from MessageType import MessageType

import PayloadGenerator

from scapy.layers.inet import IP, Ether, UDP, TCP
from scapy.packet import Raw

class Packet_Generator():
	"""docstring for Packet_Generator"""
	def __init__(self, protocol="udp"):
		super(Packet_Generator, self).__init__()
		self.protocol = protocol

	def generate_Packet(self, ip_src: str="192.168.64.32", ip_dst: str="192.168.64.48", mac_src: str="56:6D:D9:BC:70:1C",
		mac_dst: str="F4:2B:95:B3:0E:1A", port_src: int=1337, port_dst: int=6442,
		tcpflags: str="S", payload: str=""):
		"""
		Creates a Packet with the specified Values for the current protocol

		:param ip_src: the source IP address of the IP header
	    :param ip_dst the destination IP address of the IP header
	    :param mac_src: the source MAC address of the MAC header
	    :param mac_dst: the destination MAC address of the MAC header
	    :param port_src: the source port of the header
	    :param port_dst: the destination port of the header
	    :param tcpflags: the TCP flags of the TCP header
	    :param payload: the payload of the packet
	    :return: the corresponding packet
	    """

	    #directly generate packet with the current protocol
		if(self.protocol == "udp"):
			packet = generate_udp_packet(ip_src=ip_src, ip_dst=ip_dst, mac_src=mac_src, mac_dst=mac_dst,
				port_src=port_src, port_dst=port_dst, payload=payload)
		elif(self.protocol == "tcp"):
			packet = generate_tcp_packet(ip_src=ip_src, ip_dst=ip_dst, mac_src=mac_src, mac_dst=mac_dst,
				port_src=port_src, port_dst=port_dst, tcpflags=tcpflags, payload=payload)
		#else raise exception?
		return packet
		

	def generate_MMCOM_Packet(self, ip_src: str="192.168.64.32", ip_dst: str="192.168.64.48", mac_src: str="56:6D:D9:BC:70:1C",
			mac_dst: str="F4:2B:95:B3:0E:1A", port_src: int=1337, port_dst: int=6442, tcpflags: str="S",
			message_type: MessageType=MessageType.HELLO, neighborlist_entries: int=1):
		"""
		Creates a Packet for Members-Management-Communication with the specified Values and the current protocol

		:param ip_src: the source IP address of the IP header
	    :param ip_dst the destination IP address of the IP header
	    :param mac_src: the source MAC address of the MAC header
	    :param mac_dst: the destination MAC address of the MAC header
	    :param port_src: the source port of the header
	    :param port_dst: the destination port of the header
	    :param tcpflags: the TCP flags of the TCP header
	    :param message_type: affects the size of the payload
	    :param neighborlist_entries: Number of entries for the payload
	    :return: the corresponding packet
	    """

	    #Determine length of the payload that has to be generated
		if(message_type == MessageType.HELLO):
			payload_len = 0
		elif(message_type == MessageType.HELLO_REPLY):
			payload_len = 22
		elif(message_type == MessageType.NEIGHBORLIST_REQUEST):
			payload_len = 28
		elif(message_type == MessageType.NEIGHBORLIST_REPLY):
			payload_len = 24 + 6 * neighborlist_entries
		else:
			payload_len = 0

		#generate payload
		payload = PayloadGenerator.generate_Payload(payload_len)

		#generate the packet
		if(self.protocol == "udp"):
			packet = generate_udp_packet(ip_src=ip_src, ip_dst=ip_dst, mac_src=mac_src, mac_dst=mac_dst,
				port_src=port_src, port_dst=port_dst, payload=payload)
		elif(self.protocol == "tcp"):
			packet = generate_tcp_packet(ip_src=ip_src, ip_dst=ip_dst, mac_src=mac_src, mac_dst=mac_dst,
				port_src=port_src, port_dst=port_dst, tcpflags=tcpflags, payload=payload)
		#else raise exception?
		return packet


def generate_tcp_packet(ip_src:str="192.168.64.32", ip_dst:str="192.168.64.48", mac_src:str="56:6D:D9:BC:70:1C", 
					   mac_dst:str="F4:2B:95:B3:0E:1A", port_src:int=1337, port_dst:int=6442, tcpflags:str="S", payload:str=""):
	"""
    Builds an TCP packet with the values specified by the caller. If a parameter was not specified by the caller, 
    it is set to a default value.
    
    :param ip_src: the source IP address of the IP header
    :param ip_dst the destination IP address of the IP header
    :param mac_src: the source MAC address of the MAC header
    :param mac_dst: the destination MAC address of the MAC header
    :param port_src: the source port of the TCP header
    :param port_dst: the destination port of the TCP header
    :param tcpflags: the TCP flags of the TCP header
    :param payload: the payload of the packet
    :return: the corresponding IP packet
    """

	ether = Ether(src=mac_src, dst=mac_dst)
	ip = IP(src=ip_src, dst=ip_dst)
	tcp = TCP(sport=port_src, dport=port_dst, flags=tcpflags)
	packet = ether / ip / tcp / Raw(load=payload)
	return packet


def generate_udp_packet(ip_src:str="192.168.64.32", ip_dst:str="192.168.64.48", mac_src:str="56:6D:D9:BC:70:1C", 
					   mac_dst:str="F4:2B:95:B3:0E:1A", port_src:int=1337, port_dst:int=6442, payload:str=""):
	"""
    Builds an UDP packet with the values specified by the caller. If a parameter was not specified by the caller, 
    it is set to a default value.
    
    :param ip_src: the source IP address of the IP header
    :param ip_dst the destination IP address of the IP header
    :param mac_src: the source MAC address of the MAC header
    :param mac_dst: the destination MAC address of the MAC header
    :param port_src: the source port of the UDP header
    :param port_dst: the destination port of the UDP header
    :param udp_len: length of the UDP packet, 8Byte header + payload
    :param udp_chksum: checksum of the UDP packet
    :param payload: the payload of the packet
    :return: the corresponding UDP packet
    """

	ether = Ether(src=mac_src, dst=mac_dst)
	ip = IP(src=ip_src, dst=ip_dst)
	udp = UDP(sport=port_src, dport=port_dst)
	packet = ether / ip / udp / Raw(load=payload)
	return packet