Implement NavigationBar theme

package io.heckel.ntfy.ui

import android.content.res.Configuration

import android.os.Build

import android.os.Bundle

import android.view.WindowInsetsController

import androidx.annotation.RequiresApi

import androidx.appcompat.app.AppCompatActivity

import io.heckel.ntfy.R

import io.heckel.ntfy.databinding.MainSettingsActivityBinding

class MainSettingsActivity : AppCompatActivity() {

    private lateinit var mBinding: MainSettingsActivityBinding

    @RequiresApi(Build.VERSION_CODES.R)

    override fun onCreate(savedInstanceState: Bundle?) {

        super.onCreate(savedInstanceState)

        mBinding = MainSettingsActivityBinding.inflate(layoutInflater)

        setContentView(mBinding.root)

        setupToolbar()

        setSystemBarsAppearance()

        showPreferencesFragment()

    }

    private fun setupToolbar() {

        mBinding.toolbar.setNavigationOnClickListener {

            onBackPressed()

            onBackPressedDispatcher.onBackPressed()

        }

    }

    @RequiresApi(Build.VERSION_CODES.R)

    private fun setSystemBarsAppearance() {

        val insetsController = window.insetsController ?: return

        val isLightMode = isSystemInLightMode()

        if (isLightMode) {

            insetsController.setSystemBarsAppearance(

                WindowInsetsController.APPEARANCE_LIGHT_NAVIGATION_BARS,

                WindowInsetsController.APPEARANCE_LIGHT_NAVIGATION_BARS

            )

        } else {

            insetsController.setSystemBarsAppearance(

                0,

                WindowInsetsController.APPEARANCE_LIGHT_NAVIGATION_BARS

            )

        }

    }

    private fun isSystemInLightMode(): Boolean {

        val nightModeFlags = resources.configuration.uiMode and Configuration.UI_MODE_NIGHT_MASK

        return nightModeFlags != Configuration.UI_MODE_NIGHT_YES

    }

    private fun showPreferencesFragment() {

        supportFragmentManager

            .beginTransaction()

            .replace(R.id.fragment_container, PreferencesFragment())