import nnpy
import struct

from p4utils.utils.topology import Topology
from p4utils.utils.sswitch_API import SimpleSwitchAPI

from scapy.all import sniff, get_if_list, Ether, get_if_hwaddr, sendp
from scapy.all import IP, Raw, IPv6, TCP, TCP_client
from scapy.all import Ether, sniff, Packet, BitField

import sys
import re

import logging
import argparse
import ipaddress
import subprocess


logging.basicConfig()
log = logging.getLogger("main")

class L2Controller(object):
    def __init__(self, sw_name):
        # Command line mapping
        self.modes = ['base']

        # Network / egress
        self.v6_routes = {}
        self.v6_routes['base'] = []
        self.v6_routes['base'].append({ "net": "2001:db8:61::/64", "port": "1"})
        self.v6_routes['base'].append({ "net": "2001:db8:62::/64", "port": "2"})

        self.v4_routes = {}
        self.v4_routes['base'] = []
        self.v4_routes['base'].append({ "net": "10.0.41.0/24", "port": "3"})
        self.v4_routes['base'].append({ "net": "10.0.42.0/24", "port": "4"})

        self.init_boilerplate(sw_name)

    def init_boilerplate(self, sw_name):
        self.topo = Topology(db="topology.db")
        self.sw_name = sw_name
        self.thrift_port = self.topo.get_thrift_port(sw_name)
        self.cpu_port =  self.topo.get_cpu_port_index(self.sw_name)
        self.controller = SimpleSwitchAPI(self.thrift_port)
        self.intf = str(self.topo.get_cpu_port_intf(self.sw_name).replace("eth0", "eth1"))
        self.controller.reset_state()

        if self.cpu_port:
            self.controller.mirroring_add(100, self.cpu_port)

    def config(self):
        self.fill_tables()
        self.config_hosts()

    def fill_tables(self):
        self.controller.table_clear("v6_routing")
        for v6route in self.v6_routes[self.mode]:
            self.controller.table_add("v6_routing", "set_egress_port", [v6route['net']], [v6route['port']])

        self.controller.table_clear("v4_routing")
        for v4route in self.v4_routes[self.mode]:
            self.controller.table_add("v4_routing", "set_egress_port", [v4route['net']], [v4route['port']])

    def config_hosts(self):
        """ Assumptions:
        - all routes are networks (no /128 v6 or /32 v4
        - hosts get the first ip address in the network
        """

        for v6route in self.v6_routes[self.mode]:
            host   = "h{}".format(v6route['port'])
            dev    = "{}-eth0".format(host)
            net    = ipaddress.ip_network(v6route['net'])
            ipaddr = "{}/{}".format(net[1],net.prefix_length)

            subprocess.run(["mx", host, "ip", "addr", "flush", "dev", dev])
            subprocess.run(["mx", host, "sysctl", "net.ipv6.conf.lo.disable_ipv6=0"])
            subprocess.run(["mx", host, "sysctl", "net.ipv6.conf.{}.disable_ipv6=0".format(dev)])
            subprocess.run(["mx", host, "ip", "addr", "add", ipaddr, "dev", dev])

            # mx h$i "ip -6 route add default via 2001:db8:6::42"

        #for v4route in self.v4_routes[self.mode]:


    def debug_print_pkg(self, pkg, msg="INCOMING"):
        log.info("{}: {}".format(msg, self.debug_format_pkg(pkg)))

    def debug_format_pkg(self, pkg):
        packet = Ether(str(pkg))

        if packet.type == 0x800:
            ip = pkg.getlayer(IP)
        elif packet.type == 0x86dd:
            ip = pkg.getlayer(IPv6)

        # tcp = pkg.getlayer(TCP)

        # raw = pkg.getlayer(Raw)

        # return "{}:{} => {}:{}: flags={} seq={} ack={} raw={}".format(
        #     ip.src, tcp.sport,
        #     ip.dst, tcp.dport,
        #     tcp.flags,
        #     tcp.seq,
        #     tcp.ack,
        #     raw)


    def recv_msg_cpu(self, pkg):
        packet = Ether(str(pkg))

        if packet.type == 0x800:
            pass
        elif packet.type == 0x86dd:
            pass
        else:
            print("Broken pkg: {}".format(pkg))
            return

    def run_cpu_port_loop(self):
        sniff(iface=self.intf, prn=self.recv_msg_cpu)

    def commandline(self):
        parser = argparse.ArgumentParser(description='controller++')
        parser.add_argument('--mode', help='Select mode / settings to use', choices=self.modes)
        args = parser.parse_args()
        self.mode = args.mode


if __name__ == "__main__":
    import sys
    import os

    if "DEBUG" in os.environ:
        log.setLevel(logging.DEBUG)
    else:
        log.setLevel(logging.INFO)

    log.info("Booting...")
    log.debug("Debug enabled.")

    sw_name = "s1"
    controller = L2Controller(sw_name)

    controller.commandline()
    controller.config()
    controller.run_cpu_port_loop()