import cors from 'cors';
import 'dotenv/config';

interface AppConfig {
  readonly isProd: boolean;
  readonly host: string;
  readonly port: number;
  readonly limit: { readonly limit: string };
  readonly origin: string[];
  readonly corsOptions: cors.CorsOptions;
  readonly greeting: string;
  readonly accessToken: TokenConfig;
  readonly refreshToken: RefreshTokenConfig;
}

interface TokenConfig {
  readonly secret: string;
  readonly expiresIn: number;
}

interface RefreshTokenConfig extends TokenConfig {
  readonly maxAge: number;
}

export function toAppConfig(): AppConfig {
  const MODE = process.env.VITE_MODE || 'prod';
  const isProd = MODE === 'prod';

  const host = process.env.VITE_HOST || 'localhost';
  const port = parseInt(process.env.VITE_PORT || '3000');

  const urlRemote = `https://${host}:${port}`;
  const urlLocal = host !== 'localhost' ? `https://localhost:${port}` : undefined;

  const limit = { limit: '50mb' };

  const origin = urlLocal != null ? [urlLocal, urlRemote] : [urlRemote];
  const corsOptions: cors.CorsOptions = {
    origin,
    credentials: true
  };

  const accessTokenExpiresIn = 24 * 60 * 60;
  const refreshTokenExpiresIn = 15 * 24 * 60 * 60;

  const accessTokenSecret = process.env.ACCESS_TOKEN_SECRET;
  const refreshTokenSecret = process.env.REFRESH_TOKEN_SECRET;
  if (accessTokenSecret == null || refreshTokenSecret == null) throw new Error('No secrets found');

  const accessToken: TokenConfig = {
    secret: accessTokenSecret,
    expiresIn: accessTokenExpiresIn
  };

  const refreshToken: RefreshTokenConfig = {
    secret: refreshTokenSecret,
    expiresIn: refreshTokenExpiresIn,
    maxAge: refreshTokenExpiresIn * 1000
  };

  const greeting = `\n\n\n\x1b[35m-server is listening at...-\x1b[0m\n\n${urlRemote}\n${urlLocal}\n\n\n`;

  return {
    isProd,
    host,
    port,
    limit,
    origin,
    corsOptions,
    accessToken,
    refreshToken,
    greeting
  };
}