package service

import (
	"context"
	"errors"
	"time"

	"github.com/topfans/backend/pkg/logger"
	"github.com/topfans/backend/pkg/models"
	pb "github.com/topfans/backend/pkg/proto/gallery"
	pbCommon "github.com/topfans/backend/pkg/proto/common"
	"github.com/topfans/backend/services/galleryService/client"
	"github.com/topfans/backend/services/galleryService/config"
	"github.com/topfans/backend/services/galleryService/repository"
	"go.uber.org/zap"
)

// ExhibitionService 展品服务接口
type ExhibitionService interface {
	PlaceAsset(userID, starID int64, req *pb.PlaceAssetRequest) (*pb.PlaceAssetData, error)
	// RemoveFromSlot 从展位移除资产（统一接口，支持展位所有者踢走和占位者下架）
	RemoveFromSlot(userID, starID int64, req *pb.RemoveFromSlotRequest) error
	// GetMyExhibitedAssets 获取我展出的作品列表
	GetMyExhibitedAssets(ctx context.Context, userID, starID int64, req *pb.GetMyExhibitedAssetsRequest) (*pb.GetMyExhibitedAssetsResponse, error)
	// GetUserExhibitedAssets 获取他人展出的作品列表
	GetUserExhibitedAssets(ctx context.Context, userID, starID int64, req *pb.GetUserExhibitedAssetsRequest) (*pb.GetUserExhibitedAssetsResponse, error)
	// RemoveExhibitionByAsset 根据资产ID移除展品（内部RPC，用于领取收益后下架）
	RemoveExhibitionByAsset(ctx context.Context, assetID int64) error
}

// exhibitionService 展品服务实现
type exhibitionService struct {
	repo        repository.GalleryRepository
	assetClient client.AssetRPCClient
}

// NewExhibitionService 创建展品服务实例
func NewExhibitionService(repo repository.GalleryRepository, assetClient client.AssetRPCClient) ExhibitionService {
	return &exhibitionService{
		repo:        repo,
		assetClient: assetClient,
	}
}

// PlaceAsset 在展位展示藏品（支持放置到他人展馆，方案A实现）
func (s *exhibitionService) PlaceAsset(userID, starID int64, req *pb.PlaceAssetRequest) (*pb.PlaceAssetData, error) {
	// 1. 验证资产是否存在且属于当前用户 (RPC Asset Service)
	if s.assetClient == nil {
		return nil, errors.New("asset client not initialized")
	}

	asset, err := s.assetClient.GetAssetForRPC(req.AssetId, userID, starID)
	if err != nil {
		// GetAssetForRPC 已经包含了详细的错误信息，直接返回
		return nil, err
	}

	if asset == nil {
		return nil, errors.New("资产信息为空")
	}

	// 验证资产所有权（双重验证，确保安全）
	if asset.OwnerUid != userID {
		return nil, errors.New("资产不属于当前用户")
	}

	// 2. 获取目标展位信息
	slot, err := s.repo.GetSlotByID(req.SlotId)
	if err != nil {
		return nil, err
	}

	if !slot.IsEnabled {
		return nil, errors.New("展位未解锁")
	}

	// 3. 检查展位是否已被占用（使用时间判断）
	now := time.Now().UnixMilli()
	existingExhibition, err := s.repo.GetActiveExhibitionBySlot(req.SlotId, now)
	if err != nil {
		return nil, err
	}
	if existingExhibition != nil {
		return nil, errors.New("展位已被占用")
	}

	// 4. 校验权限与可见性（支持放置到他人展馆）
	isOwner := slot.UserID == userID
	if !isOwner {
		// 如果不是自己的展位，必须是 public 且在同一个明星下
		if slot.Visibility != "public" {
			return nil, errors.New("该展位是私有的，无法放置展品")
		}
		if slot.StarID != starID {
			return nil, errors.New("只能在同一明星的展馆中放置展品")
		}
	}

