package service

import (
	"errors"
	"net/http"
	"net/url"
	"strings"
	"time"

	"affiliate_dash/internal/model"
	"affiliate_dash/internal/pkg/timeutil"

	"gorm.io/gorm"
	"gorm.io/gorm/clause"
)

const defaultDeliveryBFFBaseURL = "https://www.jxya.top/bff"

// 发货提交阶段，持久化在 result_data.provider_order_stage 中，供排障与补偿扫描区分处理。
const (
	deliveryStageClaimed      = "claimed"         // 已锁定订单，尚未建 queue
	deliveryStageQueueCreated = "queue_created"   // 已在上游建 queue，尚未生成正式订单
	deliveryStageSubmitted    = "submitted"       // 已在上游创建正式订单
	deliveryStageBindVerify   = "bind_verify"     // 绑定账号校验失败
	deliveryStageBindMismatch = "bind_mismatch"   // 玩家编号与绑定账号不一致
	deliveryStageCreateQueue  = "create_queue"    // 创建上游 queue 失败
	deliveryStagePatchQueue   = "patch_queue"     // 补充 queue 账号信息失败
	deliveryStageCreateOrder  = "create_upstream" // 创建上游正式订单失败

	deliverySubmissionStaleTimeout = 10 * time.Minute
)

// deliverySubmittedUpstream 判断订单是否已成功提交到上游正式订单。
// 已提交上游的失败订单禁止自动重发，避免重复发货。
func deliverySubmittedUpstream(order *model.FulfillmentOrder) bool {
	if order == nil {
		return false
	}
	if strings.TrimSpace(order.ProviderOrderNo) != "" {
		return true
	}
	m := resultDataMap(order.ResultData)
	if _, ok := m["delivery"]; ok {
		return true
	}
	if _, ok := m["upstream_order"]; ok { // 兼容历史数据
		return true
	}
	return resultDataString(order.ResultData, "provider_order_stage") == deliveryStageSubmitted
}

type DeliveryService struct {
	fulfillment *FulfillmentService
	bffBaseURL  string
	channel     string
	linkBaseURL string
	linkSecret  string
	linkTTL     time.Duration
	httpClient  *http.Client
}

func NewDeliveryService(fulfillment *FulfillmentService, bffBaseURL, channel, linkBaseURL, linkSecret string, linkTTLMinutes int) *DeliveryService {
	bffBaseURL = strings.TrimRight(strings.TrimSpace(bffBaseURL), "/")
	if bffBaseURL == "" {
		bffBaseURL = defaultDeliveryBFFBaseURL
	}
	channel = strings.TrimSpace(channel)
	if channel == "" {
		channel = "dlc"
	}
	linkBaseURL = strings.TrimRight(strings.TrimSpace(linkBaseURL), "/")
	linkSecret = strings.TrimSpace(linkSecret)
	if linkSecret == "" {
		linkSecret = "affiliate-dash-delivery-link-secret"
	}
	// linkTTLMinutes <= 0 表示链接永久有效（0 为默认值）。
	if linkTTLMinutes < 0 {
		linkTTLMinutes = 0
	}
	return &DeliveryService{
		fulfillment: fulfillment,
		bffBaseURL:  bffBaseURL,
		channel:     channel,
		linkBaseURL: linkBaseURL,
		linkSecret:  linkSecret,
		linkTTL:     time.Duration(linkTTLMinutes) * time.Minute,
		httpClient:  &http.Client{Timeout: 15 * time.Second},
	}
}

func (s *DeliveryService) SetHTTPClient(client *http.Client) {
	if client != nil {
		s.httpClient = client
	}
}

type DeliveryOrderInfo struct {
	OrderNo          string                 `json:"order_no"`
	Status           string                 `json:"status"`
	CanShip          bool                   `json:"can_ship"`
	CannotShipReason string                 `json:"cannot_ship_reason,omitempty"`
	Product          *DeliveryProduct       `json:"product,omitempty"`
	BuyerName        string                 `json:"buyer_name"`
	Amount           int64                  `json:"amount"`
	CreatedAt        time.Time              `json:"created_at"`
	ShippedAt        *time.Time             `json:"shipped_at"`
	ShipFailReason   string                 `json:"ship_fail_reason,omitempty"`
	GameChannel      string                 `json:"game_channel,omitempty"`
	GameUID          string                 `json:"game_uid,omitempty"`
	RoleName         string                 `json:"role_name,omitempty"`
	PayScore         int                    `json:"pay_score,omitempty"`
	Data             map[string]interface{} `json:"data,omitempty"`
	Good             map[string]interface{} `json:"good,omitempty"`
}

