DiscordRichPresenceUpdate.kt

class DiscordRichPresenceUpdate(private val details: String?, private val state: String?, private val key: String?) {

    fun encode(): PacketBuilder {
        val buffer = PacketBuilder()

        val builder = PacketBuilder(PACKET_ID, PacketType.BYTE)
        var mask: Byte = 0

        if (details != null) {
            mask = mask xor DETAILS_MASK
            builder.putString(details)
        }

        if (state != null) {
            mask = mask xor STATE_MASK
            builder.putString(state)
        }

        if (key != null) {
            mask = mask xor KEY_MASK
            builder.putString(key)
        }

        buffer.putByte(mask)
        builder.writeTo(buffer)

        return buffer
    }

    companion object {

        const val PACKET_ID = 131

        const val DETAILS_MASK: Byte = 0x1

        const val STATE_MASK: Byte = 0x2

        const val KEY_MASK: Byte = 0x4

        //leaves 5 bits reserved for later usage

    }

}