import { createSelector } from 'reselect'
import { ipcRenderer } from 'electron'
// ------------------------------------
// Constants
// ------------------------------------
export const SET_CHANNEL_FORM = 'SET_CHANNEL_FORM'

export const SET_CHANNEL = 'SET_CHANNEL'

export const GET_CHANNELS = 'GET_CHANNELS'
export const RECEIVE_CHANNELS = 'RECEIVE_CHANNELS'

export const OPENING_CHANNEL = 'OPENING_CHANNEL'
export const OPENING_SUCCESSFUL = 'OPENING_SUCCESSFUL'
export const OPENING_FAILURE = 'OPENING_FAILURE'

// ------------------------------------
// Actions
// ------------------------------------
export function setChannelForm(form) {
  return {
    type: SET_CHANNEL_FORM,
    form
  }
}


export function setChannel(channel) {
  return {
    type: SET_CHANNEL,
    channel
  }
}

export function getChannels() {
  return {
    type: GET_CHANNELS
  }
}

export function openingChannel() {
  return {
    type: OPENING_CHANNEL
  }
}

export function openingSuccessful() {
  return {
    type: OPENING_SUCCESSFUL
  }
}

export function openingFailure() {
  return {
    type: OPENING_FAILURE
  }
}

// Send IPC event for peers
export const fetchChannels = () => async (dispatch) => {
  dispatch(getChannels())
  ipcRenderer.send('lnd', { msg: 'channels' })
}

// Receive IPC event for channels
export const receiveChannels = (event, { channels, pendingChannels }) => dispatch => dispatch({ type: RECEIVE_CHANNELS, channels, pendingChannels })

// Send IPC event for opening a channel
export const openChannel = ({ pubkey, localamt, pushamt }) => (dispatch) => {
  dispatch(openingChannel())
  ipcRenderer.send('lnd', { msg: 'openChannel', data: { pubkey, localamt, pushamt } })
}

// TODO: Decide how to handle streamed updates for channels
// Receive IPC event for openChannel
export const channelSuccessful = () => (dispatch) => {
  dispatch(fetchChannels())
}

// Receive IPC event for updated channel
export const pushchannelupdated = () => (dispatch) => {
  dispatch(fetchChannels())
}

// Receive IPC event for channel end
export const pushchannelend = () => (dispatch) => {
  dispatch(fetchChannels())
}

// Receive IPC event for channel error
export const pushchannelerror = () => (dispatch) => {
  dispatch(fetchChannels())
}

// Receive IPC event for channel status
export const pushchannelstatus = () => (dispatch) => {
  dispatch(fetchChannels())
}

// ------------------------------------
// Action Handlers
// ------------------------------------
const ACTION_HANDLERS = {
  [SET_CHANNEL_FORM]: (state, { form }) => (
    { ...state, channelForm: Object.assign({}, state.channelForm, form) }
  ),

  [SET_CHANNEL]: (state, { channel }) => ({ ...state, channel }),

  [GET_CHANNELS]: state => ({ ...state, channelsLoading: true }),
  [RECEIVE_CHANNELS]: (state, { channels, pendingChannels }) => (
    { ...state, channelsLoading: false, channels, pendingChannels }
  ),

  [OPENING_CHANNEL]: state => ({ ...state, openingChannel: true })
}

const channelsSelectors = {}
const channelSelector = state => state.channels.channel
const channelsSelector = state => state.channels.channels
const pendingOpenChannelsSelector = state => state.channels.pendingChannels.pending_open_channels
const pendingClosedChannelsSelector = state => state.channels.pendingChannels.pending_closing_channels
const pendingForceClosedChannelsSelector = state => state.channels.pendingChannels.pending_force_closing_channels

channelsSelectors.channelModalOpen = createSelector(
  channelSelector,
  channel => (!!channel)
)

channelsSelectors.allChannels = createSelector(
  channelsSelector,
  pendingOpenChannelsSelector,
  pendingClosedChannelsSelector,
  pendingForceClosedChannelsSelector,
  (channels, pendingOpenChannels, pendingClosedChannels, pendingForcedClosedChannels) => (
    [...channels, ...pendingOpenChannels, ...pendingClosedChannels, ...pendingForcedClosedChannels]
  )
)

export { channelsSelectors }

// ------------------------------------
// Reducer
// ------------------------------------
const initialState = {
  channelsLoading: false,
  channels: [],
  pendingChannels: {
    total_limbo_balance: '',
    pending_open_channels: [],
    pending_closing_channels: [],
    pending_force_closing_channels: []
  },
  channel: null,
  channelForm: {
    isOpen: false,
    node_key: '',
    local_amt: '',
    push_amt: ''
  },
  openingChannel: false
}

export default function channelsReducer(state = initialState, action) {
  const handler = ACTION_HANDLERS[action.type]

  return handler ? handler(state, action) : state
}