xahau.js/src/core/transaction.js

'use strict';

const assert = require('assert');
const util = require('util');
const _ = require('lodash');
const {deriveKeypair, sign} = require('ripple-keypairs');
const EventEmitter = require('events').EventEmitter;
const utils = require('./utils');
const sjclcodec = require('sjcl-codec');
const Amount = require('./amount').Amount;
const Currency = require('./currency').Currency;
const SerializedObject = require('./serializedobject').SerializedObject;
const RippleError = require('./rippleerror').RippleError;
const hashprefixes = require('./hashprefixes');
const log = require('./log').internal.sub('transaction');
const {isValidAddress, decodeAddress} = require('ripple-address-codec');

/**
 * @constructor Transaction
 *
 * Notes:
 * All transactions including those with local and malformed errors may be
 * forwarded anyway.
 *
 * A malicous server can:
 *  - may or may not forward
 *  - give any result
 *    + it may declare something correct as incorrect or something incorrect
 *      as correct
 *    + it may not communicate with the rest of the network
 */

function Transaction(remote) {
  EventEmitter.call(this);

  const self = this;
  const remoteExists = (typeof remote === 'object');

  this.remote = remote;
  this.tx_json = {Flags: 0};
  this._secret = undefined;
  this._build_path = false;
  this._should_resubmit = remoteExists
  ? this.remote.automatic_resubmission
  : true;
  this._maxFee = remoteExists ? this.remote.max_fee : undefined;
  this._lastLedgerOffset = remoteExists ? this.remote.last_ledger_offset : 3;
  this.state = 'unsubmitted';
  this.finalized = false;
  this.previousSigningHash = undefined;
  this.submitIndex = undefined;
  this.canonical = remoteExists ? this.remote.canonical_signing : true;
  this.submittedIDs = [ ];
  this.attempts = 0;
  this.submissions = 0;
  this.responses = 0;

  this.once('success', function(message) {
    // Transaction definitively succeeded
    self.setState('validated');
    self.finalize(message);
    if (self._successHandler) {
      self._successHandler(message);
    }
  });

  this.once('error', function(message) {
    // Transaction definitively failed
    self.setState('failed');
    self.finalize(message);
    if (self._errorHandler) {
      self._errorHandler(message);
    }
  });

  this.once('submitted', function() {
    // Transaction was submitted to the network
    self.setState('submitted');
  });

  this.once('proposed', function() {
    // Transaction was submitted successfully to the network
    self.setState('pending');
  });
}

util.inherits(Transaction, EventEmitter);

// This is currently a constant in rippled known as the "base reference"
// https://wiki.ripple.com/Transaction_Fee#Base_Fees
Transaction.fee_units = {
  default: 10
};

Transaction.flags = {
  // Universal flags can apply to any transaction type
  Universal: {
    FullyCanonicalSig: 0x80000000
  },

  AccountSet: {
    RequireDestTag: 0x00010000,
    OptionalDestTag: 0x00020000,
    RequireAuth: 0x00040000,
    OptionalAuth: 0x00080000,
    DisallowXRP: 0x00100000,
    AllowXRP: 0x00200000
  },

  TrustSet: {
    SetAuth: 0x00010000,
    NoRipple: 0x00020000,
    SetNoRipple: 0x00020000,
    ClearNoRipple: 0x00040000,
    SetFreeze: 0x00100000,
    ClearFreeze: 0x00200000
  },

  OfferCreate: {
    Passive: 0x00010000,
    ImmediateOrCancel: 0x00020000,
    FillOrKill: 0x00040000,
    Sell: 0x00080000
  },

  Payment: {
    NoRippleDirect: 0x00010000,
    PartialPayment: 0x00020000,
    LimitQuality: 0x00040000
  }
};

// The following are integer (as opposed to bit) flags
// that can be set for particular transactions in the
// SetFlag or ClearFlag field
Transaction.set_clear_flags = {
  AccountSet: {
    asfRequireDest: 1,
    asfRequireAuth: 2,
    asfDisallowXRP: 3,
    asfDisableMaster: 4,
    asfAccountTxnID: 5,
    asfNoFreeze: 6,
    asfGlobalFreeze: 7,
    asfDefaultRipple: 8
  }
};

Transaction.MEMO_TYPES = {};

/* eslint-disable max-len */

// URL characters per RFC 3986
Transaction.MEMO_REGEX = /^[0-9a-zA-Z-\.\_\~\:\/\?\#\[\]\@\!\$\&\'\(\)\*\+\,\;\=\%]+$/;
/* eslint-enable max-len */

Transaction.formats = require('./binformat').tx;

Transaction.prototype.consts = {
  telLOCAL_ERROR: -399,
  temMALFORMED: -299,
  tefFAILURE: -199,
  terRETRY: -99,
  tesSUCCESS: 0,
  tecCLAIMED: 100
};

Transaction.prototype.isTelLocal = function(ter) {
  return ter >= this.consts.telLOCAL_ERROR && ter < this.consts.temMALFORMED;
};

Transaction.prototype.isTemMalformed = function(ter) {
  return ter >= this.consts.temMALFORMED && ter < this.consts.tefFAILURE;
};

Transaction.prototype.isTefFailure = function(ter) {
  return ter >= this.consts.tefFAILURE && ter < this.consts.terRETRY;
};

Transaction.prototype.isTerRetry = function(ter) {
  return ter >= this.consts.terRETRY && ter < this.consts.tesSUCCESS;
};

