// @ts-check

(async () => {
  const { Octokit } = require('@octokit/rest');
  const fs = require('fs');
  const path = require('path');

  const octokit = new Octokit({
    userAgent: 'Arduino IDE compose-changelog.js',
  });

  const response = await octokit.rest.repos
    .listReleases({
      owner: 'arduino',
      repo: 'arduino-ide',
    })
    .catch((err) => {
      console.error(err);
      process.exit(1);
    });

  const releases = response.data;

  let fullChangelog = releases.reduce((acc, item, index) => {
    // Process each line separately
    const body = item.body.split('\n').map(processLine).join('\n');
    // item.name is the name of the release changelog
    return (
      acc +
      `## ${item.name}\n\n${body}${
        index !== releases.length - 1 ? '\n\n---\n\n' : '\n'
      }`
    );
  }, '');

  const args = process.argv.slice(2);
  if (args.length == 0) {
    console.error('Missing argument to destination file');
    process.exit(1);
  }
  const changelogFile = path.resolve(args[0]);

  await fs.writeFile(
    changelogFile,
    fullChangelog,
    {
      flag: 'w+',
    },
    (err) => {
      if (err) {
        console.error(err);
        process.exit(1);
      }
      console.log('Changelog written to', changelogFile);
    }
  );
})();

// processLine applies different substitutions to line string.
// We're assuming that there are no more than one substitution
// per line to be applied.
const processLine = (line) => {
  // Check if a link with one of the following format exists:
  // * [#123](https://github.com/arduino/arduino-ide/pull/123)
  // * [#123](https://github.com/arduino/arduino-ide/issues/123)
  // * [#123](https://github.com/arduino/arduino-ide/pull/123/)
  // * [#123](https://github.com/arduino/arduino-ide/issues/123/)
  // If it does return the line as is.
  let r =
    /(\(|\[)#\d+(\)|\])(\(|\[)https:\/\/github\.com\/arduino\/arduino-ide\/(pull|issues)\/(\d+)\/?(\)|\])/gm;
  if (r.test(line)) {
    return line;
  }

  // Check if a issue or PR link with the following format exists:
  // * #123
  // If it does it's changed to:
  // * [#123](https://github.com/arduino/arduino-ide/pull/123)
  r = /(?<![\w\d\/_]{1})#((\d)+)(?![\w\d\/_]{1})/gm;
  if (r.test(line)) {
    return line.replace(
      r,
      `[#$1](https://github.com/arduino/arduino-ide/pull/$1)`
    );
  }

  // Check if a link with one of the following format exists:
  // * https://github.com/arduino/arduino-ide/pull/123
  // * https://github.com/arduino/arduino-ide/issues/123
  // * https://github.com/arduino/arduino-ide/pull/123/
  // * https://github.com/arduino/arduino-ide/issues/123/
  // If it does it's changed respectively to:
  // * [#123](https://github.com/arduino/arduino-ide/pull/123)
  // * [#123](https://github.com/arduino/arduino-ide/issues/123)
  // * [#123](https://github.com/arduino/arduino-ide/pull/123/)
  // * [#123](https://github.com/arduino/arduino-ide/issues/123/)
  r =
    /(https:\/\/github\.com\/arduino\/arduino-ide\/(pull|issues)\/(\d+)\/?)/gm;
  if (r.test(line)) {
    return line.replace(r, `[#$3]($1)`);
  }

  // Check if a link with the following format exists:
  // * https://github.com/arduino/arduino-ide/compare/2.0.0-rc2...2.0.0-rc3
  // * https://github.com/arduino/arduino-ide/compare/2.0.0-rc2...2.0.0-rc3/
  // If it does it's changed to:
  // * [`2.0.0-rc2...2.0.0-rc3`](https://github.com/arduino/arduino-ide/compare/2.0.0-rc2...2.0.0-rc3)
  r =
    /(https:\/\/github\.com\/arduino\/arduino-ide\/compare\/([^\/]*))\/?\s?/gm;
  if (r.test(line)) {
    return line.replace(r, '[`$2`]($1)');
  }

  // If nothing matches just return the line as is
  return line;
};