import fs from "fs-extra";
import stream from "stream";
import { fileURLToPath } from "url";
import { promisify } from "util";
import path from "path";
import tempy from "tempy";
import execa from "execa";
import chalk from "chalk";
import got from "got";
import decompress from "decompress";
import sumchecker from "sumchecker";

// https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c#what-do-i-use-instead-of-__dirname-and-__filename
const __dirname = path.dirname(fileURLToPath(import.meta.url));

installHugo()
  .then((bin) => {
    // print output of `hugo version` to console
    const { stdout } = execa.sync(bin, ["version"]);
    return stdout;
  })
  .then((version) => {
    console.log(chalk.green("✔ Hugo installed successfully!"));
    console.log(version);
  })
  .catch((error) => {
    // pass whatever error occured along the way along to console
    console.error(chalk.red("✖ Hugo installation failed. :("));
    throw error;
  });

async function installHugo() {
  // this package's version number (should) always match the Hugo release we want
  const { version } = await fs.readJson("./package.json");
  const downloadBaseUrl = `https://github.com/gohugoio/hugo/releases/download/v${version}/`;
  const releaseFile = getArchiveFilename(version, process.platform, process.arch);
  const checksumFile = `hugo_${version}_checksums.txt`;

  // stop here if there's nothing we can download
  if (!releaseFile) {
    throw "Are you sure this platform is supported?";
  }

  const releaseUrl = downloadBaseUrl + releaseFile;
  const checksumUrl = downloadBaseUrl + checksumFile;
  const vendorDir = path.join(__dirname, "vendor");
  const tempDir = tempy.directory({ prefix: "hugo-node" });
  const archivePath = path.join(tempDir, releaseFile);
  const checksumPath = path.join(tempDir, checksumFile);
  const binName = process.platform === "win32" ? "hugo.exe" : "hugo";
  const binPath = path.join(vendorDir, binName);

  try {
    // ensure the target directory exists
    await fs.mkdirp(vendorDir, {
      mode: 0o2775, // ensure binary is executable
    });

    await Promise.all([
      // fetch the archive file from GitHub
      downloadFile(releaseUrl, archivePath),
      // fetch the checksum file from GitHub
      downloadFile(checksumUrl, checksumPath),
    ]);

    // validate the checksum of the download
    await checkChecksum(tempDir, checksumPath, releaseFile);

    // extract the downloaded file
    await decompress(archivePath, vendorDir);
  } finally {
    // delete temporary directory
    await fs.remove(tempDir);
  }

  // return the full path to our Hugo binary
  return binPath;
}

async function downloadFile(url, dest) {
  const pipeline = promisify(stream.pipeline);

  return await pipeline(
    got.stream(url, { followRedirect: true }),  // GitHub releases redirect to unpredictable URLs
    fs.createWriteStream(dest),
  );
}

async function checkChecksum(baseDir, checksumFile, binFile) {
  const checker = new sumchecker.ChecksumValidator("sha256", checksumFile, {
    defaultTextEncoding: "binary",
  });

  return await checker.validate(baseDir, binFile);
}

// Hugo Extended supports: macOS x64, macOS ARM64, Linux x64, Windows x64.
// all other combos fall back to vanilla Hugo. there are surely much better ways
// to do this but this is easy to read/update. :)
function getArchiveFilename(version, os, arch) {
  const filename =
    // macOS
    os === "darwin" && arch === "x64" ?
      `hugo_extended_${version}_macOS-64bit.tar.gz` :
    os === "darwin" && arch === "arm64" ?
      `hugo_extended_${version}_macOS-ARM64.tar.gz` :

    // Windows
    os === "win32" && arch === "x64" ?
      `hugo_extended_${version}_Windows-64bit.zip` :
    os === "win32" && arch.endsWith("32") ?
      `hugo_${version}_Windows-32bit.zip` :

    // Linux
    os === "linux" && arch === "x64" ?
      `hugo_extended_${version}_Linux-64bit.tar.gz` :
    os === "linux" && arch.endsWith("32") ?
      `hugo_${version}_Linux-32bit.tar.gz` :
    os === "linux" && arch === "arm" ?
      `hugo_${version}_Linux-ARM.tar.gz` :
    os === "linux" && arch === "arm64" ?
      `hugo_${version}_Linux-ARM64.tar.gz` :

    // FreeBSD
    os === "freebsd" && arch === "x64" ?
      `hugo_${version}_FreeBSD-64bit.tar.gz` :
    os === "freebsd" && arch.endsWith("32") ?
      `hugo_${version}_FreeBSD-32bit.tar.gz` :
    os === "freebsd" && arch === "arm" ?
      `hugo_${version}_FreeBSD-ARM.tar.gz` :
    os === "freebsd" && arch === "arm64" ?
      `hugo_${version}_FreeBSD-ARM64.tar.gz` :

    // OpenBSD
    os === "openbsd" && arch === "x64" ?
      `hugo_${version}_OpenBSD-64bit.tar.gz` :
    os === "openbsd" && arch.endsWith("32") ?
      `hugo_${version}_OpenBSD-32bit.tar.gz` :
    os === "openbsd" && arch === "arm" ?
      `hugo_${version}_OpenBSD-ARM.tar.gz` :
    os === "openbsd" && arch === "arm64" ?
      `hugo_${version}_OpenBSD-ARM64.tar.gz` :

    // not gonna work :(
    null;

  return filename;
}

export { installHugo };