/* This Source Code Form is subject to the terms of the Mozilla Public
   License, v. 2.0. If a copy of the MPL was not distributed with this
   file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.fenix.exceptions

import android.view.ViewGroup
import androidx.fragment.app.Fragment
import androidx.lifecycle.ViewModel
import androidx.lifecycle.ViewModelProvider
import androidx.lifecycle.ViewModelProviders
import io.reactivex.Observable
import org.mozilla.fenix.mvi.Action
import org.mozilla.fenix.mvi.ActionBusFactory
import org.mozilla.fenix.mvi.Change
import org.mozilla.fenix.mvi.UIComponent
import org.mozilla.fenix.mvi.UIComponentViewModel
import org.mozilla.fenix.mvi.ViewState
import org.mozilla.fenix.test.Mockable

data class ExceptionsItem(val url: String)

@Mockable
class ExceptionsComponent(
    private val container: ViewGroup,
    owner: Fragment,
    bus: ActionBusFactory,
    override var initialState: ExceptionsState = ExceptionsState(emptyList())
) :
    UIComponent<ExceptionsState, ExceptionsAction, ExceptionsChange>(
        owner,
        bus.getManagedEmitter(ExceptionsAction::class.java),
        bus.getSafeManagedObservable(ExceptionsChange::class.java)
    ) {

    override fun render(): Observable<ExceptionsState> =
        ViewModelProviders.of(owner, ExceptionsViewModel.Factory(initialState, changesObservable))
            .get(ExceptionsViewModel::class.java).render(uiView)

    override fun initView() = ExceptionsUIView(container, actionEmitter, changesObservable)

    init {
        render()
    }
}

data class ExceptionsState(val items: List<ExceptionsItem>) : ViewState

sealed class ExceptionsAction : Action {
    sealed class Delete : ExceptionsAction() {
        object All : Delete()
        data class One(val item: ExceptionsItem) : Delete()
    }
}

sealed class ExceptionsChange : Change {
    data class Change(val list: List<ExceptionsItem>) : ExceptionsChange()
}

class ExceptionsViewModel(initialState: ExceptionsState, changesObservable: Observable<ExceptionsChange>) :
    UIComponentViewModel<ExceptionsState, ExceptionsAction, ExceptionsChange>(
        initialState,
        changesObservable,
        reducer
    ) {

    class Factory(
        private val initialState: ExceptionsState,
        private val changesObservable: Observable<ExceptionsChange>
    ) : ViewModelProvider.Factory {
        @Suppress("UNCHECKED_CAST")
        override fun <T : ViewModel?> create(modelClass: Class<T>): T =
            ExceptionsViewModel(initialState, changesObservable) as T
    }

    companion object {
        val reducer: (ExceptionsState, ExceptionsChange) -> ExceptionsState = { state, change ->
            when (change) {
                is ExceptionsChange.Change -> state.copy(items = change.list)
            }
        }
    }
}