package srv_playlet

import (
	"context"
	"strings"
	"videoweb/pub/common/srvdef"
	"videoweb/pub/models/playletthememod"
	"videoweb/pub/models/playlettopicgroupmod"
	"videoweb/web/api/proto"

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

// ListPlayletTopicGroups 查询后台专题区块
func ListPlayletTopicGroups(ctx context.Context, req *proto.PlayletTopicGroupListReq) (*proto.PlayletTopicGroupListResp, *srvdef.SrvErr) {
	if req == nil {
		return nil, srvdef.New(srvdef.ErrParamError, "", "")
	}
	pageNum, pageSize := normalizePage(req.PageNum, req.PageSize)
	filter := bson.M{}
	if req.Status != nil {
		filter["status"] = *req.Status
	}
	totalCount, err := playlettopicgroupmod.Count(ctx, filter)
	if err != nil {
		return nil, err
	}
	resp := &proto.PlayletTopicGroupListResp{
		TotalCount: totalCount, PageNum: int(pageNum), PageSize: int(pageSize),
		List: make(playlettopicgroupmod.PlayletTopicGroupList, 0),
	}
	if totalCount == 0 || (pageNum-1)*pageSize >= totalCount {
		return resp, nil
	}
	list, err := playlettopicgroupmod.FindMany(ctx, filter, options.Find().SetSkip((pageNum-1)*pageSize).SetLimit(pageSize))
	if err != nil {
		return nil, err
	}
	resp.List = list
	return resp, nil
}

// AddPlayletTopicGroup 新增专题区块
func AddPlayletTopicGroup(ctx context.Context, req *proto.PlayletTopicGroupAddReq) (*proto.PlayletTopicGroupAddResp, *srvdef.SrvErr) {
	if req == nil || strings.TrimSpace(req.Name) == "" || req.Status == nil {
		return nil, srvdef.New(srvdef.ErrParamError, "专题区块参数无效", "")
	}
	ids, err := validateTopicGroupIDs(ctx, req.TopicIds)
	if err != nil {
		return nil, err
	}
	doc := &playlettopicgroupmod.PlayletTopicGroup{
		Name: strings.TrimSpace(req.Name), Desc: strings.TrimSpace(req.Desc),
		TopicIds: ids, Rank: req.Rank, Status: *req.Status,
	}
	if err := playlettopicgroupmod.Insert(ctx, doc); err != nil {
		return nil, err
	}
	return &proto.PlayletTopicGroupAddResp{Id: doc.Id}, nil
}

// UpdatePlayletTopicGroup 更新专题区块
func UpdatePlayletTopicGroup(ctx context.Context, req *proto.PlayletTopicGroupUpdateReq) *srvdef.SrvErr {
	if req == nil || req.Id <= 0 {
		return srvdef.New(srvdef.ErrParamError, "专题区块ID无效", "")
	}
	set := bson.M{}
	if req.Name != nil {
		name := strings.TrimSpace(*req.Name)
		if name == "" {
			return srvdef.New(srvdef.ErrParamError, "专题区块名称不能为空", "")
		}
		set["name"] = name
	}
	if req.Desc != nil {
		set["desc"] = strings.TrimSpace(*req.Desc)
	}
	if req.TopicIds != nil {
		ids, err := validateTopicGroupIDs(ctx, *req.TopicIds)
		if err != nil {
			return err
		}
		set["topicIds"] = ids
	}
	if req.Rank != nil {
		set["rank"] = *req.Rank
	}
	if req.Status != nil {
		set["status"] = *req.Status
	}
	if len(set) == 0 {
		return srvdef.New(srvdef.ErrParamError, "没有可更新字段", "")
	}
	return playlettopicgroupmod.Update(ctx, req.Id, set)
}

// DeletePlayletTopicGroup 删除专题区块
func DeletePlayletTopicGroup(ctx context.Context, id int64) *srvdef.SrvErr {
	if id <= 0 {
		return srvdef.New(srvdef.ErrParamError, "专题区块ID无效", "")
	}
	return playlettopicgroupmod.Delete(ctx, id)
}

func validateTopicGroupIDs(ctx context.Context, ids []int64) ([]int64, *srvdef.SrvErr) {
	if len(ids) == 0 {
		return []int64{}, nil
	}
	seen := make(map[int64]bool, len(ids))
	for _, id := range ids {
		if id <= 0 || seen[id] {
			return nil, srvdef.New(srvdef.ErrParamError, "专题ID无效或重复", "")
		}
		seen[id] = true
	}
	count, err := playletthememod.CountPlayletTheme(ctx, bson.M{playletthememod.FN.PlayletTheme.Id: bson.M{"$in": ids}})
	if err != nil {
		return nil, err
	}
	if count != int64(len(ids)) {
		return nil, srvdef.New(srvdef.ErrParamError, "专题不存在", "")
	}
	return ids, nil
}