type DeliveryProduct struct {
	Name  string `json:"name"`
	SKU   string `json:"sku"`
	Game  string `json:"game"`
	Image string `json:"image,omitempty"`
}

type DeliveryBindResult struct {
	BindUUID            string `json:"bind_uuid"`
	BindURL             string `json:"bind_url"`
	QRURL               string `json:"qr_url"`
	Bound               bool   `json:"bound"`
	GameAccount         string `json:"game_account,omitempty"`
	RoleName            string `json:"role_name,omitempty"`
	GameChannel         string `json:"game_channel,omitempty"`
	ExpectedGameAccount string `json:"expected_game_account,omitempty"`
	Mismatch            bool   `json:"mismatch,omitempty"`
	Message             string `json:"message,omitempty"`
}

type DeliveryLinkResult struct {
	OrderNo     string     `json:"order_no"`
	DeliveryURL string     `json:"delivery_url"`
	ExpiresAt   *time.Time `json:"expires_at,omitempty"` // null 表示永久有效
	Exp         int64      `json:"exp"`
	Sign        string     `json:"sign"`
}

type DeliverySubmitResult struct {
	OrderNo         string                 `json:"order_no"`
	Status          string                 `json:"status"`
	Message         string                 `json:"message"`
	ProviderOrderNo string                 `json:"provider_order_no,omitempty"`
	GameAccount     map[string]interface{} `json:"game_account,omitempty"`
	UpstreamOrder   interface{}            `json:"delivery,omitempty"`
}

type DeliveryLinkAuth struct {
	Exp  int64
	Sign string
}

type deliveryHTTPError struct {
	status  int
	message string
}

func (e deliveryHTTPError) Error() string {
	return e.message
}

func (e deliveryHTTPError) HTTPStatus() int {
	return e.status
}

func newDeliveryHTTPError(status int, message string) error {
	return deliveryHTTPError{status: status, message: message}
}

func (s *DeliveryService) GetOrder(orderNo string, auth DeliveryLinkAuth) (*DeliveryOrderInfo, error) {
	info, _, _, err := s.prepareOrder(orderNo, false, &auth)
	return info, err
}

func (s *DeliveryService) GetMerchantOrder(merchantID uint, orderNo string) (*DeliveryOrderInfo, error) {
	openOrder, order, goodID, err := s.loadMerchantOrder(merchantID, orderNo)
	if err != nil {
		return nil, err
	}
	info, _, _, err := s.buildDeliveryState(openOrder, order, goodID, false)
	return info, err
}

func (s *DeliveryService) Bind(orderNo, gameAccount string, auth DeliveryLinkAuth) (*DeliveryBindResult, error) {
	return s.bindWithOrder(orderNo, gameAccount, &auth, 0)
}

func (s *DeliveryService) BindForMerchant(merchantID uint, orderNo, gameAccount string) (*DeliveryBindResult, error) {
	return s.bindWithOrder(orderNo, gameAccount, nil, merchantID)
}

// GetBindResult 查询绑定结果（自建发货页轮询用）。
// 绑定未完成时返回 bound=false（不报错），由前端提示继续扫码。
func (s *DeliveryService) GetBindResult(merchantID uint, orderNo, bindUUID string) (*DeliveryBindResult, error) {
	bindUUID = strings.TrimSpace(bindUUID)
	if bindUUID == "" {
		return nil, errors.New("bind_uuid 不能为空")
	}
	openOrder, order, goodID, err := s.loadMerchantOrder(merchantID, orderNo)
	if err != nil {
		return nil, err
	}
	if _, _, _, err := s.buildDeliveryState(openOrder, order, goodID, false); err != nil {
		return nil, err
	}
	account, err := s.accountBound(bindUUID, goodID)
	if err != nil {
		if strings.Contains(err.Error(), "尚未绑定") || strings.Contains(err.Error(), "未绑定") {
			return &DeliveryBindResult{BindUUID: bindUUID, Bound: false, Message: "尚未绑定，请先完成扫码绑定"}, nil
		}
		return nil, err
	}
	boundAccount := stringFromMap(account, "game_account")
	result := &DeliveryBindResult{
		BindUUID:    bindUUID,
		Bound:       true,
		GameAccount: boundAccount,
		RoleName:    stringFromMap(account, "game_account_role_name"),
		GameChannel: gameChannelText(account),
		Message:     "绑定成功",
	}
	// 下单时 data 透传的预期账号：绑定账号与预期不一致时提示，供自建页提前拦截。
	if expected := requestDataString(order.RequestData, "game_account"); expected != "" {
		result.ExpectedGameAccount = expected
		if boundAccount != expected {
			result.Mismatch = true
			result.Message = "绑定成功，但绑定账号与下单预期账号不一致，请确认"
		}
	}
	return result, nil
}

