<?php
	session_start();
	global $con;
	$con = mysqli_connect('localhost', 'root', '', 'funbook');

	$salt1 = "khkh";
	$salt2 = "bvmv";
	$salt3 = "hghkfkh";

	function username_exists( $username ) {
		global $con;

		$query = "SELECT * FROM users WHERE `username` = '$username'";
		$a = mysqli_query($con, $query);

		if ( $a->num_rows > 0 ) {
			return true;
		}
		else {
			return false;
		}
	}

	function email_exists( $email ) {
		global $con;

		$query = "SELECT * FROM users WHERE `email` = '$email'";
		$a = mysqli_query($con, $query);

		if( $a->num_rows > 0 ) {
			return true;
		}
		else {
			return false;
		}
	}

	function site_url( $path = NULL ) {
		return is_null($path) ? "http://localhost/funbook" : "http://localhost/funbook/" . $path;
	}

	function username_length( $username ) {
		$length = strlen($username);

		return $length;
	}

	function is_user_valid( $username, $password ) {
		global $con;

		if ( $username == NULL || $password == NULL ) {
			return false;
		}

		$password = md5($password);

		$query = "SELECT * FROM users WHERE `username` = '$username' && `password` = '$password' && `status` = '1'";
		$a = mysqli_query($con, $query);

		if ( $a->num_rows == 1 ) {
			return true;
		}
		else {
			return false;
		}

	}

	function is_user_logged_in( $username = NULL ) {
		if ( $username == NULL ) {
			return isset($_SESSION['username']) ? true : false;
		}
		else {
			return isset($_SESSION['username']) && $username == $_SESSION['username'] ? true : false;
		}
	}

	function get_logged_user() {
		return get_user_by_username($_SESSION['username']);
	}

	function get_user_by_username($username) {
		return get_user_by("username", $username);
	}

	function get_user_by_id($id) {
		return get_user_by("id", $id);
	}

	function get_user_by($column, $value) {
		global $con;

		$query = "SELECT * FROM users WHERE `$column` = '$value'";
		$a = mysqli_query($con, $query);

		$info = $a->fetch_assoc();

		return $info;
	}