<?php
App::uses('ModelBehavior', 'Model');
App::uses('GeocodeLib', 'Tools.Lib');

/**
 * A geocoding behavior for CakePHP to easily geocode addresses.
 * Uses the GeocodeLib for actual geocoding.
 * Also provides some useful geocoding tools like validation and distance conditions
 *
 * @author Mark Scherer
 * @cakephp 2.x
 * @licence MIT
 * 2011-01-13 ms
 */
class GeocoderBehavior extends ModelBehavior {

	/**
	 * Initiate behavior for the model using specified settings. Available settings:
	 *
	 * - address: (array | string, optional) set to the field name that contains the
	 * 			string from where to generate the slug, or a set of field names to
	 * 			concatenate for generating the slug.
	 *
	 * - real: (boolean, optional) if set to true then field names defined in
	 * 			label must exist in the database table. DEFAULTS TO: false
	 *
	 * - expect: (array)postal_code, locality, sublocality, ...
	 *
	 * - accuracy: see above
	 *
	 * - override: lat/lng override on changes?
	 *
	 * - update: what fields to update (key=>value array pairs)
	 *
	 * - before: validate/save (defaults to save)
	 * 			set to false if you only want to use the validation rules etc
	 *
	 * @param object $Model Model using the behaviour
	 * @param array $settings Settings to override for model.
	 */
	public function setup(Model $Model, $settings = array()) {
		$default = array(
			'real' => false, 'address' => array('street', 'postal_code', 'city', 'country'),
			'require' => false, 'allowEmpty' => true, 'invalidate' => array(), 'expect' => array(),
			'lat' => 'lat', 'lng' => 'lng', 'formatted_address' => 'formatted_address', 'host' => null, 'language' => 'de', 'region' => '', 'bounds' => '',
			'overwrite' => false, 'update' => array(), 'before' => 'save',
			'min_accuracy' => GeocodeLib::ACC_COUNTRY, 'allow_inconclusive' => true, 'unit' => GeocodeLib::UNIT_KM,
			'log' => true, // log successfull results to geocode.log (errors will be logged to error.log in either case)
		);

		if (!isset($this->settings[$Model->alias])) {
			$this->settings[$Model->alias] = $default;
		}

		$this->settings[$Model->alias] = array_merge($this->settings[$Model->alias], is_array($settings) ? $settings : array());
	}

	public function beforeValidate(Model $Model, $options = array()) {
		parent::beforeValidate($Model, $options);

		if ($this->settings[$Model->alias]['before'] === 'validate') {
			return $this->geocode($Model);
		}

		return true;
	}

	public function beforeSave(Model $Model, $options = array()) {
		parent::beforeSave($Model, $options);

		if ($this->settings[$Model->alias]['before'] === 'save') {
			return $this->geocode($Model);
		}

		return true;
	}

	/**
	 * Run before a model is saved, used to set up slug for model.
	 *
	 * @param object $Model Model about to be saved.
	 * @return boolean True if save should proceed, false otherwise
	 */
	public function geocode(Model $Model, $return = true) {
		// Make address fields an array
		if (!is_array($this->settings[$Model->alias]['address'])) {
			$addressfields = array($this->settings[$Model->alias]['address']);
		} else {
			$addressfields = $this->settings[$Model->alias]['address'];
		}
		$addressfields = array_unique($addressfields);

		// Make sure all address fields are available
		if ($this->settings[$Model->alias]['real']) {
			foreach ($addressfields as $field) {
				if (!$Model->hasField($field)) {
					return $return;
				}
			}
		}

		$adressdata = array();
		foreach ($addressfields as $field) {
			if (!empty($Model->data[$Model->alias][$field])) {
				$adressdata[] = $Model->data[$Model->alias][$field];
			}
		}

		$Model->data[$Model->alias]['geocoder_result'] = array();

		// See if we should geocode //TODO: reverse and return here
		if ((!$this->settings[$Model->alias]['real'] || ($Model->hasField($this->settings[$Model->alias]['lat']) && $Model->hasField($this->settings[$Model->alias]['lng']))) &&
			($this->settings[$Model->alias]['overwrite'] || (empty($Model->data[$Model->alias][$this->settings[$Model->alias]['lat']]) || ((int)$Model->data[$Model->alias][$this->settings[$Model->alias]['lat']] === 0 && (int)$Model->data[$Model->alias][$this->settings[$Model->alias]['lng']] === 0))))
		{
			if (!empty($Model->whitelist) && (!in_array($this->settings[$Model->alias]['lat'], $Model->whitelist) || !in_array($this->settings[$Model->alias]['lng'], $Model->whitelist))) {
				/** HACK to prevent 0 inserts if not wanted! just use whitelist now to narrow fields down - 2009-03-18 ms */
				//$Model->whitelist[] = $this->settings[$Model->alias]['lat'];
				//$Model->whitelist[] = $this->settings[$Model->alias]['lng'];
				return $return;
			}