func (s *DeliveryService) bindWithOrder(orderNo, gameAccount string, auth *DeliveryLinkAuth, merchantID uint) (*DeliveryBindResult, error) {
	gameAccount = strings.TrimSpace(gameAccount)
	if gameAccount == "" {
		return nil, errors.New("请输入玩家编号")
	}
	var (
		openOrder *OpenOrderQuery
		order     *model.FulfillmentOrder
		goodID    string
		err       error
	)
	if merchantID > 0 {
		openOrder, order, goodID, err = s.loadMerchantOrder(merchantID, orderNo)
	} else {
		openOrder, order, goodID, err = s.loadLinkedOrder(orderNo, auth)
	}
	if err != nil {
		return nil, err
	}
	_, _, _, err = s.buildDeliveryState(openOrder, order, goodID, true)
	if err != nil {
		return nil, err
	}
	return s.bindGood(gameAccount, goodID)
}

func (s *DeliveryService) bindGood(gameAccount, goodID string) (*DeliveryBindResult, error) {
	var out struct {
		BindUUID string `json:"bind_uuid"`
		URL      string `json:"url"`
	}
	if err := s.signProxy("/public/games/bind-account", "POST", map[string]interface{}{
		"game_account": gameAccount,
		"gameAccount":  gameAccount,
		"goodId":       goodID,
		"good_id":      goodID,
	}, &out); err != nil {
		return nil, err
	}
	if out.BindUUID == "" || out.URL == "" {
		return nil, errors.New("绑定服务未返回绑定二维码")
	}
	return &DeliveryBindResult{
		BindUUID: out.BindUUID,
		BindURL:  out.URL,
		QRURL:    "https://api.qrserver.com/v1/create-qr-code/?size=240x240&data=" + url.QueryEscape(out.URL),
	}, nil
}

func (s *DeliveryService) Submit(orderNo, gameAccount, bindUUID string, auth DeliveryLinkAuth) (*DeliverySubmitResult, error) {
	return s.submit(orderNo, gameAccount, bindUUID, 0, &auth, 0)
}

func (s *DeliveryService) SubmitForMerchant(merchantID, apiClientID uint, orderNo, gameAccount, bindUUID string) (*DeliverySubmitResult, error) {
	return s.submit(orderNo, gameAccount, bindUUID, apiClientID, nil, merchantID)
}

