/**
 * @license
 * Copyright Google Inc. 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
 */
// tslint:disable:no-implicit-dependencies
import { JsonObject, logging } from '@angular-devkit/core';
import * as fs from 'fs';
import * as path from 'path';
import * as semver from 'semver';

const changelogTemplate = require('./templates/changelog').default;

const conventionalCommitsParser = require('conventional-commits-parser');
const gitRawCommits = require('git-raw-commits');
const ghGot = require('gh-got');
const through = require('through2');


export interface ChangelogOptions {
  from: string;
  to?: string;
  githubTokenFile?: string;
  githubToken?: string;

  stdout?: boolean;
}


export default function(args: ChangelogOptions, logger: logging.Logger) {
  const commits: JsonObject[] = [];
  let toSha: string | null = null;

  const githubToken = (
    args.githubToken
    || (args.githubTokenFile && fs.readFileSync(args.githubTokenFile, 'utf-8'))
    || ''
  ).trim();

  new Promise((resolve) => {
    (gitRawCommits({
      from: args.from,
      to: args.to || 'HEAD',
      format: '%B%n-hash-%n%H%n-gitTags-%n%D%n-committerDate-%n%ci%n-authorName-%n%aN%n',
    }) as NodeJS.ReadStream)
      .on('error', err => {
        logger.fatal('An error happened: ' + err.message);
        process.exit(1);
      })
      .pipe(through((chunk: Buffer, enc: string, callback: Function) => {
        // Replace github URLs with `@XYZ#123`
        const commit = chunk.toString('utf-8')
          .replace(/https?:\/\/github.com\/(.*?)\/issues\/(\d+)/g, '@$1#$2');

        callback(undefined, new Buffer(commit));
      }))
      .pipe(conventionalCommitsParser({
        headerPattern: /^(\w*)(?:\(([^)]*)\))?: (.*)$/,
        headerCorrespondence: ['type', 'scope', 'subject'],
        noteKeywords: ['BREAKING CHANGE'],
        revertPattern: /^revert:\s([\s\S]*?)\s*This reverts commit (\w*)\./,
        revertCorrespondence: [`header`, `hash`],
      }))
      .pipe(through.obj((chunk: JsonObject, _: string, cb: Function) => {
        try {
          const maybeTag = chunk.gitTags && (chunk.gitTags as string).match(/tag: (.*)/);
          const tags = maybeTag && maybeTag[1].split(/,/g);
          chunk['tags'] = tags;

          if (tags && tags.find(x => x == args.to)) {
            toSha = chunk.hash as string;
          }

          commits.push(chunk);
          cb();
        } catch (err) {
          cb(err);
        }
      }))
      .on('finish', resolve);
  })
    .then(() => {
      const markdown: string = changelogTemplate({
        ...args,
        include: (x: string, v: {}) => require('./' + path.join('templates', x)).default(v),
        commits,
      });

      if (args.stdout || !githubToken) {
        console.log(markdown);
        process.exit(0);
      }

      // Check if we need to edit or create a new one.
      return ghGot('repos/angular/angular-cli/releases').then((x: JsonObject) => [x, markdown]);
    })
    .then(([body, markdown]) => {
      const json = body.body;

      const maybeRelease = json.find((x: JsonObject) => x.tag_name == args.to);
      const id = maybeRelease ? `/${maybeRelease.id}` : '';

      const semversion = (args.to && semver.parse(args.to)) || { prerelease: '' };

      return ghGot('repos/angular/angular-cli/releases' + id, {
        body: {
          body: markdown,
          draft: !maybeRelease,
          name: args.to,
          prerelease: semversion.prerelease.length > 0,
          tag_name: args.to,
          ...(toSha ? { target_commitish: toSha } : {}),
        },
        token: githubToken,
      });
    });
}