import React, { useCallback, useEffect, useRef, useState } from 'react';
import { ActivityIndicator, StatusBar, StyleSheet, View } from 'react-native';
import { SafeAreaProvider, SafeAreaView } from 'react-native-safe-area-context';

import { colors } from './src/theme';
import { OnboardingScreen } from './src/features/onboarding/OnboardingScreen';
import {
  onboardingRepository,
  type OnboardingAnswers,
} from './src/features/onboarding/onboardingRepository';
import { CardiacMirrorScreen } from './src/features/cardiacMirror/CardiacMirrorScreen';
import { MyCoherenceScreen } from './src/features/coherence/MyCoherenceScreen';
import { coherenceSessionRepository } from './src/features/coherence/coherenceSessionRepository';
import {
  HapticWaveExerciseScreen,
  type HapticExerciseSummary,
} from './src/features/cardiacMirror/HapticWaveExerciseScreen';
import {
  getRegulationProtocol,
  recommendRegulationProtocol,
  type HapticRegulationProtocolKind,
} from './src/features/cardiacMirror/regulationProtocols';
import { compareRegulationMeasurements } from './src/features/cardiacMirror/regulationComparison';
import { regulationSessionRepository } from './src/features/cardiacMirror/regulationSessionRepository';
import type {
  RegulationComparison,
  RegulationSession,
} from './src/features/cardiacMirror/regulationSessionTypes';
import { usePPGCamera } from './src/features/ppg/camera/usePPGCamera';
import { evaluateHealthKitContext } from './src/features/ppg/health/healthContextEvaluator';
import { healthKitService } from './src/features/ppg/health/healthKitService';
import type { HealthKitContext } from './src/features/ppg/health/healthTypes';
import { PPG_ALGORITHM_VERSION } from './src/features/ppg/measurement/measurementConfiguration';
import { usePPGMeasurement } from './src/features/ppg/measurement/usePPGMeasurement';
import { PPGFailureScreen } from './src/features/ppg/screens/PPGFailureScreen';
import { PPGHistoryScreen } from './src/features/ppg/screens/PPGHistoryScreen';
import { PPGMeasurementScreen } from './src/features/ppg/screens/PPGMeasurementScreen';
import { PPGPreparationScreen } from './src/features/ppg/screens/PPGPreparationScreen';
import { PPGResultScreen } from './src/features/ppg/screens/PPGResultScreen';
import { calculatePotentialStress } from './src/features/ppg/stress/potentialStressCalculator';
import type { BaselineCalculationResult } from './src/features/ppg/stress/baselineTypes';
import { baselineRepository } from './src/features/ppg/storage/baselineRepository';
import { acquisitionPreferencesRepository } from './src/features/ppg/storage/acquisitionPreferencesRepository';
import { measurementRepository } from './src/features/ppg/storage/measurementRepository';
import { settingsRepository } from './src/features/ppg/storage/settingsRepository';
import type {
  DataRetentionPolicy,
  MeasurementSelfReport,
  StoredMeasurement,
} from './src/features/ppg/storage/storageTypes';
import {calculateWatchBaseline, type WatchBaselineV1} from './src/features/watch/watchBaseline';
import {watchRepository} from './src/features/watch/watchRepository';
import {watchSyncCoordinator} from './src/features/watch/watchService';
import type {
  WatchConnectionState,
  WatchMeasurementSummaryV1,
  WatchRegulationSessionV1,
  WatchSyncEnvelopeV1,
  WatchTombstoneV1,
} from './src/features/watch/watchTypes';

type AppView = 'measurement' | 'history' | 'cardiacMirror' | 'hapticExercise' | 'myCoherence';
type FinalizationState = 'idle' | 'saving' | 'failed';
type SelfReportState = 'idle' | 'saving' | 'saved' | 'failed';
type OnboardingStatus = 'loading' | 'required' | 'completed';

const EMPTY_WATCH_CONNECTION: WatchConnectionState = {
  supported: false,
  paired: false,
  watchAppInstalled: false,
  reachable: false,
  activationState: 'notActivated',
  latestEventId: null,
  latestEventAt: null,
};

function createMeasurementId(): string {
  return `ppg-${Date.now()}-${Math.random().toString(36).slice(2, 10)}`;
}

