text: 'use strict';
  
  var bindings = require('bindings')('bcrypt_lib');
  var crypto = require('crypto');
  
  /// generate a salt (sync)
  /// @param {Number} [rounds] number of rounds (default 10)
  /// @return {String} salt
  module.exports.genSaltSync = function(rounds) {
      // default 10 rounds
      if (!rounds) {
          rounds = 10;
      } else if (typeof rounds !== 'number') {
          throw new Error('rounds must be a number');
      }
  
      return bindings.gen_salt_sync(rounds, crypto.randomBytes(16));
  };
  
  /// generate a salt
  /// @param {Number} [rounds] number of rounds (default 10)
  /// @param {Function} cb callback(err, salt)
  module.exports.genSalt = function(rounds, ignore, cb) {
      // if callback is first argument, then use defaults for others
      if (typeof arguments[0] === 'function') {
          // have to set callback first otherwise arguments are overriden
          cb = arguments[0];
          rounds = 10;
      // callback is second argument
      } else if (typeof arguments[1] === 'function') {
          // have to set callback first otherwise arguments are overriden
          cb = arguments[1];
      }
  
      // default 10 rounds
      if (!rounds) {
          rounds = 10;
      } else if (typeof rounds !== 'number') {
          return cb(new Error('rounds must be a number'));
      }
  
      if (!cb) {
          return;
      }
  
      return bindings.gen_salt(rounds, crypto.randomBytes(16), cb);
  };
  
  /// hash data using a salt
  /// @param {String} data the data to encrypt
  /// @param {String} salt the salt to use when hashing
  /// @return {String} hash
  module.exports.hashSync = function(data, salt) {
      if (data == null || salt == null) {
          throw new Error('data and salt arguments required');
      }
  
      if (typeof data !== 'string' || (typeof salt !== 'string' && typeof salt !== 'number')) {
          throw new Error('data must be a string and salt must either be a salt string or a number of rounds');
      }
  
      if (typeof salt === 'number') {
          salt = module.exports.genSaltSync(salt);
      }
  
      return bindings.encrypt_sync(data, salt);
  };
  
  /// hash data using a salt
  /// @param {String} data the data to encrypt
  /// @param {String} salt the salt to use when hashing
  /// @param {Function} cb callback(err, hash)
  module.exports.hash = function(data, salt, cb) {
      if (typeof data === 'function') {
          return data(new Error('data must be a string and salt must either be a salt string or a number of rounds'));
      }
  
      if (typeof salt === 'function') {
          return salt(new Error('data must be a string and salt must either be a salt string or a number of rounds'));
      }
  
      if (data == null || salt == null) {
          return cb(new Error('data and salt arguments required'));
      }
  
      if (typeof data !== 'string' || (typeof salt !== 'string' && typeof salt !== 'number')) {
          return cb(new Error('data must be a string and salt must either be a salt string or a number of rounds'));
      }
  
      if (!cb || typeof cb !== 'function') {
          return;
      }
  
      if (typeof salt === 'number') {
          return module.exports.genSalt(salt, function(err, salt) {
              return bindings.encrypt(data, salt, cb);
          });
      }
  
      return bindings.encrypt(data, salt, cb);
  };
  
  /// compare raw data to hash
  /// @param {String} data the data to hash and compare
  /// @param {String} hash expected hash
  /// @return {bool} true if hashed data matches hash
  module.exports.compareSync = function(data, hash) {
      if (data == null || hash == null) {
          throw new Error('data and hash arguments required');
      }
  
      if (typeof data !== 'string' || typeof hash !== 'string') {
          throw new Error('data and hash must be strings');
      }
  
      return bindings.compare_sync(data, hash);
  };
  
  /// compare raw data to hash
  /// @param {String} data the data to hash and compare
  /// @param {String} hash expected hash
  /// @param {Function} cb callback(err, matched) - matched is true if hashed data matches hash
  module.exports.compare = function(data, hash, cb) {
      if (data == null || hash == null) {
          return cb(new Error('data and hash arguments required'));
      }
  
      if (typeof data !== 'string' || typeof hash !== 'string') {
          return cb(new Error('data and hash must be strings'));
      }
  
      if (!cb || typeof cb !== 'function') {
          return;
      }
  
      return bindings.compare(data, hash, cb);
  };
  
  /// @param {String} hash extract rounds from this hash
  /// @return {Number} the number of rounds used to encrypt a given hash
  module.exports.getRounds = function(hash) {
      if (hash == null) {
          throw new Error('hash argument required');
      }
  
      if (typeof hash !== 'string') {
          throw new Error('hash must be a string');
      }
  
      return bindings.get_rounds(hash);
  };
  