<?php

/*

Tasks:
Id Student Teacher Mark Completed Content Title Date

Users
Id Access E-mail Password Teacher Name

*/

class CUser
{
    private $db;
    public $Error;
    public function __construct( $_db )
    {
        $this->db = $_db;
    }
    public function Login( $login, $password )
    {
        $query = $this->db->prepare("SELECT `Id`, `Access`, `E-mail` FROM `Users` WHERE `E-mail` = :login AND `Password` = :pass LIMIT 1");
        $query->bindParam(':login', $login, PDO::PARAM_STR);
        $query->bindParam(':pass', $password, PDO::PARAM_STR);
        $query->execute();
        $result = $query->fetch(PDO::FETCH_ASSOC);
        if( !empty($result) )
        {
            foreach ($result as $key => $value) {
                $_SESSION[$key] = $value;
            }
            return 1;
        }
        else
        {
            $Error = "Неверный логин/пароль.";
            return 2;
        }
    }
    public function RegisterStudent( $params, $TeacherId )
    {
        $UID = $this->GetMaxUserId();
        $Access = 0;
        if( array_key_exists('Password', $params) && $params["Password"] == "" )
            $params["Password"] = chr( rand( 97,122 ) ) . chr( rand( 97,122 ) ) . chr( rand( 97,122 ) ) . chr( rand( 97,122 ) );
        $query = $this->db->prepare( "INSERT INTO `Users` (`Id`, `Name`, `E-mail`, `Password`, `Access`, `Teacher`) VALUES (:Id, :Name, :Email, :Password, :Access, :TeacherId);" );
        $query->bindParam( ':Id', $UID, PDO::PARAM_INT );
        $query->bindParam( ':Name', $params["Name"], PDO::PARAM_STR );
        $query->bindParam( ':Email', $params["E-mail"], PDO::PARAM_STR );
        $query->bindParam( ':Password', $params["Password"], PDO::PARAM_STR );
        $query->bindParam( ':Access', $Access, PDO::PARAM_INT );
        $query->bindParam( ':TeacherId', $TeacherId, PDO::PARAM_INT );
        return $query->execute();
    }
    public function OldRegisterStudent( $params, $Id )
    {
        $params["Teacher"]  = $Id;
        $params["Id"]       = $this->GetMaxUserId();
        $params["Access"]   = 0;
        if( $params["Password"] == "" )
            $params["Password"] = chr( rand( 97,122 ) ) . chr( rand( 97,122 ) ) . chr( rand( 97,122 ) ) . chr( rand( 97,122 ) );

        $tQuery = $this->db->prepare("DESCRIBE `Users`;");
        $tQuery->execute();
        $tResult = $tQuery->fetchAll(PDO::FETCH_ASSOC);
        $arTypes = array();
        foreach ($tResult as $key => $value) {
            if($value['Null'] == 'NO')
            {
                $type = preg_replace('/^(\w+)(\(.*\))?$/', '$1', $value['Type']);
                /* if(strpos($value['Type'], 'varchar') !== false) $arTypes[$value['Field']] = PDO::PARAM_STR;
                elseif(strpos($value['Type'], 'int') !== false) $arTypes[$value['Field']] = PDO::PARAM_INT; */
                switch( $type )
                {
                    case 'int':
                    case 'decimal':
                        $arTypes[ $value['Field'] ] = PDO::PARAM_INT;
                        break;
                    default:
                        $arTypes[ $value['Field'] ] = PDO::PARAM_STR;
                        break;
                }
            }
        }
        $tQuery->closeCursor();
        $arFields = "";
        $arFieldsBool = false;
        $arVals = "";
        foreach ($arTypes as $key => $value) {
            if( !array_key_exists( $key, $params ) )
            {
                $this->Error = "Missing key: " . $key;
            }
            else
            {
                if($arFieldsBool === false)
                {
                    $arFields = "`" . $key . "`";
                    $arVals = ":" . $key;
                    $arFieldsBool = true;
                }
                else
                {
                    $arFields .= ", `" . $key . "`";
                    $arVals .= ", :" . $key;
                }
            }
        }
        $dquery = $this->db->prepare("INSERT INTO `Users` (" . $arFields . ") VALUES (" . $arVals . ");");
        foreach($arTypes as $key => $value)
        {
            $dquery->bindValue(':' . $key, $params[ $key ], $value);
        }
        $dquery->execute();
        return 0;
    }
    public function GetTask( $Id )
    {
        return $this->GetCommonById( '`Id`', '`Tasks`', '`Id`', $Id );
    }
    public function GetTasksForStudent( $Id )
    {
        return $this->GetCommonById( '`Id`', '`Tasks`', '`Student`', $Id );
    }
    public function GetTasksForStudentA( $Id )
    {
        return $this->GetCommonById( '*', '`Tasks`', '`Student`', $Id );
    }
    public function GetTasksForTeacher( $Id )
    {
        return $this->GetCommonById( '`Id`', '`Tasks`', '`Teacher`', $Id );
    }
    public function GetStudentsForTeacher( $Id )
    {
        return $this->GetCommonById( '`Id`, `Name`, `E-mail`', '`Users`', '`Teacher`', $Id );
    }
    public function GetMaxUserId()
    {
        $query = $this->db->prepare("SELECT MAX(Id) FROM `Users`;");
        $query->execute();
        $res = $query->fetch(PDO::FETCH_ASSOC);
        $id = $res['MAX(Id)'];
        $query->closeCursor();
        ++$id;
        return $id;
    }
    public function GetTasksAll()
    {
        $query = $this->db->prepare("SELECT * FROM `Tasks`;");
        $query->execute();
        return $query->fetchAll();
    }
    public function GetCommonById( $SelectKeys, $TableName, $IdName, $Id )
    {
        $query = $this->db->prepare("SELECT " . $SelectKeys . " FROM " . $TableName . " WHERE " . $IdName . " = :id");
        $query->bindParam(':id', $Id, PDO::PARAM_INT);
        $query->execute();
        return $query->fetchAll();
    }
}

?>