Postcode Lookup using the Google Geocoding API

PostcodeLookupController.php

<?php

namespace App\Http\Controllers\Api;

use GuzzleHttp\Client;
use Illuminate\Http\Request;
use App\Http\Controllers\Controller as BaseController;
use Illuminate\Http\Response;
use App\Mappers\Response\Address as AddressMapper;

class PostcodeLookupController extends BaseController
{
    /**
     * @param Request $request
     * @param Client $client
     * @return \Illuminate\Http\JsonResponse
     */
    public function address(Request $request, Client $client)
    {
        $postcode = $request->query('postcode');

        if (null === $postcode) {
            return response()->json(
                ['errorMessage' => 'Please enter a postcode.'],
                Response::HTTP_UNPROCESSABLE_ENTITY
            );
        }

        if (!is_string($postcode)) {
            return response()->json(
                ['errorMessage' => 'Please enter a valid postcode.'],
                Response::HTTP_UNPROCESSABLE_ENTITY
            );
        }

        $postcode = preg_replace('/[^A-Z0-9 ]/', '', strtoupper($postcode));
        $key = config('app.api.keys.google_cloud');

        $response = $client->get(
            'https://maps.googleapis.com/maps/api/geocode/json?' . http_build_query([
                'address' => urlencode($postcode),
                'key' => $key,
            ])
        );

        $body = json_decode($response->getBody()->getContents(), true);

        if (empty($body['results'])) {
            return response()->json(
                ['errorMessage' => 'Unable to get lat and lng from postcode.'],
                Response::HTTP_UNPROCESSABLE_ENTITY
            );
        }

        $lat = $body['results'][0]['geometry']['location']['lat'];
        $lng = $body['results'][0]['geometry']['location']['lng'];

        $response = $client->get(
            'https://maps.googleapis.com/maps/api/geocode/json?' . http_build_query([
                'latlng' => $lat . ',' . $lng,
                'key' => $key,
            ])
        );

        $body = json_decode($response->getBody()->getContents(), true);

        if (empty($body['results'])) {
            return response()->json(
                ['errorMessage' => 'Unable to get address components from lat and lng.'],
                Response::HTTP_UNPROCESSABLE_ENTITY
            );
        }

        $apiResponse = [];

        foreach ($body['results'] as $i => $result) {
            $addressData = $result['address_components'];
            foreach ($addressData as $data) {
                $apiResponse[$i][$data['types'][0]] = $data['long_name'];
            }
        }

        $response = [
            'latitude' => $lat,
            'longitude' => $lng,
            'addresses' => [],
        ];

        foreach ($apiResponse as $i => $address) {
            $mappedAddress = AddressMapper::map($address);
            if (empty($mappedAddress['postcode'])) {
                continue;
            }

            $response['addresses'][$i] = [
                'text' => implode(', ', array_filter($mappedAddress)),
                'parts' => $mappedAddress,
            ];
        }

        return response()->json($response);
    }
}

// ...

namespace App\Mappers\Response;

interface MapperInterface
{
    /**
     * @param array $raw
     * @return array
     */
    public function map(array $raw);
}

class Address implements MapperInterface
{
    /**
     * @param array $raw
     * @return array
     */
    public function map($raw)
    {
        $response = [
            'subdivision' => '',
            'address' => '',
            'town' => '',
            'county' => '',
            'postcode' => '',
        ];

        if (isset($raw['premise'])) {
            $response['subdivision'] = $raw['premise'];
        }
        if (isset($raw['street_number'])) {
            $response['address'] = $raw['street_number'];
        }
        if (isset($raw['route']) && 'Unnamed Road' !== $raw['route']) {
            if ('' !== $response['address']) {
                $response['address'] .= ' ';
            }
            $response['address'] .= $raw['route'];
        }
        if (isset($raw['postal_town'])) {
            $response['town'] = $raw['postal_town'];
        }
        if (isset($raw['administrative_area_level_2'])) {
            $response['county'] = $raw['administrative_area_level_2'];
        }
        if (isset($raw['postal_code'])) {
            $response['postcode'] = $raw['postal_code'];
        }

        return $response;
    }
}