package com.lumaserv.bgp.protocol.message;

import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;

@Getter
@Setter
@NoArgsConstructor
public class BGPOpen {

    byte version;
    int asn;
    int holdTime;
    byte[] identifier;

    public BGPOpen(byte[] message) {
        version = message[0];
        asn = ((message[1] & 0xFF) << 8) | (message[2] & 0xFF);
        holdTime = ((message[3] & 0xFF) << 8) | (message[4] & 0xFF);
        identifier = new byte[4];
    }

    public byte[] build() {
        byte[] message = new byte[5 + identifier.length + 1 + 2 + 2 * 6];
        message[0] = version;
        message[1] = (byte) (asn >> 8);
        message[2] = (byte) (asn & 0xFF);
        message[3] = (byte) (holdTime >> 8);
        message[4] = (byte) (holdTime & 0xFF);
        System.arraycopy(identifier, 0, message, 5, identifier.length);
        message[5 + identifier.length + 0] = 14; // Length (0E)
        message[5 + identifier.length + 1] =  2; // Parameter Type: capability (02)
        message[5 + identifier.length + 2] = 12; // Length (0C)

        message[5 + identifier.length + 3] =  1; // Type: multiprotocol (01)
        message[5 + identifier.length + 4] =  4; // Length (04)
        message[5 + identifier.length + 5] =  0; // IPv6 (0002)
        message[5 + identifier.length + 6] =  2; //
        message[5 + identifier.length + 7] =  0; // Reserved
        message[5 + identifier.length + 8] =  1; // Unicast (01)

        message[5 + identifier.length + 9] =  1; // Type: multiprotocol (01)
        message[5 + identifier.length +10] =  4; // Length (04)
        message[5 + identifier.length +11] =  0; // IPv4 (0001)
        message[5 + identifier.length +12] =  1; //
        message[5 + identifier.length +13] =  0; // Reserved
        message[5 + identifier.length +14] =  1; // Unicast (01)
        return message;
    }

}