text: import PrivateKey from './PrivateKey';
  import PublicKey from './PublicKey';
  import Address from './address';
  import Aes from './aes';
  
  import { sha256, sha512 } from './hash';
  // import dictionary from './dictionary_en';
  import secureRandom from 'secure-random';
  import { ChainConfig } from 'vinchainjs-ws';
  
  // hash for .25 second
  var HASH_POWER_MILLS = 250;
  
  var key = {
  
      /** Uses 1 second of hashing power to create a key/password checksum.  An
      implementation can re-call this method with the same password to re-match
      the strength of the CPU (either after moving from a desktop to a mobile,
      mobile to desktop, or N years from now when CPUs are presumably stronger).
       A salt is used for all the normal reasons...
       @return object {
          aes_private: Aes,
          checksum: "{hash_iteration_count},{salt},{checksum}"
      }
      */
      aes_checksum: function aes_checksum(password) {
          if (!(typeof password === "string")) {
              throw new "password string required"();
          }
          var salt = secureRandom.randomBuffer(4).toString('hex');
          var iterations = 0;
          var secret = salt + password;
          // hash for .1 second
          var start_t = Date.now();
          while (Date.now() - start_t < HASH_POWER_MILLS) {
              secret = sha256(secret);
              iterations += 1;
          }
  
          var checksum = sha256(secret);
          var checksum_string = [iterations, salt.toString('hex'), checksum.slice(0, 4).toString('hex')].join(',');
  
          return { aes_private: Aes.fromSeed(secret),
              checksum: checksum_string
          };
      },
  
  
      /** Provide a matching password and key_checksum.  A "wrong password"
      error is thrown if the password does not match.  If this method takes
      much more or less than 1 second to return, one should consider updating
      all encyrpted fields using a new key.key_checksum.
      */
      aes_private: function aes_private(password, key_checksum) {
          var _key_checksum$split = key_checksum.split(','),
              iterations = _key_checksum$split[0],
              salt = _key_checksum$split[1],
              checksum = _key_checksum$split[2];
  
          var secret = salt + password;
          for (var i = 0; 0 < iterations ? i < iterations : i > iterations; 0 < iterations ? i++ : i++) {
              secret = sha256(secret);
          }
          var new_checksum = sha256(secret);
          if (!(new_checksum.slice(0, 4).toString('hex') === checksum)) {
              throw new Error("wrong password");
          }
          return Aes.fromSeed(secret);
      },
  
  
      /**
          A week random number generator can run out of entropy.  This should ensure even the worst random number implementation will be reasonably safe.
           @param1 string entropy of at least 32 bytes
      */
      random32ByteBuffer: function random32ByteBuffer() {
          var entropy = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : this.browserEntropy();
  
  
          if (!(typeof entropy === 'string')) {
              throw new Error("string required for entropy");
          }
  
          if (entropy.length < 32) {
              throw new Error("expecting at least 32 bytes of entropy");
          }
  
          var start_t = Date.now();
  
          while (Date.now() - start_t < HASH_POWER_MILLS) {
              entropy = sha256(entropy);
          }var hash_array = [];
          hash_array.push(entropy);
  
          // Hashing for 1 second may helps the computer is not low on entropy (this method may be called back-to-back).
          hash_array.push(secureRandom.randomBuffer(32));
  
          return sha256(Buffer.concat(hash_array));
      },
  
  
      suggest_brain_key: function suggest_brain_key() {
          var dictionary = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : ",";
          var entropy = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : this.browserEntropy();
  
  
          var randomBuffer = this.random32ByteBuffer(entropy);
  
          var word_count = 16;
          var dictionary_lines = dictionary.split(',');
  
          if (!(dictionary_lines.length === 49744)) {
              throw new Error('expecting ' + 49744 + ' but got ' + dictionary_lines.length + ' dictionary words');
          }
  
          var brainkey = [];
          var end = word_count * 2;
  
          for (var i = 0; i < end; i += 2) {
  
              // randomBuffer has 256 bits / 16 bits per word == 16 words
              var num = (randomBuffer[i] << 8) + randomBuffer[i + 1];
  
              // convert into a number between 0 and 1 (inclusive)
              var rndMultiplier = num / Math.pow(2, 16);
              var wordIndex = Math.round(dictionary_lines.length * rndMultiplier);
  
              brainkey.push(dictionary_lines[wordIndex]);
          }
          return this.normalize_brainKey(brainkey.join(' '));
      },
  
      get_random_key: function get_random_key(entropy) {
          return PrivateKey.fromBuffer(this.random32ByteBuffer(entropy));
      },
      get_brainPrivateKey: function get_brainPrivateKey(brainKey) {
          var sequence = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 0;
  
          if (sequence < 0) {
              throw new Error("invalid sequence");
          }
          brainKey = key.normalize_brainKey(brainKey);
          return PrivateKey.fromBuffer(sha256(sha512(brainKey + " " + sequence)));
      },
  
  
      // Turn invisible space like characters into a single space
      normalize_brainKey: function normalize_brainKey(brainKey) {
          if (!(typeof brainKey === 'string')) {
              throw new Error("string required for brainKey");
          }
  
          brainKey = brainKey.trim();
          return brainKey.split(/[\t\n\v\f\r ]+/).join(' ');
      },
      browserEntropy: function browserEntropy() {
  
          var entropyStr = "";
          try {
              entropyStr = new Date().toString() + " " + window.screen.height + " " + window.screen.width + " " + window.screen.colorDepth + " " + " " + window.screen.availHeight + " " + window.screen.availWidth + " " + window.screen.pixelDepth + navigator.language + " " + window.location + " " + window.history.length;
  
              for (var i = 0, mimeType; i < navigator.mimeTypes.length; i++) {
                  mimeType = navigator.mimeTypes[i];
                  entropyStr += mimeType.description + " " + mimeType.type + " " + mimeType.suffixes + " ";
              }
              console.log("INFO\tbrowserEntropy gathered");
          } catch (error) {
              //nodejs:ReferenceError: window is not defined
              entropyStr = sha256(new Date().toString());
          }
  
          var b = new Buffer(entropyStr);
          entropyStr += b.toString('binary') + " " + new Date().toString();
          return entropyStr;
      },
  
  
      // @return array of 5 legacy addresses for a pubkey string parameter.
      addresses: function addresses(pubkey) {
          var address_prefix = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : ChainConfig.address_prefix;
  
          var public_key = PublicKey.fromPublicKeyString(pubkey, address_prefix);
          // S L O W
          var address_string = [Address.fromPublic(public_key, false, 0).toString(address_prefix), // btc_uncompressed
          Address.fromPublic(public_key, true, 0).toString(address_prefix), // btc_compressed
          Address.fromPublic(public_key, false, 56).toString(address_prefix), // pts_uncompressed
          Address.fromPublic(public_key, true, 56).toString(address_prefix), // pts_compressed
          public_key.toAddressString(address_prefix) // bts_short, most recent format
          ];
          return address_string;
      }
  };
  
  export default key;