Refine telemetry-driven HUD and fitness feedback

miniprogram/game/telemetry/telemetryConfig.ts

@@ -0,0 +1,141 @@
+export interface TelemetryConfig {
+  heartRateAge: number
+  restingHeartRateBpm: number
+  userWeightKg: number
+}
+
+export type HeartRateTone = 'blue' | 'purple' | 'green' | 'yellow' | 'orange' | 'red'
+
+type HeartRateToneMeta = {
+  label: string
+  heartRateRangeText: string
+  speedRangeText: string
+}
+
+const HEART_RATE_TONE_META: Record<HeartRateTone, HeartRateToneMeta> = {
+  blue: {
+    label: '激活放松',
+    heartRateRangeText: '<=39%',
+    speedRangeText: '<3.2 km/h',
+  },
+  purple: {
+    label: '动态热身',
+    heartRateRangeText: '40~54%',
+    speedRangeText: '3.2~4.0 km/h',
+  },
+  green: {
+    label: '脂肪燃烧',
+    heartRateRangeText: '55~69%',
+    speedRangeText: '4.1~5.5 km/h',
+  },
+  yellow: {
+    label: '糖分消耗',
+    heartRateRangeText: '70~79%',
+    speedRangeText: '5.6~7.1 km/h',
+  },
+  orange: {
+    label: '心肺训练',
+    heartRateRangeText: '80~89%',
+    speedRangeText: '7.2~8.8 km/h',
+  },
+  red: {
+    label: '峰值锻炼',
+    heartRateRangeText: '>=90%',
+    speedRangeText: '>=8.9 km/h',
+  },
+}
+
+export function clampTelemetryAge(age: number): number {
+  if (!Number.isFinite(age)) {
+    return 30
+  }
+
+  return Math.max(10, Math.min(85, Math.round(age)))
+}
+
+export function estimateRestingHeartRateBpm(age: number): number {
+  const safeAge = clampTelemetryAge(age)
+  const estimated = 68 + (safeAge - 30) * 0.12
+  return Math.max(56, Math.min(76, Math.round(estimated)))
+}
+
+export function normalizeRestingHeartRateBpm(restingHeartRateBpm: number, age: number): number {
+  if (!Number.isFinite(restingHeartRateBpm) || restingHeartRateBpm <= 0) {
+    return estimateRestingHeartRateBpm(age)
+  }
+
+  return Math.max(40, Math.min(95, Math.round(restingHeartRateBpm)))
+}
+
+export function normalizeUserWeightKg(userWeightKg: number): number {
+  if (!Number.isFinite(userWeightKg) || userWeightKg <= 0) {
+    return 65
+  }
+
+  return Math.max(35, Math.min(180, Math.round(userWeightKg)))
+}
+
+export const DEFAULT_TELEMETRY_CONFIG: TelemetryConfig = {
+  heartRateAge: 30,
+  restingHeartRateBpm: estimateRestingHeartRateBpm(30),
+  userWeightKg: 65,
+}
+
+export function mergeTelemetryConfig(overrides?: Partial<TelemetryConfig> | null): TelemetryConfig {
+  const heartRateAge = overrides && overrides.heartRateAge !== undefined
+    ? clampTelemetryAge(overrides.heartRateAge)
+    : DEFAULT_TELEMETRY_CONFIG.heartRateAge
+
+  const restingHeartRateBpm = overrides && overrides.restingHeartRateBpm !== undefined
+    ? normalizeRestingHeartRateBpm(overrides.restingHeartRateBpm, heartRateAge)
+    : estimateRestingHeartRateBpm(heartRateAge)
+  const userWeightKg = overrides && overrides.userWeightKg !== undefined
+    ? normalizeUserWeightKg(overrides.userWeightKg)
+    : DEFAULT_TELEMETRY_CONFIG.userWeightKg
+
+  return {
+    heartRateAge,
+    restingHeartRateBpm,
+    userWeightKg,
+  }
+}
+
+export function getHeartRateToneSampleBpm(tone: HeartRateTone, config: TelemetryConfig): number {
+  const maxHeartRate = Math.max(120, 220 - config.heartRateAge)
+  const restingHeartRate = Math.min(maxHeartRate - 15, config.restingHeartRateBpm)
+  const reserve = Math.max(20, maxHeartRate - restingHeartRate)
+
+  if (tone === 'blue') {
+    return Math.round(restingHeartRate + reserve * 0.3)
+  }
+
+  if (tone === 'purple') {
+    return Math.round(restingHeartRate + reserve * 0.47)
+  }
+
+  if (tone === 'green') {
+    return Math.round(restingHeartRate + reserve * 0.62)
+  }
+
+  if (tone === 'yellow') {
