import type { WebSocket } from "ws";
import type { MeetingRole } from "./token";

export type Participant = {
  ws: WebSocket;
  participantId: string;
  name: string;
  role: MeetingRole;
};

type Room = {
  participants: Map<string, Participant>;
  kickedParticipantIds: Set<string>;
};

// In-memory only — this server process is the single source of truth for
// signaling (no media is ever stored or relayed through it). If this app is
// ever scaled to multiple instances, this state needs to move to a shared
// store (e.g. Redis pub/sub) alongside a real SFU.
const rooms = new Map<string, Room>();

function getOrCreateRoom(eventSlug: string): Room {
  let room = rooms.get(eventSlug);
  if (!room) {
    room = { participants: new Map(), kickedParticipantIds: new Set() };
    rooms.set(eventSlug, room);
  }
  return room;
}

export function isKicked(eventSlug: string, participantId: string): boolean {
  return rooms.get(eventSlug)?.kickedParticipantIds.has(participantId) ?? false;
}

export function joinRoom(eventSlug: string, participant: Participant): Participant[] {
  const room = getOrCreateRoom(eventSlug);
  const existing = [...room.participants.values()];
  room.participants.set(participant.participantId, participant);
  return existing;
}

export function leaveRoom(eventSlug: string, participantId: string) {
  const room = rooms.get(eventSlug);
  if (!room) return;
  room.participants.delete(participantId);
  if (room.participants.size === 0) rooms.delete(eventSlug);
}

export function kickFromRoom(eventSlug: string, participantId: string) {
  const room = rooms.get(eventSlug);
  if (!room) return;
  room.kickedParticipantIds.add(participantId);
  room.participants.delete(participantId);
}

export function getParticipant(eventSlug: string, participantId: string): Participant | undefined {
  return rooms.get(eventSlug)?.participants.get(participantId);
}

export function getRoomParticipants(eventSlug: string): Participant[] {
  return [...(rooms.get(eventSlug)?.participants.values() ?? [])];
}

export function broadcast(
  eventSlug: string,
  message: unknown,
  opts: { exclude?: string } = {},
) {
  const room = rooms.get(eventSlug);
  if (!room) return;
  const data = JSON.stringify(message);
  for (const p of room.participants.values()) {
    if (opts.exclude && p.participantId === opts.exclude) continue;
    if (p.ws.readyState === p.ws.OPEN) p.ws.send(data);
  }
}