<?php
/* For licensing terms, see /license.txt */

use Chamilo\UserBundle\Entity\User;

/**
 * @package chamilo.webservices
 */
require_once __DIR__.'/../inc/global.inc.php';

/**
 * Error returned by one of the methods of the web service. Contains an error code and an error message.
 */
class WSCMError
{
    /**
     * Error code.
     *
     * @var int
     */
    public $code;

    /**
     * Error message.
     *
     * @var string
     */
    public $message;
    /**
     * Error handler. This needs to be a class that implements the interface WSErrorHandler.
     *
     * @var WSErrorHandler
     */
    protected static $_handler;

    /**
     * Constructor.
     *
     * @param int Error code
     * @param string Error message
     */
    public function __construct($code, $message)
    {
        $this->code = $code;
        $this->message = $message;
    }

    /**
     * Sets the error handler.
     *
     * @param WSErrorHandler $handler Error handler
     */
    public static function setErrorHandler($handler)
    {
        if ($handler instanceof WSErrorHandler) {
            self::$_handler = $handler;
        }
    }

    /**
     * Returns the error handler.
     *
     * @return WSErrorHandler Error handler
     */
    public static function getErrorHandler()
    {
        return self::$_handler;
    }

    /**
     * Transforms the error into an array.
     *
     * @return array Associative array with code and message
     */
    public function toArray()
    {
        return ['code' => $this->code, 'message' => $this->message];
    }
}

/**
 * Interface that must be implemented by any error handler.
 */
interface WSCMErrorHandler
{
    /**
     * Handle method.
     *
     * @param WSError $error Error
     */
    public function handle($error);
}

/**
 * Main class of the webservice. Webservice classes extend this class.
 */
class WSCM
{
    /**
     * Chamilo configuration.
     *
     * @var array
     */
    protected $_configuration;

    /**
     * Constructor.
     */
    public function __construct()
    {
        $this->_configuration = $GLOBALS['_configuration'];
    }

    /**
     * Verifies if the user is valid.
     *
     * @param string $username of the user in chamilo
     * @param string $pass     of the same user (in MD5 of SHA)
     *
     * @return mixed "valid" if username e password are correct! Else, return a message error
     */
    public function verifyUserPass($username, $pass)
    {
        $login = $username;
        $password = $pass;

        $userRepo = UserManager::getRepository();
        /** @var User $uData */
        $uData = $userRepo->findOneBy([
            'username' => trim(addslashes($login)),
        ]);

        if ($uData) {
            if ($uData->getAuthSource() == PLATFORM_AUTH_SOURCE) {
                $passwordEncoded = UserManager::encryptPassword($password, $uData);
                // Check the user's password
                if ($passwordEncoded == $uData->getPassword() && (trim($login) == $uData->getUsername())) {
                    // Check if the account is active (not locked)
                    if ($uData->getActive()) {
                        // Check if the expiration date has not been reached
                        $now = new DateTime();
                        if ($uData->getExpirationDate() > $now || !$uData->getExpirationDate()) {
                            return "valid";
                        } else {
                            return get_lang('Account expired');
                        }
                    } else {
                        return get_lang('Account inactive');
                    }
                } else {
                    return get_lang('Login failed - incorrect login or password.');
                }
            } else {
                return get_lang('Account inactive for this URL');
            }
        }

        return get_lang('Login failed - incorrect login or password.');
    }

    /**
     * Test function. Returns the string success.
     *
     * @return string Success
     */
    public function test()
    {
        return "success";
    }

    /**
     * *Strictly* reverts PHP's nl2br() effects (whether it was used in XHTML mode or not).
     *
     * @param string $string
     *
     * @return string
     */
    public function nl2br_revert($string)
    {
        return preg_replace('`<br(?: /)?>([\\n\\r])`', '$1', $string);
    }

    /**
     * Verifies the API key.
     *
     * @param string $secret_key Secret key
     *
     * @return mixed WSError in case of failure, null in case of success
     */
    protected function verifyKey($secret_key)
    {
        $ip = trim($_SERVER['REMOTE_ADDR']);
        // if we are behind a reverse proxy, assume it will send the
        // HTTP_X_FORWARDED_FOR header and use this IP instead
        if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
            list($ip1, $ip2) = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);
            $ip = trim($ip1);
        }
        $security_key = $ip.$this->_configuration['security_key'];

        if (!api_is_valid_secret_key($secret_key, $security_key)) {
            return new WSCMError(1, "API key is invalid");
        } else {
            return null;
        }
    }

    /**
     * Gets the real user id based on the user id field name and value.
     * Note that if the user id field name is "chamilo_user_id", it will use the user id
     * in the system database.
     *
     * @param string $user_id_field_name User id field name
     * @param string $user_id_value      User id value
     *
     * @return mixed System user id if the user was found, WSError otherwise
     */
    protected function getUserId($user_id_field_name, $user_id_value)
    {
        if ($user_id_field_name == "chamilo_user_id") {
            if (UserManager::is_user_id_valid(intval($user_id_value))) {
                return intval($user_id_value);
            } else {
                return new WSCMError(100, "User not found");
            }
        } else {
            $user_id = UserManager::get_user_id_from_original_id(
                $user_id_value,
                $user_id_field_name
            );
            if ($user_id == 0) {
                return new WSCMError(100, "User not found");
            } else {
                return $user_id;
            }
        }
    }

    /**
     * Gets the real course id based on the course id field name and value.
     * Note that if the course id field name is "chamilo_course_id", it will use the course id
     * in the system database.
     *
     * @param string $course_id_field_name Course id field name
     * @param string $course_id_value      Course id value
     *
     * @return mixed System course id if the course was found, WSError otherwise
     */
    protected function getCourseId($course_id_field_name, $course_id_value)
    {
        if ($course_id_field_name == "chamilo_course_id") {
            if (CourseManager::get_course_code_from_course_id($course_id_value) != null) {
                return intval($course_id_value);
            } else {
                return new WSCMError(200, "Course not found");
            }
        } else {
            $courseId = CourseManager::get_course_code_from_original_id(
                $course_id_value,
                $course_id_field_name
            );
            if (empty($courseId)) {
                return new WSCMError(200, "Course not found");
            } else {
                return $courseId;
            }
        }
    }

    /**
     * Gets the real session id based on the session id field name and value.
     * Note that if the session id field name is "chamilo_session_id", it will use the session id
     * in the system database.
     *
     * @param string $session_id_field_name Session id field name
     * @param string $session_id_value      Session id value
     *
     * @return mixed System session id if the session was found, WSError otherwise
     */
    protected function getSessionId($session_id_field_name, $session_id_value)
    {
        if ($session_id_field_name == "chamilo_session_id") {
            $session = SessionManager::fetch((int) $session_id_value);
            if (!empty($session)) {
                return intval($session_id_value);
            } else {
                return new WSCMError(300, "Session not found");
            }
        } else {
            $session_id = SessionManager::getSessionIdFromOriginalId(
                $session_id_value,
                $session_id_field_name
            );
            if ($session_id == 0) {
                return new WSCMError(300, "Session not found");
            } else {
                return $session_id;
            }
        }
    }

    /**
     * Handles an error by calling the WSError error handler.
     *
     * @param WSError $error Error
     */
    protected function handleError($error)
    {
        $handler = WSCMError::getErrorHandler();
        $handler->handle($error);
    }

    /**
     * Gets a successful result.
     *
     * @return array Array with a code of 0 and a message 'Operation was successful'
     */
    protected function getSuccessfulResult()
    {
        return ['code' => 0, 'message' => 'Operation was successful'];
    }
}