func (s *DeliveryService) submit(orderNo, gameAccount, bindUUID string, apiClientID uint, auth *DeliveryLinkAuth, merchantID uint) (*DeliverySubmitResult, error) {
	gameAccount = strings.TrimSpace(gameAccount)
	bindUUID = strings.TrimSpace(bindUUID)
	orderNo = strings.TrimSpace(orderNo)
	if gameAccount == "" || bindUUID == "" {
		return nil, errors.New("玩家编号和绑定凭证不能为空")
	}
	var (
		openOrder *OpenOrderQuery
		order     *model.FulfillmentOrder
		goodID    string
		err       error
	)
	if merchantID > 0 {
		openOrder, order, goodID, err = s.loadMerchantOrder(merchantID, orderNo)
	} else {
		openOrder, order, goodID, err = s.loadLinkedOrder(orderNo, auth)
	}
	if err != nil {
		return nil, err
	}
	info, _, _, err := s.buildDeliveryState(openOrder, order, goodID, false)
	if err != nil {
		return nil, err
	}
	orderStatus := normalizeOrderStatus(order)
	if orderStatus == model.OrderStatusDelivering ||
		orderStatus == model.OrderStatusDelivered ||
		strings.TrimSpace(order.ProviderOrderNo) != "" ||
		strings.Contains(order.ResultData, "\"queue_order_id\"") {
		if existing := buildExistingDeliverySubmitResult(order); existing != nil {
			return existing, nil
		}
	}
	// 已在上游创建正式订单的失败订单禁止自动重发，避免重复发货。
	if orderStatus == model.OrderStatusShipFailed && deliverySubmittedUpstream(order) {
		return nil, newDeliveryHTTPError(http.StatusConflict, "该订单已进入发货流程，为避免重复发货不能直接重试，请稍后查询订单状态或联系平台处理")
	}
	if !info.CanShip {
		reason := info.CannotShipReason
		if reason == "" {
			reason = "订单暂不可发货"
		}
		return nil, newDeliveryHTTPError(http.StatusBadRequest, reason)
	}
	claimed, claimedNow, err := s.claimDeliverySubmission(order.MerchantID, apiClientID, order.OrderNo)
	if err != nil {
		return nil, err
	}
	if !claimedNow {
		if existing := buildExistingDeliverySubmitResult(claimed); existing != nil {
			return existing, nil
		}
		return nil, newDeliveryHTTPError(http.StatusConflict, "订单暂时正在发货中，请稍后查询")
	}
	boundAccount, err := s.accountBound(bindUUID, goodID)
	if err != nil {
		s.markDeliverySubmissionFailed(claimed, apiClientID, deliveryStageBindVerify, err.Error())
		return nil, err
	}
	if boundGameAccount := stringFromMap(boundAccount, "game_account"); boundGameAccount != "" && boundGameAccount != gameAccount {
		err := errors.New("玩家编号与绑定的游戏账号不一致，请重新绑定")
		s.markDeliverySubmissionFailed(claimed, apiClientID, deliveryStageBindMismatch, err.Error())
		return nil, err
	}
	queueOrderID, err := s.createOrderQueue(goodID, order.OrderNo)
	if err != nil {
		s.markDeliverySubmissionFailed(claimed, apiClientID, deliveryStageCreateQueue, err.Error())
		return nil, err
	}
	// 建 queue 后只持久化阶段信息，不提前改成 delivering。
	// 上游创建正式订单前会回查开放接口，此时订单必须仍然 can_ship=true。
	if err := s.recordDeliverySubmissionStage(claimed, deliveryStageQueueCreated, map[string]interface{}{
		"queue_order_id": queueOrderID,
	}); err != nil {
		return nil, err
	}
	if err := s.patchOrderQueue(queueOrderID, gameAccount, bindUUID); err != nil {
		s.markDeliverySubmissionFailed(claimed, apiClientID, deliveryStagePatchQueue, err.Error())
		return nil, err
	}
	upstreamOrder, err := s.createUpstreamOrder(queueOrderID, gameAccount, goodID, order.OrderNo)
	if err != nil {
		s.markDeliverySubmissionFailed(claimed, apiClientID, deliveryStageCreateOrder, err.Error())
		return nil, err
	}
	providerOrderNo := firstNonEmpty(
		stringFromMap(upstreamOrder, "order_no"),
		stringFromMap(upstreamOrder, "_id"),
		stringFromMap(upstreamOrder, "id"),
		stringFromMap(upstreamOrder, "order_sn"),
		queueOrderID,
	)
	resultData := mergeResultData(claimed.ResultData, map[string]interface{}{
		"provider_order_stage": deliveryStageSubmitted,
		"queue_order_id":       queueOrderID,
		"provider_order_no":    providerOrderNo,
		"game_uid":             gameAccount,
		"role_name":            stringFromMap(boundAccount, "game_account_role_name"),
		"game_channel":         gameChannelText(boundAccount),
		"delivery":             upstreamOrder,
	})
	nextStatus := model.OrderStatusDelivering
	message := "已提交发货，等待发货结果回传"
	if upstreamDeliverySucceeded(upstreamOrder) {
		nextStatus = model.OrderStatusDelivered
		message = "发货已完成"
	}
	updated, err := s.fulfillment.UpdateFulfillment(FulfillmentUpdateInput{
		MerchantID:      order.MerchantID,
		APIClientID:     apiClientID,
		OrderNo:         order.OrderNo,
		Status:          nextStatus,
		ProviderOrderNo: providerOrderNo,
		ResultData:      resultData,
	})
	if err != nil {
		return nil, err
	}
	return &DeliverySubmitResult{
		OrderNo:         updated.OrderNo,
		Status:          normalizeOrderStatus(updated),
		Message:         message,
		ProviderOrderNo: providerOrderNo,
		GameAccount:     boundAccount,
		UpstreamOrder:   upstreamOrder,
	}, nil
}

