<?php

/**
 * Authentication API used by server to authenticate a user using a 
 * SHARED SECRET (ApiKey)
 */
class Alternc_Api_Auth_Sharedsecret implements Alternc_Api_Auth_Interface {

    private $db; // PDO object

    const ERR_INVALID_ARGUMENT = 1111801;
    const ERR_INVALID_SECRET = 1111802;
    const ERR_INVALID_LOGIN = 1111803;
    const ERR_DISABLED_ACCOUNT = 1111804;
    const ERR_INVALID_AUTH = 1111805;

    /**
     * Constructor of the Shared Secret Api Auth
     *
     * @param $service an Alternc_Api_Service object
     * @return create the object
     */
    function __construct($service) {

        if (!($service instanceof Alternc_Api_Service))
            throw new \Exception("Invalid argument (service)", ERR_INVALID_ARGUMENT);

        $this->db = $service->getDb();
    }

    /**
     * Authenticate a user
     *
     * @param $options options, depending on the auth scheme, including uid for setuid users
     *   here, login is the alternc username, and secret is a valid shared secret for this user.
     * @return an Alternc_Api_Token
     */
    function auth($options) {

        if (!isset($options["login"]) || !is_string($options["login"])) {
            throw new \Exception("Missing required parameter login", self::ERR_INVALID_ARGUMENT);
        }
        if (!isset($options["secret"]) || !is_string($options["secret"])) {
            throw new \Exception("Missing required parameter secret", self::ERR_INVALID_ARGUMENT);
        }
        if (!preg_match("#^[0-9a-zA-Z]{32}$#", $options["secret"])) {
            return new Alternc_Api_Response(array("code" => self::ERR_INVALID_SECRET, "message" => "Invalid shared secret syntax"));
        }

        if (!preg_match("#^[0-9a-zA-Z-]{1,32}$#", $options["login"])) { // FIXME : normalize this on AlternC !!!
            return new Alternc_Api_Response(array("code" => self::ERR_INVALID_LOGIN, "message" => "Invalid login"));
        }

        $stmt = $this->db->prepare("SELECT m.enabled,m.uid,m.login,m.su FROM membres m, sharedsecret s WHERE s.uid=m.uid AND m.login=? AND s.secret=?;");
        $stmt->execute(array($options["login"], $options["secret"]));
        $me = $stmt->fetch(PDO::FETCH_OBJ);
        if (!$me)
            return new Alternc_Api_Response(array("code" => self::ERR_INVALID_AUTH, "message" => "Invalid shared secret"));
        if (!$me->enabled)
            return new Alternc_Api_Response(array("code" => self::ERR_DISABLED_ACCOUNT, "message" => "Account is disabled"));

        return Alternc_Api_Token::tokenGenerate(
                        array("uid" => (int) $me->uid, "isAdmin" => ($me->su != 0)), $this->db
        );
    }

    /**
     * instructions on how to use this Auth class
     * @return array("fields" => array("fields to send, required or not"), "description" => "description of this auth")
     */
    function instructions() {
        return array("fields" => array("login" => "AlternC user account", "secret" => "API Key, Shared secrets, valid for this account, stored in sharedsecret table."),
            "description" => "Authenticate against an Api Key, also called SharedSecret. distinct from the account's password, can be plenty and revoked independently"
        );
    }

}

// class Alternc_Api_Auth_Sharedsecret