text: 'use strict';
  
  var _ = require('lodash');
  var $ = require('./util/preconditions');
  var errors = require('./errors');
  var Base58Check = require('./encoding/base58check');
  var Networks = require('./networks');
  var Hash = require('./crypto/hash');
  var JSUtil = require('./util/js');
  var PublicKey = require('./publickey');
  
  /**
   * Instantiate an address from an address String or Buffer, a public key or script hash Buffer,
   * or an instance of {@link PublicKey} or {@link Script}.
   *
   * This is an immutable class, and if the first parameter provided to this constructor is an
   * `Address` instance, the same argument will be returned.
   *
   * An address has two key properties: `network` and `type`. The type is either
   * `Address.PayToPublicKeyHash` (value is the `'pubkeyhash'` string)
   * or `Address.PayToScriptHash` (the string `'scripthash'`). The network is an instance of {@link Network}.
   * You can quickly check whether an address is of a given kind by using the methods
   * `isPayToPublicKeyHash` and `isPayToScriptHash`
   *
   * @example
   * ```javascript
   * // validate that an input field is valid
   * var error = Address.getValidationError(input, 'testnet');
   * if (!error) {
   *   var address = Address(input, 'testnet');
   * } else {
   *   // invalid network or checksum (typo?)
   *   var message = error.messsage;
   * }
   *
   * // get an address from a public key
   * var address = Address(publicKey, 'testnet').toString();
   * ```
   *
   * @param {*} data - The encoded data in various formats
   * @param {Network|String|number=} network - The network: 'livenet' or 'testnet'
   * @param {string=} type - The type of address: 'script' or 'pubkey'
   * @returns {Address} A new valid and frozen instance of an Address
   * @constructor
   */
  function Address(data, network, type) {
    /* jshint maxcomplexity: 12 */
    /* jshint maxstatements: 20 */
  
    if (!(this instanceof Address)) {
      return new Address(data, network, type);
    }
  
    if (_.isArray(data) && _.isNumber(network)) {
      return Address.createMultisig(data, network, type);
    }
  
    if (data instanceof Address) {
      // Immutable instance
      return data;
    }
  
    $.checkArgument(data, 'First argument is required, please include address data.', 'guide/address.html');
  
    if (network && !Networks.get(network)) {
      throw new TypeError('Second argument must be "livenet" or "testnet".');
    }
  
    if (type && (type !== Address.PayToPublicKeyHash && type !== Address.PayToScriptHash)
      && (type !== Address.PayToPublicKeyHash256 && type !== Address.PayToScriptHash256)) {
      throw new TypeError('Third argument must be "pubkeyhash" or "scripthash".');
    }
  
    var info = this._classifyArguments(data, network, type);
  
    // set defaults if not set
    info.network = info.network || Networks.get(network) || Networks.defaultNetwork;
    info.type = info.type || type || Address.PayToPublicKeyHash;
  
    JSUtil.defineImmutable(this, {
      hashBuffer: info.hashBuffer,
      network: info.network,
      type: info.type
    });
  
    return this;
  }
  
  /**
   * Internal function used to split different kinds of arguments of the constructor
   * @param {*} data - The encoded data in various formats
   * @param {Network|String|number=} network - The network: 'livenet' or 'testnet'
   * @param {string=} type - The type of address: 'script' or 'pubkey'
   * @returns {Object} An "info" object with "type", "network", and "hashBuffer"
   */
  Address.prototype._classifyArguments = function(data, network, type) {
    /* jshint maxcomplexity: 10 */
    // transform and validate input data
    if ((data instanceof Buffer || data instanceof Uint8Array) && [20,32].includes(data.length)) {
      return Address._transformHash(data);
    } else if ((data instanceof Buffer || data instanceof Uint8Array) && data.length === 21) {
      return Address._transformBuffer(data, network, type);
    } else if (data instanceof PublicKey) {
      return Address._transformPublicKey(data);
    } else if (data instanceof Script) {
      return Address._transformScript(data, network);
    } else if (typeof(data) === 'string') {
      return Address._transformString(data, network, type);
    } else if (_.isObject(data)) {
      return Address._transformObject(data);
    } else {
      throw new TypeError('First argument is an unrecognized data format.');
    }
  };
  
  /** @static */
  Address.PayToPublicKeyHash = 'pubkeyhash';
  /** @static */
  Address.PayToScriptHash = 'scripthash';
  /** @static */
  Address.PayToPublicKeyHash256 = 'pubkeyhash256';
  /** @static */
  Address.PayToScriptHash256 = 'scripthash256';
  
