// Script to update certdata.txt from NSS.
import { execFileSync } from 'node:child_process';
import { randomUUID } from 'node:crypto';
import { createWriteStream } from 'node:fs';
import { basename, join, relative } from 'node:path';
import { Readable } from 'node:stream';
import { pipeline } from 'node:stream/promises';
import { fileURLToPath } from 'node:url';
import { parseArgs } from 'node:util';

// Constants for NSS release metadata.
const kNSSVersion = 'version';
const kNSSDate = 'date';
const kFirefoxVersion = 'firefoxVersion';
const kFirefoxDate = 'firefoxDate';

const __filename = fileURLToPath(import.meta.url);
const now = new Date();

const formatDate = (d) => {
  const iso = d.toISOString();
  return iso.substring(0, iso.indexOf('T'));
};

const normalizeTD = (text) => {
  // Remove whitespace and any HTML tags.
  return text?.trim().replace(/<.*?>/g, '');
};
const getReleases = (text) => {
  const releases = [];
  const tableRE = /<table [^>]+>([\S\s]*?)<\/table>/g;
  const tableRowRE = /<tr ?[^>]*>([\S\s]*?)<\/tr>/g;
  const tableHeaderRE = /<th ?[^>]*>([\S\s]*?)<\/th>/g;
  const tableDataRE = /<td ?[^>]*>([\S\s]*?)<\/td>/g;
  for (const table of text.matchAll(tableRE)) {
    const columns = {};
    const matches = table[1].matchAll(tableRowRE);
    // First row has the table header.
    let row = matches.next();
    if (row.done) {
      continue;
    }
    const headers = Array.from(row.value[1].matchAll(tableHeaderRE), (m) => m[1]);
    if (headers.length > 0) {
      for (let i = 0; i < headers.length; i++) {
        if (/NSS version/i.test(headers[i])) {
          columns[kNSSVersion] = i;
        } else if (/Release.*from branch/i.test(headers[i])) {
          columns[kNSSDate] = i;
        } else if (/Firefox version/i.test(headers[i])) {
          columns[kFirefoxVersion] = i;
        } else if (/Firefox release date/i.test(headers[i])) {
          columns[kFirefoxDate] = i;
        }
      }
    }
    // Filter out "NSS Certificate bugs" table.
    if (columns[kNSSDate] === undefined) {
      continue;
    }
    // Scrape releases.
    row = matches.next();
    while (!row.done) {
      const cells = Array.from(row.value[1].matchAll(tableDataRE), (m) => m[1]);
      const release = {};
      release[kNSSVersion] = normalizeTD(cells[columns[kNSSVersion]]);
      release[kNSSDate] = new Date(normalizeTD(cells[columns[kNSSDate]]));
      release[kFirefoxVersion] = normalizeTD(cells[columns[kFirefoxVersion]]);
      release[kFirefoxDate] = new Date(normalizeTD(cells[columns[kFirefoxDate]]));
      releases.push(release);
      row = matches.next();
    }
  }
  return releases;
};

const getLatestVersion = (releases) => {
  const arrayNumberSort = (x, y, i) => {
    if (x[i] === undefined && y[i] === undefined) {
      return 0;
    } else if (x[i] === y[i]) {
      return arrayNumberSort(x, y, i + 1);
    }
    return (x[i] ?? 0) - (y[i] ?? 0);
  };
  const extractVersion = (t) => {
    return t[kNSSVersion].split('.').map((n) => parseInt(n));
  };
  const releaseSorter = (x, y) => {
    return arrayNumberSort(extractVersion(x), extractVersion(y), 0);
  };
  return releases.sort(releaseSorter).filter(pastRelease).at(-1)[kNSSVersion];
};

const pastRelease = (r) => {
  return r[kNSSDate] < now;
};

const options = {
  help: {
    type: 'boolean',
  },
  file: {
    short: 'f',
    type: 'string',
  },
  verbose: {
    short: 'v',
    type: 'boolean',
  },
};
const {
  positionals,
  values,
} = parseArgs({
  allowPositionals: true,
  options,
});

if (values.help) {
  console.log(`Usage: ${basename(__filename)} [OPTION]... [VERSION]...`);
  console.log();
  console.log('Updates certdata.txt to NSS VERSION (most recent release by default).');
  console.log('');
  console.log('  -f, --file=FILE  writes a commit message reflecting the change to the');
  console.log('                     specified FILE');
  console.log('  -v, --verbose    writes progress to stdout');
  console.log('      --help       display this help and exit');
  process.exit(0);
}

if (values.verbose) {
  console.log('Fetching NSS release schedule');
}
const scheduleURL = 'https://wiki.mozilla.org/NSS:Release_Versions';
const schedule = await fetch(scheduleURL);
if (!schedule.ok) {
  console.error(`Failed to fetch ${scheduleURL}: ${schedule.status}: ${schedule.statusText}`);
  process.exit(-1);
}
const scheduleText = await schedule.text();
const nssReleases = getReleases(scheduleText);