	// 5. 执行放置逻辑
	expireAt := now + config.GetExhibitionDuration()*1000

	exhibition := &models.Exhibition{
		AssetID:        req.AssetId,
		SlotID:         req.SlotId,
		HostProfileID:  slot.HostProfileID,
		OccupierUID:    userID,
		OccupierStarID: starID,
		StartTime:      now,
		ExpireAt:       expireAt,
		CreatedAt:      now,
		UpdatedAt:      now,
	}

	// 6. 事务性创建展品并更新展示状态（原子操作）
	if err := s.repo.PlaceExhibitionTx(exhibition, 1); err != nil {
		return nil, err
	}

	// 7. 发布事件（不再强依赖同步更新 Asset Service 状态）
	// TODO: 实现事件发布逻辑
	// go s.publishEvent("gallery.exhibit", exhibition)

	// 9. 构造响应
	return &pb.PlaceAssetData{
		Status:        "OCCUPIED",
		OccupiedUntil: time.UnixMilli(expireAt).Format(time.RFC3339),
		OccupierUid:   userID,
	}, nil
}

// RemoveFromSlot 从展位移除资产（统一接口，支持展位所有者踢走和占位者下架）
func (s *exhibitionService) RemoveFromSlot(userID, starID int64, req *pb.RemoveFromSlotRequest) error {
	// 1. 查询展位信息
	slot, err := s.repo.GetSlotByID(req.SlotId)
	if err != nil {
		return err
	}

	// 2. 查询展品展示记录
	exhibition, err := s.repo.GetExhibitionBySlot(req.SlotId)
	if err != nil {
		return err
	}

	if exhibition == nil {
		return errors.New("展位当前没有展品")
	}

	// 3. 验证权限（展位所有者或占位者都可以移除）
	isSlotOwner := slot.UserID == userID && slot.StarID == starID
	isOccupier := exhibition.OccupierUID == userID && exhibition.OccupierStarID == starID

	if !isSlotOwner && !isOccupier {
		return errors.New("无权移除资产，只有展位所有者或占位者可以操作")
	}

	// 4. 事务性删除展品并更新展示状态（原子操作）
	if err := s.repo.RemoveExhibitionTx(exhibition.ID, exhibition.AssetID); err != nil {
		return err
	}

	// 5. 清除该资产的点赞记录（不阻断主流程）
	// 目的：允许同一用户在下次展出时可以再次点赞
	go func(assetID int64) {
		if err := s.assetClient.ClearAssetLikeRecords(assetID); err != nil {
			logger.Logger.Error("Failed to clear asset like records after removal",
				zap.Int64("asset_id", assetID),
				zap.Error(err),
			)
		}
	}(exhibition.AssetID)
	// 6. 发布事件
	// TODO: 实现事件发布逻辑
	// go s.publishEvent("gallery.remove_from_slot", exhibition)
	return nil
}

// GetMyExhibitedAssets 获取我展出的作品列表
func (s *exhibitionService) GetMyExhibitedAssets(ctx context.Context, userID, starID int64, req *pb.GetMyExhibitedAssetsRequest) (*pb.GetMyExhibitedAssetsResponse, error) {
	page := req.Page
	if page <= 0 {
		page = 1
	}
	pageSize := req.PageSize
	if pageSize <= 0 {
		pageSize = 20
	}
	if pageSize > 100 {
		pageSize = 100
	}

	items, total, err := s.repo.GetMyExhibitedAssets(userID, starID, int(page), int(pageSize))
	if err != nil {
		logger.Logger.Error("Failed to get my exhibited assets",
			zap.Error(err),
			zap.Int64("user_id", userID),
			zap.Int64("star_id", starID),
		)
		return &pb.GetMyExhibitedAssetsResponse{
			Base: &pbCommon.BaseResponse{
				Code:      pbCommon.StatusCode_STATUS_INTERNAL_ERROR,
				Message:   "Failed to get my exhibited assets: " + err.Error(),
				Timestamp: time.Now().UnixMilli(),
			},
		}, nil
	}

