<?php
// 结算下单：登录后填写收货信息，生成订单并扣减库存
require __DIR__ . '/includes/init.php';
requireLogin('checkout.php');
$pageTitle = '结算';
$user = currentUser();

$cart = $_SESSION['cart'] ?? [];
$items = [];
$total = 0;
if (!empty($cart)) {
    $ids = array_keys($cart);
    $ph  = implode(',', array_fill(0, count($ids), '?'));
    $stmt = db()->prepare('SELECT * FROM ' . tn('products') . ' WHERE id IN (' . $ph . ') AND status = 1');
    $stmt->execute($ids);
    foreach ($stmt->fetchAll() as $p) {
        $qty = (int) $cart[$p['id']];
        if ($qty > $p['stock']) $qty = $p['stock'];
        $pointsSub = (!empty($p['points_price']) ? (int)$p['points_price'] * $qty : 0);
        $items[] = ['p' => $p, 'qty' => $qty, 'points_sub' => $pointsSub];
    }
}

// 积分支付可用性：仅当订单内所有商品都设置了积分价
$pointsElg   = !empty($items);
$pointsTotal = 0;
foreach ($items as $it) {
    $pp = (int) ($it['p']['points_price'] ?? 0);
    if ($pp <= 0) { $pointsElg = false; break; }
    $pointsTotal += $pp * $it['qty'];
}
if ($pointsTotal <= 0) { $pointsElg = false; }
$userPoints = 0;
if (isLoggedIn()) {
    $userPoints = getUserPoints($user['id']);
}

$err = '';
if (empty($items)) {
    redirect('cart.php');
}

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    verifyCsrf();
    $contact = trim($_POST['contact'] ?? '');
    $contactEmail = trim($_POST['contact_email'] ?? '');
    $address = trim($_POST['address'] ?? '');
    $note    = trim($_POST['note']    ?? '');
    if ($contact === '') $err = '请填写联系人';
    elseif ($address === '') $err = '请填写收货地址';
    elseif ($contactEmail === '') $contactEmail = $user['email'];   // 留空则使用账号邮箱
    elseif (!filter_var($contactEmail, FILTER_VALIDATE_EMAIL)) $err = '联系邮箱格式不正确';

    if ($err === '') {
        $payType = ($pointsElg && ($_POST['pay_type'] ?? '') === 'points') ? 'points' : 'direct';
        if ($payType === 'points') {
            if ($userPoints < $pointsTotal) {
                $err = '积分不足，当前 ' . $userPoints . ' 分，本单需 ' . $pointsTotal . ' 分';
            }
        }
    }
    if ($err === '') {
        $pdo = db();
        try {
            $pdo->beginTransaction();
            // 二次校验库存
            foreach ($items as $it) {
                $chk = $pdo->prepare('SELECT stock FROM ' . tn('products') . ' WHERE id = ? FOR UPDATE');
                $chk->execute([$it['p']['id']]);
                $row = $chk->fetch();
                if (!$row || $row['stock'] < $it['qty']) {
                    throw new Exception('「' . $it['p']['name'] . '」库存不足，请返回购物车调整');
                }
            }
            // 计算本单周期（取商品中最大的周期天数）与到期时间
            $maxPeriod = 0;
            foreach ($items as $it) {
                $maxPeriod = max($maxPeriod, (int) ($it['p']['period_days'] ?? 0));
            }
            $expiresAt = $maxPeriod > 0 ? date('Y-m-d H:i:s', strtotime("+$maxPeriod days")) : null;

            // 本商城不收取现金，现金合计固定记 0；积分支付时抵扣并记流水
            $orderTotal = 0;
            $pointsUsed = 0;
            if ($payType === 'points') {
                $pointsUsed = $pointsTotal;
                $pdo->prepare('UPDATE ' . tn('users') . ' SET points = points - ? WHERE id = ? AND points >= ?')
                    ->execute([$pointsUsed, $user['id'], $pointsUsed]);
                $bal = getUserPoints($user['id']);
                $pdo->prepare('INSERT INTO ' . tn('points_log') . ' (user_id,type,amount,balance,remark,created_at) VALUES (?,?,?,?,?,NOW())')
                    ->execute([$user['id'], 'purchase', -$pointsUsed, $bal, '积分兑换：' . $orderNo]);
            }

