import * as fs from 'fs-extra';
import * as path from 'path';
import { IEnvironment } from '../types/environment';
import { IProcessData, spawnProcess } from '../util/run';

export class NPMExecutor {
  private installed: string[] = [];
  private packageFile: string = path.join(this.environment.path, 'package.json');

  constructor(private environment: IEnvironment, private coreModule: string) {}

  public async init(): Promise<void> {
    // Initialize npm environment
    const c1 = await spawnProcess('npm', ['init', '-y'], this.environment);
    if (c1.code > 0) {
      throw new Error(c1.stderr.join('\n'));
    }

    // Install core module
    const c2 = await spawnProcess('npm', ['install', this.coreModule], this.environment);
    if (c2.code > 0) {
      throw new Error(c2.stderr.join('\n'));
    }
  }

  public async loadPackageFile(): Promise<void> {
    if (!await fs.pathExists(this.packageFile)) {
      await this.init();
    }

    const jsonData = await fs.readJson(this.packageFile);
    if (!jsonData.dependencies) {
      return;
    }

    this.installed = Object.keys(jsonData.dependencies);
  }

  public async installPackage(pkg: string): Promise<void> {
    if (!await fs.pathExists(this.packageFile)) {
      await this.init();
    }

    const pkgNoVersion = pkg.split('@')[0];
    if (this.installed.indexOf(pkgNoVersion) !== -1) {
      return;
    }

    const { code, stderr, stdout } = await spawnProcess('npm', ['install', pkg], this.environment);
    if (code > 0) {
      throw new Error(stderr.join('\n'));
    }

    await this.loadPackageFile();
  }

  public async uninstallPackage(pkg: string): Promise<void> {
    if (!await fs.pathExists(this.packageFile)) {
      await this.init();
    }

    const { code, stderr, stdout } = await spawnProcess('npm', ['remove', pkg], this.environment);
    if (code > 0) {
      throw new Error(stderr.join('\n'));
    }

    await this.loadPackageFile();
  }
}