+    return Math.round(restingHeartRate + reserve * 0.745)
+  }
+
+  if (tone === 'orange') {
+    return Math.round(restingHeartRate + reserve * 0.845)
+  }
+
+  return Math.round(restingHeartRate + reserve * 0.93)
+}
+
+export function getHeartRateToneLabel(tone: HeartRateTone): string {
+  return HEART_RATE_TONE_META[tone].label
+}
+
+export function getHeartRateToneRangeText(tone: HeartRateTone): string {
+  return HEART_RATE_TONE_META[tone].heartRateRangeText
+}
+
+export function getSpeedToneRangeText(tone: HeartRateTone): string {
+  return HEART_RATE_TONE_META[tone].speedRangeText
+}

miniprogram/game/telemetry/telemetryEvent.ts

@@ -0,0 +1,9 @@
+import { type LonLatPoint } from '../../utils/projection'
+import { type GameSessionStatus } from '../core/gameSessionState'
+
+export type TelemetryEvent =
+  | { type: 'reset' }
+  | { type: 'session_state_updated'; at: number; status: GameSessionStatus; startedAt: number | null; endedAt: number | null }
+  | { type: 'target_updated'; controlId: string | null; point: LonLatPoint | null }
+  | { type: 'gps_updated'; at: number; lon: number; lat: number; accuracyMeters: number | null }
+  | { type: 'heart_rate_updated'; at: number; bpm: number | null }

miniprogram/game/telemetry/telemetryPresentation.ts

@@ -0,0 +1,37 @@
+export interface TelemetryPresentation {
+  timerText: string
+  mileageText: string
+  distanceToTargetValueText: string
+  distanceToTargetUnitText: string
+  speedText: string
+  heartRateTone: 'blue' | 'purple' | 'green' | 'yellow' | 'orange' | 'red'
+  heartRateZoneNameText: string
+  heartRateZoneRangeText: string
+  heartRateValueText: string
+  heartRateUnitText: string
+  caloriesValueText: string
+  caloriesUnitText: string
+  averageSpeedValueText: string
+  averageSpeedUnitText: string
+  accuracyValueText: string
+  accuracyUnitText: string
+}
+
+export const EMPTY_TELEMETRY_PRESENTATION: TelemetryPresentation = {
+  timerText: '00:00:00',
+  mileageText: '0m',
+  distanceToTargetValueText: '--',
+  distanceToTargetUnitText: '',
+  speedText: '0',
+  heartRateTone: 'blue',
+  heartRateZoneNameText: '激活放松',
+  heartRateZoneRangeText: '<=39%',
+  heartRateValueText: '--',
+  heartRateUnitText: '',
+  caloriesValueText: '0',
+  caloriesUnitText: 'kcal',
+  averageSpeedValueText: '0',
+  averageSpeedUnitText: 'km/h',
+  accuracyValueText: '--',
+  accuracyUnitText: '',
+}

miniprogram/game/telemetry/telemetryRuntime.ts

@@ -0,0 +1,473 @@
+import { type GameDefinition } from '../core/gameDefinition'
+import {
+  DEFAULT_TELEMETRY_CONFIG,
+  getHeartRateToneLabel,
+  getHeartRateToneRangeText,
+  getSpeedToneRangeText,
+  mergeTelemetryConfig,
+  type HeartRateTone,
+  type TelemetryConfig,
+} from './telemetryConfig'
+import { type GameSessionState } from '../core/gameSessionState'
+import { type TelemetryEvent } from './telemetryEvent'
+import { EMPTY_TELEMETRY_PRESENTATION, type TelemetryPresentation } from './telemetryPresentation'
+import { EMPTY_TELEMETRY_STATE, type TelemetryState } from './telemetryState'
+const SPEED_SMOOTHING_ALPHA = 0.35
+
+function getApproxDistanceMeters(
+  a: { lon: number; lat: number },
+  b: { lon: number; lat: number },
+): number {
+  const avgLatRad = ((a.lat + b.lat) / 2) * Math.PI / 180
+  const dx = (b.lon - a.lon) * 111320 * Math.cos(avgLatRad)
+  const dy = (b.lat - a.lat) * 110540
+  return Math.sqrt(dx * dx + dy * dy)
+}
+
+function formatElapsedTimerText(totalMs: number): string {
+  const safeMs = Math.max(0, totalMs)
+  const totalSeconds = Math.floor(safeMs / 1000)
+  const hours = Math.floor(totalSeconds / 3600)
+  const minutes = Math.floor((totalSeconds % 3600) / 60)