Transaction.prototype.isTepSuccess = function(ter) {
  return ter >= this.consts.tesSUCCESS;
};

Transaction.prototype.isTecClaimed = function(ter) {
  return ter >= this.consts.tecCLAIMED;
};

Transaction.prototype.isRejected = function(ter) {
  return this.isTelLocal(ter) ||
         this.isTemMalformed(ter) ||
         this.isTefFailure(ter);
};

Transaction.from_json = function(j) {
  return (new Transaction()).setJson(j);
};

Transaction.prototype.setJson =
Transaction.prototype.parseJson = function(v) {
  this.tx_json = _.merge({}, v);
  return this;
};

/**
 * Set state on the condition that the state is different
 *
 * @param {String} state
 */

Transaction.prototype.setState = function(state) {
  if (this.state !== state) {
    this.state = state;
    this.emit('state', state);
  }
};

Transaction.prototype.setResubmittable = function(v) {
  if (typeof v === 'boolean') {
    this._should_resubmit = v;
  }
};
Transaction.prototype.isResubmittable = function() {
  return this._should_resubmit;
};

/**
 * Finalize transaction. This will prevent future activity
 *
 * @param {Object} message
 * @api private
 */

Transaction.prototype.finalize = function(message) {
  this.finalized = true;

  if (this.result) {
    this.result.ledger_index = message.ledger_index;
    this.result.ledger_hash = message.ledger_hash;
  } else {
    this.result = message;
    this.result.tx_json = this.tx_json;
  }

  this.emit('cleanup');
  this.emit('final', message);

  if (this.remote && this.remote.trace) {
    log.info('transaction finalized:',
             this.tx_json, this.getManager()._pending.getLength());
  }

  return this;
};

/**
 * Get transaction Account
 *
 * @return {Account}
 */

Transaction.prototype.getAccount = function() {
  return this.tx_json.Account;
};

/**
 * Get TransactionType
 *
 * @return {String}
 */

Transaction.prototype.getType =
Transaction.prototype.getTransactionType = function() {
  return this.tx_json.TransactionType;
};

/**
 * Get transaction TransactionManager
 *
 * @param [String] account
 * @return {TransactionManager]
 */

Transaction.prototype.getManager = function(account) {
  if (!this.remote) {
    return undefined;
  }

  return this.remote.account(account || this.getAccount())._transactionManager;
};

/**
 * Get transaction secret
 *
 * @param [String] account
 */

Transaction.prototype.getSecret =
Transaction.prototype._accountSecret = function(account) {
  if (!this.remote) {
    return undefined;
  }

  return this.remote.secrets[account || this.getAccount()];
};

/**
 * Returns the number of fee units this transaction will cost.
 *
 * Each Ripple transaction based on its type and makeup costs a certain number
 * of fee units. The fee units are calculated on a per-server basis based on the
 * current load on both the network and the server.
 *
 * @see https://ripple.com/wiki/Transaction_Fee
 *
 * @return {Number} Number of fee units for this transaction.
 */

Transaction.prototype._getFeeUnits =
Transaction.prototype.feeUnits = function() {
  return Transaction.fee_units.default;
};

/**
 * Compute median server fee
 *
 * @return {String} median fee
 */

Transaction.prototype._computeFee = function() {
  if (!this.remote) {
    return undefined;
  }

  const servers = this.remote._servers;
  const fees = [ ];

  for (let i = 0; i < servers.length; i++) {
    const server = servers[i];
    if (server.isConnected()) {
      fees.push(Number(server._computeFee(this._getFeeUnits())));
    }
  }

  switch (fees.length) {
    case 0: return undefined;
    case 1: return String(fees[0]);
  }

  fees.sort(function ascending(a, b) {
    if (a > b) {
      return 1;
    } else if (a < b) {
      return -1;
    }
    return 0;
  });

  const midInd = Math.floor(fees.length / 2);
  const median = fees.length % 2 === 0
  ? Math.floor(0.5 + (fees[midInd] + fees[midInd - 1]) / 2)
  : fees[midInd];

  return String(median);
};

/**
 * Attempts to complete the transaction for submission.
 *
 * This function seeks to fill out certain fields, such as Fee and
 * SigningPubKey, which can be determined by the library based on network
 * information and other fields.
 *
 * @return {Boolean|Transaction} If succeeded, return transaction. Otherwise
 * return `false`
 */

Transaction.prototype.err = function(error, errorMessage) {
  this.emit('error', new RippleError(error, errorMessage));
  return false;
};

Transaction.prototype.complete = function() {
  // Auto-fill the secret
  this._secret = this._secret || this.getSecret();

  if (_.isUndefined(this._secret)) {
    return this.err('tejSecretUnknown', 'Missing secret');
  }

  if (this.remote && !(this.remote.local_signing || this.remote.trusted)) {
    return this.err(
      'tejServerUntrusted',
      'Attempt to give secret to untrusted server');
  }

  if (_.isUndefined(this.tx_json.SigningPubKey)) {
    try {
      this.setSigningPubKey(this.getSigningPubKey());
    } catch (e) {
      return this.err('tejSecretInvalid', 'Invalid secret');
    }
  }

  // Auto-fill transaction Fee
  if (_.isUndefined(this.tx_json.Fee)) {
    if (this.remote && (this.remote.local_fee || !this.remote.trusted)) {
      const computedFee = this._computeFee();

      if (!computedFee) {
        // Unable to compute fee due to no connected servers
        return this.err('tejUnconnected');
      }

      this.tx_json.Fee = computedFee;
    }
  }

  if (Number(this.tx_json.Fee) > this._maxFee) {
    return this.err('tejMaxFeeExceeded', 'Max fee exceeded');
  }

