const textDecoder = new TextDecoder();
const textEncoder = new TextEncoder();
const linuxCncParameterScratchFiles = ["rs274ngc.var", "rs274ngc.var.new", "rs274ngc.var.bak"];

export function createBrowserSmokeHarness(result) {
  const sectionResults = [];
  const near = (actual, expected) => Math.abs(actual - expected) < 1e-6;
  const waitFor = async (predicate, message) => {
    for (let i = 0; i < 50; i += 1) {
      if (predicate()) {
        return;
      }
      await new Promise((resolve) => setTimeout(resolve, 100));
    }
    throw new Error(message);
  };
  const runSection = async (name, action) => {
    const sectionNumber = sectionResults.length + 1;
    result.textContent = `running: ${sectionNumber}: ${name}`;
    try {
      await action();
      sectionResults.push(name);
    } catch (error) {
      const detail = error && error.stack ? error.stack : error;
      throw new Error(`section "${name}" failed: ${detail}`);
    }
  };
  const completedMessage = () => `browser wasm smoke passed (${sectionResults.length} sections)`;
  const browserHasOpfs = () => navigator.storage && navigator.storage.getDirectory;
  const expectEvent = (events, predicate, message) => {
    if (!events.some(predicate)) {
      throw new Error(message);
    }
  };
  const expectNoEvent = (events, predicate, message) => {
    if (events.some(predicate)) {
      throw new Error(message);
    }
  };
  const expectText = (actual, expected, message) => {
    if (actual !== expected) {
      throw new Error(message);
    }
  };
  const expectIncludes = (actual, expected, message) => {
    if (!actual.includes(expected)) {
      throw new Error(message);
    }
  };
  const expectFileList = (actual, expected, message) => {
    if (
      actual.length !== expected.length ||
      expected.some((entry) => !actual.includes(entry))
    ) {
      throw new Error(`${message}: ${actual.join(",")}`);
    }
  };
  const expectErrorContaining = async (action, expectedText, message) => {
    try {
      await action();
      throw new Error(message);
    } catch (error) {
      if (!String(error?.message ?? error).includes(expectedText)) {
        throw error;
      }
    }
  };
  const expectMissingOpfsFile = async (action, message) => {
    try {
      await action();
      throw new Error(message);
    } catch (error) {
      if (error?.name !== "NotFoundError") {
        throw error;
      }
    }
  };
  const expectMissingWasmPath = (action, message) => {
    try {
      action();
      throw new Error(message);
    } catch (error) {
      if (error?.errno !== 44) {
        throw error;
      }
    }
  };
  const expectWasmFilesMissing = (fs, paths, messageForPath) => {
    for (const wasmPath of paths) {
      expectMissingWasmPath(
        () => fs.readFile(wasmPath),
        messageForPath(wasmPath),
      );
    }
  };
  const decodeBytes = (bytes) => textDecoder.decode(bytes);
  const encodeText = (text) => textEncoder.encode(text);
  const readOpfsText = async (simulator, path) => decodeBytes(await simulator.fs.opfs.readFile(path));
  const readWasmText = (simulator, path) => decodeBytes(simulator.fs.module.FS.readFile(path));
  const writeWasmText = (simulator, path, text) => simulator.fs.module.FS.writeFile(path, encodeText(text));
  const removeWasmPathIfExists = (simulator, path) => {
    try {
      simulator.fs.module.FS.unlink(path);
    } catch (error) {
      if (error?.errno !== 44) {
        throw error;
      }
    }
  };
  const expectOpfsText = async (simulator, path, expected, message) => {
    expectText(await readOpfsText(simulator, path), expected, message);
  };
  const expectWasmText = (simulator, path, expected, message) => {
    expectText(readWasmText(simulator, path), expected, message);
  };
  const expectOpfsExists = async (simulator, path, message) => {
    if (!(await simulator.fs.opfs.exists(path))) {
      throw new Error(message);
    }
  };
  const expectOpfsMissing = async (simulator, path, message) => {
    if (await simulator.fs.opfs.exists(path)) {
      throw new Error(message);
    }
  };
  const expectOpfsFileStat = async (simulator, path, expectedSize, message) => {
    const stat = await simulator.fs.opfs.stat(path);
    if (stat.kind !== "file" || stat.size !== expectedSize) {
      throw new Error(message);
    }
  };
  const expectOpfsDirectoryStat = async (simulator, path, message) => {
    const stat = await simulator.fs.opfs.stat(path);
    if (stat.kind !== "directory" || stat.size !== null) {
      throw new Error(message);
    }
  };
  const expectLinuxCncParameterScratchMissing = (simulator, messageForPath) => {
    for (const parameterPath of linuxCncParameterScratchFiles) {
      expectMissingWasmPath(
        () => simulator.fs.module.FS.stat(parameterPath),
        messageForPath(parameterPath),
      );
    }
  };

  return {
    browserHasOpfs,
    completedMessage,
    decodeBytes,
    encodeText,
    expectErrorContaining,
    expectEvent,
    expectFileList,
    expectIncludes,
    expectLinuxCncParameterScratchMissing,
    expectMissingOpfsFile,
    expectMissingWasmPath,
    expectNoEvent,
    expectOpfsDirectoryStat,
    expectOpfsExists,
    expectOpfsFileStat,
    expectOpfsMissing,
    expectOpfsText,
    expectText,
    expectWasmFilesMissing,
    expectWasmText,
    near,
    readOpfsText,
    readWasmText,
    removeWasmPathIfExists,
    runSection,
    waitFor,
    writeWasmText,
  };
}