import type { WorldState } from "../types.ts";
import { pump } from "./conversation.ts";
import { changed, petEngine } from "./engine.ts";
import { store } from "./store.ts";
import { canRunLocally } from "./hosting.ts";

// The body runs in the shared engine; this module only drives its clock.
export const age = () => (store.state.pet ? Date.now() - store.state.pet.hatched : 0);
export const dayNum = () => petEngine().dayNum(Date.now());
let weather = { at: 0, value: "" };
/** The local weather, read at most once a second (the LCD draws every frame). */
export function weatherNow() {
  const now = Date.now();
  if (now - weather.at >= 1000) weather = { at: now, value: petEngine().weather(now) };
  return weather.value;
}
export function worldState(): WorldState {
  const world = petEngine().world(Date.now());
  if (!world) throw new Error("An egg has no world state.");
  return world;
}

// After an absence the engine catches up quietly (at most a week) and the pet
// notices its owner coming back after half an hour.
export function catchUp() {
  if (!canRunLocally()) return;
  const now = Date.now();
  petEngine().advance(now, true);
  lastSecond = now;
  changed();
}

let lastSecond = Date.now();
/** Restarts the body clock so time spent elsewhere (on a host) is not replayed. */
export function resetSimulationClock() {
  lastSecond = Date.now();
  petEngine().resetClock(lastSecond);
}
export function tick() {
  if (!canRunLocally()) return;
  const now = Date.now();
  if (now - lastSecond < 1000) return;
  lastSecond = now;
  changed(petEngine().advance(now));
  pump();
}