<?php

/**

 * Implementation of the Disqus API.

 *

 * http://disqus.com/api/

 *

 * @author		DISQUS <team@disqus.com>

 * @copyright	2007-2010 Big Head Labs

 * @link		http://disqus.com/

 * @package		disqusapi

 * @version		0.0.1

 * 

 * $disqus = new DisqusAPI($secret_key)

 * $disqus->trends->listThreads()

 * 

 */



if (!defined('DISQUS_API_HOST')) {

    define('DISQUS_API_HOST', 'disqus.com');

}

if (!defined('DISQUS_API_SSL_HOST')) {

    define('DISQUS_API_SSL_HOST', 'secure.disqus.com');

}

define('DISQUS_API_VERSION', '0.0.1');



require_once(dirname(__FILE__) . '/url.php');



if (!extension_loaded('json')) {

	require_once(dirname(__FILE__) . '/json.php');

	function dsq_json_decode($data) {

		$json = new JSON;

		return $json->unserialize($data);

	}

} else {

	function dsq_json_decode($data) {

		return json_decode($data);

	}	

}



global $DISQUS_API_INTERFACES;



$DISQUS_API_INTERFACES = dsq_json_decode(file_get_contents(dirname(__FILE__) . '/interfaces.json'));



class DisqusInterfaceNotDefined extends Exception {}

class DisqusAPIError extends Exception {

    public function __construct($code, $message) {

        $this->code = $code;

        $this->message = $message;

    }

}



class DisqusResource {

    public function __construct($api, $interface=null, $node=null, $tree=array()) {

        global $DISQUS_API_INTERFACES;

        

        if (!$interface) {

            $interface = $DISQUS_API_INTERFACES;

        }

        $this->api = $api;

        $this->interface = $interface;

        $this->node = $node;

        if ($node) {

            array_push($tree, $node);

        }

        $this->tree = $tree;

    }

    

    public function __get($attr) {

        $interface = $this->interface->$attr;

        if (!$interface) {

            throw new DisqusInterfaceNotDefined();

        }

        return new DisqusResource($this->api, $interface, $attr, $this->tree);

    }

    

    public function __call($name, $args) {

        $resource = $this->interface->$name;

        if (!$resource) {

            throw new DisqusInterfaceNotDefined();

        }

        $kwargs = (array)$args[0];

        

        foreach ((array)$resource->required as $k) {

            if (empty($kwargs[$k])) {

                throw new Exception('Missing required argument: '.$k);

            }

        }

        

        $api = $this->api;

        

        if (empty($kwargs['api_secret'])) {

            $kwargs['api_secret'] = $api->key;

        }

        

        // emulate a named pop

        $version = (!empty($kwargs['version']) ? $kwargs['version'] : $api->version);

        $format = (!empty($kwargs['format']) ? $kwargs['format'] : $api->format);

        unset($kwargs['version'], $kwargs['format']);

        

        $url = ($api->is_secure ? 'https://'.DISQUS_API_SSL_HOST : 'http://'.DISQUS_API_HOST);

        $path = '/api/'.$version.'/'.implode('/', $this->tree).'/'.$name.'.'.$format;

        

        if (!empty($kwargs)) {

            if ($resource->method == 'POST') {

                $post_data = $kwargs;

            } else {

                $post_data = false;

                $path .= '?'.dsq_get_query_string($kwargs);

            }

        }

        



        $response = dsq_urlopen($url.$path, $post_data);

        

        $data = call_user_func($api->formats[$format], $response['data']);

        

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

            throw new DisqusAPIError($data->code, $data->response);

        }

        

        return $data->response;

    }

}





class DisqusAPI extends DisqusResource {

    public $formats = array(

        'json' => 'dsq_json_decode'

    );



    public function __construct($key=null, $format='json', $version='3.0', $is_secure=false) {

        $this->key = $key;

        $this->format = $format;

        $this->version = $version;

        $this->is_secure = $is_secure;

        parent::__construct($this);

    }



    public function __invoke() {

        throw new Exception('You cannot call the API without a resource.');

    }



    public function setKey($key) {

        $this->key = $key;

    }



    public function setFormat($format) {

        $this->format = $format;

    }

    

    public function setVersion($version) {

        $this->version = $version;

    }

}