var imports = require('soop').imports();
var parent  = imports.parent  || require('./util/VersionedData');

function SIN(type, payload) {
  if (typeof type != 'number') {
    SIN.super(this, arguments);
    return;
  };
  this.data = new Buffer(1 + 1 + payload.length);
  this.__proto__ = this.encodings['binary'];
  this.prefix(0x0F);    // SIN magic number, in numberspace
  this.type(type);
  this.payload(payload);
};
SIN.parent = parent;
parent.applyEncodingsTo(SIN);

SIN.SIN_PERSIST_MAINNET = 0x01; // associated with sacrifice TX
SIN.SIN_PERSIST_TESTNET = 0x11; // associated with sacrifice TX
SIN.SIN_EPHEM = 0x02;     // generate off-net at any time

// get or set the prefix data (the first byte of the address)
SIN.prototype.prefix = function(num) {
  if(num || (num === 0)) {
    this.doAsBinary(function() {this.data.writeUInt8(num, 0);});
    return num;
  }
  return this.as('binary').readUInt8(0);
};

// get or set the SIN-type data (the second byte of the address)
SIN.prototype.type = function(num) {
  if(num || (num === 0)) {
    this.doAsBinary(function() {this.data.writeUInt8(num, 1);});
    return num;
  }
  return this.as('binary').readUInt8(1);
};

// get or set the payload data (as a Buffer object)
SIN.prototype.payload = function(data) {
  if(data) {
    this.doAsBinary(function() {data.copy(this.data, 2);});
    return data;
  }
  return this.as('binary').slice(1);
};

SIN.prototype.validate = function() {
  this.doAsBinary(function() {
    SIN.super(this, 'validate', arguments);
    if (this.data.length != 22) throw new Error('invalid data length');
  });
};
module.exports = require('soop')(SIN);