<?php
/**
 * Tom's Java Jive - Database Class
 * 
 * Singleton PDO database connection
 */

require_once __DIR__ . '/../config/database.php';

class Database {
    private static $instance = null;
    private $pdo;
    
    private function __construct() {
        try {
            $dsn = "mysql:host=" . DB_HOST . ";dbname=" . DB_NAME . ";charset=" . DB_CHARSET;
            $this->pdo = new PDO($dsn, DB_USER, DB_PASS, DB_OPTIONS);
        } catch (PDOException $e) {
            if (ENVIRONMENT === 'development') {
                die("Database connection failed: " . $e->getMessage());
            } else {
                die("Database connection failed. Please try again later.");
            }
        }
    }
    
    public static function getInstance() {
        if (self::$instance === null) {
            self::$instance = new self();
        }
        return self::$instance;
    }
    
    public function getConnection() {
        return $this->pdo;
    }
    
    public function query($sql, $params = []) {
        $stmt = $this->pdo->prepare($sql);
        $stmt->execute($params);
        return $stmt;
    }
    
    public function fetch($sql, $params = []) {
        return $this->query($sql, $params)->fetch();
    }
    
    public function fetchAll($sql, $params = []) {
        return $this->query($sql, $params)->fetchAll();
    }
    
    public function insert($table, $data) {
        $columns = implode(', ', array_keys($data));
        $placeholders = ':' . implode(', :', array_keys($data));
        
        $sql = "INSERT INTO {$table} ({$columns}) VALUES ({$placeholders})";
        $this->query($sql, $data);
        
        return $this->pdo->lastInsertId();
    }
    
    public function update($table, $data, $where, $whereParams = []) {
        $set = [];
        foreach (array_keys($data) as $column) {
            $set[] = "{$column} = :{$column}";
        }
        $setString = implode(', ', $set);
        
        $sql = "UPDATE {$table} SET {$setString} WHERE {$where}";
        return $this->query($sql, array_merge($data, $whereParams))->rowCount();
    }
    
    public function delete($table, $where, $params = []) {
        $sql = "DELETE FROM {$table} WHERE {$where}";
        return $this->query($sql, $params)->rowCount();
    }
    
    public function count($table, $where = '1=1', $params = []) {
        $sql = "SELECT COUNT(*) as count FROM {$table} WHERE {$where}";
        $result = $this->fetch($sql, $params);
        return $result['count'] ?? 0;
    }
    
    public function lastInsertId() {
        return $this->pdo->lastInsertId();
    }
    
    public function beginTransaction() {
        return $this->pdo->beginTransaction();
    }
    
    public function commit() {
        return $this->pdo->commit();
    }
    
    public function rollback() {
        return $this->pdo->rollBack();
    }
}

// Helper function to get database instance
function db() {
    return Database::getInstance();
}