
// TODO: Support for CCK Date granularity.

/**
 * Implementation of hook_cck_facets_collect().
 */
function date_facets_cck_facets_collect(&$facets, $field, $domain, $env, $arg = NULL) {
  if ($field['type'] == 'date' || $field['type'] == 'datestamp') {
    $facet_class = $field['type'] .'_facet';
    $category_class = $field['type'] .'_facet_category';
  
    switch ($domain) {
      case 'facets':
        $facets[] = new $facet_class($field);
        break;

      case 'text':
        // Scan the given search text for a '{field_name}:{value}'
        // token, and create facets from it.
        if ($date = search_query_extract($arg, $field['field_name'])) {
          if (preg_match('/^([12][0-9][0-9][0-9])(-([01][0-9])(-([0-3][0-9]))?)?$/', $date, $matches)) {
            if (_date_facets_check_date($matches[1], $matches[3], $matches[5])) {
              // Create an active facet with the value found in the search text.
              $active_path = array();
              if (isset($matches[1])) {
                // Found year.
                $active_path[] = new $category_class($field, $matches[1], NULL, NULL);
              }
              if (isset($matches[3])) {
                // Found month.
                $active_path[] = new $category_class($field, $matches[1], $matches[3], NULL);
              }
              if (isset($matches[5])) {
                // Found day.
                $active_path[] = new $category_class($field, $matches[1], $matches[3], $matches[5]);
              }
              $facets[] = new $facet_class($field, $active_path);
            }
          }
          // Remove the parsed text
          $arg = search_query_insert($arg, $field['field_name']);
        }
        break;

      case 'node':
        if (isset($arg->{$field['field_name']}) && is_array($arg->{$field['field_name']})) {
          if ($field['type'] == 'date') {
            // Iterate through the field's multiple values.
            foreach ($arg->{$field['field_name']} as $item) {
              $date = array_shift($item); // Take the item's main column.
              if (preg_match('/^([12][0-9][0-9][0-9])(-([01][0-9])(-([0-3][0-9]))?)?/', $date, $matches)) {
                $active_path = array(
                  new date_facet_category($field, $matches[1], NULL, NULL),
                  new date_facet_category($field, $matches[1], $matches[3], NULL),
                  new date_facet_category($field, $matches[1], $matches[3], $matches[5]),
                );
                // Create an active facet.
                $facets[] = new date_facet($field, $active_path);
              }
            }
          }
          elseif ($field['type'] == 'datestamp') {
            // Iterate through the field's multiple values.
            foreach ($arg->{$field['field_name']} as $item) {
              $timestamp = array_shift($item); // Take the item's main column.
              $date = date_make_date($timestamp, $field['timezone_db'], $field['type'], $field['granularity']);
              $year = date_format_date($date, 'custom', 'Y');
              $month = date_format_date($date, 'custom', 'n');
              $day = date_format_date($date, 'custom', 'j');
              
              $active_path = array(
                new datestamp_facet_category($field, $year, NULL, NULL),
                new datestamp_facet_category($field, $year, $month, NULL),
                new datestamp_facet_category($field, $year, $month, $day),
              );
              $facets[] = new datestamp_facet($field, $active_path);
            }
          }
        }
        break;
    }
  }
  return $arg;
}

/**
 * A facet for Date fields.
 *
 * @see date_facet_category
 */
class date_facet extends cck_facet {
  /**
   * Constructor. 
   *
   * @param $field
   *   The field corresponding to this facet.
   * @param $active_path
   *   Array representing the path leading to the active category, including the
   *   active category itself. Defaults to an empty array, meaning no active
   *   category.
   */
  function date_facet($field, $active_path = array()) {
    parent::cck_facet($field, $active_path);
  }

  /**
   * Returns the search text for this facet, taking into account this facet's
   * active path.
   */
  function get_text() {
    if ($category = $this->get_active_category()) {
      return $category->get_text();
    }
    return '';
  }

  /**
   * Handler for the 'count' sort criteria.
   */
  function build_sort_query_count(&$query) {
    $query->add_orderby('count', 'DESC');
    $this->build_sort_query_field($query);
  }

  /**
   * Handler for the 'field' sort criteria.
   */
  function build_sort_query_field(&$query) {
    $query->add_orderby($this->_field['field_name'] .'_year', 'ASC');
    if ($query->has_field($this->_field['field_name'] .'_month')) {
      $query->add_orderby($this->_field['field_name'] .'_month', 'ASC');
      if ($query->has_field($this->_field['field_name'] .'_day')) {
        $query->add_orderby($this->_field['field_name'] .'_day', 'ASC');
      }
    }
  }
  
