curl.php

<?php

class HttpError extends Exception { }

class Curl {

	private $ch;
	private $headers;

	protected function baseSettings() {
		return [
			/* Flags */
			CURLOPT_HEADER         => false,
			CURLOPT_AUTOREFERER    => false,
			CURLOPT_FORBID_REUSE   => false,
			CURLOPT_SSL_VERIFYPEER => false,
			CURLOPT_FOLLOWLOCATION => false,

			CURLOPT_RETURNTRANSFER => true,

			/* Strings */
			CURLOPT_ENCODING 			 => '',
			CURLOPT_USERAGENT			 => 'Mozilla/5.0 (X11; Linux x86_64; rv:29.0) Gecko/20100101 Firefox/27.0',

			/* Integers */
			CURLOPT_TIMEOUT				 => 10,
			CURLOPT_HTTP_VERSION   => CURL_HTTP_VERSION_1_1,
			CURLOPT_CONNECTTIMEOUT => 5,
		]; 
	}

	protected function applyBaseSettings() {
		$this->headers['DNT'] = 1;

		curl_setopt_array($this->ch, $this->baseSettings());
	}

	public static function create() {
		return new self;
	}

	public function __construct() {
		$this->ch = curl_init();
		self::applyBaseSettings($this->ch);
	}

	public function __destruct() {
		curl_close($this->ch);
	}

	public function setUrl($url) {
		curl_setopt($this->ch, CURLOPT_URL, $url);
		return $this;
	}

	public function setMethod($method) {
		$method = strtoupper(trim($method));
		curl_setopt($this->ch, CURLOPT_CUSTOMREQUEST, $method);

		return $this;
	}

	public function setBody($body) {
		curl_setopt($this->ch, CURLOPT_POSTFIELDS, $body);
		$this->setHeader('Content-Length', (string)strlen($body));

		return $this;
	}

	public function setHeader($header, $value) {
		$this->headers[$header] = $value;		
		return $this;
	}

	public function setHeaders(array $headers) {
		foreach((array)$headers as $header => $value) {
			$this->setHeader($header, $value);				
		}

		return $this;
	}

	public function setReferer($referrer) {
		curl_setopt($this->ch, CURLOPT_REFERER, $referrer);
		return $this;
	}


	public function viaProxy($host, $port, $user = NULL, $password = NULL) {
		curl_setopt($this->ch, CURLOPT_PROXY, "$host:$port");

		if (!empty($user) && !empty($password)) {
			curl_setopt($this->ch, CURLOPT_PROXYUSERPWD, "$user:$password");	
		}

		return $this;
	}

	protected function convHeaders($headers) {
		$result = [];	

		foreach((array)$headers as $header => $value) {
			$result []= "$header: $value";
		}
		
		return $result;
	}

	public function exec() {
		$headers = $this->convHeaders($this->headers);

		curl_setopt($this->ch, CURLOPT_HTTPHEADER, $headers);		
		$response = curl_exec($this->ch);

		if ($response === false) {
			$code = curl_getinfo($this->ch, CURLINFO_HTTP_CODE);
			throw new HttpError("Http request failure", $code);
		}
	
		return $response;
	}

	public function get($url = NULL) {
		$this->setMethod("GET");
		return $this->exec();
	}

	public function post() {
		$this->setMethod("POST");
		return $this->exec();
	}
}