package label_relationship

import (
	"context"
	"github.com/suyuan32/simple-admin-common/msg/errormsg"
	"wechat-api/ent/labelrelationship"
	"wechat-api/internal/svc"
	"wechat-api/internal/types"
	"wechat-api/internal/utils/dberrorhandler"

	"github.com/zeromicro/go-zero/core/logx"
)

type UpdateLabelRelationshipsLogic struct {
	logx.Logger
	ctx    context.Context
	svcCtx *svc.ServiceContext
}

func NewUpdateLabelRelationshipsLogic(ctx context.Context, svcCtx *svc.ServiceContext) *UpdateLabelRelationshipsLogic {
	return &UpdateLabelRelationshipsLogic{
		Logger: logx.WithContext(ctx),
		ctx:    ctx,
		svcCtx: svcCtx}
}

func (l *UpdateLabelRelationshipsLogic) UpdateLabelRelationships(req *types.LabelRelationshipsInfo) (resp *types.BaseMsgResp, err error) {
	l.Logger.Info("Start processing UpdateLabelRelationships request", "request", req)
	defer func() {
		if err != nil {
			l.Logger.Error("Error occurred in UpdateLabelRelationships", "error", err)
		} else {
			l.Logger.Info("Successfully processed UpdateLabelRelationships request")
		}
	}()
	// 获取联系人当前已关联的标签
	currentLabelRelationships, err := l.svcCtx.DB.LabelRelationship.Query().Where(labelrelationship.ContactID(*req.ContactId)).All(l.ctx)
	if err != nil {
		return nil, dberrorhandler.DefaultEntError(l.Logger, err, req)
	}

	// 提取当前标签ID
	var currentLabelIds []uint64
	for _, relationship := range currentLabelRelationships {
		currentLabelIds = append(currentLabelIds, relationship.LabelID)
	}

	// 对比新旧标签ID，找出需要新增和移除的标签
	addLabelIds, removeLabelIds := compareLabelIds(req.LabelIds, currentLabelIds)

	// 删除需要移除的标签关系
	for _, id := range removeLabelIds {
		_, err := l.svcCtx.DB.LabelRelationship.
			Delete().
			Where(
				labelrelationship.ContactID(*req.ContactId),
				labelrelationship.LabelID(id),
			).
			Exec(l.ctx)
		if err != nil {
			return nil, dberrorhandler.DefaultEntError(l.Logger, err, req)
		}
	}

	// 创建需要新增的标签关系
	for _, id := range addLabelIds {
		_, err := l.svcCtx.DB.LabelRelationship.Create().
			SetLabelID(id).
			SetContactID(*req.ContactId).
			SetStatus(*req.Status).
			Save(l.ctx)
		if err != nil {
			return nil, dberrorhandler.DefaultEntError(l.Logger, err, req)
		}
	}

	return &types.BaseMsgResp{
		Code: 0,
		Msg:  errormsg.Success,
	}, nil
}

// compareLabelIds compares the new label ids with the current ones and returns the ids to be added and removed
func compareLabelIds(newLabelIds []uint64, currentLabelIds []uint64) (addLabelIds []uint64, removeLabelIds []uint64) {
	newLabelIdSet := make(map[uint64]struct{}, len(newLabelIds))
	for _, id := range newLabelIds {
		newLabelIdSet[id] = struct{}{}
	}

	for _, id := range currentLabelIds {
		if _, ok := newLabelIdSet[id]; ok {
			delete(newLabelIdSet, id)
		} else {
			removeLabelIds = append(removeLabelIds, id)
		}
	}

	for id := range newLabelIdSet {
		addLabelIds = append(addLabelIds, id)
	}

	return
}