  // Set canonical flag - this enables canonicalized signature checking
  this.setCanonicalFlag();

  return this.tx_json;
};

Transaction.prototype.getSigningPubKey = function(secret) {
  return deriveKeypair(secret || this._secret).publicKey;
};

Transaction.prototype.setSigningPubKey = function(key) {
  this.tx_json.SigningPubKey = key;
  return this;
};

Transaction.prototype.setCanonicalFlag = function() {
  if (this.remote && this.remote.local_signing && this.canonical) {
    this.tx_json.Flags |= Transaction.flags.Universal.FullyCanonicalSig;

    // JavaScript converts operands to 32-bit signed ints before doing bitwise
    // operations. We need to convert it back to an unsigned int.
    this.tx_json.Flags = this.tx_json.Flags >>> 0;
  }

  return this;
};

Transaction.prototype.serialize = function() {
  return SerializedObject.from_json(this.tx_json);
};

Transaction.prototype.signingHash = function(testnet) {
  return this.hash(testnet ? 'HASH_TX_SIGN_TESTNET' : 'HASH_TX_SIGN');
};

Transaction.prototype.signingData = function() {
  const so = new SerializedObject();
  so.append(hashprefixes.HASH_TX_SIGN_BYTES);
  so.parse_json(this.tx_json);
  return so;
};

Transaction.prototype.multiSigningData = function(account) {
  const so = new SerializedObject();
  so.append(hashprefixes.HASH_TX_MULTISIGN_BYTES);
  so.parse_json(this.tx_json);
  so.append(decodeAddress(account));
  return so;
};

Transaction.prototype.hash = function(prefix_, asUINT256, serialized) {
  let prefix;

  if (typeof prefix_ !== 'string') {
    prefix = hashprefixes.HASH_TX_ID;
  } else if (!hashprefixes.hasOwnProperty(prefix_)) {
    throw new Error('Unknown hashing prefix requested: ' + prefix_);
  } else {
    prefix = hashprefixes[prefix_];
  }

  const hash = (serialized || this.serialize()).hash(prefix);

  return asUINT256 ? hash : hash.to_hex();
};

Transaction.prototype.sign = function(secret) {
  if (this.hasMultiSigners()) {
    return this;
  }

  const prev_sig = this.tx_json.TxnSignature;
  delete this.tx_json.TxnSignature;
  const hash = this.signingHash();

  // If the hash is the same, we can re-use the previous signature
  if (prev_sig && hash === this.previousSigningHash) {
    this.tx_json.TxnSignature = prev_sig;
    return this;
  }

  const keypair = deriveKeypair(secret || this._secret);
  this.tx_json.TxnSignature = sign(this.signingData().buffer,
    keypair.privateKey);
  this.previousSigningHash = hash;

  return this;
};

/**
 * Add an ID to cached list of submitted IDs
 *
 * @param {String} transaction id
 * @api private
 */

Transaction.prototype.addId = function(id) {
  if (!_.contains(this.submittedIDs, id)) {
    this.submittedIDs.unshift(id);
  }
};

/**
 * Find ID within cached received (validated) IDs. If this transaction has
 * an ID that is within the cache, it has been seen validated, so return the
 * received message
 *
 * @param {Object} cache
 * @return {Object} message
 * @api private
 */

Transaction.prototype.findId = function(cache) {
  const cachedTransactionID = _.detect(this.submittedIDs, function(id) {
    return cache.hasOwnProperty(id);
  });
  return cache[cachedTransactionID];
};

/**
 * Set client ID. This is an identifier specified by the user of the API to
 * identify a transaction in the event of a disconnect. It is not currently
 * persisted in the transaction itself, but used offline for identification.
 * In applications that require high reliability, client-specified ID should
 * be persisted such that one could map it to submitted transactions. Use
 * .summary() for a consistent transaction summary output for persisitng. In
 * the future, this ID may be stored in the transaction itself (in the ledger)
 *
 * @param {String} id
 */

Transaction.prototype.setClientID =
Transaction.prototype.clientID = function(id) {
  if (typeof id === 'string') {
    this._clientID = id;
  }
  return this;
};

Transaction.prototype.setLastLedgerSequenceOffset = function(offset) {
  this._lastLedgerOffset = offset;
};

Transaction.prototype.getLastLedgerSequenceOffset = function() {
  return this._lastLedgerOffset;
};

Transaction.prototype.lastLedger =
Transaction.prototype.setLastLedger =
Transaction.prototype.setLastLedgerSequence = function(sequence) {
  if (!_.isUndefined(sequence)) {
    this._setUInt32('LastLedgerSequence', sequence);
  } else {
    // Autofill LastLedgerSequence
    assert(this.remote, 'Unable to set LastLedgerSequence, missing Remote');

    this._setUInt32('LastLedgerSequence',
                    this.remote.getLedgerSequenceSync() + 1
                    + this.getLastLedgerSequenceOffset());
  }

  this._setLastLedger = true;

  return this;
};

/**
 * Set max fee. Submission will abort if this is exceeded. Specified fee must
 * be >= 0.
 *
 * @param {Number} fee The proposed fee
 */

