package service

import (
	"context"
	"strings"

	"git.lzcwy.cn/zhengchiliu/zt-closet-manage-backend/global"
	"git.lzcwy.cn/zhengchiliu/zt-closet-manage-backend/internal/dto"
	"git.lzcwy.cn/zhengchiliu/zt-closet-manage-backend/internal/mysqldao"
	"git.lzcwy.cn/zhengchiliu/zt-closet-manage-backend/internal/mysqlmodel"
	"git.lzcwy.cn/zhengchiliu/zt-closet-manage-backend/pkg/errcode"
)

// OrderService 订单与退款管理服务。
type OrderService struct {
	orderDao  *mysqldao.OrderDao
	refundDao *mysqldao.RefundDao
}

// NewOrderService 创建订单服务。
func NewOrderService() *OrderService {
	return &OrderService{
		orderDao:  mysqldao.NewOrderDao(),
		refundDao: mysqldao.NewRefundDao(),
	}
}

// List 分页查询订单。
func (s *OrderService) List(ctx context.Context, request *dto.OrderListRequest) (*dto.OrderListResponse, *errcode.Error) {
	ctx, span := global.Tracer.Start(ctx, "svc.AdminOrderList")
	defer span.End()

	page, pageSize := normalizePage(request.Page, request.PageSize)

	list, total, err := s.orderDao.OrderList(ctx, mysqldao.OrderListParams{
		OrderNo: strings.TrimSpace(request.OrderNo),
		UserID:  request.UserID,
		Status:  request.Status,
		Page:    page,
		Size:    pageSize,
	})
	if err != nil {
		return nil, errcode.DatabaseError
	}

	items := make([]dto.OrderItem, 0, len(list))
	for i := range list {
		items = append(items, buildOrderItem(&list[i]))
	}
	return &dto.OrderListResponse{
		PageResponse: dto.PageResponse{Total: total, Page: page, PageSize: pageSize},
		List:         items,
	}, nil
}

// Get 订单详情。
func (s *OrderService) Get(ctx context.Context, orderNo string) (*dto.OrderItem, *errcode.Error) {
	ctx, span := global.Tracer.Start(ctx, "svc.AdminOrderGet")
	defer span.End()

	order, err := s.orderDao.OrderGetByOrderNo(ctx, orderNo)
	if err != nil {
		if isNotFound(err) {
			return nil, errcode.OrderNotFound
		}
		return nil, errcode.DatabaseError
	}
	item := buildOrderItem(order)
	return &item, nil
}

// RefundList 分页查询退款单。
func (s *OrderService) RefundList(ctx context.Context, request *dto.RefundListRequest) (*dto.RefundListResponse, *errcode.Error) {
	ctx, span := global.Tracer.Start(ctx, "svc.AdminRefundList")
	defer span.End()

	page, pageSize := normalizePage(request.Page, request.PageSize)

	// status 未传时 query 绑定为 nil，与「待处理=0」天然区分。
	withStatus := request.Status != nil
	var status int8
	if withStatus {
		status = *request.Status
	}

	list, total, err := s.refundDao.RefundList(ctx, mysqldao.RefundListParams{
		Status:     status,
		WithStatus: withStatus,
		OrderNo:    strings.TrimSpace(request.OrderNo),
		Page:       page,
		Size:       pageSize,
	})
	if err != nil {
		return nil, errcode.DatabaseError
	}

	items := make([]dto.RefundItem, 0, len(list))
	for i := range list {
		items = append(items, buildRefundItem(&list[i]))
	}
	return &dto.RefundListResponse{
		PageResponse: dto.PageResponse{Total: total, Page: page, PageSize: pageSize},
		List:         items,
	}, nil
}

// RefundApprove 审核通过：待处理(0) → 退款中(1)。
// 实际打款由运营在微信商户平台人工完成，业务服务退款回调负责后续「成功(2)」流转与权益回收。
func (s *OrderService) RefundApprove(ctx context.Context, adminID int64, refundNo string, request *dto.RefundAuditRequest) *errcode.Error {
	ctx, span := global.Tracer.Start(ctx, "svc.AdminRefundApprove")
	defer span.End()

	if _, err := s.refundDao.RefundGetByRefundNo(ctx, refundNo); err != nil {
		if isNotFound(err) {
			return errcode.RefundNotFound
		}
		return errcode.DatabaseError
	}

	ok, err := s.refundDao.RefundTransition(ctx, refundNo, RefundStatusPending, RefundStatusProcessing, "")
	if err != nil {
		return errcode.DatabaseError
	}
	if !ok {
		return errcode.RefundStatusInvalid.WithDetails("仅待处理状态的退款单可审核")
	}
	return nil
}

// RefundReject 审核驳回：待处理(0) → 失败(3)，记录驳回原因。
func (s *OrderService) RefundReject(ctx context.Context, adminID int64, refundNo string, request *dto.RefundAuditRequest) *errcode.Error {
	ctx, span := global.Tracer.Start(ctx, "svc.AdminRefundReject")
	defer span.End()

	if _, err := s.refundDao.RefundGetByRefundNo(ctx, refundNo); err != nil {
		if isNotFound(err) {
			return errcode.RefundNotFound
		}
		return errcode.DatabaseError
	}

	ok, err := s.refundDao.RefundTransition(ctx, refundNo, RefundStatusPending, RefundStatusFailed, strings.TrimSpace(request.Reason))
	if err != nil {
		return errcode.DatabaseError
	}
	if !ok {
		return errcode.RefundStatusInvalid.WithDetails("仅待处理状态的退款单可审核")
	}
	return nil
}

// buildOrderItem 订单模型 → 响应。
func buildOrderItem(o *mysqlmodel.Order) dto.OrderItem {
	return dto.OrderItem{
		OrderNo:          o.OrderNo,
		UserID:           o.UserID,
		GoodsID:          o.GoodsID,
		GoodsName:        o.GoodsName,
		UnitPrice:        o.UnitPrice,
		TotalAmount:      o.TotalAmount,
		PayAmount:        o.PayAmount,
		PayChannel:       o.PayChannel,
		OrderStatus:      o.OrderStatus,
		TransactionID:    o.TransactionID,
		MemberDays:       o.MemberDays,
		UploadQuota:      o.CosQuota,
		AIRecommendQuota: o.AIRecommendQuota,
		ClosetShareQuota: o.ClosetShareQuota,
		OutfitShareQuota: o.OutfitShareQuota,
		ExpireTime:       o.ExpireTime,
		PayTime:          o.PayTime,
		RefundTime:       o.RefundTime,
		RefundAmount:     o.RefundAmount,
		Remark:           o.Remark,
		XPayProductID:    o.XPayProductID,
		XPayPlatform:     o.XPayPlatform,
		XPayEnv:          o.XPayEnv,
		CreatedAt:        o.CreatedAt,
	}
}

// buildRefundItem 退款单模型 → 响应。
func buildRefundItem(r *mysqlmodel.RefundFlowLog) dto.RefundItem {
	return dto.RefundItem{
		RefundNo:     r.RefundNo,
		OrderNo:      r.OrderNo,
		UserID:       r.UserID,
		RefundAmount: r.RefundAmount,
		RefundReason: r.RefundReason,
		Status:       r.Status,
		ApplyTime:    r.ApplyTime,
		SuccessTime:  r.SuccessTime,
		FailReason:   r.FailReason,
		CreatedAt:    r.CreatedAt,
	}
}