  /**
   * @param {Buffer} hash - An instance of a hash Buffer
   * @returns {Object} An object with keys: hashBuffer
   * @private
   */
  Address._transformHash = function(hash) {
    var info = {};
    if (!(hash instanceof Buffer) && !(hash instanceof Uint8Array)) {
      throw new TypeError('Address supplied is not a buffer.');
    }
    if (hash.length !== 20 && hash.length !== 32) {
      throw new TypeError('Address hashbuffers must be exactly 20 or 32 bytes.');
    }
    info.hashBuffer = hash;
    return info;
  };
  
  /**
   * Deserializes an address serialized through `Address#toObject()`
   * @param {Object} data
   * @param {string} data.hash - the hash that this address encodes
   * @param {string} data.type - either 'pubkeyhash' or 'scripthash'
   * @param {Network=} data.network - the name of the network associated
   * @return {Address}
   */
  Address._transformObject = function(data) {
    $.checkArgument(data.hash || data.hashBuffer, 'Must provide a `hash` or `hashBuffer` property');
    $.checkArgument(data.type, 'Must provide a `type` property');
    return {
      hashBuffer: data.hash ? new Buffer(data.hash, 'hex') : data.hashBuffer,
      network: Networks.get(data.network) || Networks.defaultNetwork,
      type: data.type
    };
  };
  
  /**
   * Internal function to discover the network and type based on the first data byte
   *
   * @param {Buffer} buffer - An instance of a hex encoded address Buffer
   * @returns {Object} An object with keys: network and type
   * @private
   */
  Address._classifyFromVersion = function(buffer) {
    var version = {};
  
    var pubkeyhashNetwork = Networks.get(buffer[0], 'pubkeyhash');
    var scripthashNetwork = Networks.get(buffer[0], 'scripthash');
  
    if (pubkeyhashNetwork) {
      version.network = pubkeyhashNetwork;
      version.type = Address.PayToPublicKeyHash;
    } else if (scripthashNetwork) {
      version.network = scripthashNetwork;
      version.type = Address.PayToScriptHash;
    } else
    {
      var pubkeyhash256Network = Networks.get(buffer[0], 'pubkeyhash256');
      var scripthash256Network = Networks.get(buffer[0], 'scripthash256');
      if (pubkeyhash256Network) {
        version.network = pubkeyhash256Network;
        version.type = Address.PayToPublicKeyHash256;
      } else if (scripthash256Network) {
        version.network = scripthash256Network;
        version.type = Address.PayToScriptHash256;
      }
    }
  
    return version;
  };
  
  /**
   * Internal function to transform a bitcoin address buffer
   *
   * @param {Buffer} buffer - An instance of a hex encoded address Buffer
   * @param {string=} network - The network: 'livenet' or 'testnet'
   * @param {string=} type - The type: 'pubkeyhash' or 'scripthash'
   * @returns {Object} An object with keys: hashBuffer, network and type
   * @private
   */
  Address._transformBuffer = function(buffer, network, type) {
    /* jshint maxcomplexity: 9 */
    var info = {};
    if (!(buffer instanceof Buffer) && !(buffer instanceof Uint8Array)) {
      // throw new TypeError('Address supplied is not a buffer.');
    }
  
    if (buffer.length == 1 + 32) {
      network = Networks.get(network);
      var bufferVersion = Address._classifyFromVersion(buffer);
  
      if (!bufferVersion.network || (network && network !== bufferVersion.network)) {
        // throw new TypeError('Address has mismatched network type.');
      }
  
      if (!bufferVersion.type || (type && type !== bufferVersion.type)) {
        // throw new TypeError('Address has mismatched type.');
      }
  
      info.hashBuffer = buffer.slice(1);
      info.network = bufferVersion.network;
      info.type = bufferVersion.type;
      return info;
    }
  
    if (buffer.length !== 1 + 20) {
      // throw new TypeError('Address buffers must be exactly 21 bytes.');
    }
  
    network = Networks.get(network);
    var bufferVersion = Address._classifyFromVersion(buffer);
  
    if (!bufferVersion.network || (network && network !== bufferVersion.network)) {
      // throw new TypeError('Address has mismatched network type.');
    }
  
    if (!bufferVersion.type || (type && type !== bufferVersion.type)) {
      // throw new TypeError('Address has mismatched type.');
    }
  
    info.hashBuffer = buffer.slice(1);
    info.network = bufferVersion.network;
    info.type = bufferVersion.type;
    return info;
  };
  
  /**
   * Internal function to transform a {@link PublicKey}
   *
   * @param {PublicKey} pubkey - An instance of PublicKey
   * @param {Boolean} sha256 - Hash with sha256
   * @returns {Object} An object with keys: hashBuffer, type
   * @private
   */
  Address._transformPublicKey = function(pubkey, sha256) {
    var info = {};
    if (!(pubkey instanceof PublicKey)) {
      throw new TypeError('Address must be an instance of PublicKey.');
    }
    info.hashBuffer = Hash[sha256 ? 'sha256' : 'sha256ripemd160'](pubkey.toBuffer());
    info.type = Address[sha256 ? 'PayToPublicKeyHash256' : 'PayToPublicKeyHash'];
    return info;
  };
  
