<?php

class AuthManager {
	public function getToken($username, $password, $userAgent = null){
		if ($userAgent == null) {
			$userAgent = $_SERVER['HTTP_USER_AGENT'];
		}

		$userManager = new UserManager();
		if ($username != '' || $password != ''){
			$userLogedIn = $userManager->loginNew($username, $password);

			if ($userLogedIn != false){
				// Create token header as a JSON string
				$header = json_encode(['typ' => 'JWT', 'alg' => 'HS256']);
				// Create token payload as a JSON string
				$payload = json_encode([
					'user_id' => $userLogedIn,
					'exp' => date('Y-m-d H:i:s',strtotime("+90 Days")),
					'iat' => date('Y-m-d H:i:s',time()),
			  ]);
				// Encode Header to Base64Url String
				$base64UrlHeader = str_replace(['+', '/', '='], ['-', '_', ''], base64_encode($header));
				// Encode Payload to Base64Url String
				$base64UrlPayload = str_replace(['+', '/', '='], ['-', '_', ''], base64_encode($payload));
				// Create Signature Hash
				$signature = hash_hmac('sha256', $base64UrlHeader . "." . $base64UrlPayload, 'abC123!', true);
				// Encode Signature to Base64Url String
				$base64UrlSignature = str_replace(['+', '/', '='], ['-', '_', ''], base64_encode($signature));
				// Create JWT
				$jwt = $base64UrlHeader . "." . $base64UrlPayload . "." . $base64UrlSignature;


				$token = [
					'user_id' => $userLogedIn,
					'user_agent' => $userAgent,
					'token' => $jwt,
					'expire' => date('Y-m-d H:i:s',strtotime("+90 Days")),
					'issued' => date('Y-m-d H:i:s',time()),
				];
				if (Db::add ('tokens', $token)){
					return $jwt;
				}
			}
		}
		return false;
	}

	public function deleteToken($token){
		Db::command ('DELETE FROM tokens WHERE token=?', array ($token));
		return true;
	}

	public function validateToken($token){
		list($type, $hash) = explode(' ', $token);
		$tokens = Db::loadAll('SELECT * FROM tokens WHERE token = ? AND expire >= CURRENT_TIMESTAMP AND blocked = 0;', array($hash));
		if ($type == 'Bearer' && count($tokens) == 1) {
			return true;
		} else if (count($tokens) == 0) {
			return false;
		};
		return false;
	}

	public function getUserId($bearer){
		$token = explode(' ',  $bearer)[1];
		$userid = Db::loadOne('SELECT user_id FROM tokens WHERE token = ? AND expire >= CURRENT_TIMESTAMP AND blocked = 0;', array($token))['user_id'];
		return $userid;
	}
}