package api

import (
	"context"
	"errors"
	"time"

	"git.imall.cloud/openim/open-im-server-deploy/pkg/apistruct"
	"git.imall.cloud/openim/open-im-server-deploy/pkg/authverify"
	rediscache "git.imall.cloud/openim/open-im-server-deploy/pkg/common/storage/cache/redis"
	"git.imall.cloud/openim/open-im-server-deploy/pkg/common/storage/database"
	"git.imall.cloud/openim/open-im-server-deploy/pkg/rpcli"
	"git.imall.cloud/openim/protocol/constant"
	"git.imall.cloud/openim/protocol/sdkws"
	"github.com/gin-gonic/gin"
	"github.com/openimsdk/tools/a2r"
	"github.com/openimsdk/tools/apiresp"
	"github.com/openimsdk/tools/errs"
	"github.com/openimsdk/tools/log"
	"github.com/openimsdk/tools/utils/datautil"
	"github.com/redis/go-redis/v9"
)

type StatisticsApi struct {
	rdb         redis.UniversalClient
	msgDatabase database.Msg
	userClient  *rpcli.UserClient
	groupClient *rpcli.GroupClient
}

func NewStatisticsApi(rdb redis.UniversalClient, msgDatabase database.Msg, userClient *rpcli.UserClient, groupClient *rpcli.GroupClient) *StatisticsApi {
	return &StatisticsApi{
		rdb:         rdb,
		msgDatabase: msgDatabase,
		userClient:  userClient,
		groupClient: groupClient,
	}
}

const (
	trendIntervalMinutes15 = 15
	trendIntervalMinutes30 = 30
	trendIntervalMinutes60 = 60
	trendChatTypeSingle    = 1
	trendChatTypeGroup     = 2
	defaultTrendDuration   = 24 * time.Hour
)

// refreshOnlineUserCountAndHistory 刷新在线人数并写入历史采样
func refreshOnlineUserCountAndHistory(ctx context.Context, rdb redis.UniversalClient) {
	count, err := rediscache.RefreshOnlineUserCount(ctx, rdb)
	if err != nil {
		log.ZWarn(ctx, "refresh online user count failed", err)
		return
	}
	if err := rediscache.AppendOnlineUserCountHistory(ctx, rdb, time.Now().UnixMilli(), count); err != nil {
		log.ZWarn(ctx, "append online user count history failed", err)
	}
}

// startOnlineCountRefresher 定时刷新在线人数缓存
func startOnlineCountRefresher(ctx context.Context, cfg *Config, rdb redis.UniversalClient) {
	if cfg == nil || rdb == nil {
		return
	}
	refreshCfg := cfg.API.OnlineCountRefresh
	if !refreshCfg.Enable || refreshCfg.Interval <= 0 {
		return
	}
	log.ZInfo(ctx, "online user count refresh enabled", "interval", refreshCfg.Interval)
	go func() {
		refreshOnlineUserCountAndHistory(ctx, rdb)
		ticker := time.NewTicker(refreshCfg.Interval)
		defer ticker.Stop()
		for {
			select {
			case <-ctx.Done():
				return
			case <-ticker.C:
				refreshOnlineUserCountAndHistory(ctx, rdb)
			}
		}
	}()
}

// OnlineUserCount 在线人数统计接口
func (s *StatisticsApi) OnlineUserCount(c *gin.Context) {
	if err := authverify.CheckAdmin(c); err != nil {
		apiresp.GinError(c, err)
		return
	}
	if s.rdb == nil {
		apiresp.GinError(c, errs.ErrInternalServer.WrapMsg("redis client is nil"))
		return
	}
	count, err := rediscache.GetOnlineUserCount(c, s.rdb)
	if err != nil {
		if errors.Is(err, redis.Nil) {
			count, err = rediscache.RefreshOnlineUserCount(c, s.rdb)
			if err == nil {
				if appendErr := rediscache.AppendOnlineUserCountHistory(c, s.rdb, time.Now().UnixMilli(), count); appendErr != nil {
					log.ZWarn(c, "append online user count history failed", appendErr)
				}
			}
		}
	}
	if err != nil {
		apiresp.GinError(c, err)
		return
	}
	apiresp.GinSuccess(c, &apistruct.OnlineUserCountResp{OnlineCount: count})
}

