Torch App in Android using Jetpack Compose

package com.geeksforgeeks.demo

import android.content.Context
import android.hardware.camera2.CameraManager
import android.os.Bundle
import android.widget.Toast
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.foundation.layout.*
import androidx.compose.material3.*
import androidx.compose.runtime.*
import androidx.compose.ui.*
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.platform.LocalContext
import androidx.compose.ui.text.font.*
import androidx.compose.ui.unit.*
import com.geeksforgeeks.demo.ui.theme.DemoTheme

class MainActivity : ComponentActivity() 
{
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            DemoTheme {
                TorchApplication(LocalContext.current)
            }
        }
    }
}

@Composable
fun TorchApplication(context: Context) {
    val isTorchOn = remember { mutableStateOf(false) }
    val torchMode = remember { mutableStateOf("Off") }

    Column(
        modifier = Modifier
            .fillMaxSize()
            .padding(all = 30.dp),
        horizontalAlignment = Alignment.CenterHorizontally,
        verticalArrangement = Arrangement.Center,
    ) {
        Text(
            text = "Torch is " + torchMode.value,
            color = Color.Black,
            fontWeight = FontWeight.Bold,
            fontFamily = FontFamily.Default,
            fontSize = 20.sp, 
            modifier = Modifier.padding(5.dp)
        )
        // switch to toggle torch on/off
        Switch(checked = isTorchOn.value, onCheckedChange = {
            isTorchOn.value = it
            lateinit var cameraID: String
            val cameraManager: CameraManager = context.getSystemService(Context.CAMERA_SERVICE) as CameraManager
            try {
                
                // O -> back camera,
                // 1 -> front camera
                // since, torch is in back camera, let's use '0'
                cameraID = cameraManager.cameraIdList[0]
            } catch (e: Exception) {
                e.printStackTrace()
            }

            if (isTorchOn.value) {
                try {
                    
                    // To switch on torch, set torch mode to "true"
                    cameraManager.setTorchMode(cameraID, true)
                    Toast.makeText(context, "Torch turned on..", Toast.LENGTH_LONG).show()
                    torchMode.value = "On"
                } catch (e: Exception) {
                    e.printStackTrace()
                }
            } else {
                
                // when switch is off
                try {
                    
                    // To switch off torch, set torch mode to "false"
                    cameraManager.setTorchMode(cameraID, false)
                    Toast.makeText(context, "Torch turned off..", Toast.LENGTH_SHORT).show()
                    torchMode.value = "Off"
                } catch (e: Exception) {
                    e.printStackTrace()
                }
            }
        })
    }
}