package exchange

import (
	"context"
	"fmt"
	"io"
	"sig-pub/api/pb"
	"sig-pub/pkg/aside"
	"sig-pub/pkg/data"
	"sig-pub/pkg/storage/kvrocks"
	"sig-pub/pkg/types"
	"sig-pub/pkg/zlog"
	"sync"
	"sync/atomic"

	"google.golang.org/grpc"
)

type ExchangeGrpcServer struct {
	pb.UnimplementedExchangeServiceServer
	exchangeMap         map[types.Exchange]*Exchange
	tradeInstanceAside  *aside.TradeInstanceAside
	exchangeDataService *ExchangeDataService
	kvdb                *kvrocks.KVRocksDB

	klineStreamId  int64
	klinePublisher *Publisher[int64, grpc.BidiStreamingServer[pb.ReqStreamSubscribeKline, pb.RspStreamSubscribeKline]]
}

// exchanges: 支持的数据源交易所
func NewExchangeGrpcServer(
	tradeInstanceAside *aside.TradeInstanceAside,
	exchangeDataService *ExchangeDataService,
	kvdb *kvrocks.KVRocksDB,
	exchanges ...*Exchange,
) *ExchangeGrpcServer {
	exchangeMap := make(map[types.Exchange]*Exchange)
	for _, exchange := range exchanges {
		exchangeMap[exchange.ExType] = exchange
	}

	return &ExchangeGrpcServer{
		exchangeMap:         exchangeMap,
		tradeInstanceAside:  tradeInstanceAside,
		exchangeDataService: exchangeDataService,
		kvdb:                kvdb,
		klinePublisher:      NewPublisher[int64, grpc.BidiStreamingServer[pb.ReqStreamSubscribeKline, pb.RspStreamSubscribeKline]](16),
	}
}

func (svc *ExchangeGrpcServer) Init() (err error) {
	svc.subscribeExchanges()
	return
}

// 订阅交易所推送行情
func (svc *ExchangeGrpcServer) subscribeExchanges() {
	// consumerKline
	// 交易所订阅交易产品
	for _, exchange := range svc.exchangeMap {
		go func(exchange *Exchange) {
			// get exchange trade instances
			insts, err := svc.tradeInstanceAside.ListExchangeTradeInstance(context.Background(), exchange.ExType)
			if err != nil {
				zlog.Error(err)
				return
			}

			var exchangeInstIds []string
			var processingInsts []types.TradeInstance
			exchange.Lock()
			for _, inst := range insts {
				exchangeInstIds = append(exchangeInstIds, inst.ExchangeInstId)
				tradeInst := &types.TradeInstance{
					InstId:         inst.InstId,
					Status:         inst.Status,
					PriceSz:        0,
					QuantitySz:     0,
					ExchangeInstId: inst.ExchangeInstId,
					Exchange:       exchange.ExType,
				}
				exchange.Insts[inst.ExchangeInstId] = tradeInst
				// 待初始化币种数据
				if inst.Status == data.StatusProcessing {
					processingInsts = append(processingInsts, *tradeInst)
				}
			}
			exchange.Unlock()

			// instIds := []string{"BTC-USDT", "DOGE-USDT-SWAP"}
			err = exchange.Subscriber.SubscribeKline(exchangeInstIds...)
			if err != nil {
				zlog.Error(err)
				return
			}

			go func() {
				c := exchange.Subscriber.ConsumerKline()
				svc.consumerKline(exchange, c)
				// todo subscribe books 订单簿
				zlog.Infof("unsubscribe exchange: %s", exchange.ExType)
			}()

			// 初始化k线数据
			go svc.initialKlines(exchange, processingInsts)
		}(exchange)
	}
}

// consumerKline 消费交易所k线数据
func (svc *ExchangeGrpcServer) consumerKline(exchange *Exchange, c <-chan *types.ChannelKline) {
	exchangeType := exchange.ExType

	for {
		channelK, ok := <-c
		if !ok {
			return
		}

		// 交易所 instid 转 sig-instid
		var exInst *types.TradeInstance
		exchange.RLock()
		if inst, ok := exchange.Insts[channelK.InstId]; ok && inst != nil {
			exchange.RUnlock()
			exInst = inst
		} else {
			exchange.RUnlock()
			zlog.Errorf("unknown exchange instId: %v, %s", channelK.Exchange, channelK.InstId)
			continue
		}

		// publish to subscribers
		pubMsgMap := make(map[string]*pb.StreamKline)

