React Hooks

/**
 * Hook for monitoring battery level changes
 * @returns Current battery level (0.0 to 1.0) or null if loading
 */
function useBatteryLevel(): number | null;

/**
 * Hook for monitoring low battery events
 * @returns Battery level when low, or null
 */
function useBatteryLevelIsLow(): number | null;

/**
 * Hook for monitoring power state changes
 * @returns Current power state object
 */
function usePowerState(): Partial<PowerState>;

/**
 * Hook for monitoring screen brightness changes (iOS only)
 * @returns Current brightness level (0.0 to 1.0) or null
 */
function useBrightness(): number | null;

import React from 'react';
import { View, Text } from 'react-native';
import { 
  useBatteryLevel, 
  useBatteryLevelIsLow, 
  usePowerState,
  useBrightness 
} from 'react-native-device-info';

// Battery monitor component
const BatteryMonitor = () => {
  const batteryLevel = useBatteryLevel();
  const lowBatteryLevel = useBatteryLevelIsLow();
  const powerState = usePowerState();
  const brightness = useBrightness();
  
  const batteryPercent = batteryLevel ? Math.round(batteryLevel * 100) : 0;
  const isLowBattery = lowBatteryLevel !== null;
  
  return (
    <View>
      <Text>Battery: {batteryPercent}%</Text>
      <Text>Charging: {powerState.batteryState === 'charging' ? 'Yes' : 'No'}</Text>
      <Text>Low Power Mode: {powerState.lowPowerMode ? 'Yes' : 'No'}</Text>
      {isLowBattery && (
        <Text style={{ color: 'red' }}>
          Low Battery Warning: {Math.round(lowBatteryLevel * 100)}%
        </Text>
      )}
      {brightness !== null && (
        <Text>Screen Brightness: {Math.round(brightness * 100)}%</Text>
      )}
    </View>
  );
};

// Power-aware component
const PowerAwareComponent = () => {
  const powerState = usePowerState();
  const batteryLevel = useBatteryLevel();
  
  // Adaptive rendering based on power state
  const shouldReduceAnimations = powerState.lowPowerMode || 
    (batteryLevel && batteryLevel < 0.2);
  
  const animationDuration = shouldReduceAnimations ? 0 : 300;
  
  return (
    <View>
      <Text>Power Saving Mode: {shouldReduceAnimations ? 'On' : 'Off'}</Text>
      {/* Use animationDuration for animations */}
    </View>
  );
};

/**
 * Hook for getting device name
 * @returns AsyncHookResult with device name
 */
function useDeviceName(): AsyncHookResult<string>;

/**
 * Hook for getting manufacturer information
 * @returns AsyncHookResult with manufacturer name
 */
function useManufacturer(): AsyncHookResult<string>;

/**
 * Hook for checking if device is an emulator
 * @returns AsyncHookResult with emulator status
 */
function useIsEmulator(): AsyncHookResult<boolean>;

/**
 * Hook for getting first install time
 * @returns AsyncHookResult with install timestamp
 */
function useFirstInstallTime(): AsyncHookResult<number>;

/**
 * Hook for checking system feature availability
 * @param feature - System feature name to check
 * @returns AsyncHookResult with feature availability
 */
function useHasSystemFeature(feature: string): AsyncHookResult<boolean>;

interface AsyncHookResult<T> {
  loading: boolean;
  result: T;
}

import React from 'react';
import { View, Text, ActivityIndicator } from 'react-native';
import { 
  useDeviceName, 
  useManufacturer, 
  useIsEmulator,
  useFirstInstallTime,
  useHasSystemFeature
} from 'react-native-device-info';

// Device info component
const DeviceInfoComponent = () => {
  const deviceName = useDeviceName();
  const manufacturer = useManufacturer();
  const isEmulator = useIsEmulator();
  const firstInstall = useFirstInstallTime();
  const hasCamera = useHasSystemFeature('android.hardware.camera');
  
  if (deviceName.loading || manufacturer.loading) {
    return (
      <View>
        <ActivityIndicator />
        <Text>Loading device information...</Text>
      </View>
    );
  }
  
  const installDate = firstInstall.result > 0 ? 
    new Date(firstInstall.result).toLocaleDateString() : 'Unknown';
  
  return (
    <View>
      <Text>Device: {deviceName.result}</Text>
      <Text>Manufacturer: {manufacturer.result}</Text>
      <Text>Emulator: {isEmulator.result ? 'Yes' : 'No'}</Text>
      <Text>First Install: {installDate}</Text>
      <Text>Camera: {hasCamera.result ? 'Available' : 'Not Available'}</Text>
    </View>
  );
};

// Feature-dependent component
const CameraFeatureComponent = () => {
  const hasCamera = useHasSystemFeature('android.hardware.camera');
  
  if (hasCamera.loading) {
    return <ActivityIndicator />;
  }
  
  if (!hasCamera.result) {
    return <Text>Camera not available on this device</Text>;
  }
  
  return (
    <View>
      <Text>Camera features enabled</Text>
      {/* Camera-related UI */}
    </View>
  );
};

