package service

import (
	"context"

	"carrot_bbs/internal/cache"
	"carrot_bbs/internal/dto"
	"carrot_bbs/internal/model"
	"carrot_bbs/internal/repository"
)

// AdminPostService 管理端帖子服务接口
type AdminPostService interface {
	// GetPostList 获取帖子列表（分页、搜索、状态筛选）
	GetPostList(ctx context.Context, page, pageSize int, keyword, status, authorID, startDate, endDate string) ([]dto.AdminPostListResponse, int64, error)
	// GetPostDetail 获取帖子详情
	GetPostDetail(ctx context.Context, postID string) (*dto.AdminPostDetailResponse, error)
	// DeletePost 删除帖子
	DeletePost(ctx context.Context, postID string) error
	// ModeratePost 审核帖子
	ModeratePost(ctx context.Context, postID string, status model.PostStatus, reason, reviewedBy string) (*dto.AdminPostDetailResponse, error)
	// BatchDeletePosts 批量删除帖子
	BatchDeletePosts(ctx context.Context, ids []string) (*dto.AdminBatchOperationResponse, error)
	// BatchModeratePosts 批量审核帖子
	BatchModeratePosts(ctx context.Context, ids []string, status model.PostStatus, reviewedBy string) (*dto.AdminBatchOperationResponse, error)
	// SetPostPin 置顶/取消置顶帖子
	SetPostPin(ctx context.Context, postID string, isPinned bool) (*dto.AdminPostDetailResponse, error)
	// SetPostFeature 加精/取消加精帖子
	SetPostFeature(ctx context.Context, postID string, isFeatured bool) (*dto.AdminPostDetailResponse, error)

	// 日志服务设置
	SetLogService(logService *LogService)
}

// adminPostServiceImpl 管理端帖子服务实现
type adminPostServiceImpl struct {
	postRepo   *repository.PostRepository
	cache      cache.Cache
	logService *LogService
}

// NewAdminPostService 创建管理端帖子服务
func NewAdminPostService(postRepo *repository.PostRepository, cacheBackend cache.Cache) AdminPostService {
	return &adminPostServiceImpl{
		postRepo:   postRepo,
		cache:      cacheBackend,
		logService: nil,
	}
}

// SetLogService 设置日志服务
func (s *adminPostServiceImpl) SetLogService(logService *LogService) {
	s.logService = logService
}

// GetPostList 获取帖子列表
func (s *adminPostServiceImpl) GetPostList(ctx context.Context, page, pageSize int, keyword, status, authorID, startDate, endDate string) ([]dto.AdminPostListResponse, int64, error) {
	query := repository.AdminPostListQuery{
		Page:      page,
		PageSize:  pageSize,
		Keyword:   keyword,
		Status:    status,
		AuthorID:  authorID,
		StartDate: startDate,
		EndDate:   endDate,
	}

	posts, total, err := s.postRepo.AdminList(query)
	if err != nil {
		return nil, 0, err
	}

	responses := make([]dto.AdminPostListResponse, len(posts))
	for i, post := range posts {
		responses[i] = convertPostToAdminListResponse(post)
	}

	return responses, total, nil
}

// GetPostDetail 获取帖子详情
func (s *adminPostServiceImpl) GetPostDetail(ctx context.Context, postID string) (*dto.AdminPostDetailResponse, error) {
	post, err := s.postRepo.GetByIDForAdmin(postID)
	if err != nil {
		return nil, err
	}

	return convertPostToAdminDetailResponse(post), nil
}

// DeletePost 删除帖子
func (s *adminPostServiceImpl) DeletePost(ctx context.Context, postID string) error {
	post, err := s.postRepo.GetByID(postID)
	if err != nil {
		return err
	}

	err = s.postRepo.Delete(postID)
	if err != nil {
		return err
	}

	// 失效缓存
	cache.InvalidatePostDetail(s.cache, postID)
	cache.InvalidatePostList(s.cache)

