package srv_homebanner

import (
	"context"
	"regexp"
	"strings"
	"time"
	"videoweb/pub/common/playletcache"
	"videoweb/pub/common/response"
	"videoweb/pub/common/srvdef"
	"videoweb/pub/models/homebannermod"
	"videoweb/pub/models/mwacc"
	"videoweb/web/api/proto"

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

const (
	defaultHomeBannerPageSize int64 = 10
	maxHomeBannerPageSize     int64 = 100
)

var homeBannerWebProjection = bson.D{
	{Key: homebannermod.FN.HomeBanner.Id, Value: 1},
	{Key: homebannermod.FN.HomeBanner.Name, Value: 1},
	{Key: homebannermod.FN.HomeBanner.Image, Value: 1},
	{Key: homebannermod.FN.HomeBanner.VerticalImage, Value: 1},
	{Key: homebannermod.FN.HomeBanner.Url, Value: 1},
	{Key: homebannermod.FN.HomeBanner.Rank, Value: 1},
	{Key: homebannermod.FN.HomeBanner.Status, Value: 1},
	{Key: homebannermod.FN.HomeBanner.CreatedById, Value: 1},
	{Key: homebannermod.FN.HomeBanner.CreatedByName, Value: 1},
	{Key: homebannermod.FN.HomeBanner.UpdatedByName, Value: 1},
	{Key: homebannermod.FN.HomeBanner.CreatedAt, Value: 1},
	{Key: homebannermod.FN.HomeBanner.UpdatedAt, Value: 1},
}

// ListHomeBanner 分页查询首页 banner 列表
func ListHomeBanner(ctx context.Context, req *proto.HomeBannerListReq) (*proto.HomeBannerListPageResp, *srvdef.SrvErr) {
	if req == nil {
		return nil, srvdef.New(srvdef.ErrParamError, "", "")
	}
	filter := bson.M{}
	if req.Id != nil && *req.Id > 0 {
		filter[homebannermod.FN.HomeBanner.Id] = *req.Id
	}
	if req.Status != nil {
		filter[homebannermod.FN.HomeBanner.Status] = *req.Status
	}
	if name := strings.TrimSpace(req.Name); name != "" {
		filter[homebannermod.FN.HomeBanner.Name] = bson.M{"$regex": regexp.QuoteMeta(name)}
	}
	pageNum, pageSize := normalizeHomeBannerPage(req.PageNum, req.PageSize)
	totalCount, err := homebannermod.CountHomeBanner(ctx, filter)
	if err != nil {
		return nil, err
	}
	resp := &proto.HomeBannerListPageResp{
		BasePageResp: response.BasePageResp{
			TotalCount: totalCount,
			PageSize:   int(pageSize),
			PageNum:    int(pageNum),
			List:       make([]*proto.HomeBannerListResp, 0),
		},
	}
	if totalCount == 0 {
		return resp, nil
	}
	list, err := homebannermod.FindManyHomeBanner(ctx, filter, options.Find().
		SetProjection(homeBannerWebProjection).
		SetSort(bson.D{
			{Key: homebannermod.FN.HomeBanner.Rank, Value: -1},
			{Key: homebannermod.FN.HomeBanner.UpdatedAt, Value: -1},
			{Key: homebannermod.FN.HomeBanner.Id, Value: -1},
		}).
		SetSkip((pageNum-1)*pageSize).
		SetLimit(pageSize))
	if err != nil {
		return nil, err
	}
	items := make([]*proto.HomeBannerListResp, 0, len(list))
	for _, item := range list {
		if item == nil {
			continue
		}
		items = append(items, &proto.HomeBannerListResp{
			Id:            item.Id,
			Name:          item.Name,
			Image:         item.Image,
			VerticalImage: item.VerticalImage,
			Url:           item.Url,
			Rank:          item.Rank,
			Status:        item.Status,
			CreatedById:   item.CreatedById,
			CreatedByName: item.CreatedByName,
			UpdatedByName: item.UpdatedByName,
			CreatedAt:     item.CreatedAt,
			UpdatedAt:     item.UpdatedAt,
		})
	}
	resp.List = items
	return resp, nil
}

