<?php

/**

 * Class WordPress Twitter API

 * 

 * @version 1.0.0

 */

class Wp_Twitter_Api {

  

	var $bearer_token,



	// Default credentials

	$args = array(

		'consumer_key'			=>	'default_consumer_key',

		'consumer_secret'		=>	'default_consumer_secret'

	),



	// Default type of the resource and cache duration

	$query_args = array(

		'type'				=>	'statuses/user_timeline',

		'cache'				=>	1800

	),



	$has_error = false;



	/**

	 * WordPress Twitter API Constructor

	 * 

	 * @param array $args

	 */

	public function __construct( $args = array() ) {



		if ( is_array( $args ) && !empty( $args ) )

			$this->args = array_merge( $this->args, $args );



		if ( ! $this->bearer_token = get_option( 'twitter_bearer_token' ) )

			$this->bearer_token = $this->get_bearer_token();



	}



	/**

	 * Get the token from oauth Twitter API

	 * 

	 * @return string Oauth Token

	 */

	private function get_bearer_token() {



		$bearer_token_credentials = $this->args['consumer_key'] . ':' . $this->args['consumer_secret'];

		$bearer_token_credentials_64 = base64_encode( $bearer_token_credentials );



		$args = array(

			'method'		=> 	'POST',

			'timeout'		=> 	5,

			'redirection'	=> 	5,

			'httpversion'	=> 	'1.0',

			'blocking'		=> 	true,

			'headers'		=> 	array(

				'Authorization'		=>	'Basic ' . $bearer_token_credentials_64,

				'Content-Type'		=> 	'application/x-www-form-urlencoded;charset=UTF-8',

				'Accept-Encoding'	=>	'gzip'

			),

			'body' 			=>  array( 'grant_type'		=>	'client_credentials' ),

			'cookies' 		=> 	array()

		);



		$response = wp_remote_post( 'https://api.twitter.com/oauth2/token', $args );



		if ( is_wp_error( $response ) || 200 != $response['response']['code'] )

			return $this->bail( __( 'Can\'t get the bearer token, check your credentials', 'wp_twitter_api' ), $response );



		$result = json_decode( $response['body'] );



		update_option( 'twitter_bearer_token', $result->access_token );



		return $result->access_token;



	}



	/**

	 * Query twitter's API

	 * 

	 * @uses $this->get_bearer_token() to retrieve token if not working

	 * 

	 * @param string $query Insert the query in the format "count=1&include_entities=true&include_rts=true&screen_name=micc1983!

	 * @param array $query_args Array of arguments: Resource type (string) and cache duration (int)

	 * @param bool $stop Stop the query to avoid infinite loop

	 * 

	 * @return bool|object Return an object containing the result

	 */

	public function query( $query, $query_args = array(), $stop = false ) {



		if ( $this->has_error )

			return false;



		if ( is_array( $query_args ) && !empty( $query_args ) )

			$this->query_args = array_merge( $this->query_args, $query_args );



		$transient_name = 'wta_' . md5( $query );



		if ( false !== ( $data = get_transient( $transient_name ) ) )

			return $data;



		$args = array(

			'method'		=> 	'GET',

			'timeout'		=> 	5,

			'redirection'	=> 	5,

			'httpversion'	=> 	'1.0',

			'blocking'		=> 	true,

			'headers'		=> 	array(

				'Authorization'		=>	'Bearer ' . $this->bearer_token,

				'Accept-Encoding'	=>	'gzip'

			),

			'body' 			=> 	null,

			'cookies' 		=> 	array()

		);



		$response = wp_remote_get( 'https://api.twitter.com/1.1/' . $this->query_args['type'] . '.json?' . $query, $args );



		if ( is_wp_error( $response ) || 200 != $response['response']['code'] ){



			if ( !$stop ){

				$this->bearer_token = $this->get_bearer_token();

				return $this->query( $query, $this->query_args, true );

			} else {

				return $this->bail( __( 'Bearer Token is good, check your query', 'wp_twitter_api' ), $response );

			}



		}



		$data = json_decode( $response['body'] );



		set_transient( $transient_name, $data, $this->query_args['cache'] );



		return $data;



	}



	/**

	 * Let's manage errors

	 * 

	 * WP_DEBUG has to be set to true to show errors

	 * 

	 * @param string $error_text Error message
	 * @param string $error_object Server response or wp_error

	 */

	private function bail( $error_text, $error_object = '' ) {



		$this->has_error = true;



		if ( is_wp_error( $error_object ) ){

			$error_text .= ' - Wp Error: ' . $error_object->get_error_message();

		} elseif ( !empty( $error_object ) && isset( $error_object['response']['message'] ) ) {

			$error_text .= ' ( Response: ' . $error_object['response']['message'] . ' )';

		}



		trigger_error( $error_text , E_USER_NOTICE );



	}



}