+  const seconds = totalSeconds % 60
+  return `${String(hours).padStart(2, '0')}:${String(minutes).padStart(2, '0')}:${String(seconds).padStart(2, '0')}`
+}
+
+function formatDistanceText(distanceMeters: number): string {
+  if (distanceMeters >= 1000) {
+    return `${(distanceMeters / 1000).toFixed(distanceMeters >= 10000 ? 0 : 1)}km`
+  }
+
+  return `${Math.round(distanceMeters)}m`
+}
+
+function formatTargetDistance(distanceMeters: number | null): { valueText: string; unitText: string } {
+  if (distanceMeters === null) {
+    return {
+      valueText: '--',
+      unitText: '',
+    }
+  }
+
+  return distanceMeters >= 1000
+    ? {
+      valueText: `${(distanceMeters / 1000).toFixed(distanceMeters >= 10000 ? 0 : 1)}`,
+      unitText: 'km',
+    }
+    : {
+      valueText: String(Math.round(distanceMeters)),
+      unitText: 'm',
+    }
+}
+
+function formatSpeedText(speedKmh: number | null): string {
+  if (speedKmh === null || !Number.isFinite(speedKmh) || speedKmh < 0.05) {
+    return '0'
+  }
+
+  return speedKmh >= 10 ? speedKmh.toFixed(1) : speedKmh.toFixed(2)
+}
+
+function smoothSpeedKmh(previousSpeedKmh: number | null, nextSpeedKmh: number): number {
+  if (previousSpeedKmh === null || !Number.isFinite(previousSpeedKmh)) {
+    return nextSpeedKmh
+  }
+
+  return previousSpeedKmh + (nextSpeedKmh - previousSpeedKmh) * SPEED_SMOOTHING_ALPHA
+}
+
+function getHeartRateTone(
+  heartRateBpm: number | null,
+  telemetryConfig: TelemetryConfig,
+): HeartRateTone {
+  if (heartRateBpm === null || !Number.isFinite(heartRateBpm) || heartRateBpm <= 0) {
+    return 'blue'
+  }
+
+  const maxHeartRate = Math.max(120, 220 - telemetryConfig.heartRateAge)
+  const restingHeartRate = Math.min(maxHeartRate - 15, telemetryConfig.restingHeartRateBpm)
+  const reserve = Math.max(20, maxHeartRate - restingHeartRate)
+  const blueLimit = restingHeartRate + reserve * 0.39
+  const purpleLimit = restingHeartRate + reserve * 0.54
+  const greenLimit = restingHeartRate + reserve * 0.69
+  const yellowLimit = restingHeartRate + reserve * 0.79
+  const orangeLimit = restingHeartRate + reserve * 0.89
+
+  if (heartRateBpm <= blueLimit) {
+    return 'blue'
+  }
+
+  if (heartRateBpm <= purpleLimit) {
+    return 'purple'
+  }
+
+  if (heartRateBpm <= greenLimit) {
+    return 'green'
+  }
+
+  if (heartRateBpm <= yellowLimit) {
+    return 'yellow'
+  }
+
+  if (heartRateBpm <= orangeLimit) {
+    return 'orange'
+  }
+
+  return 'red'
+}
+
+function getSpeedFallbackTone(speedKmh: number | null): HeartRateTone {
+  if (speedKmh === null || !Number.isFinite(speedKmh) || speedKmh < 3.2) {
+    return 'blue'
+  }
+
+  if (speedKmh <= 4.0) {
+    return 'purple'
+  }
+
+  if (speedKmh <= 5.5) {
+    return 'green'
+  }
+
+  if (speedKmh <= 7.1) {
+    return 'yellow'
+  }
+
+  if (speedKmh <= 8.8) {
+    return 'orange'
+  }
+
+  return 'red'
+}
+
+function formatHeartRateMetric(heartRateBpm: number | null): { valueText: string; unitText: string } {
+  if (heartRateBpm === null || !Number.isFinite(heartRateBpm) || heartRateBpm <= 0) {
+    return {
+      valueText: '--',
+      unitText: '',
+    }
+  }
+
+  return {
+    valueText: String(Math.round(heartRateBpm)),
+    unitText: 'bpm',
+  }
+}
+
+function formatCaloriesMetric(caloriesKcal: number | null): { valueText: string; unitText: string } {
+  if (caloriesKcal === null || !Number.isFinite(caloriesKcal) || caloriesKcal < 0) {
+    return {
+      valueText: '0',
+      unitText: 'kcal',
+    }
+  }
+
+  return {
+    valueText: String(Math.round(caloriesKcal)),
+    unitText: 'kcal',
+  }
+}
+
