import { createSelector } from 'reselect'
import { map, groupBy, mapValues, maxBy, get, filter, includes, reduce } from 'lodash'
import { messageActivityGroups } from '../activityGroups/selectors'
import * as PopupSelectors from '../popup/selectors'
import { userId } from '../auth/selectors'
import { IActivityGroup } from '../activityGroups/interfaces'
import { IConversation, IMessagesById } from './interfaces'

const root = (state: any) => state.conversations
export const iconStatus = (state: any) => root(state).conversationIconStatus

export const latestMessageActivityGroups = createSelector([
  messageActivityGroups,
], (messageActivityGroups: IActivityGroup[]) => {
  const messageActivitiesGroupedByConversationId = groupBy(messageActivityGroups, 'conversationId')
  return mapValues(messageActivitiesGroupedByConversationId, data => maxBy(data, 'latestActivity'))
})

export const conversations = (state: any) => root(state).conversations

export const openAndPendingConversations = (state: any) => {
  const currentParticipants = participants(state)
  const currentUserId = userId(state)
  return filter(conversations(state), (conversation: IConversation) => {
    return conversation.status !== 'CLOSED'
      && includes(get(currentParticipants, [conversation.id, 'participantIds']), currentUserId)
  })
}

export const messagesByConversationId = (state: any): IMessagesById => root(state).messagesForConversation

export const getUnreadMessagesForConversationId = (id: number) => (state: any) => {
  const messages = messagesByConversationId(state)[id]
  const readReceiptsForConvo = readReceipts(state)[id]
  return filter(messages, message => !(get(readReceiptsForConvo, message.id)))
}


export const conversationIds = createSelector([
  conversations,
], (conversations: IConversation[]) => map(conversations, 'id'))

export const participants = (state: any) => root(state).participants

export const readReceipts = (state: any) => root(state).messageReadReceipts

export const endUserIds = (state: any) => map(conversations(state), 'endUserId') 

export const conversationIconStatus = createSelector([
  iconStatus,
  PopupSelectors.searchFocused,
  openAndPendingConversations,
], (
  iconStatus: boolean,
  searchFocused: boolean,
  openAndPendingConversations: IConversation[],
) => {
  return openAndPendingConversations.length > 0 && (searchFocused || iconStatus)
})

export const numberOfUnreadMessagesByConversationId = createSelector([
  readReceipts,
], readReceipts => mapValues(readReceipts, receipts =>
  reduce(receipts, (acc, receipt) => {
    return receipt ?  acc : acc + 1
  }, 0)))