<?php
session_start();
header('Content-Type: application/json');
require_once __DIR__ . '/../database/db_connect.php';

$input = json_decode(file_get_contents('php://input'), true);
$username = trim($input['username'] ?? '');
$password = $input['password'] ?? '';

if (!$username || !$password) {
    http_response_code(400);
    echo json_encode(['error' => 'Username and password required']);
    exit;
}

// Check if user exists
$stmt = $pdo->prepare("SELECT id FROM users WHERE username = ?");
$stmt->execute([$username]);
if ($stmt->fetch()) {
    http_response_code(409);
    echo json_encode(['error' => 'Username already taken']);
    exit;
}

// Hash password
$hash = password_hash($password, PASSWORD_DEFAULT);

// Insert user
$stmt = $pdo->prepare("INSERT INTO users (username, password) VALUES (?, ?)");
if ($stmt->execute([$username, $hash])) {
    $userId = $pdo->lastInsertId();
    $_SESSION['user_id'] = $userId;
    $_SESSION['username'] = $username;
    
    echo json_encode(['ok' => true, 'user' => ['id' => $userId, 'username' => $username]]);
} else {
    http_response_code(500);
    echo json_encode(['error' => 'Registration failed']);
}
?>