package service

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

	"affiliate_dash/internal/model"
	"affiliate_dash/internal/pkg/timeutil"
	"gorm.io/gorm"
	"gorm.io/gorm/clause"
)

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\"") ||
		strings.Contains(order.ResultData, "\"lewan_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")
	}

	providers, _ := s.router.ResolveProviders(claimed)
	if len(providers) == 0 {
		s.markDeliverySubmissionFailed(claimed, apiClientID, deliveryStageCreateOrder, "未配置发货渠道")
		return nil, errors.New("未配置发货渠道")
	}
	activeProvider := providers[0]

	submitRes, err := activeProvider.Submit(context.Background(), claimed, gameAccount, bindUUID)
	if submitRes != nil && len(submitRes.PatchResultData) > 0 {
		stage := deliveryStageCreateOrder
		if v, ok := submitRes.PatchResultData["provider_order_stage"].(string); ok && v != "" {
			stage = v
		}
		_ = s.recordDeliverySubmissionStage(claimed, stage, submitRes.PatchResultData)
	}
	if err != nil {
		failStage := deliveryStageCreateOrder
		if submitRes != nil {
			if v, ok := submitRes.PatchResultData["provider_order_stage"].(string); ok && v != "" {
				failStage = v
			}
		}
		s.markDeliverySubmissionFailed(claimed, apiClientID, failStage, err.Error())
		return nil, err
	}

	resultData := mergeResultData(claimed.ResultData, submitRes.PatchResultData)
	updated, err := s.fulfillment.UpdateFulfillment(FulfillmentUpdateInput{
		MerchantID:      order.MerchantID,
		APIClientID:     apiClientID,
		OrderNo:         order.OrderNo,
		Status:          submitRes.NextStatus,
		ProviderOrderNo: submitRes.ProviderOrderNo,
		ResultData:      resultData,
	})
	if err != nil {
		// 上游已有身份时先固化 result_data，避免重试双发
		_ = s.recordDeliverySubmissionStage(claimed, deliveryStageSubmitted, submitRes.PatchResultData)
		return nil, err
	}
	return &DeliverySubmitResult{
		OrderNo:         updated.OrderNo,
		Status:          normalizeOrderStatus(updated),
		Message:         submitRes.Message,
		ProviderOrderNo: submitRes.ProviderOrderNo,
		GameAccount:     submitRes.GameAccount,
		UpstreamOrder:   submitRes.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"}).
			Preload("MerchantProduct").
			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")
		startedAtRaw := resultDataString(order.ResultData, "submit_started_at")

		// 1. 如果已有协程正在活跃提交中（在 35 秒执行窗口内且处于 claimed/queue_created 阶段），
		//    即使已被外部 Webhook 临时推回 ship_failed，也绝对不允许并发重入发货打架
		if deliverySubmissionInProgress(stage) && startedAtRaw != "" {
			if startedAt, parseErr := time.Parse(timeutil.APITimeLayout, startedAtRaw); parseErr == nil {
				if now.Sub(startedAt) < 35*time.Second {
					updated = order
					return nil
				}
			}
		}

		// 2. 正常并发防双发：仅对 paid 等非最终失败态订单检查 10 分钟未超时
		if orderStatus != model.OrderStatusShipFailed &&
			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.Preload("MerchantProduct").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
	}
	// 确保失败时 stage 绝不能继续保持在 in_progress（claimed / queue_created），否则阻碍重试
	releaseStage := stage
	if deliverySubmissionInProgress(releaseStage) {
		releaseStage = deliveryStageCreateOrder
	}
	resultData := mergeResultData(latest.ResultData, map[string]interface{}{
		"provider_order_stage": releaseStage,
		"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,
	})
}