pkg/exchange: support market trade stream on bitget

pkg/exchange/bitget/stream.go

@@ -13,7 +13,8 @@ import (
 type Stream struct {
 	types.StandardStream
 
-	bookEventCallbacks []func(o BookEvent)
+	bookEventCallbacks        []func(o BookEvent)
+	marketTradeEventCallbacks []func(o MarketTradeEvent)
 }
 
 func NewStream() *Stream {
@@ -27,6 +28,7 @@ func NewStream() *Stream {
 	stream.OnConnect(stream.handlerConnect)
 
 	stream.OnBookEvent(stream.handleBookEvent)
+	stream.OnMarketTradeEvent(stream.handleMaretTradeEvent)
 	return stream
 }
 
@@ -87,6 +89,9 @@ func (s *Stream) dispatchEvent(event interface{}) {
 
 	case *BookEvent:
 		s.EmitBookEvent(*e)
+
+	case *MarketTradeEvent:
+		s.EmitMarketTradeEvent(*e)
 	}
 }
 
@@ -101,7 +106,7 @@ func (s *Stream) handlerConnect() {
 
 func (s *Stream) handleBookEvent(o BookEvent) {
 	for _, book := range o.ToGlobalOrderBooks() {
-		switch o.Type {
+		switch o.actionType {
 		case ActionTypeSnapshot:
 			s.EmitBookSnapshot(book)
 
@@ -131,6 +136,10 @@ func convertSubscription(sub types.Subscription) (WsArg, error) {
 			arg.Channel = ChannelOrderBook
 		}
 		return arg, nil
+
+	case types.MarketTradeChannel:
+		arg.Channel = ChannelTrade
+		return arg, nil
 	}
 
 	return arg, fmt.Errorf("unsupported stream channel: %s", sub.Channel)
@@ -156,10 +165,37 @@ func parseWebSocketEvent(in []byte) (interface{}, error) {
 			return nil, fmt.Errorf("failed to unmarshal data into BookEvent, Arg: %+v Data: %s, err: %w", event.Arg, string(event.Data), err)
 		}
 
-		book.Type = event.Action
+		book.actionType = event.Action
-		book.InstId = event.Arg.InstId
+		book.instId = event.Arg.InstId
 		return &book, nil
+
+	case ChannelTrade:
+		var trade MarketTradeEvent
+		err = json.Unmarshal(event.Data, &trade.Events)
+		if err != nil {
+			return nil, fmt.Errorf("failed to unmarshal data into MarketTradeEvent, Arg: %+v Data: %s, err: %w", event.Arg, string(event.Data), err)
+		}
+
+		trade.actionType = event.Action
+		trade.instId = event.Arg.InstId
+		return &trade, nil
 	}
 
 	return nil, fmt.Errorf("unhandled websocket event: %+v", string(in))
 }
+
+func (s *Stream) handleMaretTradeEvent(m MarketTradeEvent) {
+	if m.actionType == ActionTypeSnapshot {
+		// we don't support snapshot event
+		return
+	}
+	for _, trade := range m.Events {
+		globalTrade, err := trade.ToGlobal(m.instId)
+		if err != nil {
+			log.WithError(err).Error("failed to convert to market trade")
+			return
+		}
+
+		s.EmitMarketTrade(globalTrade)
+	}
+}

pkg/exchange/bitget/stream_callbacks.go

@@ -13,3 +13,13 @@ func (s *Stream) EmitBookEvent(o BookEvent) {
 		cb(o)
 	}
 }
+
+func (s *Stream) OnMarketTradeEvent(cb func(o MarketTradeEvent)) {
+	s.marketTradeEventCallbacks = append(s.marketTradeEventCallbacks, cb)
+}
+
+func (s *Stream) EmitMarketTradeEvent(o MarketTradeEvent) {
+	for _, cb := range s.marketTradeEventCallbacks {
+		cb(o)
+	}
+}