function App(): React.JSX.Element {
  return (
    <SafeAreaProvider>
      <StatusBar
        barStyle="light-content"
        translucent
        backgroundColor="transparent"
      />
      <SafeAreaView
        style={styles.safeArea}
        edges={['right', 'bottom', 'left']}>
        <HaptikaApp />
      </SafeAreaView>
    </SafeAreaProvider>
  );
}

function HaptikaApp(): React.JSX.Element {
  const cameraPermission = usePPGCamera();
  const measurement = usePPGMeasurement();
  const [onboardingStatus, setOnboardingStatus] =
    useState<OnboardingStatus>('loading');
  const [onboardingAnswers, setOnboardingAnswers] = useState<
    OnboardingAnswers | undefined
  >();
  const [appView, setAppView] = useState<AppView>('measurement');
  const [includeHealthKit, setIncludeHealthKit] = useState(false);
  const [sensitiveContact, setSensitiveContact] = useState(true);
  const [cameraPosition, setCameraPosition] = useState<'back' | 'front'>(
    'front',
  );
  const [atRestSelection, setAtRestSelection] = useState<boolean | null>(null);
  const [history, setHistory] = useState<StoredMeasurement[]>([]);
  const [watchHistory, setWatchHistory] = useState<WatchMeasurementSummaryV1[]>([]);
  const [watchRegulationSessions, setWatchRegulationSessions] = useState<WatchRegulationSessionV1[]>([]);
  const [watchBaseline, setWatchBaseline] = useState<WatchBaselineV1 | null>(null);
  const [watchConnection, setWatchConnection] = useState<WatchConnectionState>(EMPTY_WATCH_CONNECTION);
  const [saveMindAndBodyWorkouts, setSaveMindAndBodyWorkouts] = useState(true);
  const [retentionPolicy, setRetentionPolicy] =
    useState<DataRetentionPolicy>('forever');
  const [baselineProgress, setBaselineProgress] =
    useState<BaselineCalculationResult | null>(null);
  const [currentMeasurement, setCurrentMeasurement] =
    useState<StoredMeasurement | null>(null);
  const [exerciseProtocol, setExerciseProtocol] =
    useState<HapticRegulationProtocolKind>('coherence55');
  const [pendingProtocolIntent, setPendingProtocolIntent] =
    useState<HapticRegulationProtocolKind | null>(null);
  const [regulationBeforeMeasurement, setRegulationBeforeMeasurement] =
    useState<StoredMeasurement | null>(null);
  const [pendingRegulationSession, setPendingRegulationSession] =
    useState<RegulationSession | null>(null);
  const [pendingCoherenceSessionId, setPendingCoherenceSessionId] = useState<
    string | null
  >(null);
  const [regulationComparison, setRegulationComparison] =
    useState<RegulationComparison | null>(null);
  const [regulationSessions, setRegulationSessions] = useState<
    RegulationSession[]
  >([]);
  const [selfReportState, setSelfReportState] =
    useState<SelfReportState>('idle');
  const [finalizationState, setFinalizationState] =
    useState<FinalizationState>('idle');
  const finalizingResultRef = useRef(false);
  const measurementAtRestRef = useRef(false);
  const postRegulationMeasurementRef = useRef(false);

  const refreshHistory = useCallback(async (): Promise<void> => {
    setHistory(await measurementRepository.getAll());
  }, []);

  const refreshWatchData = useCallback(async (): Promise<void> => {
    const [measurements, sessions] = await Promise.all([
      watchRepository.getMeasurements(),
      watchRepository.getRegulationSessions(),
    ]);
    setWatchHistory(measurements);
    setWatchRegulationSessions(sessions);
    setWatchBaseline(calculateWatchBaseline(measurements));
    setWatchConnection(await watchSyncCoordinator.connectionState());
  }, []);

  const refreshBaseline =
    useCallback(async (): Promise<BaselineCalculationResult> => {
      const result = await baselineRepository.calculate({
        measurementHourLocal: new Date().getHours(),
        cameraPosition,
      });
      setBaselineProgress(result);
      return result;
    }, [cameraPosition]);

  const refreshRegulationSessions = useCallback(async (): Promise<void> => {
    setRegulationSessions(await regulationSessionRepository.getAll());
  }, []);