  /**
   * Updates a query for retrieving the root categories of this facet and their
   * associated nodes within the current search results. 
   *
   * @param $query
   *   The query object to update.
   * @return
   *   FALSE if this facet can't have root categories.
   */
  function build_root_categories_query(&$query) {
    $db_info = _cck_facets_db_info($this->_field);
    $main_column = array_shift($db_info['columns']);
    $query->add_table($db_info['table'], 'vid', 'n', 'vid');
    $query->add_field(NULL, "YEAR(${db_info['table']}.${main_column['column']})", $this->_field['field_name'] .'_year');
    $query->add_where($db_info['table'] .'.'. $main_column['column'] .' IS NOT NULL');
    $query->add_groupby($this->_field['field_name'] .'_year');
    return TRUE;
  }

  /**
   * This factory method creates categories given query results that include the
   * fields selected in get_root_categories_query() or get_subcategories_query().
   *
   * @param $results
   *   $results A database query result resource.
   *
   * @return
   *   Array of categories.
   */
  function build_categories($results) {
    $categories = array();
    while ($result = db_fetch_object($results)) {
      $categories[] = new date_facet_category($this->_field, $result->{$this->_field['field_name'] .'_year'}, $result->{$this->_field['field_name'] .'_month'}, $result->{$this->_field['field_name'] .'_day'}, $result->count);
    }
    return $categories;
  }
}

/**
 * A facet category for Date fields. 
 */
class date_facet_category extends cck_facet_category {
  
  /**
   * Constructs a category for the specified date.
   *
   * @param $year
   *   Year corresponding to this category.
   * @param $month
   *   Month corresponding to this category. Optional, but must be specified if
   *   $day is specified.
   * @param $day
   *   Day corresponding to this category. Optional.
   * @param $count
   *   The number of nodes associated to this category within the current
   *   search. Optional.
   */
  function date_facet_category($field, $year, $month = NULL, $day = NULL, $count = NULL) {
    parent::cck_facet_category($field, array('year' => $year, 'month' => $month, 'day' => $day), $count);
  }

  /**
   * Return the label of this category.
   *
   * @param $html
   *   TRUE when HTML is allowed in the label, FALSE otherwise. Checking this
   *   flag allows implementors to provide a rich-text label if desired, and an
   *   alternate plain text version for cases where HTML cannot be used. The
   *   implementor is responsible to ensure adequate security filtering.
   */
  function get_label($html = FALSE) {
    if (isset($this->_value['day'])) {
      // Format date with YYYY-MM-DD.
      $timestamp = gmmktime(0, 0, 0, (int)$this->_value['month'], (int)$this->_value['day'], (int)$this->_value['year']);
      $format = variable_get('date_facets_format_ymd', 'm/d/Y');
    }
    elseif (isset($this->_value['month'])) {
      // Format date with YYYY-MM.
      $timestamp = gmmktime(0, 0, 0, (int)$this->_value['month'], 1, (int)$this->_value['year']);
      $format = variable_get('date_facets_format_ym', 'm/Y');
    }
    elseif (isset($this->_value['year'])) {
      // Format date with YYYY.
      $timestamp = gmmktime(0, 0, 0, 1, 1, (int)$this->_value['year']);
      $format = variable_get('date_facets_format_y', 'Y');
    }
    if ($timestamp) {
      return format_date($timestamp, 'custom', $format, 0);
    }
  }

  /**
   * Return the search text for this category.
   */
  function get_text() {
    $text = sprintf('%04d', $this->_value['year']);
    if (isset($this->_value['month'])) {
      $text .= sprintf('-%02d', $this->_value['month']);
      if (isset($this->_value['day'])) {
        $text .= sprintf('-%02d', $this->_value['day']);
      }
    }
    return $text;
  }

  /**
   * Updates a query for retrieving the subcategories of this category and their
   * associated nodes within the current search results. 
   *
   * This only needs to be overridden for hierarchical facets.
   *
   * @param $query
   *   The query object to update.
   * @return
   *   FALSE if this facet can't have subcategories.
   */
  function build_subcategories_query(&$query) {
    if (isset($this->_value['day'])) {
      return FALSE; // No subcategories.
    }
    