	// 记录操作日志
	if s.logService != nil {
		s.logService.OperationLog.RecordOperation(&model.OperationLog{
			UserID:     post.UserID,
			Operation:  string(model.OpAdminDeletePost),
			Module:     "admin",
			TargetType: "post",
			TargetID:   postID,
			Status:     "success",
		})
	}

	return nil
}

// ModeratePost 审核帖子
func (s *adminPostServiceImpl) ModeratePost(ctx context.Context, postID string, status model.PostStatus, reason, reviewedBy string) (*dto.AdminPostDetailResponse, error) {
	// 先检查帖子是否存在
	_, err := s.postRepo.GetByIDForAdmin(postID)
	if err != nil {
		return nil, err
	}

	// 更新审核状态
	if err := s.postRepo.UpdateModerationStatus(postID, status, reason, reviewedBy); err != nil {
		return nil, err
	}

	// 失效缓存
	cache.InvalidatePostDetail(s.cache, postID)
	cache.InvalidatePostList(s.cache)

	// 重新获取帖子信息
	post, err := s.postRepo.GetByIDForAdmin(postID)
	if err != nil {
		return nil, err
	}

	return convertPostToAdminDetailResponse(post), nil
}

// BatchDeletePosts 批量删除帖子
func (s *adminPostServiceImpl) BatchDeletePosts(ctx context.Context, ids []string) (*dto.AdminBatchOperationResponse, error) {
	failedIDs, err := s.postRepo.BatchDelete(ids)
	if err != nil {
		return &dto.AdminBatchOperationResponse{
			Success: false,
			Message: "批量删除失败",
			Failed:  ids,
		}, err
	}

	// 失效缓存
	for _, id := range ids {
		cache.InvalidatePostDetail(s.cache, id)
	}
	cache.InvalidatePostList(s.cache)

	if len(failedIDs) == 0 {
		return &dto.AdminBatchOperationResponse{
			Success: true,
			Message: "批量删除成功",
		}, nil
	}

	return &dto.AdminBatchOperationResponse{
		Success: true,
		Message: "部分帖子删除成功",
		Failed:  failedIDs,
	}, nil
}

// BatchModeratePosts 批量审核帖子
func (s *adminPostServiceImpl) BatchModeratePosts(ctx context.Context, ids []string, status model.PostStatus, reviewedBy string) (*dto.AdminBatchOperationResponse, error) {
	failedIDs, err := s.postRepo.BatchUpdateStatus(ids, status, reviewedBy)
	if err != nil {
		return &dto.AdminBatchOperationResponse{
			Success: false,
			Message: "批量审核失败",
			Failed:  ids,
		}, err
	}

	// 失效缓存
	for _, id := range ids {
		cache.InvalidatePostDetail(s.cache, id)
	}
	cache.InvalidatePostList(s.cache)

	if len(failedIDs) == 0 {
		return &dto.AdminBatchOperationResponse{
			Success: true,
			Message: "批量审核成功",
		}, nil
	}

	return &dto.AdminBatchOperationResponse{
		Success: true,
		Message: "部分帖子审核成功",
		Failed:  failedIDs,
	}, nil
}

// SetPostPin 置顶/取消置顶帖子
func (s *adminPostServiceImpl) SetPostPin(ctx context.Context, postID string, isPinned bool) (*dto.AdminPostDetailResponse, error) {
	// 先检查帖子是否存在
	_, err := s.postRepo.GetByIDForAdmin(postID)
	if err != nil {
		return nil, err
	}

	// 更新置顶状态
	if err := s.postRepo.UpdatePinStatus(postID, isPinned); err != nil {
		return nil, err
	}

	// 失效缓存
	cache.InvalidatePostDetail(s.cache, postID)
	cache.InvalidatePostList(s.cache)

	// 重新获取帖子信息
	post, err := s.postRepo.GetByIDForAdmin(postID)
	if err != nil {
		return nil, err
	}

	return convertPostToAdminDetailResponse(post), nil
}

// SetPostFeature 加精/取消加精帖子
func (s *adminPostServiceImpl) SetPostFeature(ctx context.Context, postID string, isFeatured bool) (*dto.AdminPostDetailResponse, error) {
	// 先检查帖子是否存在
	_, err := s.postRepo.GetByIDForAdmin(postID)
	if err != nil {
		return nil, err
	}

