import {ChildProcess, spawn} from 'child_process';
import * as fs from 'fs/promises';

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

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

  async create(cwd: string): Promise<ChildProcess> {
    await fs.mkdir(cwd, { recursive: true });
    return spawn('git', ['init', '--bare'], { cwd });
  }

  async delete(cwd: string): Promise<void> {
    await fs.rm(cwd, { recursive: true, force: true, });
  }

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

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

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

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