import React, { useState, useEffect } from 'react';
import { StyleSheet, View, SafeAreaView, StatusBar, ActivityIndicator } from 'react-native';
import { GestureHandlerRootView } from 'react-native-gesture-handler';
import CameraScreen from './src/screens/CameraScreen';
import PreviewScreen from './src/screens/PreviewScreen';
import AdminScreen from './src/screens/AdminScreen';
import { loadSettings, saveSettings, AppSettings } from './src/services/settings';
import { logger, setLogsEnabled } from './src/services/logger';
import * as FileSystem from 'expo-file-system/legacy';

// Set up global error handler
const defaultErrorHandler = (global as any).ErrorUtils.getGlobalHandler();
(global as any).ErrorUtils.setGlobalHandler((error: any, isFatal: boolean) => {
  logger.error(`Unhandled Exception (Fatal: ${isFatal})`, error)
    .catch(console.error)
    .finally(() => {
      // Delay termination until log is written
      defaultErrorHandler(error, isFatal);
    });
});
import KioskMode from './modules/kiosk-mode';

type ScreenState = 'home' | 'camera' | 'preview' | 'admin';

export default function App() {
  const [currentScreen, setCurrentScreen] = useState<ScreenState>('home');
  const [photoUris, setPhotoUris] = useState<string[]>([]);
  const [captureHistory, setCaptureHistory] = useState<number[]>([]);
  const [settings, setSettings] = useState<AppSettings | null>(null);

  // 1. Load configuration settings on app start
  useEffect(() => {
    async function initApp() {
      const savedSettings = await loadSettings();
      setSettings(savedSettings);
      setLogsEnabled(savedSettings.enableLogs);

      // Auto-start Kiosk mode if it was configured as enabled
      if (savedSettings.kioskModeEnabled) {
        try {
          KioskMode.startKiosk();
        } catch (e) {
          console.warn('Failed to auto-start Kiosk mode:', e);
        }
      }
    }
    initApp();
  }, []);

  if (!settings) {
    return (
      <View style={styles.loadingContainer}>
        <StatusBar hidden={true} />
        <ActivityIndicator size="large" color="#ff2bd6" />
      </View>
    );
  }

  // 2. Navigation Actions
  const handleStartBooth = () => {
    setPhotoUris([]);
    setCaptureHistory([]);
    setCurrentScreen('camera');
  };

  const handlePhotoCaptured = async (uri: string) => {
    await logger.log(`Photo captured via CameraScreen: ${uri}`);
    try {
      setPhotoUris((prev) => {
        const next = [...prev, uri];
        return next.length > 4 ? next.slice(-4) : next;
      });
      setCaptureHistory((prev) => [...prev, 1]);
      setCurrentScreen('preview');
      await logger.log('State updated to preview screen successfully.');
    } catch (e) {
      await logger.error('Error transitioning to preview screen:', e);
    }
  };

  // Called by CameraScreen when burst mode completes all photos
  const handleBurstComplete = (uris: string[]) => {
    setPhotoUris((prev) => {
      const next = [...prev, ...uris];
      const maxKeep = Math.max(4, uris.length);
      return next.length > maxKeep ? next.slice(-maxKeep) : next;
    });
    setCaptureHistory((prev) => [...prev, uris.length]);
    setCurrentScreen('preview');
  };

  const handleRetakeLast = async () => {
    // Remove photos from the last capture event
    const lastCaptureCount = captureHistory.length > 0 ? captureHistory[captureHistory.length - 1] : 1;
    const updatedUris = [...photoUris];
    const removedUris = updatedUris.splice(-lastCaptureCount, lastCaptureCount);
    setPhotoUris(updatedUris);
    setCaptureHistory((prev) => prev.slice(0, -1));
    
    // Clean up temp files
    for (const uri of removedUris) {
      try {
        await FileSystem.deleteAsync(uri, { idempotent: true });
      } catch (e) {
        console.warn('Failed to delete temp file:', e);
      }
    }
    
    // Always let user retake
    setCurrentScreen('camera');
  };

  const handleAddAnother = () => {
    setCurrentScreen('camera');
  };

  const handleReset = async () => {
    // Clean up temp files
    for (const uri of photoUris) {
      try {
        await FileSystem.deleteAsync(uri, { idempotent: true });
      } catch (e) {
        console.warn('Failed to delete temp file:', e);
      }
    }
    setPhotoUris([]);
    setCaptureHistory([]);
    setCurrentScreen('home'); // Go to home when cancelled
  };

  const handleSaveSettings = (updated: AppSettings) => {
    setSettings(updated);
    setLogsEnabled(updated.enableLogs);
  };

  const handleOpenAdmin = () => {
    setCurrentScreen('admin');
  };

  // 3. Conditional Screen Rendering
  return (
    <GestureHandlerRootView style={styles.container}>
      <SafeAreaView style={styles.container}>
        <StatusBar hidden={true} />
        
        {/* 
          Keep CameraScreen ALWAYS mounted in the background to prevent 
          Android expo-camera hardware crashes when unmounting right after capture 
        */}
        <View 
          style={StyleSheet.absoluteFill} 
          pointerEvents={(currentScreen === 'preview' || currentScreen === 'admin') ? 'none' : 'auto'}
        >
          <CameraScreen
            countdownDuration={settings.countdownDuration}
            onPhotoCaptured={handlePhotoCaptured}
            onBurstComplete={handleBurstComplete}
            onCancel={handleReset}
            isIdle={currentScreen !== 'camera'}
            onStartBooth={handleStartBooth}
            onNavigateToAdmin={handleOpenAdmin}
            adminPassword={settings.adminPassword}
            welcomeText={settings.welcomeText}
            burstCount={settings.burstCount}
            burstIntervalSec={settings.burstIntervalSec}
            frameMode={settings.frameMode}
            selectedFrameId={settings.selectedFrameId}
            footerText={settings.footerText}
            useFrontCamera={settings.useFrontCamera}
          />
        </View>

        {/* Overlay PreviewScreen if active */}
        {currentScreen === 'preview' && (
          <View style={[StyleSheet.absoluteFill, { zIndex: 100, elevation: 100, backgroundColor: 'transparent' }]}>
            <PreviewScreen
              photoUris={photoUris}
              printerIp={settings.printerIp}
              onRetakeLast={handleRetakeLast}
              onAddAnother={handleAddAnother}
              onReset={handleReset}
              frameMode={settings.frameMode}
              initialFrameId={settings.selectedFrameId}
              availableFrameIds={settings.availableFrameIds}
              dateOverlay={settings.dateOverlay}
              dateOverlayPosition={settings.dateOverlayPosition}
              eventText={settings.eventText}
            />
          </View>
        )}

        {/* Overlay AdminScreen if active */}
        {currentScreen === 'admin' && (
          <View style={[StyleSheet.absoluteFill, { zIndex: 100, elevation: 100, backgroundColor: 'transparent' }]}>
            <AdminScreen
              currentSettings={settings}
              onSave={handleSaveSettings}
              onClose={() => setCurrentScreen('home')}
            />
          </View>
        )}
      </SafeAreaView>
    </GestureHandlerRootView>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#000',
  },
  loadingContainer: {
    flex: 1,
    backgroundColor: '#000',
    justifyContent: 'center',
    alignItems: 'center',
  },
});