Transaction.prototype.setMaxFee =
Transaction.prototype.maxFee = function(fee) {
  if (typeof fee === 'number' && fee >= 0) {
    this._setMaxFee = true;
    this._maxFee = fee;
  }
  return this;
};

/*
 * Set the fee user will pay to the network for submitting this transaction.
 * Specified fee must be >= 0.
 *
 * @param {Number} fee The proposed fee
 *
 * @returns {Transaction} calling instance for chaining
 */
Transaction.prototype.setFixedFee = function(fee) {
  return this.setFee(fee, {fixed: true});
};

Transaction.prototype.setFee = function(fee, options = {}) {
  if (_.isNumber(fee) && fee >= 0) {
    this.tx_json.Fee = String(fee);
    if (options.fixed) {
      this._setFixedFee = true;
    }
  }

  return this;
};

Transaction.prototype.setSequence = function(sequence) {
  if (_.isNumber(sequence)) {
    this._setUInt32('Sequence', sequence);
    this._setSequence = true;
  }

  return this;
};

/**
 * Set secret If the secret has been set with Remote.setSecret, it does not
 * need to be provided
 *
 * @param {String} secret
 */

Transaction.prototype.setSecret =
Transaction.prototype.secret = function(secret) {
  if (typeof secret === 'string') {
    this._secret = secret;
  }
  return this;
};

Transaction.prototype.setType = function(type) {
  if (_.isUndefined(Transaction.formats, type)) {
    throw new Error('TransactionType must be a valid transaction type');
  }

  this.tx_json.TransactionType = type;

  return this;
};

Transaction.prototype._setUInt32 = function(name, value, options_) {
  const options = _.merge({}, options_);
  const isValidUInt32 = typeof value === 'number'
  && value >= 0 && value < Math.pow(256, 4);

  if (!isValidUInt32) {
    throw new Error(name + ' must be a valid UInt32');
  }
  if (!_.isUndefined(options.min_value) && value < options.min_value) {
    throw new Error(name + ' must be >= ' + options.min_value);
  }

  this.tx_json[name] = value;

  return this;
};

/**
 * Set SourceTag
 *
 * @param {Number} source tag
 */

Transaction.prototype.setSourceTag =
Transaction.prototype.sourceTag = function(tag) {
  return this._setUInt32('SourceTag', tag);
};

Transaction.prototype._setAccount = function(name, value) {
  if (!isValidAddress(value)) {
    throw new Error(name + ' must be a valid account');
  }
  this.tx_json[name] = value;
  return this;
};

Transaction.prototype.setAccount = function(account) {
  return this._setAccount('Account', account);
};

Transaction.prototype._setAmount = function(name, amount, options_) {
  const options = _.merge({no_native: false}, options_);
  const parsedAmount = Amount.from_json(amount);

  if (parsedAmount.is_negative()) {
    throw new Error(name + ' value must be non-negative');
  }

  const isNative = parsedAmount.currency().is_native();

  if (isNative && options.no_native) {
    throw new Error(name + ' must be a non-native amount');
  }
  if (!(isNative || parsedAmount.currency().is_valid())) {
    throw new Error(name + ' must have a valid currency');
  }
  if (!(isNative || isValidAddress(parsedAmount.issuer()))) {
    throw new Error(name + ' must have a valid issuer');
  }

  this.tx_json[name] = parsedAmount.to_json();

  return this;
};

Transaction.prototype._setHash256 = function(name, value, options_) {
  if (typeof value !== 'string') {
    throw new Error(name + ' must be a valid Hash256');
  }

  const options = _.merge({pad: false}, options_);
  let hash256 = value;

  if (options.pad) {
    while (hash256.length < 64) {
      hash256 += '0';
    }
  }

  if (!/^[0-9A-Fa-f]{64}$/.test(hash256)) {
    throw new Error(name + ' must be a valid Hash256');
  }

  this.tx_json[name] = hash256;

  return this;
};

Transaction.prototype.setAccountTxnID =
Transaction.prototype.accountTxnID = function(id) {
  return this._setHash256('AccountTxnID', id);
};

/**
 * Set Flags. You may specify flags as a number, as the string name of the
 * flag, or as an array of strings.
 *
 * setFlags(Transaction.flags.AccountSet.RequireDestTag)
 * setFlags('RequireDestTag')
 * setFlags('RequireDestTag', 'RequireAuth')
 * setFlags([ 'RequireDestTag', 'RequireAuth' ])
 *
 * @param {Number|String|Array} flags
 */

Transaction.prototype.setFlags = function(flags) {
  if (flags === undefined) {
    return this;
  }

  if (typeof flags === 'number') {
    this.tx_json.Flags = flags;
    return this;
  }

  const transaction_flags = Transaction.flags[this.getType()] || { };
  const flag_set = Array.isArray(flags) ? flags : [].slice.call(arguments);

  for (let i = 0, l = flag_set.length; i < l; i++) {
    const flag = flag_set[i];

    if (transaction_flags.hasOwnProperty(flag)) {
      this.tx_json.Flags += transaction_flags[flag];
    } else {
      // XXX Should throw?
      this.emit('error', new RippleError('tejInvalidFlag'));
      return this;
    }
  }

  return this;
};

function convertStringToHex(string) {
  const utf8String = sjclcodec.utf8String.toBits(string);
  return sjclcodec.hex.fromBits(utf8String).toUpperCase();
}