    $db_info = _cck_facets_db_info($this->_field);
    $main_column = array_shift($db_info['columns']);
    $query->add_table($db_info['table'], 'vid', 'n', 'vid');
    if (isset($this->_value['month'])) {
      $from = sprintf("'%04d-%02d-01 00:00:00'", $this->_value['year'], $this->_value['month']);
      $query->add_field(NULL, "YEAR(${db_info['table']}.${main_column['column']})", $this->_field['field_name'] .'_year');
      $query->add_field(NULL, "MONTH(${db_info['table']}.${main_column['column']})", $this->_field['field_name'] .'_month');
      $query->add_field(NULL, "DAY(${db_info['table']}.${main_column['column']})", $this->_field['field_name'] .'_day');
      $query->add_where("(${db_info['table']}.${main_column['column']} >= $from)");
      $query->add_where("(${db_info['table']}.${main_column['column']} < $from + INTERVAL 1 MONTH)");
      $query->add_groupby($this->_field['field_name'] .'_day');
      return TRUE;
    }
    elseif (isset($this->_value['year'])) {
      $from = sprintf("'%04d-01-01 00:00:00'", $this->_value['year']);
      $query->add_field(NULL, "YEAR(${db_info['table']}.${main_column['column']})", $this->_field['field_name'] .'_year');
      $query->add_field(NULL, "MONTH(${db_info['table']}.${main_column['column']})", $this->_field['field_name'] .'_month');
      $query->add_where("(${db_info['table']}.${main_column['column']} >= $from)");
      $query->add_where("(${db_info['table']}.${main_column['column']} < $from + INTERVAL 1 YEAR)");
      $query->add_groupby($this->_field['field_name'] .'_month');
      return TRUE;
    }
    return FALSE; // Unreachable, unless something is wrong...
  }

  /**
   * Updates a query for selecting nodes matching this category.
   *
   * @param $query
   *   The query object to update.
   */
  function build_results_query(&$query) {
    $db_info = _cck_facets_db_info($this->_field);
    $main_column = array_shift($db_info['columns']);
    // Since the same table might be joined multiple times in the query, we use
    // the field's name as the table alias to create a unique table reference.
    $table = $query->add_table($db_info['table'], 'vid', 'n', 'vid', $this->_field['field_name']);
    if (isset($this->_value['day'])) {
      $from = sprintf("'%04d-%02d-%02d 00:00:00'", $this->_value['year'], $this->_value['month'], $this->_value['day']);
      $query->add_where("($table.${main_column['column']} >= $from)");
      $query->add_where("($table.${main_column['column']} < $from + INTERVAL 1 DAY)");
    }
    elseif (isset($this->_value['month'])) {
      $from = sprintf("'%04d-%02d-01 00:00:00'", $this->_value['year'], $this->_value['month']);
      $query->add_where("($table.${main_column['column']} >= $from)");
      $query->add_where("($table.${main_column['column']} < $from + INTERVAL 1 MONTH)");
    }
    elseif (isset($this->_value['year'])) {
      $from = sprintf("'%04d-01-01 00:00:00'", $this->_value['year']);
      $query->add_where("($table.${main_column['column']} >= $from)");
      $query->add_where("($table.${main_column['column']} < $from + INTERVAL 1 YEAR)");
    }
  }
}

/**
 * A facet for Datestamp fields.
 *
 * @see datestamp_facet_category
 */
class datestamp_facet extends date_facet {
  /**
   * Constructor. 
   *
   * @param $field
   *   The field corresponding to this facet.
   * @param $active_path
   *   Array representing the path leading to the active category, including the
   *   active category itself. Defaults to an empty array, meaning no active
   *   category.
   */
  function datestamp_facet($field, $active_path = array()) {
    parent::date_facet($field, $active_path);
  }

  /**
   * Updates a query for retrieving the root categories of this facet and their
   * associated nodes within the current search results. 
   *
   * @param $query
   *   The query object to update.
   * @return
   *   FALSE if this facet can't have root categories.
   */
  function build_root_categories_query(&$query) {
    $db_info = _cck_facets_db_info($this->_field);
    $main_column = array_shift($db_info['columns']);
    $query->add_table($db_info['table'], 'vid', 'n', 'vid');
    $query->add_field(NULL, "YEAR(FROM_UNIXTIME(${db_info['table']}.${main_column['column']}))", $this->_field['field_name'] .'_year');
    $query->add_where($db_info['table'] .'.'. $main_column['column'] .' > 0');
    $query->add_groupby($this->_field['field_name'] .'_year');
    return TRUE;
  }

  /**
   * This factory method creates categories given query results that include the
   * fields selected in get_root_categories_query() or get_subcategories_query().
   *
   * @param $results
   *   $results A database query result resource.
   *
   * @return
   *   Array of categories.
   */
  function build_categories($results) {
    $categories = array();
    while ($result = db_fetch_object($results)) {
      $categories[] = new datestamp_facet_category($this->_field, $result->{$this->_field['field_name'] .'_year'}, $result->{$this->_field['field_name'] .'_month'}, $result->{$this->_field['field_name'] .'_day'}, $result->count);
    }
    return $categories;
  }
}

/**
 * A facet category for Date fields. 
 */
class datestamp_facet_category extends date_facet_category {
  
  /**
   * Constructs a category for the specified date.
   *
   * @param $year
   *   Year corresponding to this category.
   * @param $month
   *   Month corresponding to this category. Optional, but must be specified if
   *   $day is specified.
   * @param $day
   *   Day corresponding to this category. Optional.
   * @param $count
   *   The number of nodes associated to this category within the current
   *   search. Optional.
   */
  function datestamp_facet_category($field, $year, $month = NULL, $day = NULL, $count = NULL) {
    parent::date_facet_category($field, $year, $month, $day, $count);
  }

