<?php

namespace App\Service\business;

use App\Models\business\ListItemModel;
use App\Models\business\ListModel;
use App\Models\business\OrderDeliveryModel;
use App\Models\business\OrderItemModel;
use App\Models\business\OrderModel;
use App\Models\business\OrderPaymentModel;
use App\Models\business\WxUserModel;
use App\Service\common\UtilsService;
use Illuminate\Support\Facades\DB;

/**
 * 订单核心逻辑（不含鉴权）
 *
 * 后台（OrderService，管理员身份）与小程序（WxOrderService，微信用户身份）都要用同一套
 * 建单、收款、发货规则。鉴权基类不同，所以规则收在这个中立类里，两边只做身份校验与参数整理。
 *
 * 三条纪律：金额一律整数分；状态只能通过 transition 迁移；支付确认必须行锁 + 幂等。
 */
class OrderCoreService
{
    private static mixed $_instance;

    /**
     * 允许的状态迁移，其余一律拒绝
     */
    private const TRANSITIONS = [
        OrderModel::STATUS_UNPAID => [OrderModel::STATUS_PAID, OrderModel::STATUS_CANCELLED],
        OrderModel::STATUS_PAID => [OrderModel::STATUS_SHIPPED, OrderModel::STATUS_CANCELLED],
        OrderModel::STATUS_SHIPPED => [OrderModel::STATUS_DONE],
        OrderModel::STATUS_DONE => [],
        OrderModel::STATUS_CANCELLED => [],
    ];

    public static function getInstance(): null|static
    {
        $name = get_called_class();
        if (!isset(self::$_instance[$name])) {
            self::$_instance[$name] = new static();
        }
        return self::$_instance[$name];
    }

    /**
     * 由清单生成订单
     *
     * @param int $listId 清单 ID
     * @param int $userId 下单用户（cc_wx_user.id）
     * @param array $params receiver_name/receiver_phone/receiver_address/delivery_type/remark
     * @return array 新订单详情
     */
    public function createFromList(int $listId, int $userId, array $params = []): array
    {
        $list = ListModel::where('id', $listId)->where('deleted_at', 0)->first();
        if (empty($list)) {
            UtilsService::getInstance()->errorThrow('清单不存在');
        }
        if ($userId > 0 && (int) $list['user_id'] !== $userId) {
            UtilsService::getInstance()->errorThrow('不能对他人的清单下单');
        }
        $userId = (int) $list['user_id'];

        $items = ListItemModel::with([
            'catalogue',
            'priceSheet',
        ])->where('list_id', $listId)->where('deleted_at', 0)->get();
        if ($items->isEmpty()) {
            UtilsService::getInstance()->errorThrow('清单里还没有商品');
        }

        $user = WxUserModel::where('id', $userId)->first();
        $multiplier = $user['price_number'] ?? 1;
        $price = PriceService::getInstance();

        $rows = [];
        $missing = [];
        $total = 0;
        foreach ($items as $item) {
            $catalogue = $item->catalogue;
            if (empty($catalogue)) {
                continue;
            }
            $sheet = $item->priceSheet;
            if (empty($sheet)) {
                // 老清单没有 price_sheet_id，缺规格的行必须让用户回清单补选，不能瞎猜一个价格
                $missing[] = $catalogue['title'] ?? ('#' . $item['catalogue_id']);
                continue;
            }
            $quantity = max(1, (int) $item['quantity']);
            $unitPrice = (int) $item['unit_price'];
            if ($unitPrice <= 0) {
                $unitPrice = $price->resolveUnitPrice($sheet['routine'] ?? '', (string) $item['material_key'], $multiplier);
            }
            $lineTotal = $unitPrice * $quantity;
            $total += $lineTotal;
            $rows[] = [
                'catalogue_id' => (int) $item['catalogue_id'],
                'price_sheet_id' => (int) $item['price_sheet_id'],
                'title' => (string) ($catalogue['title'] ?? ''),
                'cover' => (string) ($catalogue['cover'] ?? ''),
                'alias' => (string) ($catalogue['alias'] ?? ''),
                'specification' => (string) ($sheet['specification'] ?? ''),
                'dimension' => (string) ($sheet['dimension'] ?? ''),
                'material_key' => (string) ($item['material_key'] ?? 'routine'),
                'quantity' => $quantity,
                'unit_price' => $unitPrice,
                'total_price' => $lineTotal,
                'remark' => (string) ($item['remark'] ?? ''),
                'created_at' => time(),
            ];
        }
        if (!empty($missing)) {
            UtilsService::getInstance()->errorThrow('以下商品还没有选规格：' . implode('、', array_slice($missing, 0, 5)));
        }
        if (empty($rows)) {
            UtilsService::getInstance()->errorThrow('清单里没有可下单的商品');
        }

