// Copyright 2020 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

const fs = require('fs');
const path = require('path');
const yargs = require('yargs');
const {hideBin} = require('yargs/helpers');

const {writeIfChanged} = require('./ninja/write-if-changed.js');

const {
  template,
  outDirectory,
  entrypoints,
} = yargs(hideBin(process.argv)).parseSync();

if (!template) {
  throw new Error(
      'Must specify --template location with the location of the HTML entrypoint template.',
  );
}

if (!outDirectory) {
  throw new Error(
      'Must specify --out-directory location where the outputs must live.',
  );
}

if (!entrypoints) {
  throw new Error('Must specify at least one entrypoint name.');
}

if (!Array.isArray(entrypoints)) {
  throw new Error('Must specify multiple entrypoints as array');
}

const templateContent = fs.readFileSync(template, 'utf-8');

for (const entrypoint of entrypoints) {
  const rewrittenTemplateContent = templateContent.replace(
      new RegExp('%ENTRYPOINT_NAME%', 'g'),
      entrypoint,
  );
  writeIfChanged(
      path.join(outDirectory, `${entrypoint}.html`),
      rewrittenTemplateContent,
  );
}