/**
 * @license
 * Copyright 2017 The Bazel Authors. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 *
 * You may obtain a copy of the License at
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/**
 * @fileoverview This script runs as a postinstall in the published npm packages
 * and checks that the version of the build_bazel_rules_typescript external
 * repository matches that of the published npm package.
 *
 * Note, this check is only performed with bazel managed deps when the yarn or
 * npm install is from a yarn_install or npm_install repository rule. For self
 * managed bazel deps this check is not performed and it is the responsibility
 * of the user to ensure that the versions match.
 */
'use strict';

const path = require('path');
const fs = require('fs');

// Version in package.bzl should match the npm package version
// but this should be tolerant of development stamped versions such as
// "0.17.0-7-g76dc057"
const npmPackageVersion = process.env.npm_package_version.split('-')[0];

// If this is a bazel managed deps yarn_install or npm_install then the
// cwd is $(bazel info
// output_base)/external/<wksp>/node_modules/@bazel/typescript and there should
// be $(bazel info output_base)/external/<wksp>/generate_build_file.js
// folder
function isBazelManagedDeps() {
  try {
    fs.statSync('../../../generate_build_file.js');
    return true;
  } catch (e) {
    return false;
  }
}

if (isBazelManagedDeps()) {
  let contents;
  try {
    // If this is a yarn_install or npm_install then the cwd is $(bazel info
    // output_base)/external/<wksp>/node_modules/@bazel/pkg so we can look for
    // the package.bzl file under $(bazel info
    // output_base)/external/build_bazel_rules_typescript/package.bzl
    const packagePath = path.resolve(
        process.cwd(), '../../../../build_bazel_rules_typescript/package.bzl');
    contents = fs.readFileSync(packagePath, 'utf8');
  } catch (e) {
    throw new Error(
        'The build_bazel_rules_typescript repository is not installed in your Bazel WORKSPACE file');
  }
  if (!contents.includes('def rules_typescript_dependencies():')) {
    throw new Error('Invalid package.bzl in build_bazel_rules_typescript');
  } else if (!contents.includes(`VERSION = "${npmPackageVersion}"`)) {
    // TODO: we might need to support a range here.
    // For example, if you end up with @bazel/typescript@1.0.0 and
    // @bazel/typescript@1.0.1 both installed one of the postinstalls is
    // guaranteed to fail since there's only one version of
    // build_bazel_rules_typescript
    throw new Error(`Expected build_bazel_rules_typescript to be version ${
        npmPackageVersion}`);
  }
} else {
  // No version check
  console.warn(
      `WARNING: With self managed deps you must ensure the @bazel/typescript
npm package version matches the build_bazel_rules_typescript repository version.
Use yarn_install or npm_install for this version to be checked automatically.
`);
}