/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */

import {join} from 'path';

import {getRepoBaseDir} from '../../utils/config';
import {exec as _exec} from '../../utils/shelljs';

export type EnvStampMode = 'snapshot'|'release';

/**
 * Log the environment variables expected by bazel for stamping.
 *
 * See the section on stamping in docs / BAZEL.md
 *
 * This script must be a NodeJS script in order to be cross-platform.
 * See https://github.com/bazelbuild/bazel/issues/5958
 * Note: git operations, especially git status, take a long time inside mounted docker volumes
 * in Windows or OSX hosts (https://github.com/docker/for-win/issues/188).
 */
export function buildEnvStamp(mode: EnvStampMode) {
  console.info(`BUILD_SCM_BRANCH ${getCurrentBranch()}`);
  console.info(`BUILD_SCM_COMMIT_SHA ${getCurrentSha()}`);
  console.info(`BUILD_SCM_HASH ${getCurrentSha()}`);
  console.info(`BUILD_SCM_LOCAL_CHANGES ${hasLocalChanges()}`);
  console.info(`BUILD_SCM_USER ${getCurrentGitUser()}`);
  console.info(`BUILD_SCM_VERSION ${getSCMVersion(mode)}`);
  process.exit(0);
}

/** Run the exec command and return the stdout as a trimmed string. */
function exec(cmd: string) {
  return _exec(cmd).trim();
}

/** Whether the repo has local changes. */
function hasLocalChanges() {
  return !!exec(`git status --untracked-files=no --porcelain`);
}

/**
 * Get the version for generated packages.
 *
 * In snapshot mode, the version is based on the most recent semver tag.
 * In release mode, the version is based on the base package.json version.
 */
function getSCMVersion(mode: EnvStampMode) {
  if (mode === 'release') {
    const packageJsonPath = join(getRepoBaseDir(), 'package.json');
    const {version} = require(packageJsonPath);
    return version;
  }
  if (mode === 'snapshot') {
    const version = exec(`git describe --match [0-9]*.[0-9]*.[0-9]* --abbrev=7 --tags HEAD`);
    return `${version.replace(/-([0-9]+)-g/, '+$1.sha-')}${
        (hasLocalChanges() ? '.with-local-changes' : '')}`;
  }
  return '0.0.0';
}

/** Get the current SHA of HEAD. */
function getCurrentSha() {
  return exec(`git rev-parse HEAD`);
}

/** Get the currently checked out branch. */
function getCurrentBranch() {
  return exec(`git symbolic-ref --short HEAD`);
}

/** Get the current git user based on the git config. */
function getCurrentGitUser() {
  const userName = exec(`git config user.name`);
  const userEmail = exec(`git config user.email`);

  return `${userName} <${userEmail}>`;
}