+function formatAccuracyMetric(accuracyMeters: number | null): { valueText: string; unitText: string } {
+  if (accuracyMeters === null || !Number.isFinite(accuracyMeters) || accuracyMeters < 0) {
+    return {
+      valueText: '--',
+      unitText: '',
+    }
+  }
+
+  return {
+    valueText: String(Math.round(accuracyMeters)),
+    unitText: 'm',
+  }
+}
+
+function estimateCaloriesKcal(
+  elapsedMs: number,
+  heartRateBpm: number,
+  telemetryConfig: TelemetryConfig,
+): number {
+  if (elapsedMs <= 0) {
+    return 0
+  }
+
+  if (!Number.isFinite(heartRateBpm) || heartRateBpm <= 0) {
+    return 0
+  }
+
+  const maxHeartRate = Math.max(120, 220 - telemetryConfig.heartRateAge)
+  const restingHeartRate = Math.min(maxHeartRate - 15, telemetryConfig.restingHeartRateBpm)
+  const reserve = Math.max(20, maxHeartRate - restingHeartRate)
+  const intensity = Math.max(0, Math.min(1, (heartRateBpm - restingHeartRate) / reserve))
+  const met = 2 + intensity * 10
+
+  return met * telemetryConfig.userWeightKg * (elapsedMs / 3600000)
+}
+
+function estimateCaloriesFromSpeedKcal(
+  elapsedMs: number,
+  speedKmh: number | null,
+  telemetryConfig: TelemetryConfig,
+): number {
+  if (elapsedMs <= 0 || speedKmh === null || !Number.isFinite(speedKmh) || speedKmh < 0.5) {
+    return 0
+  }
+
+  let met = 2
+  if (speedKmh >= 8.9) {
+    met = 9.8
+  } else if (speedKmh >= 7.2) {
+    met = 7.8
+  } else if (speedKmh >= 5.6) {
+    met = 6
+  } else if (speedKmh >= 4.1) {
+    met = 4.3
+  } else if (speedKmh >= 3.2) {
+    met = 3.0
+  }
+
+  return (met * 3.5 * telemetryConfig.userWeightKg / 200) * (elapsedMs / 60000)
+}
+
+function hasHeartRateSignal(state: TelemetryState): boolean {
+  return state.heartRateBpm !== null
+    && Number.isFinite(state.heartRateBpm)
+    && state.heartRateBpm > 0
+}
+
+function hasSpeedSignal(state: TelemetryState): boolean {
+  return state.currentSpeedKmh !== null
+    && Number.isFinite(state.currentSpeedKmh)
+    && state.currentSpeedKmh >= 0.5
+}
+
+function shouldTrackCalories(state: TelemetryState): boolean {
+  return state.sessionStatus === 'running'
+    && state.sessionEndedAt === null
+    && (hasHeartRateSignal(state) || hasSpeedSignal(state))
+}
+
+export class TelemetryRuntime {
+  state: TelemetryState
+  config: TelemetryConfig
+
+  constructor() {
+    this.state = { ...EMPTY_TELEMETRY_STATE }
+    this.config = { ...DEFAULT_TELEMETRY_CONFIG }
+  }
+
+  reset(): void {
+    this.state = { ...EMPTY_TELEMETRY_STATE }
+  }
+
+  configure(config?: Partial<TelemetryConfig> | null): void {
+    this.config = mergeTelemetryConfig(config)
+  }
+
+  loadDefinition(_definition: GameDefinition): void {
+    this.reset()
+  }
+
+  syncGameState(definition: GameDefinition | null, state: GameSessionState | null): void {
+    if (!definition || !state) {
+      this.dispatch({ type: 'reset' })
+      return
+    }
+
+    const targetControl = state.currentTargetControlId
+      ? definition.controls.find((control) => control.id === state.currentTargetControlId) || null
+      : null
+
+    this.dispatch({
+      type: 'session_state_updated',
+      at: Date.now(),
+      status: state.status,
+      startedAt: state.startedAt,
+      endedAt: state.endedAt,
+    })
+    this.dispatch({
+      type: 'target_updated',
+      controlId: targetControl ? targetControl.id : null,
+      point: targetControl ? targetControl.point : null,
+    })
+  }
+
+  dispatch(event: TelemetryEvent): void {
+    if (event.type === 'reset') {
+      this.reset()
+      return
+    }
+
+    if (event.type === 'session_state_updated') {
+      this.syncCalorieAccumulation(event.at)
