"use strict";

const { createHash } = require("node:crypto");
const { mkdir, readFile, writeFile } = require("node:fs/promises");
const path = require("node:path");
const { deflateRawSync } = require("node:zlib");

const FIREFOX_ARCHIVE_FILES = Object.freeze([
  "background.js",
  "content.css",
  "content.js",
  "fonts/NotoSansGlagolitic-Regular.ttf",
  "fonts/OFL.txt",
  "fonts/Shafarik-OFL.txt",
  "fonts/Shafarik-Regular.ttf",
  "icons/icon-16.svg",
  "icons/icon-32.svg",
  "icons/icon-48.svg",
  "icons/icon-96.svg",
  "manifest.json",
  "popup.css",
  "popup.html",
  "popup.js",
  "transliterate.js"
]);
const CHROMIUM_ARCHIVE_FILES = Object.freeze([
  ...FIREFOX_ARCHIVE_FILES.map((relativePath) =>
    relativePath.endsWith(".svg") ? relativePath.replace(/\.svg$/, ".png") : relativePath
  ),
  "icons/icon-128.png",
  "icons/icon-48.svg"
]);
const TARGETS = new Set(["firefox", "chromium"]);

const VERSION_PATTERN = /^(0|[1-9][0-9]{0,8})(\.(0|[1-9][0-9]{0,8})){0,3}$/;
const UTF8_FLAG = 0x0800;
const DEFLATE_METHOD = 8;
const DOS_TIME = 0;
const DOS_DATE = (1 << 5) | 1;

function normalizeVersion(value) {
  if (typeof value !== "string" || value.length === 0) {
    throw new Error("A package or release version is required.");
  }

  const version = /^[vV]/.test(value) ? value.slice(1) : value;
  if (!VERSION_PATTERN.test(version)) {
    throw new Error(
      `Invalid Mozilla extension version ${JSON.stringify(value)}. ` +
        "Use one to four dot-separated integers without leading zeroes; a leading v is allowed."
    );
  }

  return version;
}

function createManifest(contents, version, target) {
  const manifest = JSON.parse(contents.toString("utf8"));
  manifest.version = version;

  if (target === "firefox") {
    return manifest;
  }

  if (version.split(".").some((part) => Number(part) > 65535)) {
    throw new Error(`Chromium extension version parts cannot exceed 65535: ${version}`);
  }

  manifest.manifest_version = 3;
  manifest.minimum_chrome_version = "102";
  delete manifest.browser_specific_settings;
  manifest.host_permissions = manifest.permissions.filter(
    (permission) => permission === "<all_urls>" || permission.includes("://")
  );
  manifest.permissions = manifest.permissions.filter(
    (permission) => !manifest.host_permissions.includes(permission)
  );
  manifest.background = { service_worker: "background.js" };
  manifest.action = manifest.browser_action;
  delete manifest.browser_action;
  manifest.web_accessible_resources = [
    {
      resources: manifest.web_accessible_resources,
      matches: ["<all_urls>"]
    }
  ];

  for (const icons of [manifest.icons, manifest.action.default_icon]) {
    for (const size of Object.keys(icons)) {
      icons[size] = icons[size].replace(/\.svg$/, ".png");
    }
  }
  manifest.icons["128"] = "icons/icon-128.png";

  return manifest;
}

function crc32(buffer) {
  let crc = 0xffffffff;

  for (const byte of buffer) {
    crc ^= byte;
    for (let bit = 0; bit < 8; bit += 1) {
      crc = (crc >>> 1) ^ (0xedb88320 & -(crc & 1));
    }
  }

  return (crc ^ 0xffffffff) >>> 0;
}

function createZip(entries) {
  const localRecords = [];
  const centralRecords = [];
  let offset = 0;

  for (const entry of entries) {
    const name = Buffer.from(entry.name, "utf8");
    const compressed = deflateRawSync(entry.contents, { level: 9 });
    const checksum = crc32(entry.contents);

    const localHeader = Buffer.alloc(30);
    localHeader.writeUInt32LE(0x04034b50, 0);
    localHeader.writeUInt16LE(20, 4);
    localHeader.writeUInt16LE(UTF8_FLAG, 6);
    localHeader.writeUInt16LE(DEFLATE_METHOD, 8);
    localHeader.writeUInt16LE(DOS_TIME, 10);
    localHeader.writeUInt16LE(DOS_DATE, 12);
    localHeader.writeUInt32LE(checksum, 14);
    localHeader.writeUInt32LE(compressed.length, 18);
    localHeader.writeUInt32LE(entry.contents.length, 22);
    localHeader.writeUInt16LE(name.length, 26);
    localHeader.writeUInt16LE(0, 28);

    const localRecord = Buffer.concat([localHeader, name, compressed]);
    localRecords.push(localRecord);

