// Language-neutral expression to match ER_UPDATE_INFO
var ER_UPDATE_INFO_REGEXP = /^[^:0-9]+: [0-9]+[^:0-9]+: ([0-9]+)[^:0-9]+: [0-9]+[^:0-9]*$/;

module.exports = OkPacket;
function OkPacket(options) {
  options = options || {};

  this.fieldCount   = undefined;
  this.affectedRows = undefined;
  this.insertId     = undefined;
  this.serverStatus = undefined;
  this.warningCount = undefined;
  this.message      = undefined;
  this.protocol41   = options.protocol41;
}

OkPacket.prototype.parse = function(parser) {
  this.fieldCount   = parser.parseUnsignedNumber(1);
  this.affectedRows = parser.parseLengthCodedNumber();
  this.insertId     = parser.parseLengthCodedNumber();
  if (this.protocol41) {
    this.serverStatus = parser.parseUnsignedNumber(2);
    this.warningCount = parser.parseUnsignedNumber(2);
  }
  this.message      = parser.parsePacketTerminatedString();
  this.changedRows  = 0;

  var m = ER_UPDATE_INFO_REGEXP.exec(this.message);
  if (m !== null) {
    this.changedRows = parseInt(m[1], 10);
  }
};

OkPacket.prototype.write = function(writer) {
  writer.writeUnsignedNumber(1, 0x00);
  writer.writeLengthCodedNumber(this.affectedRows || 0);
  writer.writeLengthCodedNumber(this.insertId || 0);
  if (this.protocol41) {
    writer.writeUnsignedNumber(2, this.serverStatus || 0);
    writer.writeUnsignedNumber(2, this.warningCount || 0);
  }
  writer.writeString(this.message);
};