+      this.state = {
+        ...this.state,
+        sessionStatus: event.status,
+        sessionStartedAt: event.startedAt,
+        sessionEndedAt: event.endedAt,
+        elapsedMs: event.startedAt === null ? 0 : Math.max(0, (event.endedAt || Date.now()) - event.startedAt),
+      }
+      this.alignCalorieTracking(event.at)
+      this.recomputeDerivedState()
+      return
+    }
+
+    if (event.type === 'target_updated') {
+      this.state = {
+        ...this.state,
+        targetControlId: event.controlId,
+        targetPoint: event.point,
+      }
+      this.recomputeDerivedState()
+      return
+    }
+
+    if (event.type === 'gps_updated') {
+      this.syncCalorieAccumulation(event.at)
+      const nextPoint = { lon: event.lon, lat: event.lat }
+      const previousPoint = this.state.lastGpsPoint
+      const previousAt = this.state.lastGpsAt
+      let nextDistanceMeters = this.state.distanceMeters
+      let nextSpeedKmh = this.state.currentSpeedKmh
+
+      if (previousPoint && previousAt !== null && event.at > previousAt) {
+        const segmentMeters = getApproxDistanceMeters(previousPoint, nextPoint)
+        nextDistanceMeters += segmentMeters
+        const rawSpeedKmh = segmentMeters <= 0
+          ? 0
+          : (segmentMeters / ((event.at - previousAt) / 1000)) * 3.6
+        nextSpeedKmh = smoothSpeedKmh(this.state.currentSpeedKmh, rawSpeedKmh)
+      }
+
+      this.state = {
+        ...this.state,
+        distanceMeters: nextDistanceMeters,
+        currentSpeedKmh: nextSpeedKmh,
+        lastGpsPoint: nextPoint,
+        lastGpsAt: event.at,
+        lastGpsAccuracyMeters: event.accuracyMeters,
+      }
+      this.alignCalorieTracking(event.at)
+      this.recomputeDerivedState()
+      return
+    }
+
+    if (event.type === 'heart_rate_updated') {
+      this.syncCalorieAccumulation(event.at)
+      this.state = {
+        ...this.state,
+        heartRateBpm: event.bpm,
+      }
+      this.alignCalorieTracking(event.at)
+      this.recomputeDerivedState()
+    }
+  }
+
+  recomputeDerivedState(now = Date.now()): void {
+    const elapsedMs = this.state.sessionStartedAt === null
+      ? 0
+      : Math.max(0, (this.state.sessionEndedAt || now) - this.state.sessionStartedAt)
+    const distanceToTargetMeters = this.state.lastGpsPoint && this.state.targetPoint
+      ? getApproxDistanceMeters(this.state.lastGpsPoint, this.state.targetPoint)
+      : null
+    const averageSpeedKmh = elapsedMs > 0
+      ? (this.state.distanceMeters / (elapsedMs / 1000)) * 3.6
+      : null
+
+    this.state = {
+      ...this.state,
+      elapsedMs,
+      distanceToTargetMeters,
+      averageSpeedKmh,
+    }
+  }
+
+  getPresentation(now = Date.now()): TelemetryPresentation {
+    this.syncCalorieAccumulation(now)
+    this.alignCalorieTracking(now)
+    this.recomputeDerivedState(now)
+    const targetDistance = formatTargetDistance(this.state.distanceToTargetMeters)
+    const hasHeartRate = hasHeartRateSignal(this.state)
+    const heartRateTone = hasHeartRate
+      ? getHeartRateTone(this.state.heartRateBpm, this.config)
+      : getSpeedFallbackTone(this.state.currentSpeedKmh)
+    const heartRate = formatHeartRateMetric(this.state.heartRateBpm)
+    const calories = formatCaloriesMetric(this.state.caloriesKcal)
+    const accuracy = formatAccuracyMetric(this.state.lastGpsAccuracyMeters)
+
+    return {
+      ...EMPTY_TELEMETRY_PRESENTATION,
+      timerText: formatElapsedTimerText(this.state.elapsedMs),
+      mileageText: formatDistanceText(this.state.distanceMeters),
+      distanceToTargetValueText: targetDistance.valueText,