			$geocode = $this->_geocode($adressdata, $this->settings[$Model->alias]);

			if (empty($geocode) && !empty($this->settings[$Model->alias]['allowEmpty'])) {
				return true;
			}
			if (empty($geocode)) {
				return false;
			}

			// if both are 0, thats not valid, otherwise continue
			if (!empty($geocode['lat']) || !empty($geocode['lng'])) { /** HACK to prevent 0 inserts of incorrect runs - 2009-04-07 ms */
				$Model->data[$Model->alias][$this->settings[$Model->alias]['lat']] = $geocode['lat'];
				$Model->data[$Model->alias][$this->settings[$Model->alias]['lng']] = $geocode['lng'];
			} else {
				if (isset($Model->data[$Model->alias][$this->settings[$Model->alias]['lat']])) {
					unset($Model->data[$Model->alias][$this->settings[$Model->alias]['lat']]);
				}
				if (isset($Model->data[$Model->alias][$this->settings[$Model->alias]['lng']])) {
					unset($Model->data[$Model->alias][$this->settings[$Model->alias]['lng']]);
				}
				if ($this->settings[$Model->alias]['require']) {
					if ($fields = $this->settings[$Model->alias]['invalidate']) {
						$Model->invalidate($fields[0], $fields[1], isset($fields[2]) ? $fields[2] : true);
					}
					return false;
				}
			}

			if (!empty($this->settings[$Model->alias]['formatted_address'])) {
				$Model->data[$Model->alias][$this->settings[$Model->alias]['formatted_address']] = $geocode['formatted_address'];
			} else {
				if (isset($Model->data[$Model->alias][$this->settings[$Model->alias]['formatted_address']])) {
					unset($Model->data[$Model->alias][$this->settings[$Model->alias]['formatted_address']]);
				}
			}

			if (!empty($geocode['inconclusive'])) {
				$Model->data[$Model->alias]['geocoder_inconclusive'] = $geocode['inconclusive'];
				$Model->data[$Model->alias]['geocoder_results'] = $geocode['results'];
			} else {
				$Model->data[$Model->alias]['geocoder_result'] = $geocode;
			}

			$Model->data[$Model->alias]['geocoder_result']['address_data'] = implode(' ', $adressdata);

			if (!empty($this->settings[$Model->alias]['update'])) {
				foreach ($this->settings[$Model->alias]['update'] as $key => $field) {
					if (!empty($geocode[$key])) {
						$Model->data[$Model->alias][$field] = $geocode[$key];
					}
				}
			}
		}

		return $return;
	}

	/**
	 * Add the distance to this point as a virtual field
	 *
	 * @param Model $Model
	 * @param string|float $lat Fieldname (Model.lat) or float value
	 * @param string|float $lng Fieldname (Model.lng) or float value
	 * @return void
	 */
	public function setDistanceAsVirtualField(Model $Model, $lat, $lng, $modelName = null) {
		$Model->virtualFields['distance'] = $this->distance($Model, $lat, $lng, null, null, $modelName);
	}

	/**
	 * Form a sql snippet for distance calculation on db level using two lat/lng points
	 *
	 * @param string|float $lat Fieldname (Model.lat) or float value
	 * @param string|float $lng Fieldname (Model.lng) or float value
	 * @return string
	 */
	public function distance(Model $Model, $lat, $lng, $fieldLat = null, $fieldLng = null, $modelName = null) {
		if ($fieldLat === null) {
			$fieldLat = $this->settings[$Model->alias]['lat'];
		}
		if ($fieldLng === null) {
			$fieldLng = $this->settings[$Model->alias]['lng'];
		}
		if ($modelName === null) {
			$modelName = $Model->alias;
		}

		$value = $this->_calculationValue($this->settings[$Model->alias]['unit']);

		return $value . ' * ACOS(COS(PI()/2 - RADIANS(90 - '.$modelName.'.'.$fieldLat.')) * ' .
			'COS(PI()/2 - RADIANS(90 - '. $lat .')) * ' .
			'COS(RADIANS('.$modelName.'.'.$fieldLng.') - RADIANS('. $lng .')) + ' .
			'SIN(PI()/2 - RADIANS(90 - '.$modelName.'.'.$fieldLat.')) * ' .
			'SIN(PI()/2 - RADIANS(90 - '. $lat . ')))';
	}

