import * as fs from 'fs';
import * as path from 'path';
import { MetarpheusCLIOptions, MetarpheusConfig, PartialMetarpheusConfig } from '../../model';
import { valueOrThrow } from '../../util';

const defaultConfig: MetarpheusConfig = {
  isReadonly: false,
  runtime: true,
  modelsForciblyInUse: [],
  discardRouteErrorModels: false,
  useLegacyNewtype: false,
  modelPrelude: undefined,
  apiPrelude: undefined,
  apiPaths: [path.resolve(process.cwd(), '../api/src/main/scala')],
  modelOut: path.resolve(process.cwd(), 'src/metarpheus/model.ts'),
  apiOut: path.resolve(process.cwd(), 'src/metarpheus/api.ts')
};

export default function(options: MetarpheusCLIOptions): MetarpheusConfig {
  const userMetarpheusConfigPath = path.resolve(process.cwd(), options.metarpheusConfig);

  if (fs.existsSync(userMetarpheusConfigPath)) {
    const userMetarpheusConfig = valueOrThrow(
      PartialMetarpheusConfig,
      require(userMetarpheusConfigPath)
    );

    return {
      ...defaultConfig,
      ...userMetarpheusConfig
    };
  }

  return defaultConfig;
}