// OnlineUserCountTrend 在线人数走势统计接口
func (s *StatisticsApi) OnlineUserCountTrend(c *gin.Context) {
	if err := authverify.CheckAdmin(c); err != nil {
		apiresp.GinError(c, err)
		return
	}
	req, err := a2r.ParseRequest[apistruct.OnlineUserCountTrendReq](c)
	if err != nil {
		apiresp.GinError(c, err)
		return
	}
	if s.rdb == nil {
		apiresp.GinError(c, errs.ErrInternalServer.WrapMsg("redis client is nil"))
		return
	}
	intervalMillis, err := parseTrendIntervalMillis(req.IntervalMinutes)
	if err != nil {
		apiresp.GinError(c, err)
		return
	}
	startTime, endTime, err := normalizeTrendTimeRange(req.StartTime, req.EndTime)
	if err != nil {
		apiresp.GinError(c, err)
		return
	}
	bucketStart, bucketEnd := alignTrendRange(startTime, endTime, intervalMillis)
	// 使用对齐后的时间范围获取历史数据，确保数据范围与构建数据点的范围一致
	samples, err := rediscache.GetOnlineUserCountHistory(c, s.rdb, bucketStart, bucketEnd)
	if err != nil {
		apiresp.GinError(c, err)
		return
	}
	// 将当前在线人数作为最新采样，确保最后一个时间段展示该段内的最大在线人数
	now := time.Now().UnixMilli()
	currentBucket := now - (now % intervalMillis)
	if now < 0 && now%intervalMillis != 0 {
		currentBucket = now - ((now % intervalMillis) + intervalMillis)
	}
	if currentBucket >= bucketStart && currentBucket <= bucketEnd {
		if currentCount, err := rediscache.GetOnlineUserCount(c, s.rdb); err == nil {
			samples = append(samples, rediscache.OnlineUserCountSample{
				Timestamp: now,
				Count:     currentCount,
			})
		}
	}
	points := buildOnlineUserCountTrendPoints(samples, bucketStart, bucketEnd, intervalMillis)
	apiresp.GinSuccess(c, &apistruct.OnlineUserCountTrendResp{
		IntervalMinutes: req.IntervalMinutes,
		Points:          points,
	})
}

// UserSendMsgCount 用户发送消息总数统计
func (s *StatisticsApi) UserSendMsgCount(c *gin.Context) {
	if err := authverify.CheckAdmin(c); err != nil {
		apiresp.GinError(c, err)
		return
	}
	_, err := a2r.ParseRequest[apistruct.UserSendMsgCountReq](c)
	if err != nil {
		apiresp.GinError(c, err)
		return
	}
	if s.msgDatabase == nil {
		apiresp.GinError(c, errs.ErrInternalServer.WrapMsg("msg database is nil"))
		return
	}
	now := time.Now()
	endTime := now.UnixMilli()
	start24h := now.Add(-24 * time.Hour).UnixMilli()
	start7d := now.Add(-7 * 24 * time.Hour).UnixMilli()
	start30d := now.Add(-30 * 24 * time.Hour).UnixMilli()

	count24h, err := s.msgDatabase.CountUserSendMessages(c, "", start24h, endTime, "")
	if err != nil {
		apiresp.GinError(c, err)
		return
	}
	count7d, err := s.msgDatabase.CountUserSendMessages(c, "", start7d, endTime, "")
	if err != nil {
		apiresp.GinError(c, err)
		return
	}
	count30d, err := s.msgDatabase.CountUserSendMessages(c, "", start30d, endTime, "")
	if err != nil {
		apiresp.GinError(c, err)
		return
	}
	apiresp.GinSuccess(c, &apistruct.UserSendMsgCountResp{
		Count24h: count24h,
		Count7d:  count7d,
		Count30d: count30d,
	})
}