pkg/exchange/bitget/stream_test.go

@@ -92,6 +92,20 @@ func TestStream(t *testing.T) {
 		c := make(chan struct{})
 		<-c
 	})
+
+	t.Run("trade test", func(t *testing.T) {
+		s.Subscribe(types.MarketTradeChannel, "BTCUSDT", types.SubscribeOptions{})
+		s.SetPublicOnly()
+		err := s.Connect(context.Background())
+		assert.NoError(t, err)
+
+		s.OnMarketTrade(func(trade types.Trade) {
+			t.Log("got update", trade)
+		})
+		c := make(chan struct{})
+		<-c
+	})
+
 }
 
 func TestStream_parseWebSocketEvent(t *testing.T) {
@@ -247,8 +261,8 @@ func TestStream_parseWebSocketEvent(t *testing.T) {
 						Checksum: 0,
 					},
 				},
-				Type:   actionType,
+				actionType: actionType,
-				InstId: "BTCUSDT",
+				instId:     "BTCUSDT",
 			}, *book)
 		}
 
@@ -264,6 +278,181 @@ func TestStream_parseWebSocketEvent(t *testing.T) {
 	})
 }
 
+func Test_parseWebSocketEvent_MarketTrade(t *testing.T) {
+	t.Run("MarketTrade event", func(t *testing.T) {
+		input := `{
+		   "action":"%s",
+		   "arg":{
+			  "instType":"sp",
+			  "channel":"trade",
+			  "instId":"BTCUSDT"
+		   },
+		   "data":[
+			  [
+				 "1697697791663",
+				 "28303.43",
+				 "0.0452",
+				 "sell"
+			  ],
+			  [
+				 "1697697794663",
+				 "28345.67",
+				 "0.1234",
+				 "sell"
+			  ]
+		   ],
+		   "ts":1697697791670
+		}`
+
+		eventFn := func(in string, actionType ActionType) {
+			res, err := parseWebSocketEvent([]byte(in))
+			assert.NoError(t, err)
+			book, ok := res.(*MarketTradeEvent)
+			assert.True(t, ok)
+			assert.Equal(t, MarketTradeEvent{
+				Events: MarketTradeSlice{
+					{
+						Ts:    types.NewMillisecondTimestampFromInt(1697697791663),
+						Price: fixedpoint.NewFromFloat(28303.43),
+						Size:  fixedpoint.NewFromFloat(0.0452),
+						Side:  "sell",
+					},
+
+					{
+						Ts:    types.NewMillisecondTimestampFromInt(1697697794663),
+						Price: fixedpoint.NewFromFloat(28345.67),
+						Size:  fixedpoint.NewFromFloat(0.1234),
+						Side:  "sell",
+					},
+				},
+				actionType: actionType,
+				instId:     "BTCUSDT",
+			}, *book)
+		}
+
+		t.Run("snapshot type", func(t *testing.T) {
+			snapshotInput := fmt.Sprintf(input, ActionTypeSnapshot)
+			eventFn(snapshotInput, ActionTypeSnapshot)
+		})
+
+		t.Run("update type", func(t *testing.T) {
+			snapshotInput := fmt.Sprintf(input, ActionTypeUpdate)
+			eventFn(snapshotInput, ActionTypeUpdate)
+		})
+	})
+
+	t.Run("Unexpected length of market trade", func(t *testing.T) {
+		input := `{
+		   "action":"%s",
+		   "arg":{
+			  "instType":"sp",
+			  "channel":"trade",
+			  "instId":"BTCUSDT"
