Major update to the data service. Added gRPC and socket servers. Switched to using only a single go.mod at the root.

services/data_service/internal/provider/binance/futures_websocket.go

@@ -0,0 +1,153 @@
+package binance
+
+import (
+	"encoding/json"
+	"fmt"
+	"sync"
+
+	"github.com/gorilla/websocket"
+	"gitlab.michelsen.id/phillmichelsen/tessera/services/data_service/internal/domain"
+)
+
+type FuturesWebsocket struct {
+	conn          *websocket.Conn
+	activeStreams map[string]chan domain.Message
+	mu            sync.Mutex
+}
+
+func NewFuturesWebsocket() *FuturesWebsocket {
+	return &FuturesWebsocket{
+		activeStreams: make(map[string]chan domain.Message),
+	}
+}
+
+func (b *FuturesWebsocket) Start() error {
+	c, _, err := websocket.DefaultDialer.Dial("wss://fstream.binance.com/stream", nil)
+	if err != nil {
+		return fmt.Errorf("connect failed: %w", err)
+	}
+	b.conn = c
+	go b.readLoop()
+	return nil
+}
+
+func (b *FuturesWebsocket) Stop() {
+	if b.conn != nil {
+		err := b.conn.Close()
+		if err != nil {
+			panic(fmt.Errorf("failed to close websocket connection: %w", err))
+		}
+	}
+}
+
+func (b *FuturesWebsocket) RequestStream(subject string, ch chan domain.Message) error {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if _, ok := b.activeStreams[subject]; ok {
+		return nil
+	}
+
+	msg := map[string]interface{}{
+		"method": "SUBSCRIBE",
+		"params": []string{subject},
+		"id":     len(b.activeStreams) + 1,
+	}
+	if err := b.conn.WriteJSON(msg); err != nil {
+		return fmt.Errorf("subscribe failed: %w", err)
+	}
+
+	b.activeStreams[subject] = ch
+	fmt.Println("Subscribed to stream:", subject)
+	return nil
+}
+
+func (b *FuturesWebsocket) CancelStream(subject string) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if _, ok := b.activeStreams[subject]; !ok {
+		return
+	}
+
+	msg := map[string]interface{}{
+		"method": "UNSUBSCRIBE",
+		"params": []string{subject},
+		"id":     len(b.activeStreams) + 1000,
+	}
+	_ = b.conn.WriteJSON(msg)
+
+	delete(b.activeStreams, subject)
+}
+
+func (b *FuturesWebsocket) GetActiveStreams() []string {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	var streams []string
+	for k := range b.activeStreams {
+		streams = append(streams, k)
+	}
+	return streams
+}
+
+func (b *FuturesWebsocket) IsStreamActive(subject string) bool {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	_, ok := b.activeStreams[subject]
+	return ok
+}
+
+func (b *FuturesWebsocket) Fetch(subject string) (domain.Message, error) {
+	return domain.Message{}, fmt.Errorf("not supported: websocket provider does not implement fetch")
+}
+
+func (b *FuturesWebsocket) IsValidSubject(subject string, isFetch bool) bool {
+	if isFetch {
+		return false
+	}
+	return len(subject) > 0 // Extend with regex or lookup if needed
+}
+
+func (b *FuturesWebsocket) readLoop() {
+	for {
+		_, msgBytes, err := b.conn.ReadMessage()
+		if err != nil {
+			if websocket.IsCloseError(err, websocket.CloseNormalClosure) {
+				return
+			}
+			fmt.Printf("read error: %v\n", err)
+			continue
+		}
+
+		var container struct {
+			Stream string          `json:"stream"`
+			Data   json.RawMessage `json:"data"`
+		}
+		if err := json.Unmarshal(msgBytes, &container); err != nil {
+			continue
+		}
+
+		b.mu.Lock()
+		ch, ok := b.activeStreams[container.Stream]
+		b.mu.Unlock()
+		if !ok {
+			continue
+		}
+
+		msg := domain.Message{
+			Identifier: domain.Identifier{
+				Provider: "binance_futures_websocket",
+				Subject:  container.Stream,
+			},
+			Payload: container.Data,
+		}
+
+		select {
+		case ch <- msg:
+		default:
+			fmt.Printf("channel for %s is full, dropping message\n", container.Stream)
+		}
+	}
+}

services/data_service/internal/provider/provider.go

@@ -0,0 +1,19 @@
+package provider
+
+import (
+	"gitlab.michelsen.id/phillmichelsen/tessera/services/data_service/internal/domain"
+)
+
+type Provider interface {
+	Start() error
+	Stop()
+
+	RequestStream(subject string, channel chan domain.Message) error
+	CancelStream(subject string)
+	GetActiveStreams() []string
+	IsStreamActive(subject string) bool
+
+	Fetch(subject string) (domain.Message, error)
+
+	IsValidSubject(subject string, isFetch bool) bool
+}