+      distanceToTargetUnitText: targetDistance.unitText,
+      speedText: formatSpeedText(this.state.currentSpeedKmh),
+      heartRateTone,
+      heartRateZoneNameText: hasHeartRate || hasSpeedSignal(this.state) ? getHeartRateToneLabel(heartRateTone) : '--',
+      heartRateZoneRangeText: hasHeartRate
+        ? getHeartRateToneRangeText(heartRateTone)
+        : hasSpeedSignal(this.state)
+          ? getSpeedToneRangeText(heartRateTone)
+          : '',
+      heartRateValueText: heartRate.valueText,
+      heartRateUnitText: heartRate.unitText,
+      caloriesValueText: calories.valueText,
+      caloriesUnitText: calories.unitText,
+      averageSpeedValueText: formatSpeedText(this.state.averageSpeedKmh),
+      averageSpeedUnitText: 'km/h',
+      accuracyValueText: accuracy.valueText,
+      accuracyUnitText: accuracy.unitText,
+    }
+  }
+
+  private syncCalorieAccumulation(now: number): void {
+    if (!shouldTrackCalories(this.state)) {
+      return
+    }
+
+    if (this.state.calorieTrackingAt === null) {
+      this.state = {
+        ...this.state,
+        calorieTrackingAt: now,
+        caloriesKcal: this.state.caloriesKcal === null ? 0 : this.state.caloriesKcal,
+      }
+      return
+    }
+
+    if (now <= this.state.calorieTrackingAt) {
+      return
+    }
+
+    const deltaMs = now - this.state.calorieTrackingAt
+    const calorieDelta = hasHeartRateSignal(this.state)
+      ? estimateCaloriesKcal(deltaMs, this.state.heartRateBpm as number, this.config)
+      : estimateCaloriesFromSpeedKcal(deltaMs, this.state.currentSpeedKmh, this.config)
+
+    this.state = {
+      ...this.state,
+      calorieTrackingAt: now,
+      caloriesKcal: (this.state.caloriesKcal === null ? 0 : this.state.caloriesKcal) + calorieDelta,
+    }
+  }
+
+  private alignCalorieTracking(now: number): void {
+    if (shouldTrackCalories(this.state)) {
+      if (this.state.calorieTrackingAt === null) {
+        this.state = {
+          ...this.state,
+          calorieTrackingAt: now,
+          caloriesKcal: this.state.caloriesKcal === null ? 0 : this.state.caloriesKcal,
+        }
+      }
+      return
+    }
+
+    if (this.state.calorieTrackingAt !== null) {
+      this.state = {
+        ...this.state,
+        calorieTrackingAt: null,
+        caloriesKcal: this.state.caloriesKcal === null ? 0 : this.state.caloriesKcal,
+      }
+    }
+  }
+}

miniprogram/game/telemetry/telemetryState.ts

@@ -0,0 +1,40 @@
+import { type LonLatPoint } from '../../utils/projection'
+import { type GameSessionStatus } from '../core/gameSessionState'
+
+export interface TelemetryState {
+  sessionStatus: GameSessionStatus
+  sessionStartedAt: number | null
+  sessionEndedAt: number | null
+  elapsedMs: number
+  distanceMeters: number
+  currentSpeedKmh: number | null
+  averageSpeedKmh: number | null
+  distanceToTargetMeters: number | null
+  targetControlId: string | null
+  targetPoint: LonLatPoint | null
+  lastGpsPoint: LonLatPoint | null
+  lastGpsAt: number | null
+  lastGpsAccuracyMeters: number | null
+  heartRateBpm: number | null
+  caloriesKcal: number | null
+  calorieTrackingAt: number | null
+}
+
+export const EMPTY_TELEMETRY_STATE: TelemetryState = {
+  sessionStatus: 'idle',
+  sessionStartedAt: null,
+  sessionEndedAt: null,
+  elapsedMs: 0,
+  distanceMeters: 0,
+  currentSpeedKmh: null,
+  averageSpeedKmh: null,
+  distanceToTargetMeters: null,
+  targetControlId: null,
+  targetPoint: null,
+  lastGpsPoint: null,
+  lastGpsAt: null,
+  lastGpsAccuracyMeters: null,
+  heartRateBpm: null,
+  caloriesKcal: null,
+  calorieTrackingAt: null,
+}