import { useEffect, useState } from 'react'
import { Group } from 'common/group'
import { User } from 'common/user'
import {
  GroupMemberDoc,
  groupMembers,
  listenForGroup,
  listenForGroupContractDocs,
  listenForGroups,
  listenForMemberGroupIds,
  listenForMemberGroups,
  listenForOpenGroups,
  listGroups,
} from 'web/lib/firebase/groups'
import { getUser } from 'web/lib/firebase/users'
import { filterDefined } from 'common/util/array'
import { Contract } from 'common/contract'
import { uniq } from 'lodash'
import { listenForValues } from 'web/lib/firebase/utils'

export const useGroup = (groupId: string | undefined) => {
  const [group, setGroup] = useState<Group | null | undefined>()

  useEffect(() => {
    if (groupId) return listenForGroup(groupId, setGroup)
  }, [groupId])

  return group
}

export const useGroups = () => {
  const [groups, setGroups] = useState<Group[] | undefined>()

  useEffect(() => {
    return listenForGroups(setGroups)
  }, [])

  return groups
}

export const useOpenGroups = () => {
  const [groups, setGroups] = useState<Group[]>([])

  useEffect(() => {
    return listenForOpenGroups(setGroups)
  }, [])

  return groups
}

export const useMemberGroups = (userId: string | null | undefined) => {
  const [memberGroups, setMemberGroups] = useState<Group[] | undefined>()
  useEffect(() => {
    if (userId)
      return listenForMemberGroups(userId, (groups) => setMemberGroups(groups))
  }, [userId])
  return memberGroups
}

// Note: We cache member group ids in localstorage to speed up the initial load
export const useMemberGroupIds = (user: User | null | undefined) => {
  const [memberGroupIds, setMemberGroupIds] = useState<string[] | undefined>(
    undefined
  )

  useEffect(() => {
    if (user) {
      return listenForMemberGroupIds(user.id, (groupIds) => {
        setMemberGroupIds(groupIds)
      })
    }
  }, [user])

  return memberGroupIds
}

export function useMembers(groupId: string | undefined) {
  const [members, setMembers] = useState<User[]>([])
  useEffect(() => {
    if (groupId)
      listenForValues<GroupMemberDoc>(groupMembers(groupId), (memDocs) => {
        const memberIds = memDocs.map((memDoc) => memDoc.userId)
        Promise.all(memberIds.map((id) => getUser(id))).then((users) => {
          setMembers(users)
        })
      })
  }, [groupId])
  return members
}

export function useMemberIds(groupId: string | null) {
  const [memberIds, setMemberIds] = useState<string[]>([])
  useEffect(() => {
    if (groupId)
      return listenForValues<GroupMemberDoc>(groupMembers(groupId), (docs) => {
        setMemberIds(docs.map((doc) => doc.userId))
      })
  }, [groupId])
  return memberIds
}

export const useGroupsWithContract = (contract: Contract) => {
  const [groups, setGroups] = useState<Group[]>([])

  useEffect(() => {
    if (contract.groupSlugs)
      listGroups(uniq(contract.groupSlugs)).then((groups) =>
        setGroups(filterDefined(groups))
      )
  }, [contract.groupSlugs])

  return groups
}

export function useGroupContractIds(groupId: string) {
  const [contractIds, setContractIds] = useState<string[]>([])

  useEffect(() => {
    if (groupId)
      return listenForGroupContractDocs(groupId, (docs) =>
        setContractIds(docs.map((doc) => doc.contractId))
      )
  }, [groupId])

  return contractIds
}