		// instId := channelK.InstId
		pbExType, err := channelK.Exchange.Exchange2PB()
		if err != nil {
			zlog.Error(err)
			continue
		}

		var confirmKlines []*types.Kline
		for _, kline := range channelK.Klines {
			// zlog.Infof("recv kline: %#v", kline)
			confirm := 0
			if kline.Confirm {
				confirm = 1
				confirmKlines = append(confirmKlines, kline)
			}
			pubKey := fmt.Sprintf("/kline/%s/%s/%s/%d", exchangeType, exInst.InstId, kline.Interval, confirm)
			// todo 优化没有订阅者就跳过
			msg, ok := pubMsgMap[pubKey]
			if !ok {
				msg = new(pb.StreamKline)
				msg.InstId = exInst.InstId
				msg.Exchange = pbExType
				pubMsgMap[pubKey] = msg
			}

			pbk := kline.ToPBKline()
			msg.Klines = append(msg.Klines, pbk)
		}

		// tsdb storage
		if len(confirmKlines) > 0 {
			// todo 异步处理
			err := svc.exchangeDataService.SaveKlines(*exInst, confirmKlines)
			if err != nil {
				zlog.Errorf("kline save to tsdb error: ", err)
			}
		}

		for pubKey, msg := range pubMsgMap {
			if len(msg.Klines) == 0 {
				continue
			}
			subs := svc.klinePublisher.Publisher(pubKey)
			for _, sub := range subs {
				if err := sub.Send(&pb.RspStreamSubscribeKline{Kline: msg}); err != nil {
					zlog.Error(err)
				}
			}
		}
	}
}

// SubscribeKline 订阅k线stream
func (svc *ExchangeGrpcServer) SubscribeKline(stream grpc.BidiStreamingServer[pb.ReqStreamSubscribeKline, pb.RspStreamSubscribeKline]) (err0 error) {
	streamId := atomic.AddInt64(&svc.klineStreamId, 1)
	// subKey = /kline/exchange/instId/interval/confirm

	// 接收消息的goroutine
	recvChan := make(chan *pb.ReqStreamSubscribeKline)
	go func() {
		for {
			msg, err := stream.Recv()
			if err == io.EOF {
				zlog.Infof("关闭EOF: %v", err)
				close(recvChan)
				return
			}
			if err != nil {
				zlog.Infof("接收错误: %v", err)
				close(recvChan)
				return
			}
			zlog.Infof("recv stream msg: %#v", msg)
			recvChan <- msg
		}
	}()

	// 发送和处理消息
	for {
		select {
		case <-stream.Context().Done():
			// 客户端断开连接
			svc.klinePublisher.UnsubscribeAll(streamId)
			return stream.Context().Err()
		case msg, ok := <-recvChan:
			if !ok {
				// 接收通道关闭，结束流
				svc.klinePublisher.UnsubscribeAll(streamId)
				return
			}

			if msg.SubType == pb.SubscribeType_UnsubscribeAll {
				svc.klinePublisher.UnsubscribeAll(streamId)
				continue
			}
			for _, exchange := range msg.Exchanges {
				for _, instId := range msg.InstIds {
					for _, interval := range msg.Intervals {
						confirms := []int{1}
						if !msg.OnlyConfirm {
							confirms = append(confirms, 0)
						}
						for _, confirm := range confirms {
							subKey := fmt.Sprintf("/kline/%s/%s/%s/%d", exchange.String(), instId, interval, confirm)
							zlog.Infof("stream: %d sub: %s", streamId, subKey)
							switch msg.SubType {
							case pb.SubscribeType_Subscribe:
								svc.klinePublisher.Subscribe(subKey, streamId, stream)
							case pb.SubscribeType_Unsubscribe:
								svc.klinePublisher.Unsubscribe(subKey, streamId)
							}
						}
					}
				}
			}
		}
	}

	// for {
	// 	select {
	// 	case <-ctx.Done():
	// 		// 客户端断开连接
	// 		// log.Printf("Client disconnected from topic: %s", topic)
	// 		return
	// 	default:
	// 		// 模拟事件生成
	// 		event := &pb.SubscribeKlineStreamRsp{
	// 			Kline: &pb.StreamKline{
	// 				InstId:   "DOGE/USDT",
	// 				Exchange: pb.Exchange_OKX,
	// 				Klines: []*pb.Kline{
	// 					{
	// 						Ts: time.Now().Unix(),
	// 					},
	// 				},
	// 			},
	// 		}

	// 		// 推送事件
	// 		if err := streamRsp.Send(event); err != nil {
	// 			log.Printf("Failed to send event to client: %v", err)
	// 			return err
	// 		}

	// 		// 模拟事件间隔
	// 		time.Sleep(2 * time.Second)
	// 	}
	// }
}

const (
	KlineBefore0      int64  = 1672502400000               // k线开始数据 2023-01-01 00:00:00 GMT+8
	HistoryKlineTsKey string = "history-kline-ts:%s/%s/%s" // exchange:sig-instid:interval
)

