function ByteStream(data) {
  this.data = data;
  this.pos = 0;
}

// read the next byte off the stream
ByteStream.prototype.readByte = function() {
  return this.data[this.pos++];
};

// look at the next byte in the stream without updating the stream position
ByteStream.prototype.peekByte = function() {
  return this.data[this.pos];
};

// read an array of bytes
ByteStream.prototype.readBytes = function(n) {
  var bytes = new Array(n);
  for (var i = 0; i < n; i++) {
    bytes[i] = this.readByte();
  }
  return bytes;
};

// peek at an array of bytes without updating the stream position
ByteStream.prototype.peekBytes = function(n) {
  var bytes = new Array(n);
  for (var i = 0; i < n; i++) {
    bytes[i] = this.data[this.pos + i];
  }
  return bytes;
};

// read a string from a byte set
ByteStream.prototype.readString = function(len) {
  var str = "";
  for (var i = 0; i < len; i++) {
    str += String.fromCharCode(this.readByte());
  }
  return str;
};

// read a single byte and return an array of bit booleans
ByteStream.prototype.readBitArray = function() {
  var arr = [];
  var bite = this.readByte();
  for (var i = 7; i >= 0; i--) {
    arr.push(!!(bite & (1 << i)));
  }
  return arr;
};

// read an unsigned int with endian option
ByteStream.prototype.readUnsigned = function(littleEndian) {
  var a = this.readBytes(2);
  if (littleEndian) {
    return (a[1] << 8) + a[0];
  } else {
    return (a[0] << 8) + a[1];
  }
};

export default ByteStream