            // 生成订单号
            $orderNo = 'FNW' . date('Ymd') . strtoupper(substr(md5(uniqid($user['id'], true)), 0, 10));
            $pdo->prepare('INSERT INTO ' . tn('orders') . ' (order_no,user_id,total,status,contact,contact_email,address,note,period_days,expires_at,pay_type,points_used,created_at) VALUES (?,?,?,?,?,?,?,?,?,?,?,?,NOW())')
                ->execute([$orderNo, $user['id'], $orderTotal, 'paid', $contact, $contactEmail, $address, $note, $maxPeriod, $expiresAt, $payType, $pointsUsed]);
            $orderId = $pdo->lastInsertId();
            foreach ($items as $it) {
                // 商城已取消现金支付，价格字段保留为 0 供历史兼容
                $pdo->prepare('INSERT INTO ' . tn('order_items') . ' (order_id,product_id,name,price,qty,subtotal,period_days) VALUES (?,?,?,?,?,?,?)')
                    ->execute([$orderId, $it['p']['id'], $it['p']['name'], 0, $it['qty'], 0, (int) ($it['p']['period_days'] ?? 0)]);
                $pdo->prepare('UPDATE ' . tn('products') . ' SET stock = stock - ? WHERE id = ?')
                    ->execute([$it['qty'], $it['p']['id']]);
            }
            $pdo->commit();
            $_SESSION['cart'] = [];
            redirect('myorders.php?paid=' . urlencode($orderNo));
        } catch (Exception $e) {
            $pdo->rollBack();
            $err = $e->getMessage();
        }
    }
}

require 'includes/header.php';
?>
<section class="section">
    <h2 class="sec-title"><i class="fas fa-credit-card"></i> 订单结算</h2>
    <div class="checkout">
        <div class="co-items">
            <h3>商品清单</h3>
            <?php foreach ($items as $it): ?>
                <div class="co-row">
                    <span><?= h($it['p']['name']) ?> × <?= $it['qty'] ?></span>
                    <span><?= $it['points_sub'] > 0 ? (int)$it['points_sub'] . ' 积分' : '直接下单' ?></span>
                </div>
            <?php endforeach; ?>
        </div>

        <form method="post" action="" class="co-form">
            <?= csrfField() ?>
            <h3>收货信息</h3>
            <?php if ($err): ?><p class="form-err"><?= h($err) ?></p><?php endif; ?>
            <label>联系人<input type="text" name="contact" value="<?= h($_POST['contact'] ?? $user['username']) ?>" required></label>
            <label>联系邮箱<input type="email" name="contact_email" value="<?= h($_POST['contact_email'] ?? $user['email']) ?>" placeholder="用于接收订单/发货通知" required></label>
            <label>收货地址<input type="text" name="address" value="<?= h($_POST['address'] ?? '') ?>" required></label>
            <label>备注<input type="text" name="note" value="<?= h($_POST['note'] ?? '') ?>" placeholder="选填"></label>
            <?php if ($pointsElg): ?>
                <div class="co-pay">
                    <h3>支付方式</h3>
                    <input type="hidden" name="pay_type" value="points">
                    <p class="pay-opt"><i class="fas fa-coins"></i> 积分支付（<?= $pointsTotal ?> 积分）<span class="muted" style="margin-left:10px;font-size:.85em;">当前积分 <?= (int)$userPoints ?></span></p>
                </div>
            <?php else: ?>
                <input type="hidden" name="pay_type" value="direct">
            <?php endif; ?>
            <p class="co-tip">下单后如有积分价格要求，用积分支付；无积分价格，直接支付即可（发工单即代表您已同意资源领取/续期规定）。</p>
            <button type="submit" class="btn btn-primary" style="width:100%;">提交订单</button>
        </form>
    </div>
</section>
<?php require 'includes/footer.php'; ?>