package playletser

import (
	"context"
	"videoweb/app/api/proto"
	"videoweb/pub/common/srvdef"
	"videoweb/pub/models/playletlikemod"
	"videoweb/pub/models/playletmod"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo/options"
)

type playletLikePage struct {
	Total []struct {
		Count int64 `bson:"count"`
	} `bson:"total"`
	List playletlikemod.PlayletLikeList `bson:"list"`
}

// LikeList 按点赞时间倒序分页查询当前用户仍上架的短剧。
func LikeList(ctx context.Context, userId int64, req *proto.PlayletLikeListReq) (*proto.PlayletLikeListResp, *srvdef.SrvErr) {
	if userId <= 0 {
		return nil, srvdef.New(srvdef.InvalidToken, "请先登录", "请先登录")
	}
	if req == nil {
		return nil, srvdef.New(srvdef.ErrParamError, "", "")
	}
	pageNum, pageSize := normalizePlayletPage(req.PageNum, req.PageSize)
	resp := &proto.PlayletLikeListResp{
		PageNum: int(pageNum), PageSize: int(pageSize), List: make([]proto.PlayletLikeData, 0),
	}

	// 在分页之前过滤下架或已删除的短剧，避免总数和当前页不一致。
	pipeline := []bson.M{
		{"$match": bson.M{playletlikemod.FN.PlayletLike.UserId: userId}},
		{"$sort": bson.D{
			{Key: playletlikemod.FN.PlayletLike.CreatedAt, Value: -1},
			{Key: playletlikemod.FN.PlayletLike.Id, Value: -1},
		}},
		{"$lookup": bson.M{
			"from": playletmod.TN.Playlet, "localField": playletlikemod.FN.PlayletLike.PlayletId,
			"foreignField": playletmod.FN.Playlet.Id, "as": "playlet",
		}},
		{"$unwind": "$playlet"},
		{"$match": bson.M{"playlet." + playletmod.FN.Playlet.Status: playletmod.StatusUp}},
		{"$facet": bson.M{
			"total": bson.A{bson.M{"$count": "count"}},
			"list": bson.A{
				bson.M{"$skip": (pageNum - 1) * pageSize},
				bson.M{"$limit": pageSize},
				bson.M{"$project": bson.M{
					playletlikemod.FN.PlayletLike.Id: 1, playletlikemod.FN.PlayletLike.PlayletId: 1,
					playletlikemod.FN.PlayletLike.CreatedAt: 1,
				}},
			},
		}},
	}
	var pages []playletLikePage
	if err := playletlikemod.AggregatePlayletLike(ctx, &pages, pipeline); err != nil {
		return nil, err
	}
	if len(pages) == 0 {
		return resp, nil
	}
	page := pages[0]
	if len(page.Total) > 0 {
		resp.TotalCount = page.Total[0].Count
	}
	if len(page.List) == 0 {
		return resp, nil
	}
	ids := make([]int64, 0, len(page.List))
	for _, like := range page.List {
		if like != nil {
			ids = append(ids, like.PlayletId)
		}
	}
	playlets, err := playletmod.FindManyPlaylet(ctx, homeUpPlayletFilter(bson.M{
		playletmod.FN.Playlet.Id: bson.M{"$in": ids},
	}), options.Find().SetProjection(playletHomeProjection))
	if err != nil {
		return nil, err
	}
	themeNames, err := buildHomeThemeNameMap(ctx, playlets)
	if err != nil {
		return nil, err
	}
	tagNames, err := buildHomeTagNameMap(ctx, playlets)
	if err != nil {
		return nil, err
	}
	dataByID := make(map[int64]*proto.CommonData, len(playlets))
	for _, data := range playletsToHomeCommonData(ctx, playlets, themeNames, tagNames) {
		dataByID[data.Id] = data
	}
	for _, like := range page.List {
		if like == nil {
			continue
		}
		if data := dataByID[like.PlayletId]; data != nil {
			resp.List = append(resp.List, proto.PlayletLikeData{
				CommonData: *data, IsLike: operateStatusYes, LikedAt: like.CreatedAt,
			})
		}
	}
	return resp, nil
}