import {ChildProcess} from 'child_process';
import {spawn} from '../../utils/process';
import {mkdirp, unlink} from '../../utils/fs';

export interface GitService {
  create(repoBasePath: string): Promise<ChildProcess>
  delete(repoBasePath: string): Promise<void>
  advertiseReceivePackRefs(repoBasePath: string): Promise<ChildProcess>
  advertiseUploadPackRefs(repoBasePath: string): Promise<ChildProcess>
  receivePack(repoBasePath: string): Promise<ChildProcess>
  uploadPack(repoBasePath: string): Promise<ChildProcess>
}

export class GitServiceImpl implements GitService {
  private static isWindows() {
    return /^win/.test(process.platform);
  }

  async create(repoBasePath: string): Promise<ChildProcess> {
    await mkdirp(repoBasePath);
    return spawn(
      repoBasePath,
      'git', ['init', '--bare'],
    );
  }

  async delete(repoBasePath: string): Promise<void> {
    await unlink(repoBasePath);
  }

  async advertiseReceivePackRefs(repoBasePath: string): Promise<ChildProcess> {
    const command = GitServiceImpl.isWindows() ? 'git' : 'git-receive-pack';
    const commonArgs = ['--stateless-rpc', '--advertise-refs', '.'];
    const args = GitServiceImpl.isWindows() ? ['receive-pack', ...commonArgs] : commonArgs;
    return spawn(repoBasePath, command, args);
  }

  async advertiseUploadPackRefs(repoBasePath: string): Promise<ChildProcess> {
    const command = GitServiceImpl.isWindows() ? 'git' : 'git-upload-pack';
    const commonArgs = ['--stateless-rpc', '--advertise-refs', '.'];
    const args = GitServiceImpl.isWindows() ? ['upload-pack', ...commonArgs] : commonArgs;
    return spawn(repoBasePath, command, args);
  }

  async receivePack(repoBasePath: string): Promise<ChildProcess> {
    const command = GitServiceImpl.isWindows() ? 'git' : 'git-receive-pack';
    const commonArgs = ['--stateless-rpc', '.'];
    const args = GitServiceImpl.isWindows() ? ['receive-pack', ...commonArgs] : commonArgs;
    return spawn(repoBasePath, command, args);
  }

  async uploadPack(repoBasePath: string): Promise<ChildProcess> {
    const command = GitServiceImpl.isWindows() ? 'git' : 'git-upload-pack';
    const commonArgs = ['--stateless-rpc', '.'];
    const args = GitServiceImpl.isWindows() ? ['upload-pack', ...commonArgs] : commonArgs;
    return spawn(repoBasePath, command, args);
  }
}