  useEffect(() => {
    onboardingRepository
      .get()
      .then(state => {
        if (state !== null) {
          setOnboardingAnswers(state);
        }
        setOnboardingStatus(
          state?.completed === true ? 'completed' : 'required',
        );
      })
      .catch(() => setOnboardingStatus('required'));
    settingsRepository.get().then(settings => {
      setIncludeHealthKit(settings.includeHealthKitContext);
      setSaveMindAndBodyWorkouts(settings.saveMindAndBodyWorkouts);
      watchSyncCoordinator.updatePreferences({
        schemaVersion: 1,
        saveMindAndBodyWorkouts: settings.saveMindAndBodyWorkouts,
        protocolCatalogVersion: '1',
        updatedAt: new Date().toISOString(),
      });
    });
    acquisitionPreferencesRepository.get().then(preferences => {
      setCameraPosition(preferences.cameraPosition);
      setSensitiveContact(preferences.sensitiveContact);
    });
    refreshHistory();
    refreshBaseline();
    refreshRegulationSessions();
    refreshWatchData();
    watchSyncCoordinator.start(refreshWatchData);
    measurementRepository.getRetentionPolicy().then(setRetentionPolicy);
    const connectionTimer = setInterval(() => {
      watchSyncCoordinator.connectionState().then(setWatchConnection).catch(() => undefined);
    }, 2_000);
    return () => {
      clearInterval(connectionTimer);
      watchSyncCoordinator.stop();
    };
  }, [refreshBaseline, refreshHistory, refreshRegulationSessions, refreshWatchData]);

  useEffect(() => {
    if (measurement.snapshot.value === 'cancelled') {
      measurement.reset();
    }
  }, [measurement, measurement.snapshot.value]);

  useEffect(() => {
    const result = measurement.snapshot.context.result;
    if (
      measurement.snapshot.value !== 'completed' ||
      result === null ||
      finalizingResultRef.current ||
      finalizationState !== 'idle' ||
      currentMeasurement !== null
    ) {
      return;
    }

    finalizingResultRef.current = true;
    setFinalizationState('saving');
    (async (): Promise<void> => {
      let healthContext: HealthKitContext | null = null;
      let contextConsistency = 0.5;
      if (
        measurement.snapshot.context.healthPermission === 'requestCompleted'
      ) {
        try {
          healthContext = await healthKitService.fetchContext(14);
          if (healthContext !== null) {
            const evaluation = evaluateHealthKitContext(healthContext);
            if (evaluation.hasUsableContext) {
              contextConsistency = evaluation.contextConfidence;
            }
          }
        } catch {
          healthContext = null;
        }
      }

      const baselineResult = await baselineRepository.calculate({
        measurementHourLocal: new Date().getHours(),
        cameraPosition,
      });
      const potentialStress = calculatePotentialStress({
        atRest: measurementAtRestRef.current,
        bpm: result.bpm.bpm,
        estimatedRmssdMs: result.prv.estimatedRmssdMs,
        prvReliable: result.prv.reliable,
        validIntervalCount: result.prv.validIntervalCount,
        signalQuality: result.quality.score,
        usableDurationSeconds: result.quality.usableDurationSeconds,
        peakConfidence: result.bpm.confidence,
        methodAgreementScore: result.quality.methodAgreementScore,
        contextConsistency,
        baseline: baselineResult.baseline,
      });
      const record: StoredMeasurement = {
        schemaVersion: 1,
        algorithmVersion: PPG_ALGORITHM_VERSION,
        id: createMeasurementId(),
        acquisition: {
          cameraPosition,
          torchUsed: cameraPosition === 'back',
        },
        measuredAt: new Date().toISOString(),
        atRest: measurementAtRestRef.current,
        baselineEligible:
          measurementAtRestRef.current && !postRegulationMeasurementRef.current,
        cameraResult: result,
        potentialStress,
        healthKitContext: healthContext,
        selfReport: null,
      };
      await measurementRepository.add(record);
      if (
        pendingRegulationSession !== null &&
        regulationBeforeMeasurement !== null
      ) {
        try {
          await regulationSessionRepository.complete(
            pendingRegulationSession.id,
            record.id,
            record.measuredAt,
          );
          if (pendingCoherenceSessionId !== null) {
            await coherenceSessionRepository.attachAfterMeasurement(
              pendingCoherenceSessionId,
              record.id,
            );
          }
          await refreshRegulationSessions();
        } catch {
          // The physiological result remains usable even if the local journey
          // link cannot be persisted. Never discard a completed measurement.
        }
        setRegulationComparison(
          compareRegulationMeasurements(regulationBeforeMeasurement, record),
        );
        setPendingRegulationSession(null);
        setPendingCoherenceSessionId(null);
      }
      await refreshBaseline();
      setCurrentMeasurement(record);
      if (pendingProtocolIntent !== null && pendingRegulationSession === null) {
        setExerciseProtocol(pendingProtocolIntent);
        setRegulationBeforeMeasurement(record);
        setPendingProtocolIntent(null);
        setAppView('hapticExercise');
      }
      setSelfReportState('idle');
      refreshHistory().catch(() => undefined);
    })()
      .catch(() => {
        setFinalizationState('failed');
      })
      .finally(() => {
        finalizingResultRef.current = false;
      });
  }, [
    currentMeasurement,
    cameraPosition,
    finalizationState,
    measurement.snapshot.context.healthPermission,
    measurement.snapshot.context.result,
    measurement.snapshot.value,
    pendingRegulationSession,
    pendingCoherenceSessionId,
    pendingProtocolIntent,
    regulationBeforeMeasurement,
    refreshHistory,
    refreshBaseline,
    refreshRegulationSessions,
  ]);

