/*
 * File: SetupBiometricScreen.tsx
 * Description: Screen for setting up and authenticating with device biometrics or PIN.
 * Design & Developed by Tech4Biz Solutions
 * Copyright (c) Spurrin Innovations. All rights reserved.
 */

import React, { useState, useEffect } from 'react';
import {
  View,
  Text,
  TouchableOpacity,
  Alert,
  StyleSheet,
  SafeAreaView,
} from 'react-native';
import ReactNativeBiometrics, {
  BiometryTypes,
  BiometryType,
} from 'react-native-biometrics';
import AsyncStorage from '@react-native-async-storage/async-storage';
import { Colors, Spacing, Typography, Shadows } from '../../../../shared/src/theme';
import { BASE_URL } from '../../../constants/URLS';

const PAYLOAD = 'neo-scan-secure-payload'; // A static payload for signature

/**
 * SetupBiometricScreen - Manages user authentication using the device's
 * built-in biometrics or PIN/password.
 */
const SetupBiometricScreen: React.FC = () => {
  const [isAuthenticated, setIsAuthenticated] = useState(false);
  const [biometryType, setBiometryType] = useState<BiometryType | null>(null);
  const [isAvailable, setIsAvailable] = useState(false);
  const rnBiometrics = new ReactNativeBiometrics({ allowDeviceCredentials: true });
  console.log('base url',BASE_URL)
  useEffect(() => {
    checkBiometricAvailability();
    checkAuthStatus();
  }, []);

  const checkBiometricAvailability = async () => {
    try {
      const { available, biometryType: bioType } = await rnBiometrics.isSensorAvailable();
      setIsAvailable(available);
      setBiometryType(bioType || null);
    } catch (error) {
      console.error('Biometric check failed:', error);
      Alert.alert('Error', 'Could not check for biometric features.');
    }
  };

  const checkAuthStatus = async () => {
    try {
      const authStatus = await AsyncStorage.getItem('isAuthenticated');
      setIsAuthenticated(authStatus === 'true');
    } catch (error) {
      console.error('Auth status check failed:', error);
    }
  };

  const handleSuccessfulAuth = async () => {
    setIsAuthenticated(true);
    await AsyncStorage.setItem('isAuthenticated', 'true');
    Alert.alert('Success', 'Authentication successful!');
  };

  const authenticateUser = async () => {
    if (!isAvailable) {
      Alert.alert('Not Available', 'Biometrics are not supported on this device.');
      return;
    }

    try {
      // Check if keys exist. If not, create them.
      const { keysExist } = await rnBiometrics.biometricKeysExist();
      if (!keysExist) {
        await rnBiometrics.createKeys();
      }

      // Create a signature to authenticate. This will fallback to device PIN.
      const { success, signature } = await rnBiometrics.createSignature({
        promptMessage: 'Authenticate',
        payload: PAYLOAD,
      });

      if (success && signature) {
        // In a real app, you would verify the signature on your server.
        // For this example, we'll assume it's valid.
        await handleSuccessfulAuth();
      } else {
        Alert.alert('Authentication Failed', 'You could not be authenticated.');
      }
    } catch (error) {
      console.error('Authentication failed:', error);
      Alert.alert('Error', 'An unexpected error occurred during authentication.');
    }
  };

  const getBiometricTypeText = () => {
    switch (biometryType) {
      case BiometryTypes.TouchID: return 'Touch ID';
      case BiometryTypes.FaceID: return 'Face ID';
      case BiometryTypes.Biometrics: return 'Fingerprint';
      default: return 'Device Credentials';
    }
  };

  const logout = async () => {
    try {
      setIsAuthenticated(false);
      await AsyncStorage.setItem('isAuthenticated', 'false');
    } catch (error) {
      console.error('Logout failed:', error);
    }
  };

  return (
    <SafeAreaView style={styles.container}>
      {isAuthenticated ? (
        <View style={styles.content}>
          <Text style={styles.title}>Welcome!</Text>
          <Text style={styles.subtitle}>You are successfully authenticated.</Text>
          <TouchableOpacity style={styles.button} onPress={logout}>
            <Text style={styles.buttonText}>Logout</Text>
          </TouchableOpacity>
        </View>
      ) : (
        <View style={styles.content}>
          <Text style={styles.title}>Authentication Required</Text>
          {isAvailable ? (
            <Text style={styles.subtitle}>
              Use {getBiometricTypeText()} or your device PIN to continue.
            </Text>
          ) : (
            <Text style={styles.subtitle}>
              Biometrics not available. Please use your device PIN to continue.
            </Text>
          )}
          <TouchableOpacity style={styles.button} onPress={authenticateUser}>
            <Text style={styles.buttonText}>Authenticate</Text>
          </TouchableOpacity>
        </View>
      )}
    </SafeAreaView>
  );
};

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: Colors.backgroundAlt,
  },
  content: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    padding: Spacing.lg,
  },
  title: {
    fontFamily: Typography.fontFamily.bold,
    fontSize: Typography.fontSize.title,
    color: Colors.textPrimary,
    marginBottom: Spacing.md,
    textAlign: 'center',
  },
  subtitle: {
    fontFamily: Typography.fontFamily.regular,
    fontSize: Typography.fontSize.md,
    color: Colors.textSecondary,
    textAlign: 'center',
    marginBottom: Spacing.xl,
    paddingHorizontal: Spacing.lg,
  },
  button: {
    backgroundColor: Colors.primary,
    paddingHorizontal: Spacing.xl,
    paddingVertical: Spacing.md,
    borderRadius: 8,
    marginVertical: Spacing.sm,
    ...Shadows.sm,
    minWidth: '80%',
    alignItems: 'center',
  },
  buttonText: {
    color: Colors.background,
    fontSize: Typography.fontSize.md,
    fontFamily: Typography.fontFamily.bold,
  },
});

export default SetupBiometricScreen;