  /**
   * Internal function to transform a {@link Script} into a `info` object.
   *
   * @param {Script} script - An instance of Script
   * @returns {Object} An object with keys: hashBuffer, type
   * @private
   */
  Address._transformScript = function(script, network) {
    $.checkArgument(script instanceof Script, 'script must be a Script instance');
    var info = script.getAddressInfo(network);
    if (!info) {
      throw new errors.Script.CantDeriveAddress(script);
    }
    return info;
  };
  
  /**
   * Creates a P2SH address from a set of public keys and a threshold.
   *
   * The addresses will be sorted lexicographically, as that is the trend in bitcoin.
   * To create an address from unsorted public keys, use the {@link Script#buildMultisigOut}
   * interface.
   *
   * @param {Array} publicKeys - a set of public keys to create an address
   * @param {number} threshold - the number of signatures needed to release the funds
   * @param {String|Network} network - either a Network instance, 'livenet', or 'testnet'
   * @return {Address}
   */
  Address.createMultisig = function(publicKeys, threshold, network) {
    network = network || publicKeys[0].network || Networks.defaultNetwork;
    return Address.payingTo(Script.buildMultisigOut(publicKeys, threshold), network);
  };
  
  /**
   * Internal function to transform a bitcoin address string
   *
   * @param {string} data
   * @param {String|Network=} network - either a Network instance, 'livenet', or 'testnet'
   * @param {string=} type - The type: 'pubkeyhash' or 'scripthash'
   * @returns {Object} An object with keys: hashBuffer, network and type
   * @private
   */
  Address._transformString = function(data, network, type) {
    if (typeof(data) !== 'string') {
      throw new TypeError('data parameter supplied is not a string.');
    }
    data = data.trim();
    var addressBuffer = Base58Check.decode(data);
    var info = Address._transformBuffer(addressBuffer, network, type);
    return info;
  };
  
  /**
   * Instantiate an address from a PublicKey instance
   *
   * @param {PublicKey} data
   * @param {String|Network} network - either a Network instance, 'livenet', or 'testnet'
   * @param {Boolean} sha256
   * @returns {Address} A new valid and frozen instance of an Address
   */
  Address.fromPublicKey = function(data, network, sha256) {
    var info = Address._transformPublicKey(data, sha256);
    network = network || Networks.defaultNetwork;
    return new Address(info.hashBuffer, network, info.type);
  };
  
  /**
   * Instantiate an address from a ripemd160 public key hash
   *
   * @param {Buffer} hash - An instance of buffer of the hash
   * @param {String|Network} network - either a Network instance, 'livenet', or 'testnet'
   * @returns {Address} A new valid and frozen instance of an Address
   */
  Address.fromPublicKeyHash = function(hash, network) {
    var info = Address._transformHash(hash);
    return new Address(info.hashBuffer, network, Address.PayToPublicKeyHash);
  };
  
  /**
   * Instantiate an address from a ripemd160 script hash
   *
   * @param {Buffer} hash - An instance of buffer of the hash
   * @param {String|Network} network - either a Network instance, 'livenet', or 'testnet'
   * @returns {Address} A new valid and frozen instance of an Address
   */
  Address.fromScriptHash = function(hash, network) {
    $.checkArgument(hash, 'hash parameter is required');
    var info = Address._transformHash(hash);
    return new Address(info.hashBuffer, network, Address.PayToScriptHash);
  };
  
  /**
   * Builds a p2sh address paying to script. This will hash the script and
   * use that to create the address.
   * If you want to extract an address associated with a script instead,
   * see {{Address#fromScript}}
   *
   * @param {Script} script - An instance of Script
   * @param {String|Network} network - either a Network instance, 'livenet', or 'testnet'
   * @returns {Address} A new valid and frozen instance of an Address
   */
  Address.payingTo = function(script, network) {
    $.checkArgument(script, 'script is required');
    $.checkArgument(script instanceof Script, 'script must be instance of Script');
  
    return Address.fromScriptHash(Hash.sha256ripemd160(script.toBuffer()), network);
  };
  
  /**
   * Extract address from a Script. The script must be of one
   * of the following types: p2pkh input, p2pkh output, p2sh input
   * or p2sh output.
   * This will analyze the script and extract address information from it.
   * If you want to transform any script to a p2sh Address paying
   * to that script's hash instead, use {{Address#payingTo}}
   *
   * @param {Script} script - An instance of Script
   * @param {String|Network} network - either a Network instance, 'livenet', or 'testnet'
   * @returns {Address} A new valid and frozen instance of an Address
   */
  Address.fromScript = function(script, network) {
    $.checkArgument(script instanceof Script, 'script must be a Script instance');
    var info = Address._transformScript(script, network);
    return new Address(info.hashBuffer, network, info.type);
  };
  
