var path = require('path');
var fs = require('fs');
var common = require('./common');
var glob = require('fast-glob');

// glob patterns use the UNIX path seperator
var globPatternRecursive = '/**';

common.register('ls', _ls, {
  cmdOptions: {
    'R': 'recursive',
    'A': 'all',
    'L': 'link',
    'a': 'all_deprecated',
    'd': 'directory',
    'l': 'long',
  },
});

//@
//@ ### ls([options,] [path, ...])
//@ ### ls([options,] path_array)
//@
//@ Available options:
//@
//@ + `-R`: recursive
//@ + `-A`: all files (include files beginning with `.`, except for `.` and `..`)
//@ + `-L`: follow symlinks
//@ + `-d`: list directories themselves, not their contents
//@ + `-l`: provides more details for each file. Specifically, each file is
//@         represented by a structured object with separate fields for file
//@         metadata (see
//@         [`fs.Stats`](https://nodejs.org/api/fs.html#fs_class_fs_stats)). The
//@         return value also overrides `.toString()` to resemble `ls -l`'s
//@         output format for human readability, but programmatic usage should
//@         depend on the stable object format rather than the `.toString()`
//@         representation.
//@
//@ Examples:
//@
//@ ```javascript
//@ ls('projs/*.js');
//@ ls('projs/**/*.js'); // Find all js files recursively in projs
//@ ls('-R', '/users/me', '/tmp');
//@ ls('-R', ['/users/me', '/tmp']); // same as above
//@ ls('-l', 'file.txt'); // { name: 'file.txt', mode: 33188, nlink: 1, ...}
//@ ```
//@
//@ Returns a [ShellString](#shellstringstr) (with array-like properties) of all
//@ the files in the given `path`, or files in the current directory if no
//@ `path` is  provided.
function _ls(options, paths) {
  if (options.all_deprecated) {
    // We won't support the -a option as it's hard to image why it's useful
    // (it includes '.' and '..' in addition to '.*' files)
    // For backwards compatibility we'll dump a deprecated message and proceed as before
    common.log('ls: Option -a is deprecated. Use -A instead');
    options.all = true;
  }

  if (!paths) {
    paths = ['.'];
  } else {
    paths = [].slice.call(arguments, 1);
  }

  var list = [];

  function pushFile(abs, relName, stat) {
    if (process.platform === 'win32') {
      relName = relName.replace(/\\/g, '/');
    }
    if (options.long) {
      stat = stat || (options.link ? common.statFollowLinks(abs) : common.statNoFollowLinks(abs));
      list.push(addLsAttributes(relName, stat));
    } else {
      // list.push(path.relative(rel || '.', file));
      list.push(relName);
    }
  }

  paths.forEach(function (p) {
    var stat;

    try {
      stat = options.link ? common.statFollowLinks(p) : common.statNoFollowLinks(p);
      // follow links to directories by default
      if (stat.isSymbolicLink()) {
        /* istanbul ignore next */
        // workaround for https://github.com/shelljs/shelljs/issues/795
        // codecov seems to have a bug that miscalculate this block as uncovered.
        // but according to nyc report this block does get covered.
        try {
          var _stat = common.statFollowLinks(p);
          if (_stat.isDirectory()) {
            stat = _stat;
          }
        } catch (_) {} // bad symlink, treat it like a file
      }
    } catch (e) {
      common.error('no such file or directory: ' + p, 2, { continue: true });
      return;
    }

    // If the stat succeeded
    if (stat.isDirectory() && !options.directory) {
      if (options.recursive) {
        // use glob, because it's simple
        glob.sync(p + globPatternRecursive, {
          // These options are just to make fast-glob be compatible with POSIX
          // (bash) wildcard behavior.
          onlyFiles: false,

          // These options depend on the cmdOptions provided to ls.
          dot: options.all,
          followSymbolicLinks: options.link,
        }).forEach(function (item) {
          // Glob pattern returns the directory itself and needs to be filtered out.
          if (path.relative(p, item)) {
            pushFile(item, path.relative(p, item));
          }
        });
      } else if (options.all) {
        // use fs.readdirSync, because it's fast
        fs.readdirSync(p).forEach(function (item) {
          pushFile(path.join(p, item), item);
        });
      } else {
        // use fs.readdirSync and then filter out secret files
        fs.readdirSync(p).forEach(function (item) {
          if (item[0] !== '.') {
            pushFile(path.join(p, item), item);
          }
        });
      }
    } else {
      pushFile(p, p, stat);
    }
  });

  // Add methods, to make this more compatible with ShellStrings
  return list;
}

function addLsAttributes(pathName, stats) {
  // Note: this object will contain more information than .toString() returns
  stats.name = pathName;
  stats.toString = function () {
    // Return a string resembling unix's `ls -l` format
    return [this.mode, this.nlink, this.uid, this.gid, this.size, this.mtime, this.name].join(' ');
  };
  return stats;
}

module.exports = _ls;
