var common = require('./common');
var fs = require('fs');

//@
//@ ### test(expression)
//@ Available expression primaries:
//@
//@ + `'-b', 'path'`: true if path is a block device
//@ + `'-c', 'path'`: true if path is a character device
//@ + `'-d', 'path'`: true if path is a directory
//@ + `'-e', 'path'`: true if path exists
//@ + `'-f', 'path'`: true if path is a regular file
//@ + `'-L', 'path'`: true if path is a symbolic link
//@ + `'-p', 'path'`: true if path is a pipe (FIFO)
//@ + `'-S', 'path'`: true if path is a socket
//@
//@ Examples:
//@
//@ ```javascript
//@ if (test('-d', path)) { /* do something with dir */ };
//@ if (!test('-f', path)) continue; // skip if it's a regular file
//@ ```
//@
//@ Evaluates expression using the available primaries and returns corresponding value.
function _test(options, path) {
  if (!path)
    common.error('no path given');

  // hack - only works with unary primaries
  options = common.parseOptions(options, {
    'b': 'block',
    'c': 'character',
    'd': 'directory',
    'e': 'exists',
    'f': 'file',
    'L': 'link',
    'p': 'pipe',
    'S': 'socket'
  });

  var canInterpret = false;
  for (var key in options)
    if (options[key] === true) {
      canInterpret = true;
      break;
    }

  if (!canInterpret)
    common.error('could not interpret expression');

  if (options.link) {
    try {
      return fs.lstatSync(path).isSymbolicLink();
    } catch(e) {
      return false;
    }
  }

  if (!fs.existsSync(path))
    return false;

  if (options.exists)
    return true;

  var stats = fs.statSync(path);

  if (options.block)
    return stats.isBlockDevice();

  if (options.character)
    return stats.isCharacterDevice();

  if (options.directory)
    return stats.isDirectory();

  if (options.file)
    return stats.isFile();

  if (options.pipe)
    return stats.isFIFO();

  if (options.socket)
    return stats.isSocket();
} // test
module.exports = _test;
