/*
 * Copyright © 2014-2021 The Android Password Store Authors. All Rights Reserved.
 * SPDX-License-Identifier: GPL-3.0-only
 */

package app.passwordstore.util.extensions

import android.view.LayoutInflater
import android.view.View
import androidx.appcompat.app.AppCompatActivity
import androidx.fragment.app.Fragment
import androidx.lifecycle.DefaultLifecycleObserver
import androidx.lifecycle.Lifecycle
import androidx.lifecycle.LifecycleOwner
import androidx.viewbinding.ViewBinding
import kotlin.properties.ReadOnlyProperty
import kotlin.reflect.KProperty

/**
 * Imported from
 * https://medium.com/@Zhuinden/simple-one-liner-viewbinding-in-fragments-and-activities-with-kotlin-961430c6c07c
 */
class FragmentViewBindingDelegate<T : ViewBinding>(
  val fragment: Fragment,
  val viewBindingFactory: (View) -> T,
) : ReadOnlyProperty<Fragment, T> {

  private var binding: T? = null

  init {
    fragment.lifecycle.addObserver(
      object : DefaultLifecycleObserver {
        override fun onCreate(owner: LifecycleOwner) {
          fragment.viewLifecycleOwnerLiveData.observe(fragment) { viewLifecycleOwner ->
            viewLifecycleOwner.lifecycle.addObserver(
              object : DefaultLifecycleObserver {
                override fun onDestroy(owner: LifecycleOwner) {
                  binding = null
                }
              }
            )
          }
        }
      }
    )
  }

  override fun getValue(thisRef: Fragment, property: KProperty<*>): T {
    val binding = binding
    if (binding != null) {
      return binding
    }

    val lifecycle = fragment.viewLifecycleOwner.lifecycle
    if (!lifecycle.currentState.isAtLeast(Lifecycle.State.INITIALIZED)) {
      throw IllegalStateException(
        "Should not attempt to get bindings when Fragment views are destroyed."
      )
    }

    return viewBindingFactory(thisRef.requireView()).also { this.binding = it }
  }
}

fun <T : ViewBinding> Fragment.viewBinding(viewBindingFactory: (View) -> T) =
  FragmentViewBindingDelegate(this, viewBindingFactory)

inline fun <T : ViewBinding> AppCompatActivity.viewBinding(
  crossinline bindingInflater: (LayoutInflater) -> T
) = unsafeLazy { bindingInflater.invoke(layoutInflater) }
