<?php

class User_Manager
{

    private static $table_users = 'users';
    private static $table_groups = 'groups';


    //could append 'ldap', 'cas':
    private static $available_auth_methods = array('local'); 


    public static function get_table_users_str()
    {
        return self::$table_users;
    }
    public static function get_table_groups_str()
    {
        return self::$table_groups;
    }
    public static function get_table_users_groups_rel_str()
    {
        return self::get_table_users_str() . "_" . self::get_table_groups_str() ."_rel";
    }

    const QUERY_CREATE_TABLE_USERS = "
        CREATE TABLE %table_users% (
            `id` int(11) NOT NULL AUTO_INCREMENT,
            `login` varchar(16) NOT NULL,
            `display_name` text NOT NULL,
            `auth_method` enum('local','ldap','cas','none') NOT NULL,
            `password` char(128) NOT NULL,
            `external_uid` char(45) NOT NULL,
            `admin` tinyint(1) NOT NULL,
            `active` tinyint(1) NOT NULL DEFAULT '1',
            `created_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
            `created_by` int(11) NOT NULL,
            `updated_time` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00' ON UPDATE CURRENT_TIMESTAMP,
            `updated_by` int(11) NOT NULL,
            PRIMARY KEY (`id`)
        );
        
        ";
    const QUERY_CREATE_SYSTEM_USER = "INSERT INTO  %table_users% 
                                    (id,login,display_name,auth_method,active,created_time,created_by)
                                    VALUES (0,'','SYSTEM','none',0, NOW(),0);";

    const QUERY_CREATE_TABLE_GROUPS = "
        CREATE TABLE %table_groups% ( 
            `id` int(11) NOT NULL AUTO_INCREMENT,
            `name` text NOT NULL,
            `active` tinyint(1) NOT NULL DEFAULT '1',
            `created_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
            `created_by` int(11) NOT NULL,
            `updated_time` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00' ON UPDATE CURRENT_TIMESTAMP,
            `updated_by` int(11) NOT NULL,
            PRIMARY KEY (`id`)
        );
    ";

    const QUERY_CREATE_DEFAULT_GROUPS = "
        INSERT INTO %table_groups% (id,name,active,created_time,created_by,updated_time,updated_by)
        VALUES ('0','Administrateurs','1',NOW(),'0',NOW(),'0'),
               ('1','Responsables sécurité','1',NOW(),'0',NOW(),'0'),
               ('2','Agent de prévention HSE','1', NOW(),'0',NOW(),'0')
        ;
    ";

    const QUERY_CREATE_REL_USERS_GROUPS = "  
        CREATE TABLE `%table_users%_%table_groups%_rel` (
            `user_id` int(11) NOT NULL,
            `group_id` int(11) NOT NULL,
            PRIMARY KEY (`user_id`,`group_id`),
            KEY `users_id` (`user_id`),
            KEY `group_id` (`group_id`),
            CONSTRAINT `%table_users%_%table_groups%_rel_ibfk_1` FOREIGN KEY (`user_id`) REFERENCES `%table_users%` (`id`),
            CONSTRAINT `%table_users%_%table_groups%_rel_ibfk_2` FOREIGN KEY (`group_id`) REFERENCES `%table_groups%` (`id`)
        );
    ";

    
    /*
    * Erase the list of avaliable methods
    * @ input methods: Array (non associative)
    * return true
    */
    public static function set_available_auth_methods($methods)
    {
        self::$available_auth_methods = $methods;
    }
    public static function create_local_tables(PDO $db)
    {
        $searched = array('%table_users%','%table_groups%');
        $replace = array(self::$table_users,self::$table_groups);

        $queries = array(
            str_replace($searched,$replace,self::QUERY_CREATE_TABLE_USERS),
            str_replace($searched,$replace,self::QUERY_CREATE_SYSTEM_USER),
            str_replace($searched,$replace,self::QUERY_CREATE_TABLE_GROUPS),
            str_replace($searched,$replace,self::QUERY_CREATE_REL_USERS_GROUPS),
            str_replace($searched,$replace,self::QUERY_CREATE_DEFAULT_GROUPS)
        );
        foreach($queries as $query)
        {
            $rs = $db->query($query);
            if($rs === false){
                throw new \UnexpectedValueException("SQL ERROR ON QUERY " . $query );
            }
        }
    }


    public function authentificate(PDO $db, STRING $login, STRING $password){

        foreach(self::$available_auth_methods as $method){

            switch($method)
            {
                case "local":
                case "sql'":
                    $user = new User_Sql($db);
                    if($user->authentificate($login,$password)){
                        return $user;
                    }
                    break;
                default:
                    return false;
            }
        }