	/**
	 * snippet for custom pagination
	 *
	 * @return array
	 */
	public function distanceConditions(Model $Model, $distance = null, $fieldName = null, $fieldLat = null, $fieldLng = null, $modelName = null) {
		if ($fieldLat === null) {
			$fieldLat = $this->settings[$Model->alias]['lat'];
		}
		if ($fieldLng === null) {
			$fieldLng = $this->settings[$Model->alias]['lng'];
		}
		if ($modelName === null) {
			$modelName = $Model->alias;
		}
		$conditions = array(
			$modelName . '.'.$fieldLat.' <> 0',
			$modelName . '.'.$fieldLng.' <> 0',
		);
		$fieldName = !empty($fieldName) ? $fieldName : 'distance';
		if ($distance !== null) {
			$conditions[] = '1=1 HAVING '.$modelName.'.'.$fieldName.' < ' . intval($distance);
		}
		return $conditions;
	}

	/**
	 * snippet for custom pagination
	 *
	 * @return string
	 */
	public function distanceField(Model $Model, $lat, $lng, $fieldName = null, $modelName = null) {
		if ($modelName === null) {
			$modelName = $Model->alias;
		}
		$fieldName = (!empty($fieldName) ? $fieldName : 'distance');
		return $this->distance($Model, $lat, $lng, null, null, $modelName) . ' AS '.$modelName.'.'.$fieldName;
	}

	/**
	 * snippet for custom pagination
	 * still useful?
	 *
	 * @return string
	 */
	public function distanceByField(Model $Model, $lat, $lng, $byFieldName = null, $fieldName = null, $modelName = null) {
		if ($modelName === null) {
			$modelName = $Model->alias;
		}
		if ($fieldName === null) {
			$fieldName = 'distance';
		}
		if ($byFieldName === null) {
			$byFieldName = 'radius';
		}

		return $this->distance($Model, $lat, $lng, null, null, $modelName).' '.$byFieldName;
	}

	/**
	 * snippet for custom pagination
	 *
	 * @return int $count
	 */
	public function paginateDistanceCount(Model $Model, $conditions = null, $recursive = -1, $extra = array()) {
		if (!empty($extra['radius'])) {
			$conditions[] = $extra['distance'].' < '.$extra['radius'].(!empty($extra['startRadius'])?' AND '.$extra['distance'].' > '.$extra['startRadius']:'').(!empty($extra['endRadius'])?' AND '.$extra['distance'].' < '.$extra['endRadius']:'');
		}
		if (!empty($extra['group'])) {
			unset($extra['group']);
		}
		$extra['behavior'] = true;
		return $Model->paginateCount($conditions, $recursive, $extra);
	}

	/**
	 * Returns if a latitude is valid or not.
	 * validation rule for models
	 *
	 * @param Model
	 * @param float $latitude
	 * @return bool
	 */
	public function validateLatitude(Model $Model, $latitude) {
		if (is_array($latitude)) {
			$latitude = array_shift($latitude);
		}
		return ($latitude <= 90 && $latitude >= -90);
	}

	/**
	 * Returns if a longitude is valid or not.
	 * validation rule for models
	 *
	 * @param Model
	 * @param float $longitude
	 * @return bool
	 */
	public function validateLongitude(Model $Model, $longitude) {
		if (is_array($longitude)) {
			$longitude = array_shift($longitude);
		}
		return ($longitude <= 180 && $longitude >= -180);
	}

	/**
	 * uses the GeocodeLib to query
	 * @param array $addressFields (simple array of address pieces)
	 * @return array
	 */
	protected function _geocode($addressFields, $options = array()) {
		$address = implode(' ', $addressFields);
		if (empty($address)) {
			return array();
		}

		$geocodeOptions = array(
			'log' => $options['log'], 'min_accuracy' => $options['min_accuracy'],
			'expect' => $options['expect'], 'allow_inconclusive' => $options['allow_inconclusive'],
			'host' => $options['host']
		);
		$this->Geocode = new GeocodeLib($geocodeOptions);

		$settings = array('language' => $options['language']);
		if (!$this->Geocode->geocode($address, $settings)) {
			return array('lat' => 0, 'lng' => 0, 'formatted_address' => '');
		}

		$res = $this->Geocode->getResult();
		if (isset($res[0])) {
			$res = $res[0];
		}
		return $res;
	}

	/**
	 * Get the current unit factor
	 *
	 * @param integer $unit Unit constant
	 * @return float Value
	 */
	protected function _calculationValue($unit) {
		if (!isset($this->Geocode)) {
			$this->Geocode = new GeocodeLib();
		}
		return $this->Geocode->convert(6371.04, GeocodeLib::UNIT_KM, $unit);
	}

}