using System;
using System.Text;
using UnityEngine;

namespace Utility.Packets
{
    public class PacketSerializer
    {
        public static byte[] Build(UInt16 op_code, byte[] data = null)
        {
            byte[] op = BitConverter.GetBytes(op_code);

            UInt32 packet_length = Convert.ToUInt32(op.Length);
            byte[] header = BitConverter.GetBytes(packet_length);

            byte[] packet = new byte[op.Length + header.Length + data.Length];

            System.Buffer.BlockCopy(header, 0, packet, 0, header.Length);
            System.Buffer.BlockCopy(op, 0, packet, header.Length, op.Length);
            System.Buffer.BlockCopy(data, 0, packet, op.Length, data.Length);

            return packet;
        }

        public static string Beautify(byte[] packet)
        {
            string beautified = "{";

            for (int i = 0; i < packet.Length; i++)
            {
                if(i == packet.Length - 1)
                    beautified += packet[i];
                else
                    beautified += packet[i] + ", ";
            }

            return beautified + "}";
        }
    }

    public static class PacketBuilder {
        public static byte[] Pong()
        {
            return PacketSerializer.Build(OpCode.PONG);
        }

        public static byte[] Login(UInt16 _version, string _username, string _password)
        {
            byte[] username = System.Text.Encoding.UTF8.GetBytes(_username);
            byte[] password = System.Text.Encoding.UTF8.GetBytes(_password);

            UInt16 _user_len = Convert.ToUInt16(username.Length);
            UInt16 _pass_len = Convert.ToUInt16(password.Length);

            byte[] version  = BitConverter.GetBytes(_version);
            byte[] user_len = BitConverter.GetBytes(_user_len);
            byte[] pass_len = BitConverter.GetBytes(_pass_len);

            byte[] packet = new byte[version.Length + user_len.Length + username.Length + pass_len.Length + password.Length];

            Buffer.BlockCopy(version, 0, packet, 0, version.Length);
            Buffer.BlockCopy(user_len, 0, packet, version.Length, user_len.Length);
            Buffer.BlockCopy(username, 0, packet, user_len.Length, username.Length);
            Buffer.BlockCopy(pass_len, 0, packet, username.Length, pass_len.Length);
            Buffer.BlockCopy(password, 0, packet, pass_len.Length, password.Length);

            Debug.Log(">> " + PacketSerializer.Beautify(packet));

            return PacketSerializer.Build(OpCode.LOGIN, packet);
        }
    }
}