/*
 * Copyright 2019 New Vector Ltd
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package im.vector.riotx.features.roomdirectory.createroom

import androidx.fragment.app.FragmentActivity
import com.airbnb.mvrx.ActivityViewModelContext
import com.airbnb.mvrx.Fail
import com.airbnb.mvrx.Loading
import com.airbnb.mvrx.MvRxViewModelFactory
import com.airbnb.mvrx.Success
import com.airbnb.mvrx.ViewModelContext
import com.squareup.inject.assisted.Assisted
import com.squareup.inject.assisted.AssistedInject
import im.vector.matrix.android.api.MatrixCallback
import im.vector.matrix.android.api.session.Session
import im.vector.matrix.android.api.session.room.model.RoomDirectoryVisibility
import im.vector.matrix.android.api.session.room.model.create.CreateRoomParams
import im.vector.matrix.android.api.session.room.model.create.CreateRoomPreset
import im.vector.riotx.core.platform.EmptyViewEvents
import im.vector.riotx.core.platform.VectorViewModel
import im.vector.riotx.features.roomdirectory.RoomDirectoryActivity

class CreateRoomViewModel @AssistedInject constructor(@Assisted initialState: CreateRoomViewState,
                                                      private val session: Session
) : VectorViewModel<CreateRoomViewState, CreateRoomAction, EmptyViewEvents>(initialState) {

    @AssistedInject.Factory
    interface Factory {
        fun create(initialState: CreateRoomViewState): CreateRoomViewModel
    }

    companion object : MvRxViewModelFactory<CreateRoomViewModel, CreateRoomViewState> {

        @JvmStatic
        override fun create(viewModelContext: ViewModelContext, state: CreateRoomViewState): CreateRoomViewModel? {
            val activity: FragmentActivity = (viewModelContext as ActivityViewModelContext).activity()

            return when (activity) {
                is CreateRoomActivity    -> activity.createRoomViewModelFactory.create(state)
                is RoomDirectoryActivity -> activity.createRoomViewModelFactory.create(state)
                else                     -> error("Wrong activity")
            }
        }
    }

    override fun handle(action: CreateRoomAction) {
        when (action) {
            is CreateRoomAction.SetName              -> setName(action)
            is CreateRoomAction.SetIsPublic          -> setIsPublic(action)
            is CreateRoomAction.SetIsInRoomDirectory -> setIsInRoomDirectory(action)
            is CreateRoomAction.SetIsEncrypted       -> setIsEncrypted(action)
            is CreateRoomAction.Create               -> doCreateRoom()
        }
    }

    private fun setName(action: CreateRoomAction.SetName) = setState { copy(roomName = action.name) }

    private fun setIsPublic(action: CreateRoomAction.SetIsPublic) = setState { copy(isPublic = action.isPublic) }

    private fun setIsInRoomDirectory(action: CreateRoomAction.SetIsInRoomDirectory) = setState { copy(isInRoomDirectory = action.isInRoomDirectory) }

    private fun setIsEncrypted(action: CreateRoomAction.SetIsEncrypted) = setState { copy(isEncrypted = action.isEncrypted) }

    private fun doCreateRoom() = withState { state ->
        if (state.asyncCreateRoomRequest is Loading || state.asyncCreateRoomRequest is Success) {
            return@withState
        }

        setState {
            copy(asyncCreateRoomRequest = Loading())
        }

        val createRoomParams = CreateRoomParams(
                name = state.roomName.takeIf { it.isNotBlank() },
                // Directory visibility
                visibility = if (state.isInRoomDirectory) RoomDirectoryVisibility.PUBLIC else RoomDirectoryVisibility.PRIVATE,
                // Public room
                preset = if (state.isPublic) CreateRoomPreset.PRESET_PUBLIC_CHAT else CreateRoomPreset.PRESET_PRIVATE_CHAT
        )
                // Encryption
                .enableEncryptionWithAlgorithm(state.isEncrypted)

        session.createRoom(createRoomParams, object : MatrixCallback<String> {
            override fun onSuccess(data: String) {
                setState {
                    copy(asyncCreateRoomRequest = Success(data))
                }
            }

            override fun onFailure(failure: Throwable) {
                setState {
                    copy(asyncCreateRoomRequest = Fail(failure))
                }
            }
        })
    }
}