func (s *DeliveryService) claimDeliverySubmission(merchantID, apiClientID uint, orderNo string) (*model.FulfillmentOrder, bool, error) {
	var updated model.FulfillmentOrder
	claimedNow := false
	err := s.fulfillment.db.Transaction(func(tx *gorm.DB) error {
		var order model.FulfillmentOrder
		if err := tx.Clauses(clause.Locking{Strength: "UPDATE"}).
			Where("merchant_id = ? AND order_no = ?", merchantID, orderNo).
			First(&order).Error; err != nil {
			if errors.Is(err, gorm.ErrRecordNotFound) {
				return errors.New("订单不存在")
			}
			return err
		}
		orderStatus := normalizeOrderStatus(&order)
		if orderStatus == model.OrderStatusDelivering || orderStatus == model.OrderStatusDelivered {
			updated = order
			return nil
		}
		if err := validateOrderStatusTransition(&order, model.OrderStatusDelivering, fulfillmentTransitionUpdate); err != nil {
			return newDeliveryHTTPError(http.StatusConflict, "订单暂不可发货")
		}
		now := time.Now()
		stage := resultDataString(order.ResultData, "provider_order_stage")
		if deliverySubmissionInProgress(stage) && !deliverySubmissionStale(&order, now) {
			updated = order
			return nil
		}
		patch := map[string]interface{}{
			"source":               "delivery_proxy",
			"submit_started_at":    timeutil.FormatAPITime(now),
			"provider_order_stage": deliveryStageClaimed,
			"ship_attempts":        resultDataNumber(order.ResultData, "ship_attempts") + 1,
		}
		if err := tx.Model(&order).Updates(map[string]interface{}{
			"result_data":    mergeResultData(order.ResultData, patch),
			"failure_reason": "",
		}).Error; err != nil {
			return err
		}
		claimedNow = true
		if err := tx.First(&updated, order.ID).Error; err != nil {
			return err
		}
		apiClientIDPtr := optionalUint(apiClientID)
		if err := writeAudit(tx, &merchantID, nil, apiClientIDPtr, "delivery.submit.claim", "fulfillment_order", order.OrderNo, nil); err != nil {
			return err
		}
		return nil
	})
	if err != nil {
		return nil, false, err
	}
	return &updated, claimedNow, nil
}

func (s *DeliveryService) recordDeliverySubmissionStage(order *model.FulfillmentOrder, stage string, patch map[string]interface{}) error {
	if order == nil {
		return errors.New("订单不存在")
	}
	if patch == nil {
		patch = map[string]interface{}{}
	}
	patch["provider_order_stage"] = stage
	resultData := mergeResultData(order.ResultData, patch)
	if err := s.fulfillment.db.Model(&model.FulfillmentOrder{}).
		Where("id = ?", order.ID).
		Update("result_data", resultData).Error; err != nil {
		return err
	}
	order.ResultData = resultData
	return nil
}

func (s *DeliveryService) markDeliverySubmissionFailed(order *model.FulfillmentOrder, apiClientID uint, stage, reason string) {
	if order == nil {
		return
	}
	latest := order
	if fresh, err := s.fulfillment.GetOrder(order.MerchantID, order.OrderNo); err == nil {
		latest = fresh
	}
	resultData := mergeResultData(latest.ResultData, map[string]interface{}{
		"provider_order_stage": stage,
		"fail_stage":           stage,
		"fail_reason":          reason,
		"fail_at":              timeutil.FormatAPITime(time.Now()),
	})
	_, _ = s.fulfillment.UpdateFulfillment(FulfillmentUpdateInput{
		MerchantID:    order.MerchantID,
		APIClientID:   apiClientID,
		OrderNo:       order.OrderNo,
		Status:        model.OrderStatusShipFailed,
		FailureReason: reason,
		ResultData:    resultData,
	})
}

func (s *DeliveryService) loadLinkedOrder(orderNo string, auth *DeliveryLinkAuth) (*OpenOrderQuery, *model.FulfillmentOrder, string, error) {
	openOrder, err := s.fulfillment.QueryOpenOrder(orderNo)
	if err != nil {
		return nil, nil, "", err
	}
	order, err := s.fulfillment.GetByOrderNo(orderNo)
	if err != nil {
		return nil, nil, "", err
	}
	if auth != nil {
		if err := s.authorizeDeliveryLink(order, *auth); err != nil {
			return nil, nil, "", err
		}
	}
	goodID := ""
	if openOrder.Product != nil {
		goodID = deliveryGoodID(s.channel, openOrder.Product.SKU)
	}
	return openOrder, order, goodID, nil
}

