package exchange

import (
	"context"
	"fmt"
	"io"
	"sig-pub/api/pb"
	"sig-pub/pkg/zlog"
	"sync/atomic"

	"google.golang.org/grpc"
)

type ExchangeGrpcServer struct {
	pb.UnimplementedExchangeServiceServer
	exchangeService *ExchangeService
	klineStreamId   int64

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

// exchanges: 支持的数据源交易所
func NewExchangeGrpcServer(exchangeService *ExchangeService) *ExchangeGrpcServer {
	return &ExchangeGrpcServer{
		exchangeService: exchangeService,
	}
}

func (svr *ExchangeGrpcServer) Init() (err error) {
	svr.klineSubscriber = svr.exchangeService.GetKlineSubscriber()
	return
}

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

	// 接收消息的goroutine
	recvChan := make(chan *pb.ReqStreamSubscribeKline)
	go func() {
		for {
			msg, err := stream.Recv()
			if err == io.EOF {
				zlog.Infof("recv close EOF")
				close(recvChan)
				return
			}
			if err != nil {
				zlog.Infof("recv error: %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
			svr.klineSubscriber.UnsubscribeAll(streamId)
			return stream.Context().Err()
		case msg, ok := <-recvChan:
			if !ok {
				// 接收通道关闭，结束流
				svr.klineSubscriber.UnsubscribeAll(streamId)
				return
			}

			if msg.SubType == pb.SubscribeType_UnsubscribeAll {
				svr.klineSubscriber.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.Debugf("stream: id=%d, sub %s", streamId, subKey)
							switch msg.SubType {
							case pb.SubscribeType_Subscribe:
								svr.klineSubscriber.Subscribe(subKey, streamId, stream)
							case pb.SubscribeType_Unsubscribe:
								svr.klineSubscriber.Unsubscribe(subKey, streamId)
							}
						}
					}
				}
			}
		}
	}
}

// Exchanges 获取支持的交易所列表
func (svr *ExchangeGrpcServer) Exchanges(ctx context.Context, req *pb.ReqExchanges) (rsp *pb.RspExchanges, err error) {
	exchanges, err := svr.exchangeService.Exchanges()
	if err != nil {
		return
	}
	return &pb.RspExchanges{Exchanges: exchanges}, nil
}

// ExchangeInstanceState 获取交易产品系统状态
func (svr *ExchangeGrpcServer) ExchangeInstanceState(ctx context.Context, req *pb.ReqExchangeInstanceState) (rsp *pb.RspExchangeInstanceState, err error) {
	states, err := svr.exchangeService.ExchangeInstanceState(req.AllExchange, req.Exchanges, req.Insts)
	if err != nil {
		return
	}
	return &pb.RspExchangeInstanceState{InstsState: states}, nil
}

// HistoryKline 获取交易产品历史k线 (before < klines... < after)
func (svr *ExchangeGrpcServer) HistoryKline(ctx context.Context, req *pb.ReqHistoryKline) (rsp *pb.RspHistoryKline, err error) {
	rsp = &pb.RspHistoryKline{
		Exchange: req.Exchange,
		InstId:   req.InstId,
		Interval: req.Interval,
	}
	// for before := req.Before; ; {
	// }
	klines, err := svr.exchangeService.HistoryKline(ctx, req, rsp)
	if err != nil {
		return
	}

	rsp.Klines = make([]*pb.Kline, 0, len(klines))
	for _, k := range klines {
		rsp.Klines = append(rsp.Klines, k.ToPBKline())
	}
	return
}