"use strict";

(function (global) {
  const DomainIds = global.TarinaiDomainIds;
  if (!DomainIds) throw new Error("TarinaiDomainIds must be loaded before weather_system.js");
  const WEATHER_IDS = DomainIds.WEATHER_IDS;
  function canonicalWeather(value = "sunny") {
    return DomainIds.canonicalWeatherId(value);
  }

  function chooseNext(current = "sunny") {
    const id = canonicalWeather(current);
    const choices = id === "light_rain"
      ? WEATHER_IDS.filter(weather => weather !== "light_rain")
      : WEATHER_IDS;
    return pick(choices);
  }

  function resetTimer() {
    return rand(CONFIG.weatherChangeMin, CONFIG.weatherChangeMax);
  }

  function fixedWeatherFor(worldRef) {
    const fixed = global.TarinaiGround.fixedWeather(worldRef?.groundType || "soil") || "";
    return fixed || null;
  }

  function enforceFixedWeather(worldRef) {
    const fixed = fixedWeatherFor(worldRef);
    if (!fixed || !worldRef) return false;
    const previous = canonicalWeather(worldRef.weather || "sunny");
    worldRef.weather = canonicalWeather(fixed);
    worldRef.nextWeatherChange = resetTimer();
    if (previous !== worldRef.weather) {
      worldRef.log?.(`\u5929\u6C17: ${weatherLabel(worldRef.weather)}`);
    }
    return true;
  }

  function shouldDropRainWater(worldRef, dt = 0) {
    return Boolean(
      worldRef?.weather === "light_rain" &&
      Math.random() < Math.max(0, Number(dt) || 0) * 0.24
    );
  }

  function createRainWaterItem(worldRef, opts = {}) {
    const px = Number(opts?.x);
    const py = Number(opts?.y);
    const hasX = Number.isFinite(px);
    const hasY = Number.isFinite(py);
    const x = hasX ? px : rand(58, worldRef.w - 58);
    const y = hasY ? py : rand(58, worldRef.h - 58);
    const drop = new Item("water", x, y);
    drop.rainDrop = opts?.rainDrop === true || (!hasX && !hasY);
    const amount = Number(opts?.amount);
    drop.amount = Number.isFinite(amount) ? amount : rand(24, 58);
    // Rain drops, placed water drops, and water-balloon splashes all use the
    // same Item("water") object.  Optional velocity only gives that same water
    // item a short ballistic motion; it is not a separate splash item type.
    const vx = Number(opts?.vx);
    const vy = Number(opts?.vy);
    if (Number.isFinite(vx) || Number.isFinite(vy)) {
      drop.prevX = drop.x;
      drop.prevY = drop.y;
      drop.vx = Number.isFinite(vx) ? vx : 0;
      drop.vy = Number.isFinite(vy) ? vy : 0;
    }
    const flight = Number(opts?.splashFlightTimer ?? opts?.flightTimer);
    if (Number.isFinite(flight) && flight > 0) drop.splashFlightTimer = flight;
    return drop;
  }

  function applyNextWeather(worldRef) {
    if (!worldRef) return null;
    if (enforceFixedWeather(worldRef)) return worldRef.weather || "sunny";
    const previous = canonicalWeather(worldRef.weather || "sunny");
    const next = chooseNext(previous);
    worldRef.weather = canonicalWeather(next);
    worldRef.nextWeatherChange = resetTimer();
    if (next !== previous) {
      worldRef.log?.(`\u5929\u6C17: ${weatherLabel(next)}`);
    }
    return next;
  }

  global.TarinaiWeatherSystem = Object.freeze({
    enforceFixedWeather,
    shouldDropRainWater,
    createRainWaterItem,
    applyNextWeather,
  });
})(typeof window !== "undefined" ? window : globalThis);