refactor(settings): improve source selection code for better readability

     */

    private val sourceCheckboxListener =

        OnPreferenceChangeListener { preference: Preference, newValue: Any? ->

            val otherBoxesChecked =

                allSourceCheckboxes.filter { it != preference }.any { it?.isChecked == true }

            val isChecked = newValue == true

            if (newValue == false && !otherBoxesChecked) {

                (preference as CheckBoxPreference).isChecked = true

            if (!isChecked && isOnlyRemainingSourceChecked(preference)) {

                showOnlyRemainingSourceWarning(preference)

                return@OnPreferenceChangeListener false

            }

            applySourceChange(preference, isChecked)

            true

        }

    private fun isOnlyRemainingSourceChecked(preference: Preference): Boolean {

        return allSourceCheckboxes

            .filter { it != preference }

            .none { it?.isChecked == true }

    }

    private fun showOnlyRemainingSourceWarning(preference: Preference) {

        (preference as? CheckBoxPreference)?.isChecked = true

        Toast.makeText(

            requireActivity(),

            R.string.select_one_source_of_applications,

            Toast.LENGTH_SHORT

        ).show()

                false

            } else {

                when (preference.key) {

                    Constants.PREFERENCE_SHOW_GPLAY -> updateStore(Source.PLAY_STORE, newValue == true)

                    Constants.PREFERENCE_SHOW_FOSS -> updateStore(Source.OPEN_SOURCE, newValue == true)

                    Constants.PREFERENCE_SHOW_PWA -> updateStore(Source.PWA, newValue == true)

    }

    private fun applySourceChange(preference: Preference, isEnabled: Boolean) {

        val sourceMap = mapOf(

            Constants.PREFERENCE_SHOW_GPLAY to Source.PLAY_STORE,

            Constants.PREFERENCE_SHOW_FOSS to Source.OPEN_SOURCE,

            Constants.PREFERENCE_SHOW_PWA to Source.PWA

        )

        val source = sourceMap[preference.key]

            ?: error("No Source mapping found for preference key: ${preference.key}")

        updateStore(source, isEnabled)

        sourcesChangedFlag = true

        loginViewModel.authObjects.value = null

                true

            }

    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {