import { IsString, IsUrl, validateSync } from 'class-validator';
import { plainToInstance } from 'class-transformer';

export class EnvironmentVariables {
  @IsString()
  NODE_ENV: string;

  @IsUrl({ protocols: ['postgres', 'postgresql'], require_tld: false })
  DATABASE_URL: string;
}

export function validate(config: Record<string, any>) {
  const validatedConfig = plainToInstance(EnvironmentVariables, config);

  const errors = validateSync(validatedConfig);
  if (errors.length > 0) {
    throw new Error(errors.toString());
  }
  return validatedConfig;
}