        $orderId = 0;
        DB::connection('business')->transaction(function () use (&$orderId, $list, $userId, $user, $params, $rows, $total) {
            $now = time();
            $orderId = OrderModel::insertGetId([
                'order_no' => SerialNoService::getInstance()->generate(SerialNoService::PREFIX_ORDER, 'order', 'order_no'),
                'list_id' => (int) $list['id'],
                'user_id' => $userId,
                'enterprise_id' => (int) ($list['enterprise_id'] ?: ($user['enterprise_id'] ?? 0)),
                'total_amount' => $total,
                'delivery_type' => (int) ($params['delivery_type'] ?? 0),
                'receiver_name' => (string) ($params['receiver_name'] ?? ($user['nick_name'] ?? '')),
                'receiver_phone' => (string) ($params['receiver_phone'] ?? ($user['phone'] ?? '')),
                'receiver_address' => (string) ($params['receiver_address'] ?? ''),
                'remark' => (string) ($params['remark'] ?? ''),
                'status' => OrderModel::STATUS_UNPAID,
                'created_at' => $now,
            ]);
            foreach ($rows as &$row) {
                $row['order_id'] = $orderId;
            }
            unset($row);
            OrderItemModel::insert($rows);
            ListModel::where('id', $list['id'])->update(['status' => 1, 'updated_at' => $now]);
        });

        return $this->detail($orderId);
    }

    /**
     * 订单详情（含明细、支付记录、发货记录）
     */
    public function detail(int $orderId): array
    {
        $order = OrderModel::with([
            'items' => fn ($query) => $query->where('deleted_at', 0),
            'payments' => fn ($query) => $query->where('deleted_at', 0)->orderBy('id', 'desc'),
            'deliveries' => fn ($query) => $query->where('deleted_at', 0)->orderBy('id', 'desc'),
            'user',
            'enterprise',
        ])->where('id', $orderId)->where('deleted_at', 0)->first();
        if (empty($order)) {
            UtilsService::getInstance()->errorThrow('订单不存在');
        }
        $order = $order->toArray();
        $order['voucher_list'] = [];
        foreach ($order['payments'] ?? [] as $payment) {
            foreach (array_filter(explode(',', (string) $payment['voucher'])) as $image) {
                $order['voucher_list'][] = $image;
            }
        }
        return $order;
    }

    /**
     * 提交转账凭证，进入待审核
     */
    public function submitVoucher(int $orderId, array $params, int $userId = 0): array
    {
        $order = $this->lockOrder($orderId, $userId);
        if ((int) $order['pay_status'] === OrderModel::PAY_STATUS_PAID) {
            UtilsService::getInstance()->errorThrow('订单已付款');
        }
        $voucher = $params['voucher'] ?? '';
        $voucher = is_array($voucher) ? implode(',', array_filter($voucher)) : (string) $voucher;
        if ($voucher === '') {
            UtilsService::getInstance()->errorThrow('请上传转账凭证');
        }
        $amount = (int) ($params['amount'] ?? 0);
        if ($amount <= 0) {
            $amount = (int) $order['total_amount'] - (int) $order['paid_amount'];
        }
        $now = time();
        DB::connection('business')->transaction(function () use ($orderId, $voucher, $amount, $now) {
            OrderPaymentModel::insert([
                'order_id' => $orderId,
                'pay_type' => OrderModel::PAY_TYPE_VOUCHER,
                'amount' => $amount,
                'voucher' => $voucher,
                // 转账没有微信单号，用订单 + 时间占位，仍受唯一索引约束防重复提交
                'out_trade_no' => 'TR' . $orderId . '_' . $now,
                'status' => OrderPaymentModel::STATUS_AUDITING,
                'created_at' => $now,
            ]);
            OrderModel::where('id', $orderId)->update([
                'pay_type' => OrderModel::PAY_TYPE_VOUCHER,
                'pay_status' => OrderModel::PAY_STATUS_AUDITING,
                'updated_at' => $now,
            ]);
        });
        return $this->detail($orderId);
    }

    /**
     * 审核转账凭证
     *
     * @param int $status OrderPaymentModel::STATUS_CONFIRMED|STATUS_REJECTED
     */
    public function auditPayment(int $paymentId, int $status, int $adminId, string $remark = ''): array
    {
        $orderId = 0;
        DB::connection('business')->transaction(function () use ($paymentId, $status, $adminId, $remark, &$orderId) {
            $payment = OrderPaymentModel::where('id', $paymentId)->lockForUpdate()->first();
            if (empty($payment)) {
                UtilsService::getInstance()->errorThrow('支付记录不存在');
            }
            if ((int) $payment['status'] !== OrderPaymentModel::STATUS_AUDITING) {
                UtilsService::getInstance()->errorThrow('该支付记录已处理');
            }
            $orderId = (int) $payment['order_id'];
            $now = time();
            OrderPaymentModel::where('id', $paymentId)->update([
                'status' => $status,
                'auditor_id' => $adminId,
                'audited_at' => $now,
                'audit_remark' => $remark,
                'updated_at' => $now,
            ]);
            if ($status !== OrderPaymentModel::STATUS_CONFIRMED) {
                OrderModel::where('id', $orderId)->update([
                    'pay_status' => OrderModel::PAY_STATUS_REJECTED,
                    'updated_at' => $now,
                ]);
                return;
            }
            $this->applyPaid($orderId, (int) $payment['amount'], $now);
        });
        return $this->detail($orderId);
    }