/**
 * Hook for monitoring headphone connections
 * @returns AsyncHookResult with headphone connection status
 */
function useIsHeadphonesConnected(): AsyncHookResult<boolean>;

/**
 * Hook for monitoring wired headphone connections
 * @returns AsyncHookResult with wired headphone status
 */
function useIsWiredHeadphonesConnected(): AsyncHookResult<boolean>;

/**
 * Hook for monitoring Bluetooth headphone connections
 * @returns AsyncHookResult with Bluetooth headphone status
 */
function useIsBluetoothHeadphonesConnected(): AsyncHookResult<boolean>;

import React, { useEffect } from 'react';
import { View, Text } from 'react-native';
import { 
  useIsHeadphonesConnected, 
  useIsWiredHeadphonesConnected,
  useIsBluetoothHeadphonesConnected 
} from 'react-native-device-info';

// Audio device monitor component
const AudioDeviceMonitor = () => {
  const headphones = useIsHeadphonesConnected();
  const wiredHeadphones = useIsWiredHeadphonesConnected();
  const bluetoothHeadphones = useIsBluetoothHeadphonesConnected();
  
  return (
    <View>
      <Text>Headphones: {headphones.result ? 'Connected' : 'Disconnected'}</Text>
      <Text>Wired: {wiredHeadphones.result ? 'Connected' : 'Disconnected'}</Text>
      <Text>Bluetooth: {bluetoothHeadphones.result ? 'Connected' : 'Disconnected'}</Text>
    </View>
  );
};

// Audio-aware media player
const AudioAwarePlayer = () => {
  const headphones = useIsHeadphonesConnected();
  const bluetoothHeadphones = useIsBluetoothHeadphonesConnected();
  
  // Adjust audio quality based on output device
  const audioQuality = headphones.result ? 'high' : 'standard';
  const showVolumeWarning = !headphones.result;
  
  useEffect(() => {
    if (bluetoothHeadphones.result) {
      console.log('Bluetooth headphones connected - enabling wireless features');
      // Handle wireless-specific features
    }
  }, [bluetoothHeadphones.result]);
  
  return (
    <View>
      <Text>Audio Quality: {audioQuality}</Text>
      {showVolumeWarning && (
        <Text style={{ color: 'orange' }}>
          Warning: Playing through speakers
        </Text>
      )}
      {bluetoothHeadphones.result && (
        <Text>Bluetooth audio active</Text>
      )}
    </View>
  );
};

import React, { useState, useEffect, useMemo } from 'react';
import { View, Text } from 'react-native';
import { 
  useBatteryLevel, 
  usePowerState, 
  useIsHeadphonesConnected,
  useDeviceName,
  useManufacturer 
} from 'react-native-device-info';

// Performance-aware component
const PerformanceAwareComponent = () => {
  const batteryLevel = useBatteryLevel();
  const powerState = usePowerState();
  const headphones = useIsHeadphonesConnected();
  
  // Memoized performance profile
  const performanceProfile = useMemo(() => {
    const batteryOk = batteryLevel ? batteryLevel > 0.2 : false;
    const isCharging = powerState.batteryState === 'charging';
    const lowPowerMode = powerState.lowPowerMode;
    
    if (isCharging || (batteryOk && !lowPowerMode)) {
      return 'high';
    } else if (batteryOk && !lowPowerMode) {
      return 'balanced';
    } else {
      return 'power_saver';
    }
  }, [batteryLevel, powerState]);
  
  const settings = useMemo(() => ({
    animationsEnabled: performanceProfile !== 'power_saver',
    highQualityAudio: headphones.result && performanceProfile === 'high',
    backgroundRefreshRate: performanceProfile === 'high' ? 30 : 
                          performanceProfile === 'balanced' ? 60 : 300
  }), [performanceProfile, headphones.result]);
  
  return (
    <View>
      <Text>Performance Profile: {performanceProfile}</Text>
      <Text>Animations: {settings.animationsEnabled ? 'On' : 'Off'}</Text>
      <Text>HQ Audio: {settings.highQualityAudio ? 'On' : 'Off'}</Text>
      <Text>Refresh Rate: {settings.backgroundRefreshRate}s</Text>
    </View>
  );
};

// Device-specific component
const DeviceSpecificComponent = () => {
  const deviceName = useDeviceName();
  const manufacturer = useManufacturer();
  const [deviceConfig, setDeviceConfig] = useState(null);
  
  useEffect(() => {
    if (!deviceName.loading && !manufacturer.loading) {
      // Configure based on specific device
      const config = {
        device: deviceName.result,
        manufacturer: manufacturer.result,
        optimizations: getDeviceOptimizations(
          manufacturer.result, 
          deviceName.result
        )
      };
      setDeviceConfig(config);
    }
  }, [deviceName.loading, manufacturer.loading, deviceName.result, manufacturer.result]);
  
  const getDeviceOptimizations = (mfg, device) => {
    const opts = { performanceMode: 'standard' };
    
