import assert from "node:assert/strict";
import { readFileSync } from "node:fs";
import { test } from "node:test";
import ts from "typescript";
import { parseHTML } from "linkedom";

const source = readFileSync(new URL("../src/player/movie.ts", import.meta.url), "utf8");
const { outputText } = ts.transpileModule(source, { compilerOptions: { target: ts.ScriptTarget.ES2022, module: ts.ModuleKind.ESNext } });
const { applyMovieMask, movieDisplayable } = await import(`data:text/javascript;base64,${Buffer.from(outputText).toString("base64")}`);

test("video opacity uses the mask's red channel and retains existing transparency", () => {
  const pixels = new Uint8ClampedArray([200, 10, 20, 255, 30, 40, 50, 128]);
  applyMovieMask(pixels, new Uint8ClampedArray([0, 255, 255, 255, 128, 0, 0, 255]));
  assert.deepEqual([...pixels], [200, 10, 20, 0, 30, 40, 50, 64]);
});

test("masked movie composites frames, synchronizes the mask and stops when removed", () => {
  const { document } = parseHTML("<!doctype html><html><body></body></html>");
  globalThis.document = document;
  const create = document.createElement.bind(document);
  const videos = [], frames = [], painted = [];
  let canvases = 0;
  globalThis.requestAnimationFrame = (callback) => frames.push(callback);
  document.createElement = (name) => {
    const element = create(name);
    if (name === "video") {
      Object.assign(element, { readyState: 2, videoWidth: 2, videoHeight: 1, currentTime: 0, ended: false,
        play: () => Promise.resolve(), pause: () => { element.paused = true; } });
      videos.push(element);
    }
    if (name === "canvas") {
      const mask = canvases++ > 0;
      element.getContext = () => ({ clearRect() {}, drawImage() {},
        getImageData: () => ({ data: new Uint8ClampedArray(mask
          ? [0, 0, 0, 255, 128, 128, 128, 255] : [200, 10, 20, 255, 30, 40, 50, 255]) }),
        putImageData: (image) => painted.push([...image.data]),
      });
    }
    return element;
  };
  const canvas = movieDisplayable("/movie.webm", "/mask.webm", false);
  document.body.append(canvas);
  videos[1].currentTime = 2;
  frames.shift()();
  assert.deepEqual(painted[0], [200, 10, 20, 0, 30, 40, 50, 128]);
  assert.equal(videos[1].currentTime, 0);
  canvas.remove();
  frames.shift()();
  assert.ok(videos.every((video) => video.paused));
  assert.equal(frames.length, 0);
});