        $user = new User($db);

        return $user;
    }
    public static function add_user_to_group(PDO $db, $userId,$groupId)
    {
        $tableRel = self::get_table_users_groups_rel_str();
        $sql = "INSERT INTO $tableRel (user_id,group_id) VALUES (:userid, :groupid)";
        $rs = $db->prepare($sql);

        $rs->execute( array(
                ":userid" => $userId,
                ":groupid" => $groupId
        ));

    }
    public static function del_user_from_group(PDO $db, $userId,$groupId)
    {
        $tableRel = self::get_table_users_groups_rel_str();
        $sql = "DELETE FROM $tableRel WHERE user_id=:userid AND group_id=:groupid;";
        $rs = $db->prepare($sql);
        $rs->execute( array(
                ":userid" => $userId,
                ":groupid" => $groupId
        ));
    }
    /*
    *   Return an array of users objects.
    *   is_connected for each ones is set to false
    */
    public static function get_users_list(PDO $db, $activesOnly = true, $groups = null)
    {
        $tableUsers = self::get_table_users_str();
        $tableGroups = self::get_table_groups_str();
        $tableRel = $tableUsers . "_" . $tableGroups ."_rel";

        //conditions
        $conditions = array();
        if($activesOnly){
            $conditions[] = "$tableUsers.active='1'";
        }
        if(!is_null($groups)){
            //$ groups is an untrusted entry; check it before using it on a non a query
            foreach($groups as $group){
                if (!preg_match('/^[0-9]+$/',$group)){
                    throw new \UnexpectedValueException('$groups must be a list  containing only digits'. $group);
                }
            }
            $conditions[] = "$tableUsers.id IN(
                                                    SELECT $tableUsers.id
                                                    FROM $tableUsers, $tableRel
                                                    WHERE $tableRel.user_id = $tableUsers.id
                                                    AND $tableRel.group_id IN ('" . implode("','",$groups) ."')
                                                )";      
        }

        
        $sql = "
            SELECT 
                $tableUsers.id as id,
                $tableUsers.login as login,
                $tableUsers.display_name as display_name,
                $tableUsers.auth_method as auth_method,
                $tableUsers.external_uid as external_id,
                $tableUsers.admin as is_admin,
                $tableUsers.active as active,
                GROUP_CONCAT(groupsrel.group_id SEPARATOR \",\") as groups_ids,
                GROUP_CONCAT(groups.name SEPARATOR \",\") as groups_name
            FROM
                $tableUsers LEFT JOIN  $tableRel as groupsrel ON groupsrel.user_id = $tableUsers.id
                    LEFT JOIN $tableGroups as groups ON groups.id = groupsrel.group_id"
            .(empty($conditions) ? "" :  " WHERE " . implode(" AND ", $conditions))
            ." GROUP BY $tableUsers.id; ";
      
        $rs = $db->query($sql);
    
        $list = array();
        while ($r = $rs->fetch())
        {

            $groups_id = explode(",", $r["groups_ids"]);
            $groups_names = explode(",", $r["groups_name"]);
            $groups = array();
            for($i = 0; $i < count($groups_id); $i++){
                $groups[ $groups_id[$i] ] = $groups_names[$i];
            }

            $user = new User($db);

            // array("login","external_id","id","display_name","auth_method","is_admin","group");
            $user-> set_properties(
                array(
                    "login" => $r["login"],
                    "id"    => $r["id"],
                    "display_name"  => $r["display_name"],
                    "external_id"   => $r["external_id"],
                    "auth_method"   => $r["auth_method"],
                    "is_admin"      => ($r["is_admin"] == "1"),
                    "groups"        => $groups
                )
            );
            $list[] = $user;
        }
        return $list;
    }
}