feat(live): add team radio ticker

Subscribe to TeamRadio on the F1 live feed, parse defensive capture snapshots and patches, and relay capped captures through live snapshots with the SessionInfo static path. Add the frontend CDN URL helper and ticker using one shared audio element.

internal/live/state.go

@@ -8,6 +8,8 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"log"
+	"sort"
 	"strings"
 	"time"
 )
@@ -23,6 +25,7 @@ type State struct {
 	RCMessages         []LiveRCMessage
 	Weather            LiveWeatherData
 	Session            LiveSessionMeta
+	TeamRadio          []LiveRadioCapture
 	TrackStatus        string
 	CurrentLap         int
 	TotalLaps          int
@@ -34,6 +37,7 @@ type State struct {
 }
 
 const signalRRecordSeparator = byte(0x1e)
+const maxTeamRadioCaptures = 20
 
 // NewState returns an empty live timing accumulator.
 func NewState() *State {
@@ -71,6 +75,8 @@ func (s *State) Snapshot() LiveStreamData {
 	}
 	cpyRC := make([]LiveRCMessage, len(s.RCMessages))
 	copy(cpyRC, s.RCMessages)
+	cpyRadio := make([]LiveRadioCapture, len(s.TeamRadio))
+	copy(cpyRadio, s.TeamRadio)
 	cpyStints := make(map[string][]LiveStintData, len(s.Stints))
 	for k, v := range s.Stints {
 		st := make([]LiveStintData, len(v))
@@ -86,6 +92,7 @@ func (s *State) Snapshot() LiveStreamData {
 		RCMessages:         cpyRC,
 		Weather:            s.Weather,
 		Session:            s.Session,
+		TeamRadio:          cpyRadio,
 		TrackStatus:        s.TrackStatus,
 		CurrentLap:         s.CurrentLap,
 		TotalLaps:          s.TotalLaps,
@@ -335,6 +342,7 @@ func (s *State) ProcessTopic(topic string, data json.RawMessage) bool {
 			} `json:"Meeting"`
 			Name string `json:"Name"`
 			Type string `json:"Type"`
+			Path string `json:"Path"`
 		}
 		if json.Unmarshal(data, &si) == nil {
 			if si.Meeting.Name != "" {
@@ -349,8 +357,13 @@ func (s *State) ProcessTopic(topic string, data json.RawMessage) bool {
 			if si.Type != "" {
 				s.Session.SessionType = si.Type
 			}
+			if si.Path != "" {
+				s.Session.Path = si.Path
+			}
 			updated = true
 		}
+	case "TeamRadio":
+		updated = s.updateTeamRadio(data)
 	case "CurrentTyres":
 		var ct map[string]json.RawMessage
 		if json.Unmarshal(data, &ct) == nil {
@@ -483,6 +496,62 @@ func readCompressed(r io.ReadCloser, err error) ([]byte, bool) {
 	return out, err == nil
 }
 
+func (s *State) updateTeamRadio(data json.RawMessage) bool {
+	var payload struct {
+		Captures json.RawMessage `json:"Captures"`
+	}
+	if err := json.Unmarshal(data, &payload); err != nil {
+		log.Printf("live: skipping malformed TeamRadio payload: %v", err)
+		return false
+	}
+	if len(payload.Captures) == 0 || string(payload.Captures) == "null" {
+		log.Printf("live: skipping TeamRadio payload without Captures")
+		return false
+	}
+
+	captures := indexedRawValues(payload.Captures)
+	if len(captures) == 0 {
+		log.Printf("live: skipping TeamRadio payload with unexpected Captures shape")
+		return false
+	}
+
+	updated := false
+	for _, captureRaw := range captures {
+		var capture LiveRadioCapture
+		if err := json.Unmarshal(captureRaw.Raw, &capture); err != nil {
+			log.Printf("live: skipping malformed TeamRadio capture: %v", err)
+			continue
+		}
+		if capture.Utc == "" || capture.RacingNumber == "" || capture.Path == "" {
+			log.Printf("live: skipping incomplete TeamRadio capture: utc=%q racing_number=%q path=%q", capture.Utc, capture.RacingNumber, capture.Path)
+			continue
+		}
+		if s.hasTeamRadioCapture(capture) {
+			continue
+		}
+		s.TeamRadio = append(s.TeamRadio, capture)
+		updated = true
+	}
+	if updated {
+		sort.SliceStable(s.TeamRadio, func(i, j int) bool {
+			return s.TeamRadio[i].Utc < s.TeamRadio[j].Utc
+		})
+		if len(s.TeamRadio) > maxTeamRadioCaptures {
+			s.TeamRadio = append([]LiveRadioCapture(nil), s.TeamRadio[len(s.TeamRadio)-maxTeamRadioCaptures:]...)
+		}
+	}
+	return updated
+}
+
+func (s *State) hasTeamRadioCapture(capture LiveRadioCapture) bool {
+	for _, existing := range s.TeamRadio {
+		if existing.Utc == capture.Utc && existing.RacingNumber == capture.RacingNumber && existing.Path == capture.Path {
+			return true
+		}
+	}
+	return false
+}
+
 func (s *State) updatePositions(data json.RawMessage) bool {
 	var payload struct {
 		Position json.RawMessage `json:"Position"`
@@ -799,6 +868,9 @@ func indexedRawValues(raw json.RawMessage) []indexedRaw {
 			fmt.Sscanf(k, "%d", &i)
 			values = append(values, indexedRaw{Index: i, Raw: v})
 		}
+		sort.Slice(values, func(i, j int) bool {
+			return values[i].Index < values[j].Index
+		})
 		return values
 	}