  const handleHealthKitPreference = useCallback((value: boolean): void => {
    setIncludeHealthKit(value);
    settingsRepository.setIncludeHealthKitContext(value);
  }, []);

  const handleSaveMindAndBodyPreference = useCallback((value: boolean): void => {
    setSaveMindAndBodyWorkouts(value);
    settingsRepository.setSaveMindAndBodyWorkouts(value).catch(() => undefined);
    watchSyncCoordinator.updatePreferences({
      schemaVersion: 1,
      saveMindAndBodyWorkouts: value,
      protocolCatalogVersion: '1',
      updatedAt: new Date().toISOString(),
    });
  }, []);

  const handleOnboardingHealthKit = useCallback(async (): Promise<boolean> => {
    if (!healthKitService.isAvailable()) {
      return false;
    }
    try {
      const accepted = await healthKitService.requestReadAuthorization();
      if (accepted) {
        setIncludeHealthKit(true);
        await settingsRepository.setIncludeHealthKitContext(true);
      }
      return accepted;
    } catch {
      return false;
    }
  }, []);

  const handleCameraPositionPreference = useCallback(
    (value: 'back' | 'front'): void => {
      setCameraPosition(value);
      acquisitionPreferencesRepository
        .set({ cameraPosition: value, sensitiveContact })
        .catch(() => undefined);
    },
    [sensitiveContact],
  );

  const handleSensitiveContactPreference = useCallback(
    (value: boolean): void => {
      setSensitiveContact(value);
      acquisitionPreferencesRepository
        .set({ cameraPosition, sensitiveContact: value })
        .catch(() => undefined);
    },
    [cameraPosition],
  );

  const startMeasurement = useCallback((atRestOverride?: boolean): void => {
    const selectedAtRest = atRestOverride ?? atRestSelection;
    if (selectedAtRest === null) return;
    setAppView('measurement');
    setCurrentMeasurement(null);
    setSelfReportState('idle');
    setFinalizationState('idle');
    finalizingResultRef.current = false;
    measurementAtRestRef.current = selectedAtRest;
    postRegulationMeasurementRef.current = pendingRegulationSession !== null;
    if (pendingRegulationSession === null) {
      setRegulationComparison(null);
      setRegulationBeforeMeasurement(null);
    }
    measurement.start({
      includeHealthKitContext: includeHealthKit,
      sensitiveContact,
      requestCameraPermission: cameraPermission.requestCameraPermission,
    });
  }, [
    cameraPermission.requestCameraPermission,
    atRestSelection,
    includeHealthKit,
    measurement,
    pendingRegulationSession,
    sensitiveContact,
  ]);

  const restartMeasurement = useCallback((): void => {
    measurement.reset();
    setCurrentMeasurement(null);
    setAtRestSelection(null);
    setFinalizationState('idle');
    finalizingResultRef.current = false;
    postRegulationMeasurementRef.current = false;
    setPendingRegulationSession(null);
    setPendingCoherenceSessionId(null);
    setRegulationBeforeMeasurement(null);
    setRegulationComparison(null);
  }, [measurement]);