/**
 * Add a Memo to transaction.
 *
 * @param [String] memoType
 * - describes what the data represents, must contain valid URL characters
 * @param [String] memoFormat
 * - describes what format the data is in, MIME type, must contain valid URL
 * - characters
 * @param [String] memoData
 * - data for the memo, can be any JS object. Any object other than string will
 *   be stringified (JSON) for transport
 */

Transaction.prototype.addMemo = function(options_) {
  let options;

  if (typeof options_ === 'object') {
    options = _.merge({}, options_);
  } else {
    options = {
      memoType: arguments[0],
      memoFormat: arguments[1],
      memoData: arguments[2]
    };
  }

  const memo = {};
  const memoRegex = Transaction.MEMO_REGEX;
  let memoType = options.memoType;
  const memoFormat = options.memoFormat;
  let memoData = options.memoData;

  if (memoType) {
    if (!(_.isString(memoType) && memoRegex.test(memoType))) {
      throw new Error(
        'MemoType must be a string containing only valid URL characters');
    }
    if (Transaction.MEMO_TYPES[memoType]) {
      // XXX Maybe in the future we want a schema validator for
      // memo types
      memoType = Transaction.MEMO_TYPES[memoType];
    }
    memo.MemoType = convertStringToHex(memoType);
  }

  if (memoFormat) {
    if (!(_.isString(memoFormat) && memoRegex.test(memoFormat))) {
      throw new Error(
        'MemoFormat must be a string containing only valid URL characters');
    }

    memo.MemoFormat = convertStringToHex(memoFormat);
  }

  if (memoData) {
    if (typeof memoData !== 'string') {
      if (memoFormat.toLowerCase() === 'json') {
        try {
          memoData = JSON.stringify(memoData);
        } catch (e) {
          throw new Error(
            'MemoFormat json with invalid JSON in MemoData field');
        }
      } else {
        throw new Error(
          'MemoData can only be a JSON object with a valid json MemoFormat');
      }
    }

    memo.MemoData = convertStringToHex(memoData);
  }

  this.tx_json.Memos = (this.tx_json.Memos || []).concat({Memo: memo});

  return this;
};

/**
 * Construct an 'AccountSet' transaction
 *
 * Note that bit flags can be set using the .setFlags() method but for
 * 'AccountSet' transactions there is an additional way to modify AccountRoot
 * flags. The values available for the SetFlag and ClearFlag are as follows:
 *
 * asfRequireDest:    Require a destination tag
 * asfRequireAuth:    Authorization is required to extend trust
 * asfDisallowXRP:    XRP should not be sent to this account
 * asfDisableMaster:  Disallow use of the master key
 * asfNoFreeze:       Permanently give up the ability to freeze individual
 *                    trust lines. This flag can never be cleared.
 * asfGlobalFreeze:   Freeze all assets issued by this account
 *
 * @param [String] set flag
 * @param [String] clear flag
 */

Transaction.prototype.accountSet = function(options_) {
  let options;

  if (typeof options_ === 'object') {
    options = _.merge({}, options_);

    if (_.isUndefined(options.account)) {
      options.account = options.src;
    }
    if (_.isUndefined(options.set_flag)) {
      options.set_flag = options.set;
    }
    if (_.isUndefined(options.clear_flag)) {
      options.clear_flag = options.clear;
    }
  } else {
    options = {
      account: arguments[0],
      set_flag: arguments[1],
      clear_flag: arguments[2]
    };
  }

  this.setType('AccountSet');
  this.setAccount(options.account);

  if (!_.isUndefined(options.set_flag)) {
    this.setSetFlag(options.set_flag);
  }
  if (!_.isUndefined(options.clear_flag)) {
    this.setClearFlag(options.clear_flag);
  }

  return this;
};

Transaction.prototype.setAccountSetFlag = function(name, value) {
  const accountSetFlags = Transaction.set_clear_flags.AccountSet;
  let flagValue = value;

  if (typeof flagValue === 'string') {
    flagValue = /^asf/.test(flagValue)
    ? accountSetFlags[flagValue]
    : accountSetFlags['asf' + flagValue];
  }

  if (!_.contains(_.values(accountSetFlags), flagValue)) {
    throw new Error(name + ' must be a valid AccountSet flag');
  }

  this.tx_json[name] = flagValue;

  return this;
};

Transaction.prototype.setSetFlag = function(flag) {
  return this.setAccountSetFlag('SetFlag', flag);
};

Transaction.prototype.setClearFlag = function(flag) {
  return this.setAccountSetFlag('ClearFlag', flag);
};

/**
 * Set TransferRate for AccountSet
 *
 * @param {Number} transfer rate
 */

Transaction.prototype.setTransferRate =
Transaction.prototype.transferRate = function(rate) {
  const transferRate = rate;

  if (transferRate === 0) {
    // Clear TransferRate
    this.tx_json.TransferRate = transferRate;
    return this;
  }

  // if (rate >= 1 && rate < 2) {
    // transferRate *= 1e9;
  // }

  return this._setUInt32('TransferRate', transferRate, {min_value: 1e9});
};

/**
 * Construct a 'SetRegularKey' transaction
 *
 * If the RegularKey is set, the private key that corresponds to it can be
 * used to sign transactions instead of the master key
 *
 * The RegularKey must be a valid Ripple Address, or a Hash160 of the public
 * key corresponding to the new private signing key.
 *
 * @param {String} account
 * @param {String} regular key
 */

