"use client"

import useSWR from "swr"
import * as api from "./api"
import type { CalendarEvent, SignupStatus } from "./types"

export function useRooms() {
  const { data, error, isLoading, mutate } = useSWR("rooms", () => api.getRooms())
  return { rooms: data ?? [], error, isLoading, mutate }
}

// activeRoomId === null => all rooms combined via /events
export function useEvents(activeRoomId: number | null, from?: string, to?: string) {
  const key = activeRoomId === null ? ["events", from, to] : ["room-events", activeRoomId, from, to]
  const { data, error, isLoading, mutate } = useSWR(
    key,
    () =>
      activeRoomId === null
        ? api.getUserEvents(from, to)
        : api.getRoomEvents(activeRoomId, from, to),
    // Keep showing the previous week/room's events while the new key loads,
    // instead of flashing an empty/loading state on every switch.
    { keepPreviousData: true },
  )
  return { events: data ?? [], error, isLoading, mutate }
}

export function useRoomMembers(roomId: number | null) {
  const { data, error, isLoading, mutate } = useSWR(
    roomId === null ? null : ["room-members", roomId],
    () => api.getRoomMembers(roomId as number),
  )
  return { members: data ?? [], error, isLoading, mutate }
}

export function useRoomPermissions(roomId: number | null) {
  const { data, error, isLoading, mutate } = useSWR(
    roomId === null ? null : ["room-whoami", roomId],
    () => api.roomWhoami(roomId as number),
  )
  return { permissions: data, error, isLoading, mutate }
}

// Bulk-fetch the current user's own RSVP status for every visible proposal
// event, so the week view can color-code events the user has declined.
// Only proposal-type events carry RSVPs, so we skip busy/private blocks.
export function useMyResponses(events: CalendarEvent[], currentUserId: number | null) {
  const proposalIds = events
    .filter((e) => e.type === "proposal")
    .map((e) => e.id)
    .sort((a, b) => a - b)

  const key =
    currentUserId !== null && proposalIds.length > 0
      ? ["my-responses", currentUserId, proposalIds.join(",")]
      : null

  const { data, isLoading } = useSWR(key, async () => {
    const entries = await Promise.all(
      proposalIds.map(async (id) => {
        const responses = await api.getEventResponses(id)
        const mine = responses.find((r) => r.user_id === currentUserId)?.status
        return [id, mine] as [number, SignupStatus | undefined]
      }),
    )
    return Object.fromEntries(entries) as Record<number, SignupStatus | undefined>
  })

  return { myResponses: data ?? {}, isLoading }
}