  const retryMeasurement = useCallback((): void => {
    setCurrentMeasurement(null);
    finalizingResultRef.current = false;
    measurement.retry();
    if (measurement.snapshot.context.cameraPermission !== 'granted') {
      Promise.resolve().then(() => startMeasurement());
    }
  }, [measurement, startMeasurement]);

  const backToPreparation = useCallback((): void => {
    measurement.reset();
    setCurrentMeasurement(null);
    setAtRestSelection(null);
    setFinalizationState('idle');
    setSelfReportState('idle');
    setAppView('measurement');
    finalizingResultRef.current = false;
    postRegulationMeasurementRef.current = false;
    setPendingRegulationSession(null);
    setPendingCoherenceSessionId(null);
    setRegulationBeforeMeasurement(null);
    setRegulationComparison(null);
  }, [measurement]);

  const startRegulationJourney = useCallback(
    (protocolKind: HapticRegulationProtocolKind): void => {
      if (currentMeasurement === null) return;
      setExerciseProtocol(protocolKind);
      setRegulationBeforeMeasurement(currentMeasurement);
      setRegulationComparison(null);
      setAppView('hapticExercise');
    },
    [currentMeasurement],
  );

  const completeRegulationExercise = useCallback(
    (summary: HapticExerciseSummary, coherenceSessionId?: string): void => {
      if (regulationBeforeMeasurement === null || !summary.completed) return;
      (async (): Promise<void> => {
        const created = await regulationSessionRepository.create({
          protocolKind: summary.protocolKind,
          beforeMeasurementId: regulationBeforeMeasurement.id,
          startedAt: summary.startedAt,
        });
        if (coherenceSessionId !== undefined) {
          await coherenceSessionRepository.attachRegulationSession(
            coherenceSessionId,
            created.id,
          );
          setPendingCoherenceSessionId(coherenceSessionId);
        } else {
          setPendingCoherenceSessionId(null);
        }
        const awaitingAfter =
          await regulationSessionRepository.markAwaitingAfter(
            created.id,
            summary.completedAt,
          );
        await refreshRegulationSessions();
        setPendingRegulationSession(awaitingAfter);
        measurement.reset();
        setCurrentMeasurement(null);
        setAtRestSelection(true);
        setFinalizationState('idle');
        setSelfReportState('idle');
        finalizingResultRef.current = false;
        postRegulationMeasurementRef.current = true;
        setAppView('measurement');
      })().catch(() => {
        setPendingRegulationSession(null);
        setPendingCoherenceSessionId(null);
        setAppView('measurement');
      });
    },
    [measurement, refreshRegulationSessions, regulationBeforeMeasurement],
  );

  const saveSelfReport = useCallback(
    (report: MeasurementSelfReport): void => {
      if (currentMeasurement === null) return;
      setSelfReportState('saving');
      measurementRepository
        .attachSelfReport(currentMeasurement.id, report)
        .then(async () => {
          const baselineEligible =
            currentMeasurement.atRest &&
            regulationComparison === null &&
            ![
              report.recentExercise,
              report.recentCaffeine,
              report.recentMeal,
              report.movementDuringMeasurement,
              report.phoneUnusuallyWarm,
            ].some(value => value === true);
          setCurrentMeasurement({
            ...currentMeasurement,
            selfReport: report,
            baselineEligible,
          });
          setSelfReportState('saved');
          await Promise.all([refreshHistory(), refreshBaseline()]);
        })
        .catch(() => setSelfReportState('failed'));
    },
    [currentMeasurement, refreshBaseline, refreshHistory, regulationComparison],
  );

  const deleteMeasurement = useCallback(
    async (measurementId: string): Promise<void> => {
      await Promise.all([
        measurementRepository.deleteById(measurementId),
        regulationSessionRepository.deleteRelatedToMeasurement(measurementId),
        coherenceSessionRepository.deleteRelatedToMeasurement(measurementId),
      ]);
      await Promise.all([
        refreshHistory(),
        refreshBaseline(),
        refreshRegulationSessions(),
      ]);
    },
    [refreshBaseline, refreshHistory, refreshRegulationSessions],
  );

  const transferWatchTombstone = useCallback((tombstone: WatchTombstoneV1): void => {
    const envelope: WatchSyncEnvelopeV1<WatchTombstoneV1> = {
      schemaVersion: 1,
      eventId: `iphone-delete-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`,
      deviceId: 'iphone',
      sequence: 0,
      sentAt: new Date().toISOString(),
      kind: 'tombstone',
      payload: tombstone,
    };
    watchSyncCoordinator.transferEvent(envelope);
  }, []);