    // Device-specific optimizations
    if (mfg === 'Apple') {
      opts.performanceMode = 'high';
      opts.useHardwareAcceleration = true;
    } else if (mfg === 'Samsung') {
      opts.useCustomEffects = true;
      opts.performanceMode = 'balanced';
    }
    
    return opts;
  };
  
  if (!deviceConfig) {
    return <Text>Loading device configuration...</Text>;
  }
  
  return (
    <View>
      <Text>Device: {deviceConfig.device}</Text>
      <Text>Manufacturer: {deviceConfig.manufacturer}</Text>
      <Text>Performance: {deviceConfig.optimizations.performanceMode}</Text>
    </View>
  );
};

// Composite monitoring component
const DeviceMonitorDashboard = () => {
  const batteryLevel = useBatteryLevel();
  const powerState = usePowerState();
  const deviceName = useDeviceName();
  const headphones = useIsHeadphonesConnected();
  const brightness = useBrightness();
  
  const [alerts, setAlerts] = useState([]);
  
  useEffect(() => {
    const newAlerts = [];
    
    if (batteryLevel && batteryLevel < 0.1) {
      newAlerts.push('Critical battery level');
    }
    
    if (powerState.lowPowerMode) {
      newAlerts.push('Low power mode active');
    }
    
    if (brightness && brightness > 0.9) {
      newAlerts.push('High screen brightness - impacts battery');
    }
    
    setAlerts(newAlerts);
  }, [batteryLevel, powerState.lowPowerMode, brightness]);
  
  return (
    <View>
      <Text style={{ fontSize: 18, fontWeight: 'bold' }}>Device Status</Text>
      
      <View style={{ marginTop: 10 }}>
        <Text>Device: {deviceName.loading ? 'Loading...' : deviceName.result}</Text>
        <Text>Battery: {batteryLevel ? `${Math.round(batteryLevel * 100)}%` : 'Loading...'}</Text>
        <Text>Charging: {powerState.batteryState === 'charging' ? 'Yes' : 'No'}</Text>
        <Text>Headphones: {headphones.result ? 'Connected' : 'Disconnected'}</Text>
        {brightness !== null && (
          <Text>Brightness: {Math.round(brightness * 100)}%</Text>
        )}
      </View>
      
      {alerts.length > 0 && (
        <View style={{ marginTop: 10 }}>
          <Text style={{ color: 'red', fontWeight: 'bold' }}>Alerts:</Text>
          {alerts.map((alert, index) => (
            <Text key={index} style={{ color: 'red' }}>• {alert}</Text>
          ))}
        </View>
      )}
    </View>
  );
};

export {
  PerformanceAwareComponent,
  DeviceSpecificComponent,
  DeviceMonitorDashboard
};

import { useState, useEffect } from 'react';
import { 
  useBatteryLevel, 
  usePowerState, 
  useIsHeadphonesConnected 
} from 'react-native-device-info';

// Custom hook for power management
const usePowerManagement = () => {
  const batteryLevel = useBatteryLevel();
  const powerState = usePowerState();
  const [powerProfile, setPowerProfile] = useState('balanced');
  
  useEffect(() => {
    if (batteryLevel === null) return;
    
    const isCharging = powerState.batteryState === 'charging';
    const isLowPower = powerState.lowPowerMode;
    
    if (isCharging || batteryLevel > 0.5) {
      setPowerProfile('high');
    } else if (batteryLevel > 0.2 && !isLowPower) {
      setPowerProfile('balanced');
    } else {
      setPowerProfile('power_saver');
    }
  }, [batteryLevel, powerState]);
  
  return {
    batteryLevel,
    powerState,
    powerProfile,
    isCharging: powerState.batteryState === 'charging',
    shouldOptimize: powerProfile === 'power_saver'
  };
};

// Custom hook for audio context
const useAudioContext = () => {
  const headphones = useIsHeadphonesConnected();
  const powerInfo = usePowerManagement();
  
  const audioQuality = headphones.result && powerInfo.powerProfile === 'high' ? 
    'high' : 'standard';
  
  const shouldShowVolumeWarning = !headphones.result;
  const canUseHighQualityEffects = headphones.result && 
    powerInfo.powerProfile !== 'power_saver';
  
  return {
    headphonesConnected: headphones.result,
    audioQuality,
    shouldShowVolumeWarning,
    canUseHighQualityEffects,
    loading: headphones.loading
  };
};

// Usage of custom hooks
const MediaPlayerComponent = () => {
  const powerInfo = usePowerManagement();
  const audioContext = useAudioContext();
  
  return (
    <View>
      <Text>Power Profile: {powerInfo.powerProfile}</Text>
      <Text>Audio Quality: {audioContext.audioQuality}</Text>
      
      {audioContext.shouldShowVolumeWarning && (
        <Text style={{ color: 'orange' }}>Volume warning: Using speakers</Text>
      )}
      
      {powerInfo.shouldOptimize && (
        <Text style={{ color: 'blue' }}>Power saving active</Text>
      )}
    </View>
  );
};

interface AsyncHookResult<T> {
  loading: boolean;
  result: T;
}

interface PowerState {
  batteryLevel: number;
  batteryState: BatteryState;
  lowPowerMode: boolean;
  [key: string]: any;
}

type BatteryState = 'unknown' | 'unplugged' | 'charging' | 'full';