// initialKline 初始化交易产品历史k线数据
func (svc *ExchangeGrpcServer) initialKlines(exchange *Exchange, insts []types.TradeInstance) {
	var err error
	defer func() {
		if err != nil {
			zlog.Error(err)
		}
	}()

	type task struct {
		inst     types.TradeInstance
		interval types.Interval
		afterTs  int64
		beforeTs int64
	}

	// 任务 channel
	ch := make(chan task)

	// 任务生成器
	go func() {
		for _, inst := range insts {
			// for interval, intervalAdder := range types.SupportedIntervals {
			interval := types.Interval1h
			intervalAdder := types.SupportedIntervals[interval]
			tsKey := fmt.Sprintf(HistoryKlineTsKey, inst.Exchange, inst.InstId, interval)
			beforeTs, e := svc.kvdb.GetI64(context.Background(), tsKey)
			if e != nil {
				err = e
				return
			}
			if beforeTs == 0 {
				beforeTs = intervalAdder(KlineBefore0, -1)
			}
			for {
				afterTs := intervalAdder(beforeTs, 101)
				ch <- task{
					inst:     inst,
					interval: interval,
					afterTs:  afterTs,
					beforeTs: beforeTs,
				}
				beforeTs = afterTs
				// todo compare ws live ts
			}
			// }
		}
		close(ch)
	}()

	// 任务消费器 8协程并行
	wg := new(sync.WaitGroup)
	for range 11 {
		wg.Add(1)
		go func() {
			defer wg.Done()
			for {
				task, ok := <-ch
				if !ok {
					break
				}

				interval, afterTs, beforeTs := task.interval, task.afterTs, task.beforeTs
				klines, e := exchange.Fetcher.FetchHistoryKlines(context.Background(), task.inst.ExchangeInstId, interval, afterTs, beforeTs)
				if e != nil {
					// todo retry
					err = e
					return
				}
				if len(klines) == 0 {
					continue // todo ....
				}

				zlog.Infof("fetch interval %s %d~%d klines: ret=%d~%d, %d klines", interval, afterTs, beforeTs, klines[0].Ts, klines[len(klines)-1].Ts, len(klines))

				// store to tsdb
				err = svc.exchangeDataService.SaveKlines(task.inst, klines)
				if err != nil {
					return
				}
			}
		}()
	}
	wg.Wait()

	zlog.Infof("%d insts initial finished", len(insts))

	// var intervals []types.Interval
	// for interval := range types.SupportedIntervals {
	// 	intervals = append(intervals, interval)
	// }
	// var intervalsTs = make([]int, len(intervals))
	// var index int

	// var lock sync.Mutex
	// var getTask = func() (interval types.Interval, afterTs, beforeTs int64) {
	// 	lock.Lock()
	// 	ts := intervalsTs[index]
	// 	if ts == -1 {
	// 		index++
	// 	}

	// 	lock.Unlock()
	// 	return
	// }
	// var finishTask = func(interval types.Interval) {

	// }

	// ctx := context.Background()

	// inst := insts[0]
	// // for interval, intervalAdder := range types.SupportedIntervals {
	// interval := types.Interval1h
	// intervalAdder := types.SupportedIntervals[interval]
	// // kvrocks get exchange+inst+interval last/ts
	// tsKey := fmt.Sprintf(HistoryKlineTsKey, inst.Exchange, inst.InstId, interval)
	// beforeTs, e := svc.kvdb.GetI64(ctx, tsKey)
	// if e != nil {
	// 	err = e
	// 	return
	// }
	// if beforeTs == 0 {
	// 	beforeTs = intervalAdder(KlineBefore0, -1)
	// }

	// for {
	// 	afterTs := intervalAdder(beforeTs, 101)
	// 	klines, e := exchange.Fetcher.FetchHistoryKlines(ctx, inst.ExchangeInstId, interval, afterTs, beforeTs)
	// 	if e != nil {
	// 		err = e
	// 		return
	// 	}
	// 	if len(klines) == 0 {
	// 		break
	// 	}

	// 	zlog.Infof("fetch interval %s %d~%d klines: ret=%d~%d, %d klines", interval, afterTs, beforeTs, klines[0].Ts, klines[len(klines)-1].Ts, len(klines))

	// 	// store to tsdb
	// 	err = svc.exchangeDataService.SaveKlines(inst, klines)
	// 	if err != nil {
	// 		return
	// 	}

	// 	// set kvdb inst ts mark
	// 	beforeTs = klines[0].Ts
	// }
	// // }

	// zlog.Infof("%s %s initial finished", inst.Exchange, inst.InstId)
}