Transaction.prototype.setRegularKey = function(options_) {
  let options;

  if (typeof options_ === 'object') {
    options = _.merge({}, options_);

    if (_.isUndefined(options.account)) {
      options.account = options.src;
    }
  } else {
    options = {
      account: arguments[0],
      regular_key: arguments[1]
    };
  }

  this.setType('SetRegularKey');
  this.setAccount(options.account);

  if (!_.isUndefined(options.regular_key)) {
    this._setAccount('RegularKey', options.regular_key);
  }

  return this;
};

/**
 * Construct a 'TrustSet' transaction
 *
 * @param {String} account
 * @param [Amount] limit
 * @param [Number] quality in
 * @param [Number] quality out
 */

Transaction.prototype.trustSet =
Transaction.prototype.rippleLineSet = function(options_) {
  let options;

  if (typeof options_ === 'object') {
    options = _.merge({}, options_);

    if (_.isUndefined(options.account)) {
      options.account = options.src;
    }
  } else {
    options = {
      account: arguments[0],
      limit: arguments[1],
      quality_in: arguments[2],
      quality_out: arguments[3]
    };
  }

  this.setType('TrustSet');
  this.setAccount(options.account);

  if (!_.isUndefined(options.limit)) {
    this.setLimit(options.limit);
  }
  if (!_.isUndefined(options.quality_in)) {
    this.setQualityIn(options.quality_in);
  }
  if (!_.isUndefined(options.quality_out)) {
    this.setQualityOut(options.quality_out);
  }

  // XXX Throw an error if nothing is set.

  return this;
};

Transaction.prototype.setLimit = function(amount) {
  return this._setAmount('LimitAmount', amount, {no_native: true});
};

Transaction.prototype.setQualityIn = function(quality) {
  return this._setUInt32('QualityIn', quality);
};

Transaction.prototype.setQualityOut = function(quality) {
  return this._setUInt32('QualityOut', quality);
};

/**
 * Construct a 'Payment' transaction
 *
 * Relevant setters:
 *  - setPaths()
 *  - setBuildPath()
 *  - addPath()
 *  - setSourceTag()
 *  - setDestinationTag()
 *  - setSendMax()
 *  - setFlags()
 *
 *  @param {String} source account
 *  @param {String} destination account
 *  @param {Amount} payment amount
 */

Transaction.prototype.payment = function(options_) {
  let options;

  if (typeof options_ === 'object') {
    options = _.merge({}, options_);

    if (_.isUndefined(options.account)) {
      options.account = options.src || options.from;
    }
    if (_.isUndefined(options.destination)) {
      options.destination = options.dst || options.to;
    }
  } else {
    options = {
      account: arguments[0],
      destination: arguments[1],
      amount: arguments[2]
    };
  }

  this.setType('Payment');
  this.setAccount(options.account);
  this.setDestination(options.destination);
  this.setAmount(options.amount);

  return this;
};

Transaction.prototype.setAmount = function(amount) {
  return this._setAmount('Amount', amount);
};

Transaction.prototype.setDestination = function(destination) {
  return this._setAccount('Destination', destination);
};

/**
 * Set SendMax for Payment
 *
 * @param {String|Object} send max amount
 */

Transaction.prototype.setSendMax =
Transaction.prototype.sendMax = function(send_max) {
  return this._setAmount('SendMax', send_max);
};

/**
 * Set DeliverMin for Payment
 *
 * @param {String|Object} deliver_min minimum amount to deliver
 */

Transaction.prototype.setDeliverMin = function(deliver_min) {
  return this._setAmount('DeliverMin', deliver_min);
};

/**
 * Filter invalid properties from path objects in a path array
 *
 * Valid properties are:
 * - account
 * - currency
 * - issuer
 * - type_hex
 *
 * @param {Array} path
 * @return {Array} filtered path
 */

Transaction._rewritePath = function(path) {
  const newPath = path.map(function(node) {
    const newNode = { };

    if (node.hasOwnProperty('account')) {
      newNode.account = node.account;
    }

    if (node.hasOwnProperty('issuer')) {
      newNode.issuer = node.issuer;
    }

    if (node.hasOwnProperty('currency')) {
      newNode.currency = Currency.json_rewrite(node.currency);
    }

    if (node.hasOwnProperty('type_hex')) {
      newNode.type_hex = node.type_hex;
    }

    return newNode;
  });

  return newPath;
};

/**
 * Add a path for Payment transaction
 *
 * @param {Array} path
 */

Transaction.prototype.addPath =
Transaction.prototype.pathAdd = function(path) {
  if (!Array.isArray(path)) {
    throw new Error('Path must be an array');
  }

  this.tx_json.Paths = this.tx_json.Paths || [];
  this.tx_json.Paths.push(Transaction._rewritePath(path));

  return this;
};

/**
 * Set paths for Payment transaction
 *
 * @param {Array} paths
 */

Transaction.prototype.setPaths =
Transaction.prototype.paths = function(paths) {
  if (!Array.isArray(paths)) {
    throw new Error('Paths must be an array');
  }

  if (paths.length === 0) {
    return this;
  }

  this.tx_json.Paths = [];
  paths.forEach(this.addPath, this);

  return this;
};

/**
 * Set build_path to have server blindly construct a path for Payment
 *
 *  "blindly" because the sender has no idea of the actual cost must be less
 *  than send max.
 *
 *  @param {Boolean} build path
 */

Transaction.prototype.setBuildPath =
Transaction.prototype.buildPath = function(build) {
  this._build_path = build === undefined || build;

  return this;
};

/**
 * Set DestinationTag for Payment transaction
 *
 * @param {Number} destination tag
 */

