import { Server as IOServer } from 'socket.io';
import type { FastifyInstance } from 'fastify';
import {
  SOCKET_EVENTS,
  departmentRoom,
  DEPARTMENTS,
  type ServerToClientEvents,
  type ClientToServerEvents,
  type AuthUser,
  type Department,
  type Officer,
  type OfficerPositionUpdate,
  type OfficerDutyUpdate,
  type DispatchCall,
  type Warrant,
  type Coords,
} from '@d4rk-tablet/shared';
import { env } from '../config/env';
import { officerSnapshot } from './officers';

type AppIO = IOServer<ClientToServerEvents, ServerToClientEvents>;

let io: AppIO | null = null;

/** Departments, in denen der User Mitglied ist (für Room-Zuordnung). */
function userDepartments(user: AuthUser): Department[] {
  return DEPARTMENTS.filter((d) => user.roles.includes(d));
}

export function initSocket(app: FastifyInstance): AppIO {
  io = new IOServer<ClientToServerEvents, ServerToClientEvents>(app.server, {
    cors: { origin: env.CORS_ORIGINS, credentials: true },
    transports: ['websocket'],
  });

  // JWT-Auth beim Handshake
  io.use((socket, next) => {
    try {
      const token = (socket.handshake.auth as { token?: string })?.token;
      if (!token) return next(new Error('Kein Token'));
      const user = app.jwt.verify<AuthUser>(token);
      socket.data.user = user;
      next();
    } catch {
      next(new Error('Ungültiges Token'));
    }
  });

  io.on('connection', (socket) => {
    const user = socket.data.user as AuthUser;
    const depts = userDepartments(user);
    for (const d of depts) void socket.join(departmentRoom(d));

    // Initialer Snapshot der Officer der eigenen Departments
    const snapshot: Officer[] = depts.flatMap((d) => officerSnapshot(d));
    socket.emit(SOCKET_EVENTS.OFFICER_SNAPSHOT, snapshot);

    // Client → Server: Waypoint an einen Officer senden (→ Bridge in M7)
    socket.on(SOCKET_EVENTS.OFFICER_SET_WAYPOINT, (payload) => {
      app.log.info({ payload }, 'setWaypoint (Bridge-Weiterleitung folgt in M7)');
    });
  });

  app.addHook('onClose', async () => {
    await io?.close();
  });

  return io;
}

function getIO(): AppIO {
  if (!io) throw new Error('Socket.io nicht initialisiert');
  return io;
}

// ── Broadcast-Helfer (von Services genutzt) ──
export function broadcastDispatchCreated(call: DispatchCall): void {
  getIO().to(departmentRoom(call.department)).emit(SOCKET_EVENTS.DISPATCH_CREATED, call);
}

export function broadcastDispatchUpdated(call: DispatchCall): void {
  getIO().to(departmentRoom(call.department)).emit(SOCKET_EVENTS.DISPATCH_UPDATED, call);
}

export function broadcastOfficerMoved(dept: Department, update: OfficerPositionUpdate): void {
  getIO().to(departmentRoom(dept)).emit(SOCKET_EVENTS.OFFICER_MOVED, update);
}

export function broadcastOfficerDuty(dept: Department, update: OfficerDutyUpdate): void {
  getIO().to(departmentRoom(dept)).emit(SOCKET_EVENTS.OFFICER_DUTY, update);
}

export function broadcastWarrantUpdated(dept: Department, warrant: Warrant): void {
  getIO().to(departmentRoom(dept)).emit(SOCKET_EVENTS.WARRANT_UPDATED, warrant);
}

export type { Coords };