<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');



/*

 * CI-Merchant Library

 *

 * Copyright (c) 2011-2012 Adrian Macneil

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */



/**

 * Merchant GoCardless Class

 *

 * Payment processing using GoCardless

 * Documentation: https://sandbox.gocardless.com/docs

 */



class Merchant_gocardless extends Merchant_driver

{

	const PROCESS_URL = 'https://gocardless.com';

	const PROCESS_URL_TEST = 'https://sandbox.gocardless.com';



	public function default_settings()

	{

		return array(

			'app_id' => '',

			'app_secret' => '',

			'merchant_id' => '',

			'access_token' => '',

			'test_mode' => FALSE,

		);

	}



	public function purchase()

	{

		$data = array(

			'client_id' => $this->setting('app_id'),

			'nonce' => $this->_generate_nonce(),

			'timestamp' => gmdate('Y-m-d\TH:i:s\Z'),

			'redirect_uri' => $this->param('return_url'),

			'cancel_uri' => $this->param('cancel_url'),

			'bill' => array(

				'merchant_id' => $this->setting('merchant_id'),

				'amount' => $this->amount_dollars(),

				'name' => $this->param('description'),

				'user' => array(

					'first_name' => $this->param('first_name'),

					'last_name' => $this->param('last_name'),

					'email' => $this->param('email'),

					'billing_address1' => $this->param('address1'),

					'billing_address2' => $this->param('address2'),

					'billing_town' => $this->param('city'),

					'billing_county' => $this->param('country'),

					'billing_postcode' => $this->param('postcode'),

				),

			),

		);



		$data['signature'] = $this->_generate_signature($data);



		$url = $this->_process_url().'/connect/bills/new?'.$this->_generate_query_string($data);

		$this->redirect($url);

	}



	public function purchase_return()

	{

		$data = array(

			'resource_uri' => $this->CI->input->get('resource_uri'),

			'resource_id' => $this->CI->input->get('resource_id'),

			'resource_type' => $this->CI->input->get('resource_type'),

		);



		if ($this->_generate_signature($data) !== $this->CI->input->get('signature'))

		{

			return new Merchant_response(Merchant_response::FAILED, lang('merchant_invalid_response'));

		}



		unset($data['resource_uri']);

		$url = $this->_process_url().'/api/v1/confirm';

		$response = $this->post_request($url, $data, $this->setting('app_id'), $this->setting('app_secret'));

		$response = json_decode($response);



		if ( ! empty($response->success))

		{

			return new Merchant_response(Merchant_response::COMPLETE, NULL, $data['resource_id']);

		}



		$error_message = isset($response->error) ? $response->error : lang('merchant_invalid_response');

		return new Merchant_response(Merchant_response::FAILED, $error_message);

	}



	private function _process_url()

	{

		return $this->setting('test_mode') ? self::PROCESS_URL_TEST : self::PROCESS_URL;

	}



	/**

	 * Generates a random nonce

	 */

	private function _generate_nonce()

	{

		$nonce = '';

		for ($i = 0; $i < 64; $i++)

		{

			// append random ASCII character

			$nonce .= chr(mt_rand(33, 126));

		}

		return base64_encode($nonce);

	}



	/**

	 * Generate a signature for the data array

	 */

	private function _generate_signature($data)

	{

		return hash_hmac('sha256', $this->_generate_query_string($data), $this->setting('app_secret'));

	}



	/**

	 * Generates, encodes, re-orders variables for the query string.

	 * Copyright (c) 2011 GoCardless

	 * Source: https://github.com/gocardless/gocardless-php/blob/2f2e3ddb23a58fccc2d77f5860c8179905296ce2/lib/gocardless/utils.php#L38

	 *

	 * @param array $params The specific parameters for this payment

	 * @param array $pairs Pairs

	 * @param string $namespace The namespace

	 *

	 * @return string An encoded string of parameters

	 */

	private function _generate_query_string($params, &$pairs = array(), $namespace = null)

	{

		if (is_array($params))

		{

			foreach ($params as $k => $v)

			{

				if (is_int($k))

				{

					$this->_generate_query_string($v, $pairs, $namespace.'[]');

				}

				else

				{

					$this->_generate_query_string($v, $pairs, $namespace !== null ? $namespace."[$k]" : $k);

				}

			}



			if ($namespace !== null)

			{

				return $pairs;

			}



			if (empty($pairs))

			{

				return '';

			}



			sort($pairs);

			$strs = array_map('implode', array_fill(0, count($pairs), '='), $pairs);



			return implode('&', $strs);

		}

		else

		{

			$pairs[] = array(rawurlencode($namespace), rawurlencode($params));

		}

	}

}



/* End of file ./libraries/merchant/drivers/merchant_gocardless.php */