+		   },
+		   "data":[
+			  [
+				 "1697697791663",
+				 "28303.43",
+				 "28303.43",
+				 "0.0452",
+				 "sell"
+			  ]
+		   ],
+		   "ts":1697697791670
+		}`
+		_, err := parseWebSocketEvent([]byte(input))
+		assert.ErrorContains(t, err, "unexpected trades length")
+	})
+
+	t.Run("Unexpected timestamp", func(t *testing.T) {
+		input := `{
+		   "action":"%s",
+		   "arg":{
+			  "instType":"sp",
+			  "channel":"trade",
+			  "instId":"BTCUSDT"
+		   },
+		   "data":[
+			  [
+				 "TIMESTAMP",
+				 "28303.43",
+				 "0.0452",
+				 "sell"
+			  ]
+		   ],
+		   "ts":1697697791670
+		}`
+		_, err := parseWebSocketEvent([]byte(input))
+		assert.ErrorContains(t, err, "timestamp")
+	})
+
+	t.Run("Unexpected price", func(t *testing.T) {
+		input := `{
+		   "action":"%s",
+		   "arg":{
+			  "instType":"sp",
+			  "channel":"trade",
+			  "instId":"BTCUSDT"
+		   },
+		   "data":[
+			  [
+				 "1697697791663",
+				 "1p",
+				 "0.0452",
+				 "sell"
+			  ]
+		   ],
+		   "ts":1697697791670
+		}`
+		_, err := parseWebSocketEvent([]byte(input))
+		assert.ErrorContains(t, err, "price")
+	})
+
+	t.Run("Unexpected size", func(t *testing.T) {
+		input := `{
+		   "action":"%s",
+		   "arg":{
+			  "instType":"sp",
+			  "channel":"trade",
+			  "instId":"BTCUSDT"
+		   },
+		   "data":[
+			  [
+				 "1697697791663",
+				 "28303.43",
+				 "2v",
+				 "sell"
+			  ]
+		   ],
+		   "ts":1697697791670
+		}`
+		_, err := parseWebSocketEvent([]byte(input))
+		assert.ErrorContains(t, err, "size")
+	})
+
+	t.Run("Unexpected side", func(t *testing.T) {
+		input := `{
+		   "action":"%s",
+		   "arg":{
+			  "instType":"sp",
+			  "channel":"trade",
+			  "instId":"BTCUSDT"
+		   },
+		   "data":[
+			  [
+				 "1697697791663",
+				 "28303.43",
+				 "0.0452",
+				 12345
+			  ]
+		   ],
+		   "ts":1697697791670
+		}`
+		_, err := parseWebSocketEvent([]byte(input))
+		assert.ErrorContains(t, err, "side")
+	})
+}
+
 func Test_convertSubscription(t *testing.T) {
 	t.Run("BookChannel.ChannelOrderBook5", func(t *testing.T) {
 		res, err := convertSubscription(types.Subscription{
@@ -310,4 +499,17 @@ func Test_convertSubscription(t *testing.T) {
 			InstId:   "BTCUSDT",
 		}, res)
 	})
+	t.Run("TradeChannel", func(t *testing.T) {
+		res, err := convertSubscription(types.Subscription{
+			Symbol:  "BTCUSDT",
+			Channel: types.MarketTradeChannel,
+			Options: types.SubscribeOptions{},
+		})
+		assert.NoError(t, err)
+		assert.Equal(t, WsArg{
+			InstType: instSp,
+			Channel:  ChannelTrade,
+			InstId:   "BTCUSDT",
+		}, res)
+	})
 }

