import { slashJoin } from '../utils/path';
import { readFile, checkPath } from '../utils/fs-async';

export const DEFAULT_FILEPATHS = [
  '.iconfontrc',
  'iconfontrc',
  '.iconfontrc.json',
  'iconfontrc.json',
  '.iconfontrc.js',
  'iconfontrc.js'
];

const attemptLoading = async (filepath: string): Promise<any | void> => {
  if (await checkPath(filepath, 'file')) {
    try {
      return require(slashJoin(process.cwd(), filepath));
    } catch (err) {}

    try {
      return JSON.parse(await readFile(filepath, 'utf8'));
    } catch (err) {}

    throw new Error(`Failed parsing configuration at '${filepath}'`);
  }
};

export const loadConfig = async (filepath?: string) => {
  let loadedConfigPath: string | null = null;
  let loadedConfig = {};

  if (filepath) {
    loadedConfig = await attemptLoading(filepath);
    loadedConfigPath = filepath;
  } else {
    for (const path of DEFAULT_FILEPATHS) {
      loadedConfig = await attemptLoading(path);

      if (loadedConfig) {
        loadedConfigPath = path;
        break;
      }
    }
  }

  return { loadedConfig, loadedConfigPath };
};