<?php

namespace App;

use PDO;
use PDOException;
use Exception;

class Database
{
    private static $instance = null;
    private $connection;

    private function __construct() 
    {
        $dbPath = \Config::PATH['root'] . '/database/database.db';
        try {
            $this->connection = new PDO('sqlite:' . $dbPath);
            $this->connection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
            $this->connection->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
        } catch (PDOException $e) {
            throw new Exception('Database connection failed: ' . $e->getMessage());
        }
    }

    public static function getInstance() 
    {
        if (self::$instance === null) {
            self::$instance = new self();
        }
        return self::$instance;
    }

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

    public function query($sql, $params = []) 
    {
        try {
            $stmt = $this->connection->prepare($sql);
            $stmt->execute($params);
            return $stmt;
        } catch (PDOException $e) {
            throw new Exception('Query failed: ' . $e->getMessage());
        }
    }

    public function fetchAll($sql, $params = []) 
    {
        $stmt = $this->query($sql, $params);
        return $stmt->fetchAll();
    }

    public function fetchOne($sql, $params = []) 
    {
        $stmt = $this->query($sql, $params);
        return $stmt->fetch();
    }

    public function execute($sql, $params = []) 
    {
        $stmt = $this->query($sql, $params);
        return $stmt->rowCount();
    }

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