// UserSendMsgCountTrend 用户发送消息走势统计
func (s *StatisticsApi) UserSendMsgCountTrend(c *gin.Context) {
	if err := authverify.CheckAdmin(c); err != nil {
		apiresp.GinError(c, err)
		return
	}
	req, err := a2r.ParseRequest[apistruct.UserSendMsgCountTrendReq](c)
	if err != nil {
		apiresp.GinError(c, err)
		return
	}
	if s.msgDatabase == nil {
		apiresp.GinError(c, errs.ErrInternalServer.WrapMsg("msg database is nil"))
		return
	}
	intervalMillis, err := parseTrendIntervalMillis(req.IntervalMinutes)
	if err != nil {
		apiresp.GinError(c, err)
		return
	}
	startTime, endTime, err := normalizeTrendTimeRange(req.StartTime, req.EndTime)
	if err != nil {
		apiresp.GinError(c, err)
		return
	}
	sessionTypes, err := mapTrendChatType(req.ChatType)
	if err != nil {
		apiresp.GinError(c, err)
		return
	}
	bucketStart, bucketEnd := alignTrendRange(startTime, endTime, intervalMillis)
	countMap, err := s.msgDatabase.CountUserSendMessagesTrend(c, req.UserID, sessionTypes, startTime, endTime, intervalMillis)
	if err != nil {
		apiresp.GinError(c, err)
		return
	}
	points := buildUserSendMsgCountTrendPoints(countMap, bucketStart, bucketEnd, intervalMillis)
	apiresp.GinSuccess(c, &apistruct.UserSendMsgCountTrendResp{
		UserID:          req.UserID,
		ChatType:        req.ChatType,
		IntervalMinutes: req.IntervalMinutes,
		Points:          points,
	})
}

// UserSendMsgQuery 用户发送消息查询
func (s *StatisticsApi) UserSendMsgQuery(c *gin.Context) {
	if err := authverify.CheckAdmin(c); err != nil {
		apiresp.GinError(c, err)
		return
	}
	req, err := a2r.ParseRequest[apistruct.UserSendMsgQueryReq](c)
	if err != nil {
		apiresp.GinError(c, err)
		return
	}
	if req.StartTime > 0 && req.EndTime > 0 && req.EndTime <= req.StartTime {
		apiresp.GinError(c, errs.ErrArgs.WrapMsg("invalid time range"))
		return
	}
	if s.msgDatabase == nil {
		apiresp.GinError(c, errs.ErrInternalServer.WrapMsg("msg database is nil"))
		return
	}
	pageNumber := req.PageNumber
	if pageNumber <= 0 {
		pageNumber = 1
	}
	showNumber := req.ShowNumber
	if showNumber <= 0 {
		showNumber = 50
	}
	const maxShowNumber int32 = 200
	if showNumber > maxShowNumber {
		showNumber = maxShowNumber
	}
	total, msgs, err := s.msgDatabase.SearchUserMessages(c, req.UserID, req.StartTime, req.EndTime, req.Content, pageNumber, showNumber)
	if err != nil {
		apiresp.GinError(c, err)
		return
	}
	sendIDs := make([]string, 0, len(msgs))
	recvIDs := make([]string, 0, len(msgs))
	groupIDs := make([]string, 0, len(msgs))
	for _, item := range msgs {
		if item == nil || item.Msg == nil {
			continue
		}
		msg := item.Msg
		if msg.SendID != "" {
			sendIDs = append(sendIDs, msg.SendID)
		}
		switch msg.SessionType {
		case constant.ReadGroupChatType, constant.WriteGroupChatType:
			if msg.GroupID != "" {
				groupIDs = append(groupIDs, msg.GroupID)
			}
		default:
			if msg.RecvID != "" {
				recvIDs = append(recvIDs, msg.RecvID)
			}
		}
	}
	sendIDs = datautil.Distinct(sendIDs)
	recvIDs = datautil.Distinct(recvIDs)
	groupIDs = datautil.Distinct(groupIDs)

	sendMap, recvMap, groupMap := map[string]*sdkws.UserInfo{}, map[string]*sdkws.UserInfo{}, map[string]*sdkws.GroupInfo{}
	if s.userClient != nil {
		if len(sendIDs) > 0 {
			if users, err := s.userClient.GetUsersInfo(c, sendIDs); err == nil {
				sendMap = datautil.SliceToMap(users, (*sdkws.UserInfo).GetUserID)
			}
		}
		if len(recvIDs) > 0 {
			if users, err := s.userClient.GetUsersInfo(c, recvIDs); err == nil {
				recvMap = datautil.SliceToMap(users, (*sdkws.UserInfo).GetUserID)
			}
		}
	}
	if s.groupClient != nil && len(groupIDs) > 0 {
		if groups, err := s.groupClient.GetGroupsInfo(c, groupIDs); err == nil {
			groupMap = datautil.SliceToMap(groups, (*sdkws.GroupInfo).GetGroupID)
		}
	}

