<?php
/**
 * AUTHY API CLASS
 *
 * Handles Authy API requests in a WordPress way.
 *
 * @package Authy
 * @since 1.0.0
 */

class Authy_API {
	/**
	 * Class variables
	 */
	// Oh look, a singleton
	private static $__instance = null;

	// Authy API
	protected $api_key = null;
	protected $api_endpoint = null;

	/**
	 * Singleton implementation
	 *
	 * @uses this::setup
	 * @return object
	 */
	public static function instance( $api_key, $api_endpoint ) {
		if ( ! is_a( self::$__instance, 'Authy_API' ) ) {
			if ( is_null( $api_key ) || is_null( $api_endpoint ) )
				return null;

			self::$__instance = new Authy_API;

			self::$__instance->api_key = $api_key;
			self::$__instance->api_endpoint = $api_endpoint;

			self::$__instance->setup();
		}

		return self::$__instance;
	}

	/**
	 * Silence is golden.
	 */
	private function __construct() {}

	/**
	 * Really, silence is golden.
	 */
	private function setup() {}

	/**
	 * Attempt to retrieve an Authy ID for a given request
	 *
	 * @param string $email
	 * @param string $phone
	 * @param string $country_code
	 * @uses sanitize_email, add_query_arg, wp_remote_post, wp_remote_retrieve_response_code, wp_remote_retrieve_body
	 * @return mixed
	 */
	public function register_user( $email, $phone, $country_code ) {
		// Sanitize arguments
		$email = sanitize_email( $email );
		$phone = preg_replace( '#[^\d]#', '', $phone );
		$country_code = preg_replace( '#[^\d\+]#', '', $country_code );

		// Build API endpoint
		$endpoint = sprintf( '%s/protected/json/users/new', $this->api_endpoint );
		$endpoint = add_query_arg( array(
			'api_key' =>$this->api_key,
			'user[email]' => $email,
			'user[cellphone]' => $phone,
			'user[country_code]' => $country_code
		), $endpoint );

		// Make API request up to three times and parse response
		for ( $i = 1; $i <= 3; $i++ ) {
			$response = wp_remote_post( $endpoint );
			$status_code = wp_remote_retrieve_response_code( $response );

			if ( '200' == $status_code || '400' == $status_code ) {
				$body = wp_remote_retrieve_body( $response );

				if ( ! empty( $body ) ) {
					$body = json_decode( $body );

					return $body;
				}

				break;
			}
		}

		return false;
	}

	/**
	 * Validate a given token and Authy ID
	 *
	 * @param int $id
	 * @param string $token
	 * @uses add_query_arg, wp_remote_head, wp_remote_retrieve_response_code
	 * @return mixed
	 */
	public function check_token( $id, $token ) {
		// Build API endpoint
		// Token must be a string because it can have leading zeros
		$endpoint = sprintf( '%s/protected/json/verify/%s/%d', $this->api_endpoint, $token, $id );
		$endpoint = add_query_arg( array(
			'api_key' => $this->api_key,
			'force' => 'true'
		), $endpoint );

		// Make API request up to three times and check responding status code
		for ($i = 1; $i <= 3; $i++) {
			$response = wp_remote_get($endpoint);

			$status_code = wp_remote_retrieve_response_code( $response );
			$body = wp_remote_retrieve_body($response);
			$body = get_object_vars(json_decode($body));

			if ( $status_code == 200 && strtolower($body['token'])  == 'is valid')
				return true;
			elseif ( $status_code == 401)
				return __( 'Invalid Authy Token.', 'authy' );
		}

		return false;
	}

	/**
	* Request a valid token via SMS
	* @param string $id
	* @return mixed
	*/

	public function request_sms($id) {
		$endpoint = sprintf( '%s/protected/json/sms/%d', $this->api_endpoint, $id );
		$endpoint = add_query_arg( array('api_key' => $this->api_key), $endpoint);
		$response = wp_remote_head($endpoint);
		$status_code = wp_remote_retrieve_response_code($response);

		if ( $status_code == 200)
			return true;

		return false;
	}

  /**
  * Get application details
  * @return array
  */
	public function application_details() {
		$endpoint = sprintf( '%s/protected/json/app/details', $this->api_endpoint );
		$endpoint = add_query_arg( array('api_key' => $this->api_key), $endpoint);
		$response = wp_remote_get($endpoint);
		$status_code = wp_remote_retrieve_response_code($response);
		$body = wp_remote_retrieve_body($response);
		$body = get_object_vars(json_decode($body));

		if ( $status_code == 200)
			return $body;

		return array();
	}

	/**
	* Verify if the given signature is valid.
	* @return boolean
	*/
	public function verify_signature($user_data, $signature) {
		if(!isset($user_data['authy_signature'])  || !isset($user_data['signed_at']) ) {
			return false;
		}

		if((time() - $user_data['signed_at']) <= 300 && $user_data['authy_signature'] === $signature ) {
			return true;
		}

		return false;
	}

	/**
	* Generates a signature
	* @return string
	*/
	public function generate_signature() {
		return wp_generate_password(64, false, false);
	}
}