import type {Request, Response} from 'express';
import type IRoute from '../net/http/IRoutes';
import IHealthCheck from './IHealthCheck';

export default class HealthCheckRoute implements IRoute {
  private readonly _healthCheck: IHealthCheck;

  constructor(healthCheck: IHealthCheck) {
    this._healthCheck = healthCheck;
  }

  public getGETRoutes() {
    console.log('[HealthCheckRoute] getGETRoutes called');
    const routes = {
      '/ok.html': (req, res) => this.externalReadiness.call(this, req, res),
      '/ping': (req, res) => this.ping.call(this, req, res)
    };
    console.log('[HealthCheckRoute] returning routes:', Object.keys(routes));
    return routes;
  }

  public getPOSTRoutes() {
    return {};
  }

  public getPUTRoutes() {
    return {};
  }

  public getPATCHRoutes() {
    return {};
  }

  public getDELETERoutes() {
    return {};
  }

  private externalReadiness(_req: Request, res: Response) {
    console.log('[HealthCheckRoute] External readiness');
    res.setHeader('Cache-Control', 'public, max-age=0, no-cache, no-store');

    try {
      const result = this._healthCheck.checkHealth();

      if (!result || !result.status) {
        return res.status(500).end();
      }

      switch (result.status) {
        case 'ok':
        case 'draining':
        case 'draining2':
        case 'disabled':
          return res.status(200).json(result);
        case 'starting':
        case 'drained':
        case 'stopped':
          return res.status(503).json(result);
        default:
          return res.status(500).json(result);
      }
    } catch {
      return res.status(500).end();
    }
  }

  private ping(_req: Request, res: Response) {
    console.log('[HealthCheckRoute] Ping handler called from [%s]', _req.ip);

    res.status(200).send({status: 'pong'}).end();
  }
}