nEngine/packages/render/src/sync/local.ts

import type { AnimationDef, Engine, IntentSystem, MapDef, ParticleDef, ShaderDef, ShopDef, SoundDef, SpriteDef, TimeSystem } from "@nengine/core";
import type { RenderSnapshot, ViewportHandle } from "../viewport.js";
import type { SoundPlayer } from "../sound.js";
import { arrowDirection } from "../keys.js";

export interface LocalSyncHandle {
  setTimeLabel(fn: (label: string) => void): void;
  refresh(): void;
  intent(action: string, args: Record<string, unknown>): void;
  input(input: string): void;
  destroy(): void;
}

export interface LocalSyncOptions {
  sound?: SoundPlayer;
}

export function connectLocal(engine: Engine, viewport: ViewportHandle, opts?: LocalSyncOptions): LocalSyncHandle {
  const time = engine.systems.get<TimeSystem>("time");
  const sound = opts?.sound;
  let label: ((label: string) => void) | undefined;

  function refresh(): void {
    const map = engine.registry.list<MapDef>("map")[0];
    if (map) {
      const snapshot: RenderSnapshot = {
        map,
        world: engine.world.snapshot(),
        sprites: engine.registry.list<SpriteDef>("sprite"),
        sounds: engine.registry.list<SoundDef>("sound"),
        particles: engine.registry.list<ParticleDef>("particle"),
        shaders: engine.registry.list<ShaderDef>("shader"),
        shops: engine.registry.list<ShopDef>("shop"),
        animations: engine.registry.list<AnimationDef>("animation"),
        assets: Object.fromEntries(engine.assets),
      };
      sound?.setCatalog(snapshot.sounds ?? []);
      sound?.setAssets(snapshot.assets ?? {});
      viewport.render(snapshot);
    } else {
      viewport.render();
    }
    const state = time?.get();
    if (state && label) {
      label(`Day ${state.day}, ${state.season}`);
    }
  }

  refresh();

  const unsubscribeSound = engine.events.on("sound-play", (payload) => {
    sound?.onEvent({ event: "sound-play", payload });
  });
  const unsubscribeBgmPlay = engine.events.on("bgm-play", (payload) => {
    sound?.onEvent({ event: "bgm-play", payload });
  });
  const unsubscribeBgmStop = engine.events.on("bgm-stop", (payload) => {
    sound?.onEvent({ event: "bgm-stop", payload });
  });
  const unsubscribeParticle = engine.events.on("particle", (payload) => {
    viewport.onEvent({ event: "particle", payload });
  });

  return {
    setTimeLabel(fn: (label: string) => void): void {
      label = fn;
      refresh();
    },
    refresh,
    intent(action: string, args: Record<string, unknown>): void {
      engine.systems.get<IntentSystem>("intent")?.handle(action, args);
      refresh();
    },
    input(input: string): void {
      const direction = arrowDirection(input);
      if (!direction) return;
      const player = engine.world.get("player");
      if (!player) return;
      const x = (typeof player.x === "number" ? player.x : 0) + direction.dx;
      const y = (typeof player.y === "number" ? player.y : 0) + direction.dy;
      engine.systems.get<IntentSystem>("intent")?.handle("move", { tile: { x, y } });
      refresh();
    },
    destroy(): void {
      unsubscribeSound();
      unsubscribeBgmPlay();
      unsubscribeBgmStop();
      unsubscribeParticle();
      label = undefined;
    },
  };
}