<?php

namespace App\Service\Google;

use Exception;
use Qs_Config;
use Qs_Array;
use Qs_Cache;
use Zend_Cache_Core;
use App\Service\Google\Geocoding\Response;

class Geocoding
{
    const STATUS_OK           = 'OK';
    const STATUS_ZERO_RESULTS = 'ZERO_RESULTS';

    const MSG_UNKNOWN_ERROR = 'msgUnknownError';
    const MSG_ZERO_RESULTS  = 'msgZeroResults';

    /** @var  string */
    protected $_address;

    protected $_sensor = false;

    /** @var Response */
    protected $_response;

    /** @var  array */
    protected $_config;

    protected $_configAlias = 'Service\\Google\\Geocoding';

    protected $_messages = [
        self::MSG_UNKNOWN_ERROR => 'Unknown error',
        self::MSG_ZERO_RESULTS  => 'The geographical coordinates can\'t be determined for the specified address criteria'
    ];

    /** @var  string */
    protected $_error;

    /** @var  Zend_Cache_Core */
    protected $_cache;

    /**
     * @param string $address
     * @throws Exception
     */
    public function __construct($address)
    {
        if (empty($address)) {
            throw new Exception('Address is empty');
        }
        $this->_address = $address;
    }

    public function send()
    {
        $cacheId = md5($this->_address);
        $results = $this->_getCache()->load($cacheId);

        if (empty($results)) {
            $params = [
                'address' => $this->_address,
                'sensor'  => $this->_sensor,
                'key'     => $this->_getConfig('apiKey'),
            ];
            $query = http_build_query($params);
            $url = $this->_getConfig('gateway');

            $ch = curl_init();
            curl_setopt($ch, CURLOPT_URL, $url . '?' . $query);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
            curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
            $json = curl_exec($ch);
            curl_close($ch);

            $response = [];
            if ($json) {
                $response = json_decode($json, true);
            }

            if ($response) {
                switch (Qs_Array::get($response, 'status', '')) {
                    case self::STATUS_OK:
                        $results = reset($response['results']);
                        $this->_getCache()->save($results, $cacheId);
                        break;

                    case self::STATUS_ZERO_RESULTS:
                        $this->setError($this->_messages[self::MSG_ZERO_RESULTS]);
                        break;

                    default:
                        $this->setError($this->_messages[self::MSG_UNKNOWN_ERROR]
                            . ': ' . Qs_Array::get($response, 'error_message', ''));
                }
            } else {
                $this->setError($this->_messages[self::MSG_UNKNOWN_ERROR]
                    . ': ' . Qs_Array::get($response, 'error_message', ''));
            }
        }

        if (!empty($results)) {
            $this->_response = new Response($results);
            return true;
        }
        return false;
    }

    public function getResponse()
    {
        return $this->_response;
    }

    protected function _getCache()
    {
        if (null === $this->_cache) {
            $frontendOptions = array(
                'lifetime'                => null,
                'automatic_serialization' => true
            );
            $this->_cache = Qs_Cache::factory('Core', 'File', $frontendOptions);
        }
        return $this->_cache;
    }

    protected function _getConfig($field = null)
    {
        if (null === $this->_config) {
            $this->_config = Qs_Config::get($this->_configAlias, Qs_Config::APP_TYPE)->toArray();
        }
        return $field ? $this->_config[$field] : $this->_config;
    }

    /**
     * @param string $error
     * @return $this
     */
    public function setError($error)
    {
        $this->_error = $error;
        return $this;
    }

    /**
     * @return string
     */
    public function getError()
    {
        return $this->_error;
    }
}