    /**
     * 记一笔收款并推进订单状态
     *
     * 收款可能分多笔，只有累计金额够了才算付清，否则停在部分收款。
     */
    public function applyPaid(int $orderId, int $amount, int $now = 0): void
    {
        $now = $now ?: time();
        $order = OrderModel::where('id', $orderId)->lockForUpdate()->first();
        if (empty($order)) {
            UtilsService::getInstance()->errorThrow('订单不存在');
        }
        $paid = (int) $order['paid_amount'] + $amount;
        $update = [
            'paid_amount' => $paid,
            'updated_at' => $now,
        ];
        if ($paid >= (int) $order['total_amount']) {
            $update['pay_status'] = OrderModel::PAY_STATUS_PAID;
            $update['paid_at'] = $now;
            if ($this->canTransition((int) $order['status'], OrderModel::STATUS_PAID)) {
                $update['status'] = OrderModel::STATUS_PAID;
            }
        }
        OrderModel::where('id', $orderId)->update($update);
    }

    /**
     * 微信支付回调落账（幂等）
     *
     * 微信会重复推送同一笔，靠 out_trade_no 唯一索引 + 状态判断挡住重复入账。
     */
    public function confirmWechatPay(string $outTradeNo, string $transactionId, int $amount): bool
    {
        $done = false;
        DB::connection('business')->transaction(function () use ($outTradeNo, $transactionId, $amount, &$done) {
            $payment = OrderPaymentModel::where('out_trade_no', $outTradeNo)->lockForUpdate()->first();
            if (empty($payment)) {
                return;
            }
            if ((int) $payment['status'] === OrderPaymentModel::STATUS_CONFIRMED) {
                $done = true;
                return;
            }
            $now = time();
            OrderPaymentModel::where('id', $payment['id'])->update([
                'status' => OrderPaymentModel::STATUS_CONFIRMED,
                'transaction_id' => $transactionId,
                'amount' => $amount > 0 ? $amount : (int) $payment['amount'],
                'audited_at' => $now,
                'updated_at' => $now,
            ]);
            $this->applyPaid((int) $payment['order_id'], $amount > 0 ? $amount : (int) $payment['amount'], $now);
            $done = true;
        });
        return $done;
    }

    /**
     * 发货：物流 / 自提 / 公司配送
     */
    public function ship(int $orderId, array $params, int $adminId): array
    {
        $order = $this->lockOrder($orderId);
        $type = (int) ($params['delivery_type'] ?? OrderModel::DELIVERY_EXPRESS);
        if ($type === OrderModel::DELIVERY_EXPRESS && trim((string) ($params['tracking_no'] ?? '')) === '') {
            UtilsService::getInstance()->errorThrow('请填写运单号');
        }
        if ($type === OrderModel::DELIVERY_PICKUP && trim((string) ($params['pickup_point'] ?? '')) === '') {
            UtilsService::getInstance()->errorThrow('请填写自提点');
        }
        if (!$this->canTransition((int) $order['status'], OrderModel::STATUS_SHIPPED)) {
            UtilsService::getInstance()->errorThrow('当前订单状态不允许发货');
        }
        $now = time();
        DB::connection('business')->transaction(function () use ($orderId, $params, $type, $adminId, $now) {
            OrderDeliveryModel::insert([
                'order_id' => $orderId,
                'delivery_type' => $type,
                'company' => (string) ($params['company'] ?? ''),
                'tracking_no' => (string) ($params['tracking_no'] ?? ''),
                'pickup_point' => (string) ($params['pickup_point'] ?? ''),
                'driver_info' => (string) ($params['driver_info'] ?? ''),
                'shipped_at' => $now,
                'remark' => (string) ($params['remark'] ?? ''),
                'operator_id' => $adminId,
                'created_at' => $now,
            ]);
            OrderModel::where('id', $orderId)->update([
                'delivery_type' => $type,
                'status' => OrderModel::STATUS_SHIPPED,
                'updated_at' => $now,
            ]);
        });
        return $this->detail($orderId);
    }

    /**
     * 状态迁移（取消、完成等）
     */
    public function transition(int $orderId, int $target, int $userId = 0): array
    {
        $order = $this->lockOrder($orderId, $userId);
        if (!$this->canTransition((int) $order['status'], $target)) {
            UtilsService::getInstance()->errorThrow('当前状态不允许该操作');
        }
        OrderModel::where('id', $orderId)->update([
            'status' => $target,
            'updated_at' => time(),
        ]);
        return $this->detail($orderId);
    }

    public function canTransition(int $from, int $to): bool
    {
        return in_array($to, self::TRANSITIONS[$from] ?? [], true);
    }

    /**
     * 取订单并做归属校验（$userId > 0 时限定本人）
     */
    private function lockOrder(int $orderId, int $userId = 0): array
    {
        $order = OrderModel::where('id', $orderId)->where('deleted_at', 0)->first();
        if (empty($order)) {
            UtilsService::getInstance()->errorThrow('订单不存在');
        }
        if ($userId > 0 && (int) $order['user_id'] !== $userId) {
            UtilsService::getInstance()->errorThrow('无权操作该订单');
        }
        return $order->toArray();
    }
}