	records := make([]*apistruct.UserSendMsgQueryRecord, 0, len(msgs))
	for _, item := range msgs {
		if item == nil || item.Msg == nil {
			continue
		}
		msg := item.Msg
		msgID := msg.ServerMsgID
		if msgID == "" {
			msgID = msg.ClientMsgID
		}
		senderName := msg.SenderNickname
		if senderName == "" {
			if u := sendMap[msg.SendID]; u != nil {
				senderName = u.Nickname
			} else {
				senderName = msg.SendID
			}
		}
		recvID := msg.RecvID
		recvName := ""
		if msg.SessionType == constant.ReadGroupChatType || msg.SessionType == constant.WriteGroupChatType {
			if msg.GroupID != "" {
				recvID = msg.GroupID
			}
			if g := groupMap[recvID]; g != nil {
				recvName = g.GroupName
			} else if recvID != "" {
				recvName = recvID
			}
		} else {
			if u := recvMap[msg.RecvID]; u != nil {
				recvName = u.Nickname
			} else if msg.RecvID != "" {
				recvName = msg.RecvID
			}
		}
		records = append(records, &apistruct.UserSendMsgQueryRecord{
			MsgID:           msgID,
			SendID:          msg.SendID,
			SenderName:      senderName,
			RecvID:          recvID,
			RecvName:        recvName,
			ContentType:     msg.ContentType,
			ContentTypeName: contentTypeName(msg.ContentType),
			SessionType:     msg.SessionType,
			ChatTypeName:    chatTypeName(msg.SessionType),
			Content:         msg.Content,
			SendTime:        msg.SendTime,
		})
	}
	apiresp.GinSuccess(c, &apistruct.UserSendMsgQueryResp{
		Count:      total,
		PageNumber: pageNumber,
		ShowNumber: showNumber,
		Records:    records,
	})
}

// parseTrendIntervalMillis 解析走势统计间隔并转换为毫秒
func parseTrendIntervalMillis(intervalMinutes int32) (int64, error) {
	switch intervalMinutes {
	case trendIntervalMinutes15, trendIntervalMinutes30, trendIntervalMinutes60:
		return int64(intervalMinutes) * int64(time.Minute/time.Millisecond), nil
	default:
		return 0, errs.ErrArgs.WrapMsg("invalid intervalMinutes")
	}
}

// normalizeTrendTimeRange 标准化走势统计时间区间
func normalizeTrendTimeRange(startTime int64, endTime int64) (int64, int64, error) {
	now := time.Now().UnixMilli()
	if endTime <= 0 {
		endTime = now
	}
	if startTime <= 0 {
		startTime = endTime - int64(defaultTrendDuration/time.Millisecond)
	}
	if startTime < 0 {
		startTime = 0
	}
	if endTime <= startTime {
		return 0, 0, errs.ErrArgs.WrapMsg("invalid time range")
	}
	return startTime, endTime, nil
}

// alignTrendRange 对齐走势统计区间到间隔边界
func alignTrendRange(startTime int64, endTime int64, intervalMillis int64) (int64, int64) {
	if intervalMillis <= 0 {
		return startTime, endTime
	}
	// 开始时间向下对齐到间隔边界
	bucketStart := startTime - (startTime % intervalMillis)
	if startTime < 0 {
		bucketStart = startTime - ((startTime % intervalMillis) + intervalMillis)
	}
	// 结束时间向下对齐到所在间隔的起始（只包含已发生的间隔）
	bucketEnd := endTime - (endTime % intervalMillis)
	if endTime < 0 && endTime%intervalMillis != 0 {
		bucketEnd = endTime - ((endTime % intervalMillis) + intervalMillis)
	}
	// 确保至少覆盖一个间隔
	if bucketEnd < bucketStart {
		bucketEnd = bucketStart
	}
	return bucketStart, bucketEnd
}

