<?php
session_start();
require_once 'db_config.php';

// 检查登录状态
if (empty($_SESSION['user_id'])) {
    echo json_encode(['error' => '未登录']);
    exit;
}

$user_id = $_SESSION['user_id'];
$action = $_GET['action'] ?? '';

// 获取当前用户的账单列表
if ($action === 'list') {
    $stmt = $pdo->prepare("SELECT id, bill_date as date, customer, item, money, paid FROM bills WHERE user_id = ? ORDER BY id DESC");
    $stmt->execute([$user_id]);
    $bills = $stmt->fetchAll(PDO::FETCH_ASSOC);
    foreach ($bills as &$bill) {
        $bill['paid'] = (bool)$bill['paid'];
    }
    echo json_encode($bills);
    exit;
}

// 添加账单
if ($action === 'add') {
    $data = json_decode(file_get_contents('php://input'), true);
    $date = $data['date'];
    $customer = $data['customer'];
    $item = $data['item'];
    $money = $data['money'];
    $paid = isset($data['paid']) ? ($data['paid'] ? 1 : 0) : 0;
    
    $stmt = $pdo->prepare("INSERT INTO bills (bill_date, customer, item, money, paid, user_id) VALUES (?, ?, ?, ?, ?, ?)");
    $stmt->execute([$date, $customer, $item, $money, $paid, $user_id]);
    echo json_encode(['success' => true, 'id' => $pdo->lastInsertId()]);
    exit;
}

// 更新账单（必须属于当前用户）
if ($action === 'update') {
    $data = json_decode(file_get_contents('php://input'), true);
    $id = $data['id'];
    $date = $data['date'];
    $customer = $data['customer'];
    $item = $data['item'];
    $money = $data['money'];
    $paid = $data['paid'] ? 1 : 0;
    
    $stmt = $pdo->prepare("UPDATE bills SET bill_date=?, customer=?, item=?, money=?, paid=? WHERE id=? AND user_id=?");
    $stmt->execute([$date, $customer, $item, $money, $paid, $id, $user_id]);
    echo json_encode(['success' => true]);
    exit;
}

// 删除账单
if ($action === 'delete') {
    $data = json_decode(file_get_contents('php://input'), true);
    $id = $data['id'];
    $stmt = $pdo->prepare("DELETE FROM bills WHERE id=? AND user_id=?");
    $stmt->execute([$id, $user_id]);
    echo json_encode(['success' => true]);
    exit;
}

// 切换支付状态
if ($action === 'togglePaid') {
    $data = json_decode(file_get_contents('php://input'), true);
    $id = $data['id'];
    $stmt = $pdo->prepare("UPDATE bills SET paid = NOT paid WHERE id=? AND user_id=?");
    $stmt->execute([$id, $user_id]);
    echo json_encode(['success' => true]);
    exit;
}

echo json_encode(['error' => '无效请求']);
?>