from ryu.base import app_manager
from ryu.controller import ofp_event
from ryu.controller.handler import CONFIG_DISPATCHER, MAIN_DISPATCHER
from ryu.controller.handler import set_ev_cls
from ryu.ofproto import ofproto_v1_3
from ryu.lib.packet import packet
from ryu.lib.packet import ethernet
from ryu.topology import event
from ryu.lib.packet import ether_types

DEFAULT_PRIORITY = 1
FIRST_SWITCH_ID = 1
SECOND_SWITCH_ID = 2
THIRD_SWITCH_ID = 3
FOURTH_SWITCH_ID = 4


class ExampleApp(app_manager.RyuApp):
    OFP_VERSIONS = [ofproto_v1_3.OFP_VERSION]

    def __init__(self, *args, **kwargs):
        super(ExampleApp, self).__init__(*args, **kwargs)
        self.datapaths = {}

    def add_flow(self, datapath, match, actions, priority,idle_timeout,hard_timeout):
        ofprotocol = datapath.ofproto
        parser = datapath.ofproto_parser
        instruction = [parser.OFPInstructionActions(ofprotocol.OFPIT_APPLY_ACTIONS, actions)]
        flow_modification_message = datapath.ofproto_parser.OFPFlowMod(datapath=datapath, match=match,
                                                                       idle_timeout=idle_timeout,
                                                                       hard_timeout=hard_timeout, priority=priority,
                                                                       instructions=instruction)
        datapath.send_msg(flow_modification_message)



    @set_ev_cls(ofp_event.EventOFPSwitchFeatures, CONFIG_DISPATCHER)
    def switch_features_handler(self, ev):

        datapath = ev.msg.datapath
        ofproto = datapath.ofproto
        parser = datapath.ofproto_parser

        if datapath.id not in self.datapaths:
            self.datapaths[datapath.id] = datapath

        match = parser.OFPMatch()
        actions = [parser.OFPActionOutput(ofproto.OFPP_CONTROLLER,
                                          ofproto.OFPCML_NO_BUFFER)]
        self.add_flow(datapath, match, actions, 0,1000,1000)

        if datapath.id ==1:
            out_port=2
            actions = [parser.OFPActionOutput(out_port)]
            match = parser.OFPMatch(eth_type=0x0800, ipv4_src="10.0.0.1", ipv4_dst="10.0.0.2")
            self.add_flow(datapath,match,actions,DEFAULT_PRIORITY, 1000, 1000)

            out_port = 1
            actions = [parser.OFPActionOutput(out_port)]
            match = parser.OFPMatch(eth_type=0x0800, ipv4_src="10.0.0.2", ipv4_dst="10.0.0.1")
            self.add_flow(datapath, match, actions, DEFAULT_PRIORITY, 1000, 1000)


        if datapath.id ==2:
            out_port=2
            actions = [parser.OFPActionOutput(out_port)]
            match = parser.OFPMatch(eth_type=0x0800, ipv4_src="10.0.0.1", ipv4_dst="10.0.0.2")
            self.add_flow(datapath,match,actions,DEFAULT_PRIORITY, 1000, 1000)

            out_port=1
            actions = [parser.OFPActionOutput(out_port)]
            match = parser.OFPMatch(eth_type=0x0800, ipv4_src="10.0.0.2", ipv4_dst="10.0.0.1")
            self.add_flow(datapath,match,actions,DEFAULT_PRIORITY, 1000, 1000)

        if datapath.id == 5:
            out_port = 2
            actions = [parser.OFPActionOutput(out_port)]
            match = parser.OFPMatch(eth_type=0x0800, ipv4_src="10.0.0.1", ipv4_dst="10.0.0.2")
            self.add_flow(datapath, match, actions, DEFAULT_PRIORITY, 1000, 1000)

            out_port = 4
            actions = [parser.OFPActionOutput(out_port)]
            match = parser.OFPMatch(eth_type=0x0800, ipv4_src="10.0.0.2", ipv4_dst="10.0.0.1")
            self.add_flow(datapath, match, actions, DEFAULT_PRIORITY, 1000, 1000)

    @set_ev_cls(ofp_event.EventOFPPacketIn, MAIN_DISPATCHER)
    def packet_in_handler(self, ev):

        datapath = ev.msg.datapath

        in_port = ev.msg.match['in_port']

        received_packet = packet.Packet(ev.msg.data)
        ethernet_frame = received_packet.get_protocol(ethernet.ethernet)

        if ethernet_frame.ethertype != ether_types.ETH_TYPE_IP:
            return

        destination = ethernet_frame.dst
        source = ethernet_frame.src

        self.logger.info("packet in %s %s %s %s", datapath.id, source, destination, in_port)

    @set_ev_cls(event.EventPortDelete)
    def delete_port(self, port):
        switch_id = port.port.dpid

    @set_ev_cls(event.EventPortAdd)
    def add_port(self, port):
        switch_id = port.port.dpid