	// 转换为 proto 类型
	pbItems := make([]*pb.ExhibitedAssetItem, 0, len(items))
	for _, item := range items {
		pbItems = append(pbItems, &pb.ExhibitedAssetItem{
			AssetId:     item.AssetID,
			Name:        item.Name,
			CoverUrl:    item.CoverURL,
			LikeCount:   item.LikeCount,
			ExhibitedAt: item.ExhibitedAt,
			ExpireAt:    item.ExpireAt,
			Earnings:    item.Earnings,
		})
	}

	hasMore := int64(page)*int64(pageSize) < total

	return &pb.GetMyExhibitedAssetsResponse{
		Base: &pbCommon.BaseResponse{
			Code:      pbCommon.StatusCode_STATUS_OK,
			Message:   "success",
			Timestamp: time.Now().UnixMilli(),
		},
		Data: &pb.ExhibitedAssetsData{
			Items:    pbItems,
			Page:     page,
			PageSize: pageSize,
			Total:    total,
			HasMore:  hasMore,
		},
	}, nil
}

// GetUserExhibitedAssets 获取他人展出的作品列表
func (s *exhibitionService) GetUserExhibitedAssets(ctx context.Context, userID, starID int64, req *pb.GetUserExhibitedAssetsRequest) (*pb.GetUserExhibitedAssetsResponse, error) {
	page := req.Page
	if page <= 0 {
		page = 1
	}
	pageSize := req.PageSize
	if pageSize <= 0 {
		pageSize = 20
	}
	if pageSize > 100 {
		pageSize = 100
	}

	items, total, err := s.repo.GetUserExhibitedAssets(userID, starID, int(page), int(pageSize))
	if err != nil {
		logger.Logger.Error("Failed to get user exhibited assets",
			zap.Error(err),
			zap.Int64("user_id", userID),
			zap.Int64("star_id", starID),
		)
		return &pb.GetUserExhibitedAssetsResponse{
			Base: &pbCommon.BaseResponse{
				Code:      pbCommon.StatusCode_STATUS_INTERNAL_ERROR,
				Message:   "Failed to get user exhibited assets: " + err.Error(),
				Timestamp: time.Now().UnixMilli(),
			},
		}, nil
	}

	pbItems := make([]*pb.ExhibitedAssetItem, 0, len(items))
	for _, item := range items {
		pbItems = append(pbItems, &pb.ExhibitedAssetItem{
			AssetId:     item.AssetID,
			Name:        item.Name,
			CoverUrl:    item.CoverURL,
			LikeCount:   item.LikeCount,
			ExhibitedAt: item.ExhibitedAt,
			ExpireAt:    item.ExpireAt,
			Earnings:    item.Earnings,
		})
	}

	hasMore := int64(page)*int64(pageSize) < total

	return &pb.GetUserExhibitedAssetsResponse{
		Base: &pbCommon.BaseResponse{
			Code:      pbCommon.StatusCode_STATUS_OK,
			Message:   "success",
			Timestamp: time.Now().UnixMilli(),
		},
		Data: &pb.ExhibitedAssetsData{
			Items:    pbItems,
			Page:     page,
			PageSize: pageSize,
			Total:    total,
			HasMore:  hasMore,
		},
	}, nil
}

// RemoveExhibitionByAsset 根据资产ID移除展品（内部RPC，用于领取收益后下架）
func (s *exhibitionService) RemoveExhibitionByAsset(ctx context.Context, assetID int64) error {
	// 1. 查询展品展示记录
	exhibition, err := s.repo.GetExhibitionByAsset(assetID)
	if err != nil {
		return err
	}

	if exhibition == nil {
		return errors.New("资产当前没有展出记录")
	}

	// 2. 事务性删除展品并更新展示状态（原子操作）
	if err := s.repo.RemoveExhibitionTx(exhibition.ID, exhibition.AssetID); err != nil {
		return err
	}

	// 3. 清除该资产的点赞记录（不阻断主流程）
	go func(assetID int64) {
		if err := s.assetClient.ClearAssetLikeRecords(assetID); err != nil {
			logger.Logger.Error("Failed to clear asset like records after removal",
				zap.Int64("asset_id", assetID),
				zap.Error(err),
			)
		}
	}(exhibition.AssetID)

	return nil
}