#!/usr/bin/env node

/**
 * Copyright (c) 2017-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

require('babel-register')({
  babelrc: false,
  only: [__dirname, `${process.cwd()}/core`],
  plugins: [
    require('./server/translate-plugin.js'),
    'transform-class-properties',
    'transform-object-rest-spread',
  ],
  presets: ['react', 'env'],
});

const program = require('commander');
const chalk = require('chalk');
const glob = require('glob');
const fs = require('fs-extra');
const mkdirp = require('mkdirp');
const path = require('path');

const readMetadata = require('./server/readMetadata.js');
const utils = require('./server/utils.js');
const versionFallback = require('./server/versionFallback.js');
const metadataUtils = require('./server/metadataUtils.js');
const env = require('./server/env.js');

const CWD = process.cwd();
let versions;
if (fs.existsSync(`${CWD}/versions.json`)) {
  versions = require(`${CWD}/versions.json`);
} else {
  versions = [];
}

let version;

program
  .arguments('<version>')
  .action(ver => {
    version = ver;
  })
  .parse(process.argv);

if (env.versioning.missingVersionsPage) {
  env.versioning.printMissingVersionsPageError();
  process.exit(1);
}

if (typeof version === 'undefined') {
  console.error(
    `${chalk.yellow(
      'No version number specified!'
    )}\nPass the version you wish to create as an argument.\nEx: 1.0.0`
  );
  process.exit(1);
}

if (versions.includes(version)) {
  console.error(
    `${chalk.yellow(
      'This version already exists!'
    )}\nSpecify a new version to create that does not already exist.`
  );
  process.exit(1);
}

function makeHeader(metadata) {
  let header = '---\n';
  Object.keys(metadata).forEach(key => {
    header += `${key}: ${metadata[key]}\n`;
  });
  header += '---\n';
  return header;
}

function writeFileAndCreateFolder(file, content, encoding) {
  mkdirp.sync(path.dirname(file));

  fs.writeFileSync(file, content, encoding);
}

const versionFolder = `${CWD}/versioned_docs/version-${version}`;

mkdirp.sync(versionFolder);

// copy necessary files to new version, changing some of its metadata to reflect the versioning
const files = glob.sync(`${CWD}/../${readMetadata.getDocsPath()}/**`);
files.forEach(file => {
  const ext = path.extname(file);
  if (ext !== '.md' && ext !== '.markdown') {
    return;
  }

  const res = metadataUtils.extractMetadata(fs.readFileSync(file, 'utf8'));
  const metadata = res.metadata;
  // Don't version any docs without any metadata whatsoever.
  if (Object.keys(metadata).length === 0) {
    return;
  }
  const rawContent = res.rawContent;
  if (!metadata.id) {
    metadata.id = path.basename(file, path.extname(file));
  }
  if (metadata.id.includes('/')) {
    throw new Error('Document id cannot include "/".');
  }
  if (!metadata.title) {
    metadata.title = metadata.id;
  }

  if (!versionFallback.diffLatestDoc(file, metadata.id)) {
    return;
  }

  metadata.original_id = metadata.id;
  metadata.id = `version-${version}-${metadata.id}`;

  const docsDir = path.join(CWD, '../', readMetadata.getDocsPath());
  const subDir = utils.getSubDir(file, docsDir);
  const targetFile = subDir
    ? `${versionFolder}/${subDir}/${path.basename(file)}`
    : `${versionFolder}/${path.basename(file)}`;

  writeFileAndCreateFolder(
    targetFile,
    makeHeader(metadata) + rawContent,
    'utf8'
  );
});

// copy sidebar if necessary
if (versionFallback.diffLatestSidebar()) {
  mkdirp(`${CWD}/versioned_sidebars`);
  const sidebar = JSON.parse(fs.readFileSync(`${CWD}/sidebars.json`, 'utf8'));
  const versioned = {};

  Object.keys(sidebar).forEach(sb => {
    const versionSidebar = `version-${version}-${sb}`;
    versioned[versionSidebar] = {};

    const categories = sidebar[sb];
    Object.keys(categories).forEach(category => {
      versioned[versionSidebar][category] = [];

      const ids = categories[category];
      ids.forEach(id => {
        versioned[versionSidebar][category].push(`version-${version}-${id}`);
      });
    });
  });

  fs.writeFileSync(
    `${CWD}/versioned_sidebars/version-${version}-sidebars.json`,
    `${JSON.stringify(versioned, null, 2)}\n`,
    'utf8'
  );
}

// update versions.json file
versions.unshift(version);
fs.writeFileSync(
  `${CWD}/versions.json`,
  `${JSON.stringify(versions, null, 2)}\n`
);

console.log(`${chalk.green(`Version ${version} created!\n`)}`);