package com.draewil.driver.viewmodel

import android.app.Application
import android.arch.lifecycle.AndroidViewModel
import android.arch.lifecycle.ViewModel
import android.arch.lifecycle.ViewModelProvider
import com.draewil.driver.viewmodel.debug.DebugLocationViewModel
import com.draewil.driver.viewmodel.route.RouteViewModel

class ViewModelFactory internal constructor(application: Application) :
    ViewModelProvider.AndroidViewModelFactory(application) {

    private val viewModelCache: MutableMap<String, AndroidViewModel> = mutableMapOf()

    private val definedViewModels = listOf(
        BatteryViewModel::class.java
    )

    override fun <T : ViewModel?> create(modelClass: Class<T>): T {
        definedViewModels.firstOrNull {
            it.isAssignableFrom(modelClass)
        }?.let {
            @Suppress("UNCHECKED_CAST")
            return getViewModel(modelClass) as T
        }
        throw IllegalArgumentException("Unknown class: $modelClass")
    }

    private fun <T : ViewModel?> getViewModel(modelClass: Class<T>): ViewModel? =
        modelClass.name?.let {
            if (viewModelCache.containsKey(it)) {
                viewModelCache[it]
            } else {
                (super.create(modelClass) as AndroidViewModel).apply {
                    viewModelCache[it] = this
                }
            }
        }

}