// buildOnlineUserCountTrendPoints 构建在线人数走势数据点
func buildOnlineUserCountTrendPoints(samples []rediscache.OnlineUserCountSample, startTime int64, endTime int64, intervalMillis int64) []*apistruct.OnlineUserCountTrendItem {
	points := make([]*apistruct.OnlineUserCountTrendItem, 0)
	if intervalMillis <= 0 || endTime <= startTime {
		return points
	}
	maxMap := make(map[int64]int64)
	for _, sample := range samples {
		// 将采样时间戳对齐到间隔边界
		bucket := sample.Timestamp - (sample.Timestamp % intervalMillis)
		// 处理负数时间戳的情况（虽然通常不会发生）
		if sample.Timestamp < 0 && sample.Timestamp%intervalMillis != 0 {
			bucket = sample.Timestamp - ((sample.Timestamp % intervalMillis) + intervalMillis)
		}
		if sample.Count > maxMap[bucket] {
			maxMap[bucket] = sample.Count
		}
	}
	// 计算需要生成的数据点数量
	// endTime是对齐后的最后一个bucket的起始时间，所以需要包含它
	estimated := int((endTime-startTime)/intervalMillis) + 1
	if estimated > 0 {
		points = make([]*apistruct.OnlineUserCountTrendItem, 0, estimated)
	}
	// 生成从startTime到endTime（包含endTime）的所有时间点
	// endTime已经是对齐后的最后一个bucket的起始时间
	for ts := startTime; ts <= endTime; ts += intervalMillis {
		maxVal := maxMap[ts]
		points = append(points, &apistruct.OnlineUserCountTrendItem{
			Timestamp:   ts,
			OnlineCount: maxVal,
		})
	}
	return points
}

// buildUserSendMsgCountTrendPoints 构建用户发送消息走势数据点
func buildUserSendMsgCountTrendPoints(countMap map[int64]int64, startTime int64, endTime int64, intervalMillis int64) []*apistruct.UserSendMsgCountTrendItem {
	points := make([]*apistruct.UserSendMsgCountTrendItem, 0)
	if intervalMillis <= 0 || endTime <= startTime {
		return points
	}
	estimated := int((endTime - startTime) / intervalMillis)
	if estimated > 0 {
		points = make([]*apistruct.UserSendMsgCountTrendItem, 0, estimated)
	}
	for ts := startTime; ts < endTime; ts += intervalMillis {
		points = append(points, &apistruct.UserSendMsgCountTrendItem{
			Timestamp: ts,
			Count:     countMap[ts],
		})
	}
	return points
}

// mapTrendChatType 走势统计聊天类型转为 sessionType 列表
func mapTrendChatType(chatType int32) ([]int32, error) {
	switch chatType {
	case trendChatTypeSingle:
		return []int32{constant.SingleChatType}, nil
	case trendChatTypeGroup:
		return []int32{constant.ReadGroupChatType, constant.WriteGroupChatType}, nil
	default:
		return nil, errs.ErrArgs.WrapMsg("invalid chatType")
	}
}

// contentTypeName 消息类型名称转换
func contentTypeName(contentType int32) string {
	switch contentType {
	case constant.Text:
		return "文本消息"
	case constant.Picture:
		return "图片消息"
	case constant.Voice:
		return "语音消息"
	case constant.Video:
		return "视频消息"
	case constant.File:
		return "文件消息"
	case constant.AtText:
		return "艾特消息"
	case constant.Merger:
		return "合并消息"
	case constant.Card:
		return "名片消息"
	case constant.Location:
		return "位置消息"
	case constant.Custom:
		return "自定义消息"
	case constant.Revoke:
		return "撤回消息"
	case constant.MarkdownText:
		return "Markdown消息"
	default:
		return "未知消息"
	}
}

// chatTypeName 聊天类型名称转换
func chatTypeName(sessionType int32) string {
	switch sessionType {
	case constant.SingleChatType:
		return "单聊"
	case constant.ReadGroupChatType, constant.WriteGroupChatType:
		return "群聊"
	case constant.NotificationChatType:
		return "通知"
	default:
		return "未知"
	}
}