  const deleteWatchMeasurement = useCallback(async (measurementId: string): Promise<void> => {
    const tombstone = await watchRepository.deleteMeasurement(measurementId);
    transferWatchTombstone(tombstone);
    await refreshWatchData();
  }, [refreshWatchData, transferWatchTombstone]);

  const clearMeasurementData = useCallback(async (): Promise<void> => {
    const [, , , watchTombstones] = await Promise.all([
      measurementRepository.clearAll(),
      regulationSessionRepository.clearAll(),
      coherenceSessionRepository.clearAll(),
      watchRepository.clearAll(),
    ]);
    watchTombstones.forEach(transferWatchTombstone);
    setCurrentMeasurement(null);
    await Promise.all([
      refreshHistory(),
      refreshBaseline(),
      refreshRegulationSessions(),
      refreshWatchData(),
    ]);
  }, [refreshBaseline, refreshHistory, refreshRegulationSessions, refreshWatchData, transferWatchTombstone]);

  const changeRetentionPolicy = useCallback(
    async (policy: DataRetentionPolicy): Promise<void> => {
      await measurementRepository.setRetentionPolicy(policy);
      setRetentionPolicy(policy);
      await Promise.all([refreshHistory(), refreshBaseline()]);
    },
    [refreshBaseline, refreshHistory],
  );

  if (onboardingStatus === 'loading') {
    return (
      <View style={styles.loadingResult}>
        <ActivityIndicator size="large" color={colors.accent} />
      </View>
    );
  }

  if (onboardingStatus === 'required') {
    return (
      <OnboardingScreen
        initialAnswers={onboardingAnswers}
        onRequestHealthKit={handleOnboardingHealthKit}
        onComplete={answers => {
          setOnboardingAnswers(answers);
          setOnboardingStatus('completed');
        }}
      />
    );
  }

  if (appView === 'history') {
    return (
      <PPGHistoryScreen
        measurements={history}
        watchMeasurements={watchHistory}
        baselineProgress={baselineProgress}
        watchBaseline={watchBaseline}
        regulationSessions={regulationSessions}
        watchRegulationSessions={watchRegulationSessions}
        watchConnectionState={watchConnection}
        saveMindAndBodyWorkouts={saveMindAndBodyWorkouts}
        retentionPolicy={retentionPolicy}
        onDeleteMeasurement={deleteMeasurement}
        onDeleteWatchMeasurement={deleteWatchMeasurement}
        onClearAll={clearMeasurementData}
        onSaveMindAndBodyWorkoutsChange={handleSaveMindAndBodyPreference}
        onRetentionPolicyChange={changeRetentionPolicy}
        onBack={() => {
          setRegulationBeforeMeasurement(null);
          setPendingRegulationSession(null);
          setAppView('measurement');
        }}
      />
    );
  }

  if (appView === 'cardiacMirror') {
    return <CardiacMirrorScreen onBack={() => setAppView('measurement')} />;
  }

  if (appView === 'hapticExercise') {
    return (
      <HapticWaveExerciseScreen
        initialProtocolKind={exerciseProtocol}
        onBack={() => setAppView('measurement')}
        onCompleted={completeRegulationExercise}
        onRequestStart={protocol => {
          if (currentMeasurement === null) {
            setPendingProtocolIntent(protocol.kind);
            setExerciseProtocol(protocol.kind);
            setAtRestSelection(true);
            setAppView('measurement');
            return true;
          }
          setExerciseProtocol(protocol.kind);
          setRegulationBeforeMeasurement(currentMeasurement);
          if (protocol.mode === 'livePPG') {
            cameraPermission.requestCameraPermission().then(granted => {
              if (granted) setAppView('myCoherence');
            });
            return true;
          }
          return false;
        }}
        onCancelled={() => {
          setRegulationBeforeMeasurement(null);
          setPendingRegulationSession(null);
          setPendingCoherenceSessionId(null);
        }}
      />
    );
  }