func (s *DeliveryService) loadMerchantOrder(merchantID uint, orderNo string) (*OpenOrderQuery, *model.FulfillmentOrder, string, error) {
	if merchantID == 0 {
		return nil, nil, "", errors.New("无效的商户")
	}
	openOrder, err := s.fulfillment.QueryOpenOrder(orderNo)
	if err != nil {
		return nil, nil, "", err
	}
	order, err := s.fulfillment.GetOrder(merchantID, orderNo)
	if err != nil {
		return nil, nil, "", err
	}
	goodID := ""
	if openOrder.Product != nil {
		goodID = deliveryGoodID(s.channel, openOrder.Product.SKU)
	}
	return openOrder, order, goodID, nil
}

func (s *DeliveryService) buildDeliveryState(openOrder *OpenOrderQuery, order *model.FulfillmentOrder, goodID string, requireCanShip bool) (*DeliveryOrderInfo, *model.FulfillmentOrder, string, error) {
	if openOrder == nil || order == nil {
		return nil, nil, "", errors.New("订单不存在")
	}
	canShip, reason := CanFulfill(order)
	if !openOrder.CanShip {
		reason = openOrder.CannotShipReason
		canShip = false
	}
	if !canShip && reason == "" {
		reason = "订单暂不可发货"
	}
	if openOrder.Product == nil || openOrder.Product.SKU == "" {
		canShip = false
		reason = "订单缺少商品 SKU"
	} else if goodID == "" {
		goodID = deliveryGoodID(s.channel, openOrder.Product.SKU)
		if goodID == "" {
			canShip = false
			reason = "未找到对应的商品发货配置"
		}
	}
	if requireCanShip && !canShip {
		return nil, nil, "", newDeliveryHTTPError(http.StatusBadRequest, reason)
	}
	var good map[string]interface{}
	if goodID != "" {
		good, _ = s.goodsDetail(goodID)
	}
	product := buildDeliveryProduct(openOrder.Product, good)
	info := &DeliveryOrderInfo{
		OrderNo:          openOrder.OrderNo,
		Status:           openOrder.Status,
		CanShip:          canShip,
		CannotShipReason: reason,
		Product:          product,
		BuyerName:        openOrder.BuyerName,
		Amount:           openOrder.Amount,
		CreatedAt:        openOrder.CreatedAt,
		ShippedAt:        openOrder.ShippedAt,
		ShipFailReason:   openOrder.ShipFailReason,
		GameChannel:      openOrder.GameChannel,
		GameUID:          openOrder.GameUID,
		RoleName:         openOrder.RoleName,
		PayScore:         openOrder.PayScore,
		Data:             requestDataMap(order.RequestData),
		Good:             good,
	}
	return info, order, goodID, nil
}

func (s *DeliveryService) GetOrCreateDeliveryLink(merchantID uint, orderNo, requestBaseURL string) (*DeliveryLinkResult, error) {
	orderNo = strings.TrimSpace(orderNo)
	if orderNo == "" {
		return nil, errors.New("订单号不能为空")
	}
	order, err := s.fulfillment.GetOrder(merchantID, orderNo)
	if err != nil {
		return nil, err
	}
	// 已取消订单即使存在未过期链接也不再发放（买家侧授权同样拦截已取消订单）。
	if normalizeOrderStatus(order) == model.OrderStatusCancelled {
		return nil, newDeliveryHTTPError(http.StatusBadRequest, "订单已取消，无法获取发货链接")
	}
	now := time.Now().UTC()
	if order.DeliveryLinkRevokedAt != nil {
		return nil, newDeliveryHTTPError(http.StatusForbidden, "发货链接已作废")
	}
	// 复用未过期链接：已交付/发货中订单也允许查看兑换结果或进度，仅停止发放新链接。
	if order.DeliveryLinkExpiresAt != nil && order.DeliveryLinkExpiresAt.After(now) {
		expiresAt := order.DeliveryLinkExpiresAt.UTC().Truncate(time.Second)
		return s.buildDeliveryLinkResult(order.OrderNo, &expiresAt, requestBaseURL), nil
	}
	// 永久有效链接（已生成、未作废、无有效期）直接复用，不重复生成。
	if order.DeliveryLinkGeneratedAt != nil && order.DeliveryLinkExpiresAt == nil {
		return s.buildDeliveryLinkResult(order.OrderNo, nil, requestBaseURL), nil
	}
	// 仅待发货（含可重试的发货失败）订单能生成或续期新链接。
	canShip, reason := CanFulfill(order)
	if !canShip {
		if reason == "" {
			reason = "订单暂不可发货"
		}
		return nil, newDeliveryHTTPError(http.StatusBadRequest, reason)
	}
	var expiresAt *time.Time
	if s.linkTTL > 0 {
		value := now.Add(s.linkTTL).UTC().Truncate(time.Second)
		expiresAt = &value
	}
	if err := s.fulfillment.db.Model(&model.FulfillmentOrder{}).
		Where("id = ?", order.ID).
		Updates(map[string]interface{}{
			"delivery_link_expires_at":   expiresAt,
			"delivery_link_revoked_at":   nil,
			"delivery_link_generated_at": now,
		}).Error; err != nil {
		return nil, err
	}
	return s.buildDeliveryLinkResult(order.OrderNo, expiresAt, requestBaseURL), nil
}

