/**
 * @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 {writeFileSync} from 'fs';
import {join} from 'path';
import {SemVer} from 'semver';
import {Arguments, Argv, CommandModule} from 'yargs';

import {debug, info} from '../../utils/console';
import {GitClient} from '../../utils/git/git-client';

import {ReleaseNotes} from './release-notes';

/** Command line options for building a release. */
export interface ReleaseNotesOptions {
  from?: string;
  to: string;
  outFile?: string;
  releaseVersion: SemVer;
  type: 'github-release'|'changelog';
}

/** Yargs command builder for configuring the `ng-dev release build` command. */
function builder(argv: Argv): Argv<ReleaseNotesOptions> {
  return argv
      .option(
          'releaseVersion',
          {type: 'string', default: '0.0.0', coerce: (version: string) => new SemVer(version)})
      .option('from', {
        type: 'string',
        description: 'The git tag or ref to start the changelog entry from',
        defaultDescription: 'The latest semver tag',
      })
      .option('to', {
        type: 'string',
        description: 'The git tag or ref to end the changelog entry with',
        default: 'HEAD',
      })
      .option('type', {
        type: 'string',
        description: 'The type of release notes to create',
        choices: ['github-release', 'changelog'] as const,
        default: 'changelog' as const,
      })
      .option('outFile', {
        type: 'string',
        description: 'File location to write the generated release notes to',
        coerce: (filePath?: string) => filePath ? join(process.cwd(), filePath) : undefined
      });
}

/** Yargs command handler for generating release notes. */
async function handler({releaseVersion, from, to, outFile, type}: Arguments<ReleaseNotesOptions>) {
  // Since `yargs` evaluates defaults even if a value as been provided, if no value is provided to
  // the handler, the latest semver tag on the branch is used.
  from = from || GitClient.get().getLatestSemverTag().format();
  /** The ReleaseNotes instance to generate release notes. */
  const releaseNotes = await ReleaseNotes.fromRange(releaseVersion, from, to);

  /** The requested release notes entry. */
  const releaseNotesEntry = await (
      type === 'changelog' ? releaseNotes.getChangelogEntry() :
                             releaseNotes.getGithubReleaseEntry());

  if (outFile) {
    writeFileSync(outFile, releaseNotesEntry);
    info(`Generated release notes for "${releaseVersion}" written to ${outFile}`);
  } else {
    process.stdout.write(releaseNotesEntry);
  }
}

/** CLI command module for generating release notes. */
export const ReleaseNotesCommandModule: CommandModule<{}, ReleaseNotesOptions> = {
  builder,
  handler,
  command: 'notes',
  describe: 'Generate release notes',
};