<?php

namespace app\controllers;
use Yii;
use yii\rest\Controller;
use sizeg\jwt\Jwt;
use sizeg\jwt\JwtHttpBearerAuth;

class AttendanceController extends \yii\web\Controller
{

    public function actionIndex()
    {
        return $this->render('index');
    }

	public function actionLogin(){

		$request = Yii::$app->request;

		$username = $request->post('username');
		$password = $request->post('password');

		$header = [
    	"alg"     => "HS256",
    	"typ"     => "JWT"
		];

		// JWT Payload data

		$cmd = Yii::$app->db->createCommand('SELECT * FROM attendence WHERE username = :username');
		$result = $cmd->bindParam(':username', $username)
					  ->queryOne();

		if($result) {
			if(Yii::$app->getSecurity()->validatePassword($password, $result['password'])){


        		$cmd1 = Yii::$app->db->createCommand('SELECT id FROM attendence WHERE id = :id');
				$data = $cmd1->bindParam(':id', $result['id'])
					  		->queryOne();
        		$jwt = $this->generateJWT('sha256', $header, $data, 'shh_stfu');

        		$res = [
                'status' => true,
                'message' => 'Login Success..',
                'token' => $jwt,
            	];

			}
			else
        		{
        		    $res = [
        		        'status' => false,
        		        'message' => 'Wrong username or password.',
        		    ];
        		}
    	}
    	else
    	{
    	    $res = [
    	        'status' => false,
    	        'message' => 'Wrong username or password.',
    	    ];
    	}

		$response = Yii::$app->response;
    	$response->format = \yii\web\Response::FORMAT_JSON;
    	$response->data = ['data' => $res ];

	}

	public function actionFacultyDetails() {

		//$request = Yii::$app->request;
		$headers = Yii::$app->request->headers;
		$token = $headers->get('token');

		if($token){

			$verify = $this->verifyJWT('sha256', $token, 'shh_stfu');

			if($verify){
				$data = $this->decodeJWT($token);
				//var_dump(json_decode($data,true)) ;
				//print $data->{'id'};
				$cmd1 = Yii::$app->db->createCommand('SELECT id,name,exp,start_date FROM attendence WHERE id = :id');
				$data1 = $cmd1->bindParam(':id', $data->{'id'})
					  		 ->queryOne();
				$res = [
                'success' => true,
                'data' => $data1,
            	];
            }

			else {
				$res = [
                'success' => false,
            	];
			}

		}
		else {
			$res = [
                'sucess' => false,
                'message' => 'no headers provided',
            	];
			}


		$response = Yii::$app->response;
    	$response->format = \yii\web\Response::FORMAT_JSON;
    	$response->data = ['res' => $res ];
	}

	public function actionTimeTable {
		$request = Yii::$app->request;

		$emp_id = $request->post('emp_id');
		$month = $request->post('month');
		$year = $request->post('year');

		$cmd1 = Yii::$app->db->createCommand('SELECT * FROM acerp-class-timetable-creation WHERE emp_id = 									:emp_id AND month = :month AND year = :year');
		$data = $cmd1->bindParam(':emp_id', $emp_id)
					 ->bindParam(':month', $month)
					 ->bindParam(':year', $year)
					 ->queryAll();

		$response = Yii::$app->response;
    	$response->format = \yii\web\Response::FORMAT_JSON;
    	$response->data = ['res' => $data ];
	}

    public function action
	private function base64UrlEncode(string $data): string
	{
	    $urlSafeData = strtr(base64_encode($data), '+/', '-_');

	    return rtrim($urlSafeData, '=');
	}

	private function base64UrlDecode(string $data): string
	{
	    $urlUnsafeData = strtr($data, '-_', '+/');

	    $paddedData = str_pad($urlUnsafeData, strlen($data) % 4, '=', STR_PAD_RIGHT);

	    return base64_decode($paddedData);
	}

	private function generateJWT(

	    string $algo,
    	array $header,
	    array $payload,
	    string $secret
	): string {
	    $headerEncoded = $this->base64UrlEncode(json_encode($header));

	    $payloadEncoded = $this->base64UrlEncode(json_encode($payload));

	    // Delimit with period (.)
	    $dataEncoded = "$headerEncoded.$payloadEncoded";

	    $rawSignature = hash_hmac($algo, $dataEncoded, $secret, true);

	    $signatureEncoded = $this->base64UrlEncode($rawSignature);

	    // Delimit with second period (.)
	    $jwt = "$dataEncoded.$signatureEncoded";

	    return $jwt;
	}

	private function decodeJWT(string $token) {

		$decode = explode('.', $token);
		$data = $this->base64UrlDecode($decode[1]);
		$decode = json_decode($data);
		return $decode;

	}
	private function verifyJWT(string $algo, string $jwt, string $secret): bool
	{
	    list($headerEncoded, $payloadEncoded, $signatureEncoded) = explode('.', $jwt);

	    $dataEncoded = "$headerEncoded.$payloadEncoded";

	    $signature = $this->base64UrlDecode($signatureEncoded);

	    $rawSignature = hash_hmac($algo, $dataEncoded, $secret, true);

	    return hash_equals($rawSignature, $signature);
	}

}