Transaction.prototype.setDestinationTag =
Transaction.prototype.destinationTag = function(tag) {
  return this._setUInt32('DestinationTag', tag);
};

/**
 * Set InvoiceID for Payment transaction
 *
 * @param {String} id
 */

Transaction.prototype.setInvoiceID =
Transaction.prototype.invoiceID = function(id) {
  return this._setHash256('InvoiceID', id, {pad: true});
};

/**
 * Construct an 'OfferCreate transaction
 *
 * @param {String} account
 * @param {Amount} taker pays amount
 * @param {Amount} taker gets amount
 * @param [Number|Date] expiration
 * @param [Number] sequence of an existing offer to replace
 */

Transaction.prototype.offerCreate = function(options_) {
  let options;

  if (typeof options_ === 'object') {
    options = _.merge({}, options_);

    if (_.isUndefined(options.account)) {
      options.account = options.src;
    }
    if (_.isUndefined(options.taker_pays)) {
      options.taker_pays = options.buy;
    }
    if (_.isUndefined(options.taker_gets)) {
      options.taker_gets = options.sell;
    }
    if (_.isUndefined(options.offer_sequence)) {
      options.offer_sequence = options.cancel_sequence || options.sequence;
    }
  } else {
    options = {
      account: arguments[0],
      taker_pays: arguments[1],
      taker_gets: arguments[2],
      expiration: arguments[3],
      offer_sequence: arguments[4]
    };
  }

  this.setType('OfferCreate');
  this.setAccount(options.account);
  this.setTakerGets(options.taker_gets);
  this.setTakerPays(options.taker_pays);

  if (!_.isUndefined(options.expiration)) {
    this.setExpiration(options.expiration);
  }
  if (!_.isUndefined(options.offer_sequence)) {
    this.setOfferSequence(options.offer_sequence);
  }

  return this;
};

Transaction.prototype.setTakerGets = function(amount) {
  return this._setAmount('TakerGets', amount);
};

Transaction.prototype.setTakerPays = function(amount) {
  return this._setAmount('TakerPays', amount);
};

Transaction.prototype.setExpiration = function(expiration) {
  const timeOffset = expiration instanceof Date
  ? expiration.getTime()
  : expiration;

  return this._setUInt32('Expiration', utils.time.toRipple(timeOffset));
};

Transaction.prototype.setOfferSequence = function(offerSequence) {
  return this._setUInt32('OfferSequence', offerSequence);
};

/**
 * Construct an 'OfferCancel' transaction
 *
 * @param {String} account
 * @param [Number] sequence of an existing offer
 */

Transaction.prototype.offerCancel = function(options_) {
  let options;

  if (typeof options_ === 'object') {
    options = _.merge({}, options_);

    if (_.isUndefined(options.account)) {
      options.account = options.src;
    }
    if (_.isUndefined(options.offer_sequence)) {
      options.offer_sequence = options.sequence || options.cancel_sequence;
    }
  } else {
    options = {
      account: arguments[0],
      offer_sequence: arguments[1]
    };
  }

  this.setType('OfferCancel');
  this.setAccount(options.account);
  this.setOfferSequence(options.offer_sequence);

  return this;
};

Transaction._prepareSignerEntry = function(signer) {
  const {account, weight} = signer;

  assert(isValidAddress(account), 'Signer account invalid');
  assert(_.isNumber(weight), 'Signer weight missing');
  assert(weight > 0 && weight <= 65535, 'Signer weight must be 1-65535');

  return {
    SignerEntry: {
      Account: account,
      SignerWeight: weight
    }
  };
};

Transaction.prototype.setSignerList = function(options = {}) {
  this.setType('SignerListSet');
  this.setAccount(options.account);
  this.setSignerQuorum(options.signerQuorum);

  if (!_.isEmpty(options.signers)) {
    this.tx_json.SignerEntries =
      options.signers.map(Transaction._prepareSignerEntry);
  }

  return this;
};

Transaction.prototype.setSignerQuorum = function(quorum) {
  this._setUInt32('SignerQuorum', quorum);
};

/**
 * Submit transaction to the network
 *
 * @param [Function] callback
 */

Transaction.prototype.submit = function(callback = function() {}) {
  const self = this;

  this.callback = callback;

  this._errorHandler = function transactionError(error_, message) {
    let error = error_;

    if (!(error instanceof RippleError)) {
      error = new RippleError(error, message);
    }

    self.callback(error);
  };

  this._successHandler = function transactionSuccess(message) {
    self.callback(null, message);
  };

  if (!this.remote) {
    this.emit('error', new Error('No remote found'));
    return this;
  }

  this.getManager().submit(this);

  return this;
};

Transaction.prototype.abort = function() {
  if (!this.finalized) {
    this.emit('error', new RippleError('tejAbort', 'Transaction aborted'));
  }

  return this;
};

/**
 * Return summary object containing important information for persistence
 *
 * @return {Object} transaction summary
 */

Transaction.prototype.getSummary =
Transaction.prototype.summary = function() {
  const txSummary = {
    tx_json: this.tx_json,
    clientID: this._clientID,
    submittedIDs: this.submittedIDs,
    submissionAttempts: this.attempts,
    submitIndex: this.submitIndex,
    initialSubmitIndex: this.initialSubmitIndex,
    lastLedgerSequence: this.tx_json.LastLedgerSequence,
    state: this.state,
    finalized: this.finalized
  };

  if (this.result) {
    const transaction_hash = this.result.tx_json
    ? this.result.tx_json.hash
    : undefined;

    txSummary.result = {
      engine_result: this.result.engine_result,
      engine_result_message: this.result.engine_result_message,
      ledger_hash: this.result.ledger_hash,
      ledger_index: this.result.ledger_index,
      transaction_hash: transaction_hash
    };
  }

  return txSummary;
};