pkg/exchange/bitget/types.go

@@ -2,8 +2,10 @@ package bitget
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 
+	"github.com/c9s/bbgo/pkg/fixedpoint"
 	"github.com/c9s/bbgo/pkg/types"
 )
 
@@ -23,6 +25,7 @@ const (
 	ChannelOrderBook5 ChannelType = "books5"
 	// ChannelOrderBook15 top 15 order book of "books" that begins from bid1/ask1
 	ChannelOrderBook15 ChannelType = "books15"
+	ChannelTrade       ChannelType = "trade"
 )
 
 type WsArg struct {
@@ -119,15 +122,15 @@ type BookEvent struct {
 	}
 
 	// internal use
-	Type   ActionType
+	actionType ActionType
-	InstId string
+	instId     string
 }
 
 func (e *BookEvent) ToGlobalOrderBooks() []types.SliceOrderBook {
 	books := make([]types.SliceOrderBook, len(e.Events))
 	for i, event := range e.Events {
 		books[i] = types.SliceOrderBook{
-			Symbol: e.InstId,
+			Symbol: e.instId,
 			Bids:   event.Bids,
 			Asks:   event.Asks,
 			Time:   event.Ts.Time(),
@@ -136,3 +139,124 @@ func (e *BookEvent) ToGlobalOrderBooks() []types.SliceOrderBook {
 
 	return books
 }
+
+type SideType string
+
+const (
+	SideBuy  SideType = "buy"
+	SideSell SideType = "sell"
+)
+
+func (s SideType) ToGlobal() (types.SideType, error) {
+	switch s {
+	case SideBuy:
+		return types.SideTypeBuy, nil
+	case SideSell:
+		return types.SideTypeSell, nil
+	default:
+		return "", fmt.Errorf("unexpceted side type: %s", s)
+	}
+}
+
+type MarketTrade struct {
+	Ts    types.MillisecondTimestamp
+	Price fixedpoint.Value
+	Size  fixedpoint.Value
+	Side  SideType
+}
+
+type MarketTradeSlice []MarketTrade
+
+func (m *MarketTradeSlice) UnmarshalJSON(b []byte) error {
+	if m == nil {
+		return errors.New("nil pointer of market trade slice")
+	}
+	s, err := parseMarketTradeSliceJSON(b)
+	if err != nil {
+		return err
+	}
+
+	*m = s
+	return nil
+}
+
+// ParseMarketTradeSliceJSON tries to parse a 2 dimensional string array into a MarketTradeSlice
+//
+// [
+//
+//	[
+//	   "1697694819663",
+//	   "28312.97",
+//	   "0.1653",
+//	   "sell"
+//	],
+//	[
+//	   "1697694818663",
+//	   "28313",
+//	   "0.1598",
+//	   "buy"
+//	]
+//
+// ]
+func parseMarketTradeSliceJSON(in []byte) (slice MarketTradeSlice, err error) {
+	var rawTrades [][]json.RawMessage
+
+	err = json.Unmarshal(in, &rawTrades)
+	if err != nil {
+		return slice, err
+	}
+
+	for _, raw := range rawTrades {
+		if len(raw) != 4 {
+			return nil, fmt.Errorf("unexpected trades length: %d, data: %q", len(raw), raw)
+		}
+		var trade MarketTrade
+		if err = json.Unmarshal(raw[0], &trade.Ts); err != nil {
+			return nil, fmt.Errorf("failed to unmarshal into timestamp: %q", raw[0])
+		}
+		if err = json.Unmarshal(raw[1], &trade.Price); err != nil {
+			return nil, fmt.Errorf("failed to unmarshal into price: %q", raw[1])
+		}
+		if err = json.Unmarshal(raw[2], &trade.Size); err != nil {
+			return nil, fmt.Errorf("failed to unmarshal into size: %q", raw[2])
+		}
+		if err = json.Unmarshal(raw[3], &trade.Side); err != nil {
+			return nil, fmt.Errorf("failed to unmarshal into side: %q", raw[3])
+		}
+
+		slice = append(slice, trade)
+	}
+
+	return slice, nil
+}
+
+func (m MarketTrade) ToGlobal(symbol string) (types.Trade, error) {
+	side, err := m.Side.ToGlobal()
+	if err != nil {
+		return types.Trade{}, err
+	}
+
+	return types.Trade{
+		ID:            0, // not supported
+		OrderID:       0, // not supported
+		Exchange:      types.ExchangeBitget,
+		Price:         m.Price,
+		Quantity:      m.Size,
+		QuoteQuantity: m.Price.Mul(m.Size),
+		Symbol:        symbol,
+		Side:          side,
+		IsBuyer:       side == types.SideTypeBuy,
+		IsMaker:       false, // not supported
+		Time:          types.Time(m.Ts.Time()),
+		Fee:           fixedpoint.Zero, // not supported
+		FeeCurrency:   "",              // not supported
+	}, nil
+}
+
+type MarketTradeEvent struct {
+	Events MarketTradeSlice
+
+	// internal use
+	actionType ActionType
+	instId     string
+}