Add reverse geocoding functionality

Author: DivineOmega

README.md

@@ -56,5 +56,14 @@ formula.
 $distance = $fromCoords->distanceTo($toCoords);
 ```
 
+### Reverse Geocoding
 
+To lookup an address from a set of GPD coordinate, use the `reverseGeocode` method, as shown below.
+
+```php
+$address = $simpleGoogleMaps->reverseGeocode(new LatLong(51.5033635, -0.1276248));
+```
+
+This method will return a string containing the address found at the specified coordinates. If no address
+could be found, `null` will be returned.
 

src/Objects/SimpleGoogleMaps.php

@@ -106,4 +106,48 @@ public function geocode(string $address)
         return new LatLong($result->geometry->location->lat, $result->geometry->location->lng);
 
     }
+
+    /**
+     * Look ups an LatLng location, and returns a string containing the address of that location.
+     *
+     * @param LatLong $latLong
+     * @return string
+     * @throws \GuzzleHttp\Exception\GuzzleException
+     */
+    public function reverseGeocode(LatLong $latLong)
+    {
+        $queryUrl = $this->authObject->applyToUrl(
+            $this->baseUrl . "geocode/json?latlng=" . urlencode($latLong->lat.','.$latLong->long)
+        );
+
+        $cacheKey = sha1(serialize([__FUNCTION__, func_get_args()]));
+
+        if (($results = $this->cache->get($cacheKey)) === false) {
+            $response = (new Client())->request('GET', $queryUrl);
+            $results = json_decode($response->getBody());
+        }
+
+        if (!$results) {
+            throw new \Exception('Unable to parse response.');
+        }
+
+        if (!empty($results->error_message)) {
+            throw new \Exception('Error from Google Maps API: '.$results->error_message);
+        }
+
+        if (!$results->results) {
+            return null;
+        }
+
+        $result = $results->results[0];
+
+        if (!isset($result->formatted_address)) {
+            return null;
+        }
+
+        $this->cache->set($cacheKey, $results);
+
+        return (string) $result->formatted_address;
+
+    }
 }

src/example.php

@@ -2,6 +2,7 @@
 require_once __DIR__.'/../vendor/autoload.php';
 
 use LangleyFoxall\SimpleGoogleMaps\Factories\SimpleGoogleMapsFactory;
+use LangleyFoxall\SimpleGoogleMaps\Objects\LatLong;
 
 $address1 = "10 Downing St, Westminster, London SW1A UK";
 $address2 = "Schott House, Drummond Rd, Stafford ST16 3EL";
@@ -12,13 +13,22 @@
 // Enterprise / premium plan authentication:
 // $simpleGoogleMaps = SimpleGoogleMapsFactory::getByClientNameAndCryptKey(getenv('CLIENT_NAME'), getenv('CRYPT_KEY'));
 
+echo 'Geocoding:'.PHP_EOL;
+
 $fromCoords = $simpleGoogleMaps->geocode($address1);
 $toCoords = $simpleGoogleMaps->geocode($address2);
 
 var_dump($fromCoords, $toCoords);
 
+echo 'Distance calculation:'.PHP_EOL;
+
 $distance = $fromCoords->distanceTo($toCoords);
 
 var_dump($distance);
 
+echo 'Reverse geocoding:'.PHP_EOL;
+
+$reverseGeocodeAddress1 = $simpleGoogleMaps->reverseGeocode(new LatLong(51.5033635, -0.1276248));
+$reverseGeocodeAddress2 = $simpleGoogleMaps->reverseGeocode(new LatLong(52.8220531, -2.1127185));
 
+var_dump($reverseGeocodeAddress1, $reverseGeocodeAddress2);