/**
 * Construct a 'SuspendedPaymentCreate' transaction
 *
 * Relevant setters:
 *  - setSourceTag()
 *  - setFlags()
 *  - setDigest()
 *  - setAllowCancelAfter()
 *  - setAllowExecuteAfter()
 *
 *  @param {String} options.account source account
 *  @param {String} options.destination account
 *  @param {Amount} options.amount payment amount
 */

Transaction.prototype.suspendedPaymentCreate = function(options) {
  this.setType('SuspendedPaymentCreate');
  this.setAccount(options.account);
  this.setDestination(options.destination);
  this.setAmount(options.amount);
  return this;
};

/**
 * Construct a 'SuspendedPaymentFinish' transaction
 *
 * Relevant setters:
 *  - setSourceTag()
 *  - setFlags()
 *  - setOwner()
 *  - setOfferSequence()
 *  - setMethod()
 *  - setDigest()
 *  - setProof()
 *
 *  @param {String} options.account source account
 *  @param {String} options.owner SuspendedPaymentCreate's Account
 *  @param {Integer} options.paymentSequence SuspendedPaymentCreate's Sequence
 */

Transaction.prototype.suspendedPaymentFinish = function(options) {
  this.setType('SuspendedPaymentFinish');
  this.setAccount(options.account);
  this.setOwner(options.owner);
  this.setOfferSequence(options.paymentSequence);
  return this;
};

/**
 * Construct a 'SuspendedPaymentCancel' transaction
 *
 * Relevant setters:
 *  - setSourceTag()
 *  - setFlags()
 *  - setOwner()
 *  - setOfferSequence()
 *
 *  @param {String} options.account source account
 *  @param {String} options.owner SuspendedPaymentCreate's Account
 *  @param {Integer} options.paymentSequence SuspendedPaymentCreate's Sequence
 */

Transaction.prototype.suspendedPaymentCancel = function(options) {
  this.setType('SuspendedPaymentCancel');
  this.setAccount(options.account);
  this.setOwner(options.owner);
  this.setOfferSequence(options.paymentSequence);
  return this;
};

Transaction.prototype.setDigest = function(digest) {
  return this._setHash256('Digest', digest);
};

Transaction.prototype.setAllowCancelAfter = function(after) {
  return this._setUInt32('CancelAfter', utils.time.toRipple(after));
};

Transaction.prototype.setAllowExecuteAfter = function(after) {
  return this._setUInt32('FinishAfter', utils.time.toRipple(after));
};

Transaction.prototype.setOwner = function(owner) {
  return this._setAccount('Owner', owner);
};

Transaction.prototype.setMethod = function(method) {
  return this._setUInt8('Method', method);
};

Transaction.prototype.setProof = function(proof) {
  this.tx_json.Proof = convertStringToHex(proof);
  return this;
};

Transaction.prototype._setUInt8 = function(name, value) {
  const isValidUInt8 = typeof value === 'number' && value >= 0 && value < 256;
  if (!isValidUInt8) {
    throw new Error(name + ' must be a valid UInt8');
  }
  this.tx_json[name] = value;
  return this;
};

Transaction.prototype.setSigners = function(signers) {
  if (_.isArray(signers)) {
    this.tx_json.Signers = signers;
  }

  return this;
};

Transaction.prototype.addMultiSigner = function(signer) {
  assert(isValidAddress(signer.Account), 'Signer must have a valid Account');

  if (_.isUndefined(this.tx_json.Signers)) {
    this.tx_json.Signers = [];
  }

  this.tx_json.Signers.push({Signer: signer});

  this.tx_json.Signers.sort((a, b) => {
    return (new Buffer(decodeAddress(a.Signer.Account))).compare(
      new Buffer(decodeAddress(b.Signer.Account)));
  });

  return this;
};

Transaction.prototype.hasMultiSigners = function() {
  return !_.isEmpty(this.tx_json.Signers);
};

Transaction.prototype.getMultiSigners = function() {
  return this.tx_json.Signers;
};

Transaction.prototype.getMultiSigningJson = function() {
  assert(this.tx_json.Sequence, 'Sequence must be set before multi-signing');
  assert(this.tx_json.Fee, 'Fee must be set before multi-signing');

  if (_.isUndefined(this.tx_json.LastLedgerSequence)) {
    // Auto-fill LastLedgerSequence
    this.setLastLedgerSequence();
  }

  const cleanedJson = _.omit(this.tx_json, [
    'SigningPubKey',
    'Signers',
    'TxnSignature'
  ]);

  const signingTx = Transaction.from_json(cleanedJson);
  signingTx.remote = this.remote;
  signingTx.setSigningPubKey('');
  signingTx.setCanonicalFlag();

  return signingTx.tx_json;
};

Transaction.prototype.multiSign = function(account, secret) {
  const signingData = this.multiSigningData(account);
  const keypair = deriveKeypair(secret);

  const signer = {
    Account: account,
    TxnSignature: sign(signingData.buffer, keypair.privateKey),
    SigningPubKey: keypair.publicKey
  };

  return signer;
};

exports.Transaction = Transaction;