<?php
include_once './includes/Database.php';

const USER_LEVEL_MODERATOR = 1;

class User
{
	public $id;
	public $name;
	public $password;
	public $date;
	public $level = 0;

	private $has_value = false;

	// Can't use a constructor here because we have two possible ways to get the user from the database
	// and PHP does not allow function overloading. 
	public function get_by_id($id)
	{
		$sql = "SELECT user_name, user_date, user_level, user_pass FROM users WHERE user_id = ?;";
		$result = Database::get()->query($sql, "i", $id);

		if (empty($result)) {
			return;
		}

		$this->id = $id;
		$this->name = $result[0]['user_name'];
		$this->password = $result[0]['user_pass'];
		$this->date = $result[0]['user_date'];
		$this->level = $result[0]['user_level'];

		$this->has_value = true;
	}

	public function get_by_name($name)
	{
		$sql = "SELECT user_id, user_date, user_level, user_pass FROM users WHERE user_name = ?";
		$result = Database::get()->query($sql, "s", $name);

		if (empty($result)) {
			return;
		}

		$this->id = $result[0]['user_id'];
		$this->name = $name;
		$this->password = $result[0]['user_pass'];
		$this->date = $result[0]['user_date'];
		$this->level = $result[0]['user_level'];

		$this->has_value = true;
	}

	public function has_value()
	{
		return $this->has_value;
	}

	public static function register(string $username, string $pass_hash)
	{
		$sql = "INSERT INTO users(user_name, user_pass, user_date, user_level) VALUES(?, ?, NOW(), 0);";
		Database::get()->query($sql, "ss", $username, $pass_hash);
	}

	public function change_password(string $pass_hash)
	{
		if (!Session::get()->is_signed_in()) {
			trigger_error('You are not signed in.');
			return;
		}

		if (Session::get()->get_current_user()->id != $this->id) {
			trigger_error("You can't change another user's password.");
			return;
		}

		$sql = "UPDATE users SET user_pass = ? WHERE user_id = ?;";
		Database::get()->query($sql, "si", $pass_hash, $this->id);
	}
}

function username_exists(string $username): bool
{
	$sql = "SELECT * FROM users WHERE user_name = ?;";
	$result = Database::get()->query($sql, "s", $username);

	return !empty($result);
}