  /**
   * Instantiate an address from a buffer of the address
   *
   * @param {Buffer} buffer - An instance of buffer of the address
   * @param {String|Network=} network - either a Network instance, 'livenet', or 'testnet'
   * @param {string=} type - The type of address: 'script' or 'pubkey'
   * @returns {Address} A new valid and frozen instance of an Address
   */
  Address.fromBuffer = function(buffer, network, type) {
    var info = Address._transformBuffer(buffer, network, type);
    return new Address(info.hashBuffer, info.network, info.type);
  };
  
  /**
   * Instantiate an address from an address string
   *
   * @param {string} str - An string of the bitcoin address
   * @param {String|Network=} network - either a Network instance, 'livenet', or 'testnet'
   * @param {string=} type - The type of address: 'script' or 'pubkey'
   * @returns {Address} A new valid and frozen instance of an Address
   */
  Address.fromString = function(str, network, type) {
    var info = Address._transformString(str, network, type);
    return new Address(info.hashBuffer, info.network, info.type);
  };
  
  /**
   * Instantiate an address from an Object
   *
   * @param {string} json - An JSON string or Object with keys: hash, network and type
   * @returns {Address} A new valid instance of an Address
   */
  Address.fromObject = function fromObject(obj) {
    $.checkState(
      JSUtil.isHexa(obj.hash),
      'Unexpected hash property, "' + obj.hash + '", expected to be hex.'
    );
    var hashBuffer = new Buffer(obj.hash, 'hex');
    return new Address(hashBuffer, obj.network, obj.type);
  };
  
  /**
   * Will return a validation error if exists
   *
   * @example
   * ```javascript
   * // a network mismatch error
   * var error = Address.getValidationError('15vkcKf7gB23wLAnZLmbVuMiiVDc1Nm4a2', 'testnet');
   * ```
   *
   * @param {string} data - The encoded data
   * @param {String|Network} network - either a Network instance, 'livenet', or 'testnet'
   * @param {string} type - The type of address: 'script' or 'pubkey'
   * @returns {null|Error} The corresponding error message
   */
  Address.getValidationError = function(data, network, type) {
    var error;
    try {
      /* jshint nonew: false */
      new Address(data, network, type);
    } catch (e) {
      error = e;
    }
    return error;
  };
  
  /**
   * Will return a boolean if an address is valid
   *
   * @example
   * ```javascript
   * assert(Address.isValid('15vkcKf7gB23wLAnZLmbVuMiiVDc1Nm4a2', 'livenet'));
   * ```
   *
   * @param {string} data - The encoded data
   * @param {String|Network} network - either a Network instance, 'livenet', or 'testnet'
   * @param {string} type - The type of address: 'script' or 'pubkey'
   * @returns {boolean} The corresponding error message
   */
  Address.isValid = function(data, network, type) {
    return !Address.getValidationError(data, network, type);
  };
  
  /**
   * Returns true if an address is of pay to public key hash type
   * @return boolean
   */
  Address.prototype.isPayToPublicKeyHash = function() {
    return this.type === Address.PayToPublicKeyHash;
  };
  
  /**
   * Returns true if an address is of pay to script hash type
   * @return boolean
   */
  Address.prototype.isPayToScriptHash = function() {
    return this.type === Address.PayToScriptHash;
  };
  
  /**
   * Will return a buffer representation of the address
   *
   * @returns {Buffer} Bitcoin address buffer
   */
  Address.prototype.toBuffer = function() {
    var version = new Buffer([this.network[this.type]]);
    var buf = Buffer.concat([version, this.hashBuffer]);
    return buf;
  };
  
  /**
   * @returns {Object} A plain object with the address information
   */
  Address.prototype.toObject = Address.prototype.toJSON = function toObject() {
    return {
      hash: this.hashBuffer.toString('hex'),
      type: this.type,
      network: this.network.toString()
    };
  };
  
  /**
   * Will return a the string representation of the address
   *
   * @returns {string} Bitcoin address
   */
  Address.prototype.toString = function() {
    return Base58Check.encode(this.toBuffer());
  };
  
  /**
   * Will return a string formatted for the console
   *
   * @returns {string} Bitcoin address
   */
  Address.prototype.inspect = function() {
    return '<Address: ' + this.toString() + ', type: ' + this.type + ', network: ' + this.network + '>';
  };
  
  module.exports = Address;
  
  var Script = require('./script');
  