Add local-first refactor foundation

internal/live/signalr.go

@@ -0,0 +1,82 @@
+package live
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"net/http"
+	"net/url"
+
+	"github.com/gorilla/websocket"
+)
+
+// ConnectToF1LiveTiming negotiates with the official F1 SignalR hub, subscribes
+// to timing topics, and sends defensive snapshots on dataChan until the
+// connection closes.
+func ConnectToF1LiveTiming(dataChan chan LiveStreamData) error {
+	hubName := `[{"name":"Streaming"}]`
+	negotiateURL := fmt.Sprintf("https://livetiming.formula1.com/signalr/negotiate?clientProtocol=1.5&connectionData=%s", url.QueryEscape(hubName))
+
+	req, err := http.NewRequest("GET", negotiateURL, nil)
+	if err != nil {
+		return err
+	}
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return err
+	}
+
+	cookies := resp.Cookies()
+	defer resp.Body.Close()
+
+	var neg struct {
+		ConnectionToken string `json:"ConnectionToken"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&neg); err != nil {
+		return err
+	}
+
+	wsURL := fmt.Sprintf("wss://livetiming.formula1.com/signalr/connect?clientProtocol=1.5&transport=webSockets&connectionToken=%s&connectionData=%s",
+		url.QueryEscape(neg.ConnectionToken),
+		url.QueryEscape(hubName),
+	)
+
+	header := http.Header{}
+	for _, cookie := range cookies {
+		header.Add("Cookie", cookie.String())
+	}
+	header.Add("User-Agent", "BestHTTP")
+
+	c, _, err := websocket.DefaultDialer.Dial(wsURL, header)
+	if err != nil {
+		return err
+	}
+
+	subscribeMsg := []byte(`{"H":"Streaming","M":"Subscribe","A":[["Heartbeat","TimingData","DriverList","LapCount","ExtrapolatedClock","TrackStatus","RaceControlMessages","WeatherData","SessionInfo","CurrentTyres","TimingAppData","TimingStats"]],"I":1}`)
+	err = c.WriteMessage(websocket.TextMessage, subscribeMsg)
+	if err != nil {
+		return err
+	}
+
+	go func() {
+		defer c.Close()
+		state := NewState()
+
+		for {
+			_, message, err := c.ReadMessage()
+			if err != nil {
+				log.Println("WS Read Error:", err)
+				return
+			}
+
+			if state.ProcessMessage(message) {
+				select {
+				case dataChan <- state.Snapshot():
+				default:
+				}
+			}
+		}
+	}()
+
+	return nil
+}