<?php
    function chk_admin($uid, $pass, $dbh) {
	$query = "SELECT * FROM user_auth WHERE username = :username";
	$stmt = $dbh->prepare($query);
	$stmt->bindParam(':username', $uid, PDO::PARAM_STR);
	$stmt->execute();
	if ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
		return chk_user($uid, $pass, $dbh);
	} else {
		return 0;
	}
    }
    
    function chk_user($uid, $pass, $dbh) {
	if (chk_ldap($uid, $pass) == 1) {
	    $query = "SELECT * FROM user_data WHERE username = :username";
	    $stmt = $dbh->prepare($query);
	    $stmt->bindParam(':username', $uid, PDO::PARAM_STR);
	    $stmt->execute();
	    if ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
		    return 1;
	    }
	    //Inserting new entry in db
	    createUser($uid, $dbh);
	    return 1;
	} else {
	    return 0;
	}
    }
    
    function createUser($uid, $dbh) {
	$query = "INSERT INTO `user_data`(`username`, `name`) VALUES (:username, :name)";
	$stmt = $dbh->prepare($query);
	$stmt->bindParam(':username', strtoupper($uid), PDO::PARAM_STR);
	$stmt->bindParam(':name', user_name($uid), PDO::PARAM_STR);
	if($stmt->execute()) {
            echo 'User Successfully added to db';
        } else {
            echo 'Error: ';
            print_r($stmt->errorInfo());
        }
    }
    
    function isValidUserLdap($uid) {
	if ($uid) {
		$ds = ldap_connect("172.31.1.42");
		ldap_set_option($ds, LDAP_OPT_PROTOCOL_VERSION, 3);
		$a = ldap_search($ds, "dc=iiita,dc=ac,dc=in", "uid=$uid" );
		$b = ldap_get_entries( $ds, $a );
		if(isset($b[0])) {
			return 1;
		}
		ldap_close($ds);
	} else {
		return 0;
	}
	return 0;
    }
    
    function chk_ldap($uid, $pwd) {
	if ($pwd) {
		$ds = ldap_connect("172.31.1.42");
		ldap_set_option($ds, LDAP_OPT_PROTOCOL_VERSION, 3);
		$a = ldap_search($ds, "dc=iiita,dc=ac,dc=in", "uid=$uid" );
		$b = ldap_get_entries( $ds, $a );
		if(isset($b[0])) {
			echo "connect";
			$dn = $b[0]["dn"];
			$ldapbind=@ldap_bind($ds, $dn, $pwd);
			if ($ldapbind) {
				return 1;
			} else {
				return 0;
			}
		}
		ldap_close($ds);
	} else {
		return 0;
	}
	return 0;
    }

    function user_name($uid) {
	$ds = ldap_connect("172.31.1.42");
	ldap_set_option($ds, LDAP_OPT_PROTOCOL_VERSION, 3);
	$a = ldap_search($ds, "dc=iiita,dc=ac,dc=in", "uid=$uid");
	$b = ldap_get_entries($ds, $a);
	if(isset($b[0])) {
		return $b[0]['gecos'][0];
	} else {
		return $uid;
	}
	ldap_close($ds);
    }
    
    function encryption($username, $type) {
	$fingerprint = $type . md5($_SERVER['HTTP_USER_AGENT']);
	return $salt = $fingerprint . session_id();
    }
?>