// Retrieve metadata for the NSS release being updated to.
const version = positionals[0] ?? getLatestVersion(nssReleases);
const release = nssReleases.find((r) => {
  return new RegExp(`^${version.replace('.', '\\.')}\\b`).test(r[kNSSVersion]);
});
if (!pastRelease(release)) {
  console.warn(`Warning: NSS ${version} is not due to be released until ${formatDate(release[kNSSDate])}`);
}
if (values.verbose) {
  console.log('Found NSS version:');
  console.log(release);
}

// Fetch certdata.txt and overwrite the local copy.
const tag = `NSS_${version.replaceAll('.', '_')}_RTM`;
const certdataURL = `https://hg.mozilla.org/projects/nss/raw-file/${tag}/lib/ckfw/builtins/certdata.txt`;
if (values.verbose) {
  console.log(`Fetching ${certdataURL}`);
}
const checkoutDir = join(__filename, '..', '..', '..');
const certdata = await fetch(certdataURL);
const certdataFile = join(checkoutDir, 'tools', 'certdata.txt');
if (!certdata.ok) {
  console.error(`Failed to fetch ${certdataURL}: ${certdata.status}: ${certdata.statusText}`);
  process.exit(-1);
}
if (values.verbose) {
  console.log(`Writing ${certdataFile}`);
}
await pipeline(certdata.body, createWriteStream(certdataFile));

// Run tools/mk-ca-bundle.pl to generate src/node_root_certs.h.
if (values.verbose) {
  console.log('Running tools/mk-ca-bundle.pl');
}
const opts = { encoding: 'utf8' };
const mkCABundleTool = join(checkoutDir, 'tools', 'mk-ca-bundle.pl');
const mkCABundleOut = execFileSync(mkCABundleTool,
                                   values.verbose ? [ '-v' ] : [],
                                   opts);
if (values.verbose) {
  console.log(mkCABundleOut);
}

// Determine certificates added and/or removed.
const certHeaderFile = relative(process.cwd(), join(checkoutDir, 'src', 'node_root_certs.h'));
const diff = execFileSync('git', [ 'diff-files', '-u', '--', certHeaderFile ], opts);
if (values.verbose) {
  console.log(diff);
}
const certsAddedRE = /^\+\/\* (.*) \*\//gm;
const certsRemovedRE = /^-\/\* (.*) \*\//gm;
const added = [ ...diff.matchAll(certsAddedRE) ].map((m) => m[1]);
const removed = [ ...diff.matchAll(certsRemovedRE) ].map((m) => m[1]);

const commitMsg = [
  `crypto: update root certificates to NSS ${release[kNSSVersion]}`,
  '',
  `This is the certdata.txt[0] from NSS ${release[kNSSVersion]}, released on ${formatDate(release[kNSSDate])}.`,
  '',
  `This is the version of NSS that ${release[kFirefoxDate] < now ? 'shipped' : 'will ship'} in Firefox ${release[kFirefoxVersion]} on`,
  `${formatDate(release[kFirefoxDate])}.`,
  '',
];
if (added.length > 0) {
  commitMsg.push('Certificates added:');
  commitMsg.push(...added.map((cert) => `- ${cert}`));
  commitMsg.push('');
}
if (removed.length > 0) {
  commitMsg.push('Certificates removed:');
  commitMsg.push(...removed.map((cert) => `- ${cert}`));
  commitMsg.push('');
}
commitMsg.push(`[0] ${certdataURL}`);
const delimiter = randomUUID();
const properties = [
  `NEW_VERSION=${release[kNSSVersion]}`,
  `COMMIT_MSG<<${delimiter}`,
  ...commitMsg,
  delimiter,
  '',
].join('\n');
if (values.verbose) {
  console.log(properties);
}
const propertyFile = values.file;
if (propertyFile !== undefined) {
  console.log(`Writing to ${propertyFile}`);
  await pipeline(Readable.from(properties), createWriteStream(propertyFile));
}