// AddHomeBanner 新增首页 banner
func AddHomeBanner(ctx context.Context, req *proto.HomeBannerAddReq, operatorId int64) (*proto.HomeBannerAddResp, *srvdef.SrvErr) {
	if req == nil {
		return nil, srvdef.New(srvdef.ErrParamError, "", "")
	}
	name := strings.TrimSpace(req.Name)
	image := strings.TrimSpace(req.Image)
	if name == "" {
		return nil, srvdef.New(srvdef.ErrParamError, "名称不能为空", "")
	}
	if image == "" {
		return nil, srvdef.New(srvdef.ErrParamError, "图片不能为空", "")
	}
	if req.Status == nil {
		return nil, srvdef.New(srvdef.ErrParamError, "状态不能为空", "")
	}
	operatorId, operatorName := resolveHomeBannerOperator(ctx, operatorId)
	doc := &homebannermod.HomeBanner{
		Name:          name,
		Image:         image,
		VerticalImage: strings.TrimSpace(req.VerticalImage),
		Url:           strings.TrimSpace(req.Url),
		Rank:          req.Rank,
		Status:        *req.Status,
		CreatedById:   operatorId,
		CreatedByName: operatorName,
		UpdatedByName: operatorName,
	}
	if err := homebannermod.InsertOneHomeBanner(ctx, doc); err != nil {
		return nil, err
	}
	clearHomeBannerCache()
	return &proto.HomeBannerAddResp{Id: doc.Id}, nil
}

// UpdateHomeBanner 更新首页 banner
func UpdateHomeBanner(ctx context.Context, req *proto.HomeBannerUpdateReq, operatorId int64) *srvdef.SrvErr {
	if req == nil || req.Id <= 0 {
		return srvdef.New(srvdef.ErrParamError, "首页banner ID无效", "")
	}
	setDoc := bson.M{homebannermod.FN.HomeBanner.UpdatedAt: time.Now()}
	if req.Name != nil {
		name := strings.TrimSpace(*req.Name)
		if name == "" {
			return srvdef.New(srvdef.ErrParamError, "名称不能为空", "")
		}
		setDoc[homebannermod.FN.HomeBanner.Name] = name
	}
	if req.Image != nil {
		image := strings.TrimSpace(*req.Image)
		if image == "" {
			return srvdef.New(srvdef.ErrParamError, "图片不能为空", "")
		}
		setDoc[homebannermod.FN.HomeBanner.Image] = image
	}
	if req.VerticalImage != nil {
		setDoc[homebannermod.FN.HomeBanner.VerticalImage] = strings.TrimSpace(*req.VerticalImage)
	}
	if req.Url != nil {
		setDoc[homebannermod.FN.HomeBanner.Url] = strings.TrimSpace(*req.Url)
	}
	if req.Rank != nil {
		setDoc[homebannermod.FN.HomeBanner.Rank] = *req.Rank
	}
	if req.Status != nil {
		setDoc[homebannermod.FN.HomeBanner.Status] = *req.Status
	}
	if len(setDoc) <= 1 {
		return srvdef.New(srvdef.ErrParamError, "没有可更新字段", "")
	}
	_, operatorName := resolveHomeBannerOperator(ctx, operatorId)
	setDoc[homebannermod.FN.HomeBanner.UpdatedByName] = operatorName
	if err := homebannermod.UpdateOneHomeBanner(ctx,
		bson.M{homebannermod.FN.HomeBanner.Id: req.Id},
		bson.M{"$set": setDoc},
	); err != nil {
		return err
	}
	clearHomeBannerCache()
	return nil
}

// DelHomeBanner 删除首页 banner
func DelHomeBanner(ctx context.Context, req *proto.HomeBannerDelReq) *srvdef.SrvErr {
	if req == nil || req.Id <= 0 {
		return srvdef.New(srvdef.ErrParamError, "首页banner ID无效", "")
	}
	count, err := homebannermod.DelOneHomeBanner(ctx, bson.M{homebannermod.FN.HomeBanner.Id: req.Id})
	if err != nil {
		return err
	}
	if count == 0 {
		return srvdef.New(srvdef.ErrNoData, "", "")
	}
	clearHomeBannerCache()
	return nil
}

// normalizeHomeBannerPage 规范分页参数，限制单页数量避免大分页拖慢查询
func normalizeHomeBannerPage(pageNum, pageSize int64) (int64, int64) {
	if pageNum <= 0 {
		pageNum = 1
	}
	if pageSize <= 0 {
		pageSize = defaultHomeBannerPageSize
	}
	if pageSize > maxHomeBannerPageSize {
		pageSize = maxHomeBannerPageSize
	}
	return pageNum, pageSize
}

// resolveHomeBannerOperator 从后台账号表解析当前操作人名称
func resolveHomeBannerOperator(ctx context.Context, operatorId int64) (int64, string) {
	if operatorId <= 0 {
		return 0, ""
	}
	acc, err := mwacc.FindOneAccByFilter(ctx, bson.M{
		mwacc.FN.MwAcc.Id: operatorId,
	}, options.FindOne().SetProjection(bson.D{
		{Key: mwacc.FN.MwAcc.Id, Value: 1},
		{Key: mwacc.FN.MwAcc.UserName, Value: 1},
	}))
	if err != nil || acc == nil {
		return operatorId, ""
	}
	return acc.Id, acc.UserName
}

// clearHomeBannerCache 清除短剧首页缓存
func clearHomeBannerCache() {
	playletcache.ClearHomeCache()
}