  /**
   * Updates a query for retrieving the subcategories of this category and their
   * associated nodes within the current search results. 
   *
   * This only needs to be overridden for hierarchical facets.
   *
   * @param $query
   *   The query object to update.
   * @return
   *   FALSE if this facet can't have subcategories.
   */
  function build_subcategories_query(&$query) {
    if (isset($this->_value['day'])) {
      return FALSE; // No subcategories.
    }
    
    $db_info = _cck_facets_db_info($this->_field);
    $main_column = array_shift($db_info['columns']);
    $query->add_table($db_info['table'], 'vid', 'n', 'vid');
    if (isset($this->_value['month'])) {
      $from = sprintf("'%04d-%02d-01 00:00:00'", $this->_value['year'], $this->_value['month']);
      $query->add_field(NULL, "YEAR(FROM_UNIXTIME(${db_info['table']}.${main_column['column']}))", $this->_field['field_name'] .'_year');
      $query->add_field(NULL, "MONTH(FROM_UNIXTIME(${db_info['table']}.${main_column['column']}))", $this->_field['field_name'] .'_month');
      $query->add_field(NULL, "DAY(FROM_UNIXTIME(${db_info['table']}.${main_column['column']}))", $this->_field['field_name'] .'_day');
      $query->add_where("(${db_info['table']}.${main_column['column']} >= $from)");
      $query->add_where("(${db_info['table']}.${main_column['column']} < $from + INTERVAL 1 MONTH)");
      $query->add_groupby($this->_field['field_name'] .'_day');
      return TRUE;
    }
    elseif (isset($this->_value['year'])) {
      $from = sprintf("'%04d-01-01 00:00:00'", $this->_value['year']);
      $query->add_field(NULL, "YEAR(FROM_UNIXTIME(${db_info['table']}.${main_column['column']}))", $this->_field['field_name'] .'_year');
      $query->add_field(NULL, "MONTH(FROM_UNIXTIME(${db_info['table']}.${main_column['column']}))", $this->_field['field_name'] .'_month');
      $query->add_where("(${db_info['table']}.${main_column['column']} >= $from)");
      $query->add_where("(${db_info['table']}.${main_column['column']} < $from + INTERVAL 1 YEAR)");
      $query->add_groupby($this->_field['field_name'] .'_month');
      return TRUE;
    }
    return FALSE; // Unreachable, unless something is wrong...
  }

  /**
   * Updates a query for selecting nodes matching this category.
   *
   * @param $query
   *   The query object to update.
   */
  function build_results_query(&$query) {
    $db_info = _cck_facets_db_info($this->_field);
    $main_column = array_shift($db_info['columns']);
    // Since the same table might be joined multiple times in the query, we use
    // the field's name as the table alias to create a unique table reference.
    $table = $query->add_table($db_info['table'], 'vid', 'n', 'vid', $this->_field['field_name']);
    if (isset($this->_value['day'])) {
      $from = sprintf("'%04d-%02d-%02d 00:00:00'", $this->_value['year'], $this->_value['month'], $this->_value['day']);
      $query->add_where("($table.${main_column['column']} >= UNIX_TIMESTAMP($from))");
      $query->add_where("($table.${main_column['column']} < UNIX_TIMESTAMP($from + INTERVAL 1 DAY))");
    }
    elseif (isset($this->_value['month'])) {
      $from = sprintf("'%04d-%02d-01 00:00:00'", $this->_value['year'], $this->_value['month']);
      $query->add_where("($table.${main_column['column']} >= UNIX_TIMESTAMP($from))");
      $query->add_where("($table.${main_column['column']} < UNIX_TIMESTAMP($from + INTERVAL 1 MONTH))");
    }
    elseif (isset($this->_value['year'])) {
      $from = sprintf("'%04d-01-01 00:00:00'", $this->_value['year']);
      $query->add_where("($table.${main_column['column']} >= UNIX_TIMESTAMP($from))");
      $query->add_where("($table.${main_column['column']} < UNIX_TIMESTAMP($from + INTERVAL 1 YEAR))");
    }
  }
}

/**
 * Checks the validity of a date or partial date.
 */
// TODO: avoid duplication with _date_authored_facet_check_date
function _date_facets_check_date($year = NULL, $month = NULL, $day = NULL) {
  if (!isset($year) || !is_numeric($year) || $year < 1) {
    return FALSE;
  }
  if (isset($month) && (!is_numeric($month) || $month < 1 || $month > 12)) {
    return FALSE;
  }
  if (isset($day) && (!isset($month) || !is_numeric($month) || !is_numeric($day) || !checkdate($month, $day, $year))) {
    return FALSE;
  }
  
  return TRUE;
}