  if (appView === 'myCoherence') {
    return (
      <MyCoherenceScreen
        cameraPosition={cameraPosition}
        beforeMeasurementId={regulationBeforeMeasurement?.id ?? null}
        onCompleted={(summary, session) => {
          completeRegulationExercise(
            {
              protocolKind: 'myCoherence',
              startedAt: summary.startedAt,
              completedAt: summary.completedAt,
              elapsedSeconds: summary.elapsedSeconds,
              completed: summary.completed,
            },
            session.id,
          );
        }}
        onCancelled={() => {
          setRegulationBeforeMeasurement(null);
          setAppView('hapticExercise');
        }}
      />
    );
  }

  const state = measurement.snapshot.value;
  if (
    state === 'preparingCamera' ||
    state === 'waitingForFinger' ||
    state === 'stabilizing' ||
    state === 'measuring' ||
    state === 'processing'
  ) {
    return (
      <PPGMeasurementScreen
        state={state}
        latestFrame={measurement.latestFrame}
        phaseProgress={measurement.phaseProgress}
        isCameraActive={measurement.isCameraActive}
        torchEnabled={measurement.torchEnabled}
        cameraPosition={cameraPosition}
        onCameraStarted={measurement.onCameraStarted}
        onFrameUpdate={measurement.onFrameUpdate}
        onInterrupted={measurement.onCameraInterrupted}
        onCameraError={measurement.onCameraError}
        onCancel={measurement.cancel}
      />
    );
  }

  if (state === 'completed') {
    if (currentMeasurement === null) {
      if (finalizationState === 'failed') {
        return (
          <PPGFailureScreen
            state="error"
            message="Le résultat n’a pas pu être enregistré localement. Vous pouvez réessayer sans relancer la caméra."
            onRetry={() => setFinalizationState('idle')}
            onBack={backToPreparation}
          />
        );
      }
      return (
        <View style={styles.loadingResult}>
          <ActivityIndicator size="large" color={colors.accent} />
        </View>
      );
    }
    return (
      <PPGResultScreen
        cameraResult={currentMeasurement.cameraResult}
        measurementHistory={history}
        potentialStress={currentMeasurement.potentialStress}
        healthKitContext={currentMeasurement.healthKitContext}
        baselineProgress={baselineProgress}
        regulationComparison={regulationComparison}
        recommendedProtocolKind={recommendRegulationProtocol(
          currentMeasurement.potentialStress.index,
        )}
        selfReportSaved={selfReportState === 'saved'}
        selfReportSaving={selfReportState === 'saving'}
        selfReportError={selfReportState === 'failed'}
        onSaveSelfReport={saveSelfReport}
        onStartRegulation={startRegulationJourney}
        onRestart={restartMeasurement}
        onDone={backToPreparation}
      />
    );
  }

  if (
    state === 'invalid' ||
    state === 'thermalStop' ||
    state === 'interrupted' ||
    state === 'error'
  ) {
    return (
      <PPGFailureScreen
        state={state}
        message={
          measurement.snapshot.context.failure?.message ??
          'Le signal n’a pas permis de produire un résultat fiable.'
        }
        result={measurement.snapshot.context.result}
        showOpenSettings={
          measurement.snapshot.context.failure?.code ===
          'cameraPermissionDenied'
        }
        onRetry={retryMeasurement}
        onBack={backToPreparation}
      />
    );
  }

  return (
    <PPGPreparationScreen
      includeHealthKit={includeHealthKit}
      baselineProgress={baselineProgress}
      postExerciseProtocolTitle={
        pendingRegulationSession === null
          ? null
          : getRegulationProtocol(pendingRegulationSession.protocolKind).title
      }
      onIncludeHealthKitChange={handleHealthKitPreference}
      sensitiveContact={sensitiveContact}
      onSensitiveContactChange={handleSensitiveContactPreference}
      cameraPosition={cameraPosition}
      onCameraPositionChange={handleCameraPositionPreference}
      atRest={atRestSelection}
      onAtRestChange={setAtRestSelection}
      onStart={startMeasurement}
      onOpenHistory={() => setAppView('history')}
      onOpenCardiacMirror={() => setAppView('cardiacMirror')}
      onOpenHapticExercise={() => setAppView('hapticExercise')}
      isStarting={
        state === 'requestingCameraPermission' ||
        state === 'requestingHealthPermission'
      }
    />
  );
}

const styles = StyleSheet.create({
  safeArea: {
    flex: 1,
    backgroundColor: colors.background,
  },
  loadingResult: {
    flex: 1,
    alignItems: 'center',
    justifyContent: 'center',
    backgroundColor: colors.background,
  },
});

export default App;