<?php
/**
 * Created by PhpStorm.
 * User: Christof
 * Date: 10.12.2018
 * Time: 21:29
 */

class Googlhelper {

		public $extended;
		private $target;
		private $apiKey;
		private $ch;

		private static $buffer = array();
		function __construct($apiKey = null) {
				# Extended output mode
				$extended = false;
				# Set Google Shortener API target
				$this->target = 'https://www.googleapis.com/urlshortener/v1/url?';
				# Set API key if available
				if ( $apiKey != null ) {
						$this->apiKey = $apiKey;
						$this->target .= 'key='.$apiKey.'&';
				}
				# Initialize cURL
				$this->ch = curl_init();
				# Set our default target URL
				curl_setopt($this->ch, CURLOPT_URL, $this->target);
				# We don't want the return data to be directly outputted, so set RETURNTRANSFER to true
				curl_setopt($this->ch, CURLOPT_RETURNTRANSFER, true);
		}
		public function shorten($url, $extended = false) {

				# Check buffer
				if ( !$extended && !$this->extended && !empty(self::$buffer[$url]) ) {
						return self::$buffer[$url];
				}

				# Payload
				$data = array( 'longUrl' => $url );
				$data_string = '{ "longUrl": "'.$url.'" }';
				# Set cURL options
				curl_setopt($this->ch, CURLOPT_POST, count($data));
				curl_setopt($this->ch, CURLOPT_POSTFIELDS, $data_string);
				curl_setopt($this->ch, CURLOPT_HTTPHEADER, Array('Content-Type: application/json'));
				if ( $extended || $this->extended) {
						return json_decode(curl_exec($this->ch));
				} else {
						$ret = json_decode(curl_exec($this->ch))->id;
						self::$buffer[$url] = $ret;
						return $ret;
				}
		}
		public function expand($url, $extended = false) {
				# Set cURL options
				curl_setopt($this->ch, CURLOPT_HTTPGET, true);
				curl_setopt($this->ch, CURLOPT_URL, $this->target.'shortUrl='.$url);

				if ( $extended || $this->extended ) {
						return json_decode(curl_exec($this->ch));
				} else {
						return json_decode(curl_exec($this->ch))->longUrl;
				}
		}
		function __destruct() {
				# Close the curl handle
				curl_close($this->ch);
				# Nulling the curl handle
				$this->ch = null;
		}
}