<?php

/**
 * @file
 * Module file for geocoder module.
 */

include_once('geocoder.widget.inc');
include_once('geocoder.services.inc');

define('GEOCODER_GOOGLE_AUTH_NONE', 1);
define('GEOCODER_GOOGLE_AUTH_KEY', 2);
define('GEOCODER_GOOGLE_AUTH_WORK', 3);

/**
 * The Geocoder API call.
 *
 * Given a handler and data, geocode the data into a geometry object using the handler.
 *
 * @param string $handler
 *   The geocoder handler to use. Call geocoder_handler_info() to get a list
 *
 * @param mixed $data
 *   Data to be passed into the handler for geocoding. For example a address string.
 *
 * @param array $options
 *   Additional options to pass to the handler. Exact key / values to pass depend on the handler.
 *
 * @param int $cache_type
 *   DEPRECATED. All results are cached persistently.
 *
 * @param bool $cache_reset
 *   (optional) Ignore potentially matched cache record, and live fetch. Defaults to FALSE.
 *
 * @return Geometry
 *   Returns a geoPHP geometry object. Generally a Point.
 *   See http://drupal.org/project/geoPHP and https://github.com/phayes/geoPHP/wiki/API-Reference
 *
 * @example:
 *    geocoder('google','4925 Gair Ave, Terrace, BC');
 *    geocoder('google','New York City',array('geometry_type' => 'bounds'));
 */
function geocoder($handler, $data, $options = array(), $cache_type = 'DEPRECATED', $cache_reset = FALSE) {
  ctools_include('plugins');

  $processor = ctools_get_plugins('geocoder', 'geocoder_handler', $handler);
  if (!$processor) {
    return NULL;
  }

  // Attempt to retrieve from persistent cache.
  $geometry = $cache_reset ? NULL : geocoder_cache_get($handler, $data, $options);

  // No cache record, so fetch live.
  if ($geometry === NULL) {
    try {
      // Load the file.
      geocoder_get_handler($handler);
      $geometry = call_user_func($processor['callback'], $data, $options);
    }
    catch (Exception $e) {
      watchdog_exception('geocoder', $e);
      return NULL;
    }

    // Always save result into persistent cache.
    geocoder_cache_set($geometry, $handler, $data, $options);
  }

  return $geometry;
}


/**
 * Implements hook_menu().
 */
function  geocoder_menu() {
  // Admin settings for the site.
  $items['admin/config/content/geocoder'] = array(
    'title' => 'Geocoder settings',
    'description' => 'Configuration for API keys.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('geocoder_admin_settings'),
    'file' => 'geocoder.admin.inc',
    'access arguments' => array('administer site configuration'),
    'type' => MENU_NORMAL_ITEM, // optional
  );
  $items['geocoder/service/%'] = array(
    'title' => 'AJAX / AJAJ geocoding service',
    'description' => 'Provides basic callback for geocoding using JavaScript',
    'page callback' => 'geocoder_service_callback',
    'page arguments' => array(2),
    'type' => MENU_CALLBACK,
    'access arguments' => array(arg(2)),
    'access callback' => 'geocoder_service_check_perms',
  );
  return $items;
}


/**
 * Geocoder Handler Information
 *
 * Return a list of all handlers that might geocode something for you.
 * Optionally you may pass a field-type and get back a list of
 * handlers that are compatible with that field.
 */
function geocoder_handler_info($field_type = NULL) {
  ctools_include('plugins');

  static $handlers;
  if (!$handlers) {
    $handlers = ctools_get_plugins('geocoder', 'geocoder_handler');
  }
  if ($field_type) {
    $field_handlers = $handlers;
    foreach ($field_handlers as $i => $handler) {
      if (!isset($handler['field_types']) || !in_array($field_type, $handler['field_types'])) {
        unset($field_handlers[$i]);
      }
    }
    return $field_handlers;
  }
  return $handlers;
}

/**
 * Fetch geocoder handler
 *
 * Given a name, fetch the full handler definition
 */
function geocoder_get_handler($handler_name) {
  $handlers = geocoder_handler_info();
  if (isset($handlers[$handler_name])) {
    require_once $handlers[$handler_name]['path'] . '/' . $handlers[$handler_name]['file'];
    return $handlers[$handler_name];
  }
  else return FALSE;
}

/**
 * Get supported field types
 *
 * Get a list of supported field types along with the processors that support them
 */
function geocoder_supported_field_types() {
  $supported = array();

  $processors = geocoder_handler_info();

  foreach ($processors as $processor) {
    if (isset($processor['field_types'])) {
      foreach ($processor['field_types'] as $field_type) {
        $supported[$field_type][] = $processor['name'];
      }
    }
  }

  return $supported;
}


/**
 * Implementation of hook_ctools_plugin_api().
 */
function geocoder_ctools_plugin_api() {
  return array('version' => 1);
}

/**
 * Implementation of hook_ctools_plugin_directory() to let the system know
 * we implement plugins.
 */
function geocoder_ctools_plugin_directory($module, $plugin) {
  return 'plugins/' . $plugin;
}

/**
 * Implements hook_ctools_plugin_type
 */
function geocoder_ctools_plugin_type() {
  return array(
    'geocoder_handler' => array(
      'cache' => TRUE,
    ),
  );
}

// These functions have to do with providing AJAX / AHAH
// service functionality so that users can make use of
// geocoder interactively via JavaScript.

