import * as nodePath from 'path';

const PATH_REGEXP = new RegExp('\\' + nodePath.win32.sep, 'g');
const ensureUnixPathCache = new Map<string, string>();
const IS_WINDOWS = process.platform === 'win32';

export const ensureUnixPath = IS_WINDOWS
  ? (path?: string): string | null => {
      if (!path) {
        return null;
      }

      const cachePath = ensureUnixPathCache.get(path);
      if (cachePath) {
        return cachePath;
      }

      // we use a regex instead of the character literal due to a bug in some versions of node.js
      // the path separator needs to be preceded by an escape character
      const normalizedPath = path.replace(PATH_REGEXP, nodePath.posix.sep);
      ensureUnixPathCache.set(path, normalizedPath);

      return normalizedPath;
    }
  : (path?: string) => path;