<?php
/*
 * (c) Camptocamp <info@camptocamp.com>
 * (c) Patrick Hayes
 *
 * This code is open-source and licenced under the Modified BSD License.
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/**
 * PHP Google Geocoder Adapter
 *
 *
 * @package    geoPHP
 * @author     Patrick Hayes <patrick.d.hayes@gmail.com>
 */
class GoogleGeocode extends GeoAdapter
{

	/**
	 * Read an address string or array geometry objects
	 *
	 * @param string - Address to geocode
	 * @param string - Type of Geometry to return. Can either be 'points' or 'bounds' (polygon)
	 * @param Geometry|bounds-array - Limit the search area to within this region. For example
	 *                                by default geocoding "Cairo" will return the location of Cairo Egypt.
	 *                                If you pass a polygon of illinois, it will return Cairo IL.
	 * @param return_multiple - Return all results in a multipoint or multipolygon
	 * @return Geometry|GeometryCollection
	 */
	public function read($address, $return_type = 'point', $bounds = false, $return_multiple = false)
	{
		if (is_array($address)) $address = join(',', $address);

		if (gettype($bounds) == 'object') {
			$bounds = $bounds->getBBox();
		}
		if (gettype($bounds) == 'array') {
			$bounds_string = '&bounds='.$bounds['miny'].','.$bounds['minx'].'|'.$bounds['maxy'].','.$bounds['maxx'];
		} else {
			$bounds_string = '';
		}

		$url = "http://maps.googleapis.com/maps/api/geocode/json";
		$url .= '?address='. urlencode($address);
		$url .= $bounds_string;
		$url .= '&sensor=false';
		$this->result = json_decode(@file_get_contents($url));

		if ($this->result->status == 'OK') {
			if ($return_multiple == false) {
				if ($return_type == 'point') {
					return $this->getPoint();
				}
				if ($return_type == 'bounds' || $return_type == 'polygon') {
					return $this->getPolygon();
				}
			}
			if ($return_multiple == true) {
				if ($return_type == 'point') {
					$points = array();
					foreach ($this->result->results as $delta => $item) {
						$points[] = $this->getPoint($delta);
					}
					return new MultiPoint($points);
				}
				if ($return_type == 'bounds' || $return_type == 'polygon') {
					$polygons = array();
					foreach ($this->result->results as $delta => $item) {
						$polygons[] = $this->getPolygon($delta);
					}
					return new MultiPolygon($polygons);
				}
			}
		} else {
			if ($this->result->status) throw new Exception('Error in Google Geocoder: '.$this->result->status);
			else throw new Exception('Unknown error in Google Geocoder');
			return false;
		}
	}

	/**
	 * Serialize geometries into a WKT string.
	 *
	 * @param Geometry $geometry
	 * @param string $return_type Should be either 'string' or 'array'
	 *
	 * @return string Does a reverse geocode of the geometry
	 */
	public function write(Geometry $geometry, $return_type = 'string')
	{
		$centroid = $geometry->getCentroid();
		$lat = $centroid->getY();
		$lon = $centroid->getX();

		$url = "http://maps.googleapis.com/maps/api/geocode/json";
		$url .= '?latlng='.$lat.','.$lon;
		$url .= '&sensor=false';
		$this->result = json_decode(@file_get_contents($url));

		if ($this->result->status == 'OK') {
			if ($return_type == 'string') {
				return $this->result->results[0]->formatted_address;
			}
			if ($return_type == 'array') {
				return $this->result->results[0]->address_components;
			}
		} elseif ($this->result->status == 'ZERO_RESULTS') {
			if ($return_type == 'string') {
				return '';
			}
			if ($return_type == 'array') {
				return $this->result->results;
			}
		} else {
			if ($this->result->status) throw new Exception('Error in Google Reverse Geocoder: '.$this->result->status);
			else throw new Exception('Unknown error in Google Reverse Geocoder');
			return false;
		}
	}

	private function getPoint($delta = 0)
	{
		$lat = $this->result->results[$delta]->geometry->location->lat;
		$lon = $this->result->results[$delta]->geometry->location->lng;
		return new Point($lon, $lat);
	}

	private function getPolygon($delta = 0)
	{
		$points = array (
		$this->getTopLeft($delta),
		$this->getTopRight($delta),
		$this->getBottomRight($delta),
		$this->getBottomLeft($delta),
		$this->getTopLeft($delta),
		);
		$outer_ring = new LineString($points);
		return new Polygon(array($outer_ring));
	}

	private function getTopLeft($delta = 0)
	{
		$lat = $this->result->results[$delta]->geometry->bounds->northeast->lat;
		$lon = $this->result->results[$delta]->geometry->bounds->southwest->lng;
		return new Point($lon, $lat);
	}

	private function getTopRight($delta = 0)
	{
		$lat = $this->result->results[$delta]->geometry->bounds->northeast->lat;
		$lon = $this->result->results[$delta]->geometry->bounds->northeast->lng;
		return new Point($lon, $lat);
	}

	private function getBottomLeft($delta = 0)
	{
		$lat = $this->result->results[$delta]->geometry->bounds->southwest->lat;
		$lon = $this->result->results[$delta]->geometry->bounds->southwest->lng;
		return new Point($lon, $lat);
	}

	private function getBottomRight($delta = 0)
	{
		$lat = $this->result->results[$delta]->geometry->bounds->southwest->lat;
		$lon = $this->result->results[$delta]->geometry->bounds->northeast->lng;
		return new Point($lon, $lat);
	}
}