"use strict";

const fs = require("fs");
const hash = require("./hash");
const path = require("path");
/**
 * Return the cacheFile to be used by stylelint, based on whether the provided parameter is
 * a directory or looks like a directory (ends in `path.sep`), in which case the file
 * name will be `cacheFile/.cache_hashOfCWD`.
 *
 * If cacheFile points to a file or looks like a file, then it will just use that file.
 *
 * @param {string} cacheFile - The name of file to be used to store the cache
 * @param {string} cwd - Current working directory. Used for tests
 * @returns {string} Resolved path to the cache file
 */
module.exports = function getCacheFile(cacheFile, cwd) {
  /*
   * Make sure path separators are normalized for environment/os.
   * Also, keep trailing path separator if present.
   */
  cacheFile = path.normalize(cacheFile);

  const resolvedCacheFile = path.resolve(cwd, cacheFile);
  // If the last character passed is a path separator, we assume is a directory.
  const looksLikeADirectory = cacheFile[cacheFile.length - 1] === path.sep;

  /**
   * Return the default cache file name when provided parameter is a directory.
   * @returns {string} - Resolved path to the cacheFile
   */
  function getCacheFileForDirectory() {
    return path.join(resolvedCacheFile, `.stylelintcache_${hash(cwd)}`);
  }

  let fileStats;

  try {
    fileStats = fs.lstatSync(resolvedCacheFile);
  } catch (ex) {
    fileStats = null;
  }

  if (looksLikeADirectory || (fileStats && fileStats.isDirectory())) {
    // Return path to provided directory with generated file name.
    return getCacheFileForDirectory();
  }

  // Return normalized path to cache file.
  return resolvedCacheFile;
};