/**
 * Implements hook_permission().
 *
 * We define permissions for accessing geocoder over AJAX / services.
 * There is one global permission which gives access to everything,
 * and one permission per handler. The site-administrator can therefore
 * fine tune which handlers are accessible. Note that to use AJAX with
 * geocoder these permissions need to be set.
 */
function geocoder_permission() {
  $handler_info = geocoder_handler_info();
  $perms = array(
    'geocoder_service_all_handlers' =>  array(
      'title' => t('Can use all Geocoder handlers through AJAX / service'),
    ),
  );
  foreach ($handler_info as $name => $handler) {
    $perms['geocoder_service_handler_' . $name] = array(
      'title' => t('Can geocode using @handler through AJAX / service', array('@handler' => $handler['title'])),
    );
  }
  return $perms;
}

/**
 * Geocoder service check permissions
 *
 * Given a handler, check to see if the user has
 * permission to execute it via AJAX / services
 */
function geocoder_service_check_perms($handler) {
  return (user_access('geocoder_service_all_handlers') || user_access('geocoder_service_handler_' . $handler));
}

/**
 * Page callback for AJAX / Geocoder service
 *
 * This service can be accessed at /geocoder/service/<handler>
 * and takes the query-parameter "data". Optionally a "output"
 * parameter may also be passed. "output" corresponds to
 * geoPHP output formats.
 *
 * Some examples:
 * /geocoder/service/google?data=4925 Gair Ave, Terrace, BC
 * /geocoder/service/wkt?data=POINT(10 10)
 * /geocoder/service/yahoo?data=94112&output=wkt
 */
function geocoder_service_callback($handler) {
  if (!isset($_GET['data'])) {
    throw new Exception(t('No data parameter found'));
    exit();
  }

  $format = isset($_GET['output']) ?  $_GET['output'] : 'json';

  geophp_load();
  geocoder_service_check_request($handler, $format);
  $geom = geocoder($handler, $_GET['data']);

  header('Content-Type: ' . geocoder_service_get_content_type($format));
  print $geom->out($format);
  exit();
}

/**
 * Get Content-Type for an output format
 *
 * Given an output format, this helper function passes
 * a compatible HTTP content-type to be placed in the
 * header.
 */
function geocoder_service_get_content_type($format) {
  $types = array(
    'json' => 'application/json',
    'kml' => 'application/xml',
    'georss' => 'application/xml',
    'gpx' => 'application/xml',
    'wkt' => 'text/plain',
    'wkb' => 'text/plain',
    'google_geocode' => 'text/plain',
  );
  return $types[$format];
}

/**
 * Geocoder Service Check Request
 *
 * Check to make sure the request to the service is valid. This
 * checks to make sure the handler and the format exists, and
 * also checks permission
 */
function geocoder_service_check_request($handler, $format, $check_ac = TRUE) {
  if (!geocoder_get_handler($handler)) {
    drupal_set_message(t('Could not find handler @handler', array('@handler' => $handler)), 'error');
    drupal_not_found();
    exit();
  }
  if (($format && $format != 'default') && !in_array($format, array_keys(geoPHP::getAdapterMap()))) {
    throw new Exception(t('Could not find output-format @format', array('@format' => $format)), 'error');
    exit();
  }
  if (!geocoder_service_check_perms($handler)) {
    drupal_access_denied();
    exit();
  }
}

/**
 * Create a unified cache id from relevant cache data.
 */
function _geocoder_cache_cid($data) {
  ksort($data);
  return sha1(serialize($data));
}

/**
 * Retrieve a cached geocoded location.
 *
 * @param string $handler
 *   The handler used to geocode this data.
 * @param mixed $data
 *   The data used to fetch live geo data.
 * @param array $options
 *   Handler-specific options that have effect on the result.
 *
 * @return Geometry
 *   A Geometry object, FALSE (no result), or NULL (no cache).
 */
function geocoder_cache_get($handler, $data, $options) {
  $data = compact('handler', 'data', 'options');
  $cid = _geocoder_cache_cid($data);

  geophp_load();
  if ($cache = cache_get($cid, 'cache_geocoder')) {
    return $cache->data['geometry'];
  }
}

/**
 * Cache a geocoded result.
 *
 * @param mixed $geometry
 *   A Geometry object, or FALSE (no result).
 * @param string $handler
 *   The handler used to geocode this data.
 * @param mixed $data
 *   The data used to fetch live geo data.
 * @param array $options
 *   Handler-specific options that have effect on the result.
 */
function geocoder_cache_set($geometry, $handler, $data, $options) {
  // Don't cache no-results, to live geocode the same data again next time.
  if (!$geometry && !variable_get('geocoder_cache_empty_results', TRUE)) {
    return;
  }

  // Construct the cache id from result-relevant parameters.
  $data = compact('handler', 'data', 'options');
  $cid = _geocoder_cache_cid($data);

  // Cache result-relevant parameters together with the actual result, so cache records can be traced.
  $data['geometry'] = $geometry ? $geometry : FALSE;
  cache_set($cid, $data, 'cache_geocoder', variable_get('geocoder_cache_ttl', CACHE_PERMANENT));
}