// Copyright 2020 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only

const assert = require('node:assert');
const fs = require('node:fs');
const { join } = require('node:path');
const pMap = require('p-map');
const prettier = require('prettier');

const { default: packageJson } = require('./packageJson.js');

// During development, you might use local versions of dependencies which are missing
// acknowledgment files. In this case we'll skip rebuilding the acknowledgment files.
// Enable this flag to throw an error.
const REQUIRE_SIGNAL_LIB_FILES = Boolean(process.env.REQUIRE_SIGNAL_LIB_FILES);

const { dependencies = {}, optionalDependencies = {} } = packageJson;

const SIGNAL_LIBS = [
  '@signalapp/libsignal-client',
  '@signalapp/ringrtc',
  '@signalapp/mute-state-change',
];

const SKIPPED_DEPENDENCIES = new Set(SIGNAL_LIBS);

const rootDir = join(__dirname, '..');
const nodeModulesPath = join(rootDir, 'node_modules');
const destinationPath = join(rootDir, 'ACKNOWLEDGMENTS.md');

function isLicenseFileName(fileName) {
  return /^licen[s|c]e/i.test(fileName);
}

async function getMarkdownForDependency(dependencyName) {
  let licenseBody;

  // fs-xattr is an optional dependency that may fail to install (on Windows, most
  //   commonly), so we have a special case for it here. We may need to do something
  //   similar for new optionalDependencies in the future.
  if (dependencyName === 'fs-xattr' || dependencyName === 'growing-file') {
    licenseBody = 'License: MIT';
  } else {
    const dependencyRootPath = join(nodeModulesPath, dependencyName);

    const licenseFileName = (
      await fs.promises.readdir(dependencyRootPath)
    ).find(isLicenseFileName);

    if (licenseFileName) {
      const licenseFilePath = join(dependencyRootPath, licenseFileName);
      licenseBody = (
        await fs.promises.readFile(licenseFilePath, 'utf8')
      ).trim();
    } else {
      const packageJsonPath = join(dependencyRootPath, 'package.json');
      const { license } = JSON.parse(
        await fs.promises.readFile(packageJsonPath)
      );
      if (!license) {
        throw new Error(`Could not find license for ${dependencyName}`);
      }
      licenseBody = `License: ${license}`;
    }
  }

  return [
    `## ${dependencyName}`,
    '',
    ...licenseBody.split(/\r?\n/).map(line => {
      const trimmed = line.trim();
      if (trimmed) {
        return `    ${trimmed}`;
      }
      return trimmed;
    }),
  ].join('\n');
}

async function getMarkdownForSignalLib(dependencyName) {
  const dependencyRootPath = join(nodeModulesPath, dependencyName);
  const licenseFilePath = join(
    dependencyRootPath,
    'dist',
    'acknowledgments.md'
  );

  let licenseBody;
  try {
    licenseBody = await fs.promises.readFile(licenseFilePath, 'utf8');
  } catch (err) {
    if (err) {
      if (err.code === 'ENOENT' && !REQUIRE_SIGNAL_LIB_FILES) {
        console.warn(
          `Missing acknowledgments file for ${dependencyName}. Skipping generation of acknowledgments.`
        );
        process.exit(0);
      }

      throw err;
    }
  }

  return [
    `# Acknowledgements for ${dependencyName}`,
    '',
    licenseBody.replace(/^# Acknowledgments/, '').trim(),
  ].join('\n');
}

async function main() {
  assert.deepStrictEqual(
    Object.keys(optionalDependencies),
    ['fs-xattr'],
    'Unexpected optionalDependencies when generating acknowledgments file. To ensure that this file is generated deterministically, make sure to special-case it the acknowledgments generation script.'
  );

  const dependencyNames = [
    ...Object.keys(dependencies),
    ...Object.keys(optionalDependencies),
  ]
    .filter(name => !SKIPPED_DEPENDENCIES.has(name))
    .sort();

  const markdownsForDependency = await pMap(
    dependencyNames,
    getMarkdownForDependency,
    // Without this, we may run into "too many open files" errors.
    {
      concurrency: 100,
      timeout: 1000 * 60 * 2,
    }
  );

  // For our libraries copy the respective acknowledgement lists
  const markdownsFromSignalLibs = await pMap(
    SIGNAL_LIBS,
    getMarkdownForSignalLib,
    {
      concurrency: 100,
      timeout: 1000 * 60 * 2,
    }
  );

  const markdownForChromiumDashboard = [
    '## Chromium WebRTC Internals Dashboard',
    '',
    [
      'Copyright 2015 The Chromium Authors',
      '',
      'Redistribution and use in source and binary forms, with or without',
      'modification, are permitted provided that the following conditions are',
      'met:',
      '',
      '   * Redistributions of source code must retain the above copyright',
      'notice, this list of conditions and the following disclaimer.',
      '   * Redistributions in binary form must reproduce the above',
      'copyright notice, this list of conditions and the following disclaimer',
      'in the documentation and/or other materials provided with the',
      'distribution.',
      '   * Neither the name of Google LLC nor the names of its',
      'contributors may be used to endorse or promote products derived from',
      'this software without specific prior written permission.',
      '',
      'THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS',
      '"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT',
      'LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR',
      'A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT',
      'OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,',
      'SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT',
      'LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,',
      'DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY',
      'THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT',
      '(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE',
      'OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.',
    ]
      .map(line => `\t${line}`)
      .join('\n'),
  ].join('\n');

  const unformattedOutput = [
    '<!-- Copyright 2020 Signal Messenger, LLC -->',
    '<!-- SPDX-License-Identifier: AGPL-3.0-only -->',
    '# Acknowledgments',
    '',
    'Signal Desktop makes use of the following open source projects.',
    '',
    markdownsForDependency.join('\n\n'),
    markdownForChromiumDashboard,
    '',
    '## Kyber Patent License',
    '',
    '<https://csrc.nist.gov/csrc/media/Projects/post-quantum-cryptography/documents/selected-algos-2022/nist-pqc-license-summary-and-excerpts.pdf>',
    '',
    markdownsFromSignalLibs.join('\n\n'),
  ].join('\n');

  const prettierConfig = await prettier.resolveConfig(destinationPath);
  const output = await prettier.format(unformattedOutput, {
    ...prettierConfig,
    filepath: destinationPath,
  });

  await fs.promises.writeFile(destinationPath, output);
}

main().catch(err => {
  console.error(err);
  process.exit(1);
});
