import { useGLTF } from "@react-three/drei";
import { useThree } from "@react-three/fiber";
import { useCallback, type ReactNode } from "react";
import type { WebGLRenderer } from "three";
import { KTX2Loader, type GLTFLoader } from "three-stdlib";
import { resolveContentUrl } from "../content/contentManager";
import { configureRunewakerTerrainLoader } from "./runewakerTerrainMaterial";
import { configureRunewakerSurfaceDetailLoader } from "./runewakerSurfaceDetailMaterial";
import { configureRunewakerWaterLoader } from "./runewakerWaterMaterial";
import { configureWowTerrainLoader } from "./wowTerrainMaterial";

export const KTX2_TRANSCODER_PATH = `${import.meta.env.BASE_URL}basis/`;

const ktx2Loaders = new WeakMap<WebGLRenderer, KTX2Loader>();

function ktx2LoaderFor(renderer: WebGLRenderer): KTX2Loader {
  const cached = ktx2Loaders.get(renderer);
  if (cached) return cached;

  const loader = new KTX2Loader();
  loader.setTranscoderPath(KTX2_TRANSCODER_PATH);
  loader.detectSupport(renderer);
  ktx2Loaders.set(renderer, loader);
  return loader;
}

/**
 * Marks the part of a Canvas that shares its GLTF decoder. KTX2Loader instances
 * intentionally live with their weakly referenced renderer: disposing one from
 * React cleanup can abort a GLB that is still decoding or cached by useGLTF.
 */
export function GameGltfLoaderLifecycle({ children }: { readonly children: ReactNode }) {
  return children;
}

/**
 * Loads shipped world and creature GLBs with Meshopt and KTX2 support.
 * Keeping one KTX2Loader per renderer also keeps Three from creating a worker
 * pool for every mounted model.
 */
export function useGameGLTF(url: string) {
  const resolvedUrl = resolveContentUrl(url);
  const renderer = useThree((state) => state.gl);
  const extendLoader = useCallback((loader: GLTFLoader) => {
    loader.setKTX2Loader(ktx2LoaderFor(renderer));
    configureRunewakerTerrainLoader(loader);
    configureRunewakerSurfaceDetailLoader(loader);
    configureRunewakerWaterLoader(loader);
    configureWowTerrainLoader(loader);
  }, [renderer]);

  return useGLTF(resolvedUrl, false, true, extendLoader);
}

export function useGameGLTFs(urls: readonly string[]) {
  const resolvedUrls = urls.map(resolveContentUrl);
  const renderer = useThree((state) => state.gl);
  const extendLoader = useCallback((loader: GLTFLoader) => {
    loader.setKTX2Loader(ktx2LoaderFor(renderer));
    configureRunewakerTerrainLoader(loader);
    configureRunewakerSurfaceDetailLoader(loader);
    configureRunewakerWaterLoader(loader);
    configureWowTerrainLoader(loader);
  }, [renderer]);

  return useGLTF(resolvedUrls, false, true, extendLoader);
}