	// 更新加精状态
	if err := s.postRepo.UpdateFeatureStatus(postID, isFeatured); err != nil {
		return nil, err
	}

	// 失效缓存
	cache.InvalidatePostDetail(s.cache, postID)
	cache.InvalidatePostList(s.cache)

	// 重新获取帖子信息
	post, err := s.postRepo.GetByIDForAdmin(postID)
	if err != nil {
		return nil, err
	}

	return convertPostToAdminDetailResponse(post), nil
}

// convertPostToAdminListResponse 转换帖子为管理端列表响应
func convertPostToAdminListResponse(post *model.Post) dto.AdminPostListResponse {
	images := make([]dto.PostImageResponse, len(post.Images))
	for i, img := range post.Images {
		images[i] = dto.PostImageResponse{
			ID:           img.ID,
			URL:          img.URL,
			ThumbnailURL: img.ThumbnailURL,
			Width:        img.Width,
			Height:       img.Height,
		}
	}

	var author *dto.UserResponse
	if post.User != nil {
		author = dto.ConvertUserToResponse(post.User)
	}

	return dto.AdminPostListResponse{
		ID:              post.ID,
		UserID:          post.UserID,
		Title:           post.Title,
		Content:         post.Content,
		Images:          images,
		Status:          string(post.Status),
		LikesCount:      post.LikesCount,
		CommentsCount:   post.CommentsCount,
		FavoritesCount:  post.FavoritesCount,
		ViewsCount:      post.ViewsCount,
		IsPinned:        post.IsPinned,
		IsFeatured:      post.IsFeatured,
		IsLocked:        post.IsLocked,
		RejectReason:    post.RejectReason,
		ReviewedAt:      dto.FormatTimePointer(post.ReviewedAt),
		ReviewedBy:      post.ReviewedBy,
		CreatedAt:       post.CreatedAt.Format("2006-01-02T15:04:05Z07:00"),
		UpdatedAt:       post.UpdatedAt.Format("2006-01-02T15:04:05Z07:00"),
		ContentEditedAt: dto.FormatTimePointer(post.ContentEditedAt),
		Author:          author,
	}
}

// convertPostToAdminDetailResponse 转换帖子为管理端详情响应
func convertPostToAdminDetailResponse(post *model.Post) *dto.AdminPostDetailResponse {
	images := make([]dto.PostImageResponse, len(post.Images))
	for i, img := range post.Images {
		images[i] = dto.PostImageResponse{
			ID:           img.ID,
			URL:          img.URL,
			ThumbnailURL: img.ThumbnailURL,
			Width:        img.Width,
			Height:       img.Height,
		}
	}

	var author *dto.UserResponse
	if post.User != nil {
		author = dto.ConvertUserToResponse(post.User)
	}

	return &dto.AdminPostDetailResponse{
		ID:              post.ID,
		UserID:          post.UserID,
		ChannelID:       post.ChannelID,
		Title:           post.Title,
		Content:         post.Content,
		Images:          images,
		Status:          string(post.Status),
		LikesCount:      post.LikesCount,
		CommentsCount:   post.CommentsCount,
		FavoritesCount:  post.FavoritesCount,
		SharesCount:     post.SharesCount,
		ViewsCount:      post.ViewsCount,
		IsPinned:        post.IsPinned,
		IsFeatured:      post.IsFeatured,
		IsLocked:        post.IsLocked,
		IsVote:          post.IsVote,
		RejectReason:    post.RejectReason,
		ReviewedAt:      dto.FormatTimePointer(post.ReviewedAt),
		ReviewedBy:      post.ReviewedBy,
		CreatedAt:       post.CreatedAt.Format("2006-01-02T15:04:05Z07:00"),
		UpdatedAt:       post.UpdatedAt.Format("2006-01-02T15:04:05Z07:00"),
		ContentEditedAt: dto.FormatTimePointer(post.ContentEditedAt),
		Author:          author,
	}
}