func (s *DeliveryService) RevokeDeliveryLink(merchantID, actorUserID uint, orderNo string) error {
	orderNo = strings.TrimSpace(orderNo)
	if orderNo == "" {
		return errors.New("订单号不能为空")
	}
	order, err := s.fulfillment.GetOrder(merchantID, orderNo)
	if err != nil {
		return err
	}
	now := time.Now().UTC().Truncate(time.Second)
	return s.fulfillment.db.Transaction(func(tx *gorm.DB) error {
		if err := tx.Model(&model.FulfillmentOrder{}).
			Where("id = ?", order.ID).
			Updates(map[string]interface{}{
				"delivery_link_revoked_at": now,
			}).Error; err != nil {
			return err
		}
		return writeAudit(tx, &merchantID, optionalUint(actorUserID), nil, "delivery_link.revoke", "fulfillment_order", order.OrderNo, map[string]interface{}{
			"revoked_at": timeutil.FormatAPITime(now),
		})
	})
}

func (s *DeliveryService) RestoreDeliveryLink(merchantID, actorUserID uint, orderNo, requestBaseURL string) (*DeliveryLinkResult, error) {
	orderNo = strings.TrimSpace(orderNo)
	if orderNo == "" {
		return nil, errors.New("订单号不能为空")
	}
	order, err := s.fulfillment.GetOrder(merchantID, orderNo)
	if err != nil {
		return nil, err
	}
	canShip, reason := CanFulfill(order)
	if !canShip {
		if reason == "" {
			reason = "订单暂不可发货"
		}
		return nil, newDeliveryHTTPError(http.StatusBadRequest, reason)
	}
	now := time.Now().UTC()
	var expiresAt *time.Time
	if s.linkTTL > 0 {
		value := now.Add(s.linkTTL).Truncate(time.Second)
		if order.DeliveryLinkExpiresAt != nil && value.Equal(order.DeliveryLinkExpiresAt.UTC().Truncate(time.Second)) {
			value = value.Add(time.Second)
		}
		expiresAt = &value
	}
	if err := s.fulfillment.db.Transaction(func(tx *gorm.DB) error {
		if err := tx.Model(&model.FulfillmentOrder{}).
			Where("id = ?", order.ID).
			Updates(map[string]interface{}{
				"delivery_link_expires_at":   expiresAt,
				"delivery_link_revoked_at":   nil,
				"delivery_link_generated_at": now,
			}).Error; err != nil {
			return err
		}
		metadata := map[string]interface{}{
			"generated_at": timeutil.FormatAPITime(now),
		}
		if expiresAt != nil {
			metadata["expires_at"] = timeutil.FormatAPITime(*expiresAt)
		} else {
			metadata["permanent"] = true
		}
		return writeAudit(tx, &merchantID, optionalUint(actorUserID), nil, "delivery_link.restore", "fulfillment_order", order.OrderNo, metadata)
	}); err != nil {
		return nil, err
	}
	return s.buildDeliveryLinkResult(order.OrderNo, expiresAt, requestBaseURL), nil
}

