gnu-social/actions/api.php

<?php
/*
 * Laconica - a distributed open-source microblogging tool
 * Copyright (C) 2008, Controlez-Vous, Inc.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

if (!defined('LACONICA')) { exit(1); }

class ApiAction extends Action {

	var $user;
	var $content_type;
	var $api_arg;
	var $api_method;
	var $api_action;

	function handle($args) {
		parent::handle($args);

		$this->api_action = $this->arg('apiaction');
		$method = $this->arg('method');
		$argument = $this->arg('argument');

		if (isset($argument)) {
			$cmdext = explode('.', $argument);
			$this->api_arg =  $cmdext[0];
			$this->api_method = $method;
			$this->content_type = strtolower($cmdext[1]);
		} else {
			
			# Requested format / content-type will be an extension on the method
			$cmdext = explode('.', $method);
			$this->api_method = $cmdext[0];
			$this->content_type = strtolower($cmdext[1]);
		}

		if($this->requires_auth()) {
			if (!isset($_SERVER['PHP_AUTH_USER'])) {

				# This header makes basic auth go
				header('WWW-Authenticate: Basic realm="Laconica API"');

				# If the user hits cancel -- bam!
				$this->show_basic_auth_error();
			} else {
				$nickname = $_SERVER['PHP_AUTH_USER'];
				$password = $_SERVER['PHP_AUTH_PW'];
				$user = common_check_user($nickname, $password);

				if ($user) {
					$this->user = $user;
					$this->process_command();
				} else {
					# basic authentication failed
					$this->show_basic_auth_error();
				}
			}
		} else {

			# Caller might give us a username even if not required
			if (isset($_SERVER['PHP_AUTH_USER'])) {
				$user = User::staticGet('nickname', $_SERVER['PHP_AUTH_USER']);	
				if ($user) {
					$this->user = $user;
				}
				# Twitter doesn't throw an error if the user isn't found
			}
			
			$this->process_command();
		}
	}

	function process_command() {
		$action = "twitapi$this->api_action";
		$actionfile = INSTALLDIR."/actions/$action.php";

		if (file_exists($actionfile)) {
			require_once($actionfile);
			$action_class = ucfirst($action)."Action";
			$action_obj = new $action_class();

			if (method_exists($action_obj, $this->api_method)) {
				$apidata = array(	'content-type' => $this->content_type,
									'api_method' => $this->api_method,
									'api_arg' => $this->api_arg,
									'user' => $this->user);

				call_user_func(array($action_obj, $this->api_method), $_REQUEST, $apidata);
			} else {
				common_user_error("API method not found!", $code=404);
			}
		} else {
			common_user_error("API method not found!", $code=404);
		}
	}

	# Whitelist of API methods that don't need authentication
	function requires_auth() {
		static $noauth = array(	'statuses/public_timeline',
								'statuses/show',
								'users/show',
								'help/test',
								'help/downtime_schedule');

		static $bareauth = array('statuses/user_timeline',
								 'statuses/friends',
								 'statuses/followers',
								 'favorites/favorites');

		$fullname = "$this->api_action/$this->api_method";

		if (in_array($fullname, $bareauth)) {
			# bareauth: only needs auth if without an argument
			if ($this->api_arg) {
				return false;
			} else {
				return true;
			}
		} else if (in_array($fullname, $noauth)) {
			# noauth: never needs auth
			return false;
		} else {
			# everybody else needs auth
			return true;
		}
	}

	function show_basic_auth_error() {	
	  	header('HTTP/1.1 401 Unauthorized');
	   	$msg = 'Could not authenticate you.';
	
		if ($this->content_type == 'xml') {
			header('Content-Type: application/xml; charset=utf-8');
			common_start_xml();
			common_element_start('hash');
			common_element('error', NULL, $msg);
			common_element('request', NULL, $_SERVER['REQUEST_URI']);
			common_element_end('hash');
			common_end_xml();
		} else if ($this->content_type == 'json')  {
			header('Content-Type: application/json; charset=utf-8');			
			$error_array = array('error' => $msg, 'request' => $_SERVER['REQUEST_URI']);
			print(json_encode($error_array));
		} else {
			header('Content-type: text/plain');
			print "$msg\n";
		}
	}

	function is_readonly() {
		# NOTE: before handle(), can't use $this->arg
		$apiaction = $_REQUEST['apiaction'];
		$method = $_REQUEST['method'];
		list($cmdtext, $fmt) = explode('.', $method);
		
		# FIXME: probably need a table here, instead of this switch
		
		switch ($apiaction) {
		 case 'statuses':
			switch ($cmdtext) {
			 case 'update':
			 case 'destroy':
				return false;
			 default:
				return true;
			}
		 default: 
			return false;
		}
	}
}