import {ChildProcess, spawn} from 'child_process';
import {DevLogger} from './logger';
import * as chalk from 'chalk';

const logger = new DevLogger();

export class App {
  private baseUrl?: string;

  public async install() {
    const response = await fetch(`${this.baseUrl}/lifecycle/install`, {method: 'post'});
    const json = (await response.json()) as any;
    if (!json.success) {
      throw new Error('App installation failed');
    }
  }

  public async fetchFunctionEndpoints(): Promise<string[]> {
    const response = await fetch(`${this.baseUrl}/functions`);
    const json = (await response.json()) as any;
    return Object.values(json);
  }

  public start(): Promise<ChildProcess> {
    return new Promise((resolve, reject) => {
      const app = spawn('yarn', ['run', 'start-app'], {shell: true});
      process.on('exit', () => app.kill());

      let started = false;
      app.stdout.on('data', (data) => {
        data.toString().trim().split('\n').forEach((str: string) => {
          if (!started && str.startsWith('App listening on port')) {
            started = true;
            this.baseUrl = `http://localhost:${str.replace('App listening on port ', '')}`;
            console.log(chalk.gray('App started successfully'));
            console.log(chalk.gray(`App logs will be piped to ${logger.logFile}`));
            resolve(app);
          }
          logger.log(str);
        });
      });

      app.stderr.on('data', (data) => {
        data.toString().split('\n').forEach(logger.log);
      });

      app.on('error', (e) => {
        console.error(e);
        reject('App failed to start');
      });

      app.on('close', (code) => {
        console.log(`app exited with code ${code}`);
      });
    });
  }
}