func (s *DeliveryService) prepareOrder(orderNo string, requireCanShip bool, auth *DeliveryLinkAuth) (*DeliveryOrderInfo, *model.FulfillmentOrder, string, error) {
	orderNo = strings.TrimSpace(orderNo)
	if orderNo == "" {
		return nil, nil, "", errors.New("订单号不能为空")
	}
	openOrder, err := s.fulfillment.QueryOpenOrder(orderNo)
	if err != nil {
		return nil, nil, "", err
	}
	order, err := s.fulfillment.GetByOrderNo(orderNo)
	if err != nil {
		return nil, nil, "", err
	}
	if auth != nil {
		if err := s.authorizeDeliveryLink(order, *auth); err != nil {
			return nil, nil, "", err
		}
	}
	canShip, reason := CanFulfill(order)
	if !openOrder.CanShip {
		reason = openOrder.CannotShipReason
		canShip = false
	}
	if !canShip && reason == "" {
		reason = "订单暂不可发货"
	}
	goodID := ""
	if openOrder.Product == nil || openOrder.Product.SKU == "" {
		canShip = false
		reason = "订单缺少商品 SKU"
	} else {
		goodID = deliveryGoodID(s.channel, openOrder.Product.SKU)
		if goodID == "" {
			canShip = false
			reason = "未找到对应的商品发货配置"
		}
	}
	if requireCanShip && !canShip {
		return nil, nil, "", newDeliveryHTTPError(http.StatusBadRequest, reason)
	}
	var good map[string]interface{}
	if goodID != "" {
		good, _ = s.goodsDetail(goodID)
	}
	product := buildDeliveryProduct(openOrder.Product, good)
	info := &DeliveryOrderInfo{
		OrderNo:          openOrder.OrderNo,
		Status:           openOrder.Status,
		CanShip:          canShip,
		CannotShipReason: reason,
		Product:          product,
		BuyerName:        openOrder.BuyerName,
		Amount:           openOrder.Amount,
		CreatedAt:        openOrder.CreatedAt,
		ShippedAt:        openOrder.ShippedAt,
		ShipFailReason:   openOrder.ShipFailReason,
		GameChannel:      openOrder.GameChannel,
		GameUID:          openOrder.GameUID,
		RoleName:         openOrder.RoleName,
		PayScore:         openOrder.PayScore,
		Data:             requestDataMap(order.RequestData),
		Good:             good,
	}
	return info, order, goodID, nil
}

func deliveryGoodID(channel, sku string) string {
	if channel != "dlc" {
		return ""
	}
	return map[string]string{
		"suit_alan_walker":        "682ef3c5a8f40c4234c59f47",
		"suit_shadow_gothic":      "682ef39ca8f40c4234c59f36",
		"top_black_elite_trainer": "682ef39ca8f40c4234c59f37",
		"m416_hamster_gray":       "682ef3c5a8f40c4234c59f52",
		"bag_cute_bear":           "682ef3c5a8f40c4234c59f4a",
		"suit_dual_fluffy":        "682ef3c5a8f40c4234c59f49",
		"suit_pink_sheep":         "682ef3c5a8f40c4234c59f4d",
		"suit_first_peach":        "682ef3c5a8f40c4234c59f48",
		"suit_romantic_destiny":   "682ef39ca8f40c4234c59f38",
		"pack_western_cowboy":     "682ef3c5a8f40c4234c59f4c",
		"smoke_pink_sheep":        "682ef3c5a8f40c4234c59f50",
		"frag_pink_sheep":         "682ef3c5a8f40c4234c59f51",
		"suit_hamster_gray":       "682ef3c5a8f40c4234c59f53",
		"suit_cute_bear":          "682ef3c5a8f40c4234c59f4b",
		"bag_pink_sheep":          "682ef3c5a8f40c4234c59f4f",
		"helmet_pink_sheep":       "682ef3c5a8f40c4234c59f4e",
		"bag_hamster_gray":        "682ef3c5a8f40c4234c59f55",
		"helmet_hamster_gray":     "682ef3c5a8f40c4234c59f54",
		"suit_western_mystery":    "682ef39ca8f40c4234c59f35",
		"helmet_panda_treasure":   "682ef39ca8f40c4234c59f39",
		"suit_panda_round":        "682ef39ca8f40c4234c59f3a",
		"suit_panda_tuan":         "682ef39ca8f40c4234c59f3b",
		"pack_lava_ranger":        "682ef39ca8f40c4234c59f3c",
		"suit_sand_dancer":        "682ef39ca8f40c4234c59f3d",
		"pack_star_roam_outfit":   "682ef39ca8f40c4234c59f3e",
		"pack_star_roam_weapon":   "682ef39ca8f40c4234c59f3f",
		"suit_cloud_bear":         "682ef39ca8f40c4234c59f40",
		"honor_medal_x2":          "682ef39ca8f40c4234c59f45",
		"honor_medal_x30":         "682ef39ca8f40c4234c59f43",
		"honor_medal_x90":         "682ef39ca8f40c4234c59f41",
		"lucky_coin_x2":           "682ef39ca8f40c4234c59f46",
		"lucky_coin_x30":          "682ef39ca8f40c4234c59f44",
		"lucky_coin_x90":          "682ef39ca8f40c4234c59f42",
	}[sku]
}