Magisk/app/src/main/java/com/topjohnwu/magisk/arch/BaseFragment.kt

package com.topjohnwu.magisk.arch

import android.os.Bundle
import android.view.KeyEvent
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.databinding.DataBindingUtil
import androidx.databinding.OnRebindCallback
import androidx.databinding.ViewDataBinding
import androidx.fragment.app.Fragment
import androidx.navigation.NavDirections
import com.topjohnwu.magisk.BR
import com.topjohnwu.magisk.ktx.startAnimations

abstract class BaseFragment<Binding : ViewDataBinding> : Fragment(), ViewModelHolder {

    val activity get() = getActivity() as? NavigationActivity<*>
    protected lateinit var binding: Binding
    protected abstract val layoutRes: Int

    private val navigation get() = activity?.navigation
    open val snackbarAnchorView: View? get() = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        startObserveLiveData()
    }

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        binding = DataBindingUtil.inflate<Binding>(inflater, layoutRes, container, false).also {
            it.setVariable(BR.viewModel, viewModel)
            it.lifecycleOwner = viewLifecycleOwner
        }
        savedInstanceState?.let { viewModel.onRestoreState(it) }
        return binding.root
    }

    override fun onSaveInstanceState(outState: Bundle) {
        viewModel.onSaveState(outState)
    }

    override fun onStart() {
        super.onStart()
        activity?.supportActionBar?.subtitle = null
    }

    override fun onEventDispatched(event: ViewEvent) = when(event) {
        is ContextExecutor -> event(requireContext())
        is ActivityExecutor -> activity?.let { event(it) } ?: Unit
        is FragmentExecutor -> event(this)
        else -> Unit
    }

    open fun onKeyEvent(event: KeyEvent): Boolean {
        return false
    }

    open fun onBackPressed(): Boolean = false


    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        binding.addOnRebindCallback(object : OnRebindCallback<Binding>() {
            override fun onPreBind(binding: Binding): Boolean {
                this@BaseFragment.onPreBind(binding)
                return true
            }
        })
    }

    override fun onResume() {
        super.onResume()
        viewModel.requestRefresh()
    }

    protected open fun onPreBind(binding: Binding) {
        (binding.root as? ViewGroup)?.startAnimations()
    }

    fun NavDirections.navigate() {
        navigation?.currentDestination?.getAction(actionId)?.let { navigation!!.navigate(this) }
    }

}