    const centralHeader = Buffer.alloc(46);
    centralHeader.writeUInt32LE(0x02014b50, 0);
    centralHeader.writeUInt16LE(0x0314, 4);
    centralHeader.writeUInt16LE(20, 6);
    centralHeader.writeUInt16LE(UTF8_FLAG, 8);
    centralHeader.writeUInt16LE(DEFLATE_METHOD, 10);
    centralHeader.writeUInt16LE(DOS_TIME, 12);
    centralHeader.writeUInt16LE(DOS_DATE, 14);
    centralHeader.writeUInt32LE(checksum, 16);
    centralHeader.writeUInt32LE(compressed.length, 20);
    centralHeader.writeUInt32LE(entry.contents.length, 24);
    centralHeader.writeUInt16LE(name.length, 28);
    centralHeader.writeUInt16LE(0, 30);
    centralHeader.writeUInt16LE(0, 32);
    centralHeader.writeUInt16LE(0, 34);
    centralHeader.writeUInt16LE(0, 36);
    centralHeader.writeUInt32LE((0o100644 << 16) >>> 0, 38);
    centralHeader.writeUInt32LE(offset, 42);
    centralRecords.push(Buffer.concat([centralHeader, name]));

    offset += localRecord.length;
  }

  const centralDirectory = Buffer.concat(centralRecords);
  const endRecord = Buffer.alloc(22);
  endRecord.writeUInt32LE(0x06054b50, 0);
  endRecord.writeUInt16LE(0, 4);
  endRecord.writeUInt16LE(0, 6);
  endRecord.writeUInt16LE(entries.length, 8);
  endRecord.writeUInt16LE(entries.length, 10);
  endRecord.writeUInt32LE(centralDirectory.length, 12);
  endRecord.writeUInt32LE(offset, 16);
  endRecord.writeUInt16LE(0, 20);

  return Buffer.concat([...localRecords, centralDirectory, endRecord]);
}

async function packageExtension({
  rootDirectory,
  outputDirectory,
  target = "firefox",
  version: requestedVersion
}) {
  if (!TARGETS.has(target)) {
    throw new Error(`Unknown extension target: ${target}`);
  }

  const packageMetadata = JSON.parse(
    await readFile(path.join(rootDirectory, "package.json"), "utf8")
  );
  const version = normalizeVersion(requestedVersion ?? packageMetadata.version);
  const archiveFiles =
    target === "firefox" ? FIREFOX_ARCHIVE_FILES : CHROMIUM_ARCHIVE_FILES;
  const entries = [];

  for (const relativePath of archiveFiles) {
    let contents = await readFile(path.join(rootDirectory, relativePath));

    if (relativePath === "manifest.json") {
      const manifest = createManifest(contents, version, target);
      contents = Buffer.from(`${JSON.stringify(manifest, null, 2)}\n`);
    }

    entries.push({ name: relativePath, contents });
  }

  const archive = createZip(entries);
  const archiveName =
    target === "firefox"
      ? `glagolify-${version}.xpi`
      : `glagolify-${version}-chromium.zip`;
  const archivePath = path.join(outputDirectory, archiveName);
  const checksumPath = `${archivePath}.sha256`;
  const digest = createHash("sha256").update(archive).digest("hex");

  await mkdir(outputDirectory, { recursive: true });
  await writeFile(archivePath, archive);
  await writeFile(checksumPath, `${digest}  ${archiveName}\n`);

  return { archiveName, archivePath, checksumPath, digest, target, version };
}

function parseArguments(arguments_) {
  let outputDirectory = "dist";
  let target = "all";
  let version;

  for (let index = 0; index < arguments_.length; index += 1) {
    const argument = arguments_[index];

    if (
      argument === "--version" ||
      argument === "--output-dir" ||
      argument === "--target"
    ) {
      const value = arguments_[index + 1];
      if (!value || value.startsWith("--")) {
        throw new Error(`${argument} requires a value.`);
      }

      if (argument === "--version") {
        version = value;
      } else if (argument === "--output-dir") {
        outputDirectory = value;
      } else {
        target = value;
      }
      index += 1;
    } else {
      throw new Error(`Unknown argument: ${argument}`);
    }
  }

  if (target !== "all" && !TARGETS.has(target)) {
    throw new Error(`Unknown extension target: ${target}`);
  }

  return { outputDirectory, target, version };
}

async function main() {
  const rootDirectory = path.resolve(__dirname, "..");
  const options = parseArguments(process.argv.slice(2));
  const targets = options.target === "all" ? [...TARGETS] : [options.target];

  for (const target of targets) {
    const result = await packageExtension({
      rootDirectory,
      outputDirectory: path.resolve(rootDirectory, options.outputDirectory),
      target,
      version: options.version
    });

    process.stdout.write(
      `Created ${path.relative(rootDirectory, result.archivePath)} for ${target} ` +
        `version ${result.version}\nSHA-256 ${result.digest}\n`
    );
  }
}

if (require.main === module) {
  main().catch((error) => {
    console.error(error.message);
    process.exitCode = 1;
  });
}

module.exports = {
  CHROMIUM_ARCHIVE_FILES,
  FIREFOX_ARCHIVE_FILES,
  normalizeVersion,
  packageExtension
};