"""

Copyright (c) 2014-2016 Alex Forencich

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

"""

from myhdl import *
import axis_ep
import eth_ep
import struct

class ARPFrame(object):
    def __init__(self,
                eth_dest_mac=0,
                eth_src_mac=0,
                eth_type=0,
                arp_htype=1,
                arp_ptype=0x0800,
                arp_hlen=6,
                arp_plen=4,
                arp_oper=2,
                arp_sha=0x5A5152535455,
                arp_spa=0xc0a80164,
                arp_tha=0xDAD1D2D3D4D5,
                arp_tpa=0xc0a80164
            ):

        self.eth_dest_mac = eth_dest_mac
        self.eth_src_mac = eth_src_mac
        self.eth_type = eth_type
        self.arp_htype = arp_htype
        self.arp_ptype = arp_ptype
        self.arp_hlen = arp_hlen
        self.arp_plen = arp_plen
        self.arp_oper = arp_oper
        self.arp_sha = arp_sha
        self.arp_spa = arp_spa
        self.arp_tha = arp_tha
        self.arp_tpa = arp_tpa

        if type(eth_dest_mac) is dict:
            self.eth_dest_mac = eth_dest_mac['eth_dest_mac']
            self.eth_src_mac = eth_dest_mac['eth_src_mac']
            self.eth_type = eth_dest_mac['eth_type']
            self.arp_htype = eth_dest_mac['arp_htype']
            self.arp_ptype = eth_dest_mac['arp_ptype']
            self.arp_hlen = eth_dest_mac['arp_hlen']
            self.arp_plen = eth_dest_mac['arp_plen']
            self.arp_oper = eth_dest_mac['arp_oper']
            self.arp_sha = eth_dest_mac['arp_sha']
            self.arp_spa = eth_dest_mac['arp_spa']
            self.arp_tha = eth_dest_mac['arp_tha']
            self.arp_tpa = eth_dest_mac['arp_tpa']
        if type(eth_dest_mac) is ARPFrame:
            self.eth_dest_mac = eth_dest_mac.eth_dest_mac
            self.eth_src_mac = eth_dest_mac.eth_src_mac
            self.eth_type = eth_dest_mac.eth_type
            self.arp_htype = eth_dest_mac.arp_htype
            self.arp_ptype = eth_dest_mac.arp_ptype
            self.arp_hlen = eth_dest_mac.arp_hlen
            self.arp_plen = eth_dest_mac.arp_plen
            self.arp_oper = eth_dest_mac.arp_oper
            self.arp_sha = eth_dest_mac.arp_sha
            self.arp_spa = eth_dest_mac.arp_spa
            self.arp_tha = eth_dest_mac.arp_tha
            self.arp_tpa = eth_dest_mac.arp_tpa

    def build_axis(self):
        return self.build_eth().build_axis()

    def build_eth(self):
        data = b''

        data += struct.pack('>H', self.arp_htype)
        data += struct.pack('>H', self.arp_ptype)
        data += struct.pack('B', self.arp_hlen)
        data += struct.pack('B', self.arp_plen)
        data += struct.pack('>H', self.arp_oper)
        data += struct.pack('>Q', self.arp_sha)[2:]
        data += struct.pack('>L', self.arp_spa)
        data += struct.pack('>Q', self.arp_tha)[2:]
        data += struct.pack('>L', self.arp_tpa)

        return eth_ep.EthFrame(data, self.eth_dest_mac, self.eth_src_mac, self.eth_type)

    def parse_axis(self, data):
        frame = eth_ep.EthFrame()
        frame.parse_axis(data)
        self.parse_eth(frame)

    def parse_eth(self, data):
        self.eth_src_mac = data.eth_src_mac
        self.eth_dest_mac = data.eth_dest_mac
        self.eth_type = data.eth_type

        self.arp_htype = struct.unpack('>H', data.payload.data[0:2])[0]
        self.arp_ptype = struct.unpack('>H', data.payload.data[2:4])[0]
        self.arp_hlen = struct.unpack('B', data.payload.data[4:5])[0]
        self.arp_plen = struct.unpack('B', data.payload.data[5:6])[0]
        self.arp_oper = struct.unpack('>H', data.payload.data[6:8])[0]
        self.arp_sha = struct.unpack('>Q', b'\x00\x00'+data.payload.data[8:14])[0]
        self.arp_spa = struct.unpack('>L', data.payload.data[14:18])[0]
        self.arp_tha = struct.unpack('>Q', b'\x00\x00'+data.payload.data[18:24])[0]
        self.arp_tpa = struct.unpack('>L', data.payload.data[24:28])[0]

    def __eq__(self, other):
        if type(other) is ARPFrame:
            return (
                    self.eth_src_mac == other.eth_src_mac and
                    self.eth_dest_mac == other.eth_dest_mac and
                    self.eth_type == other.eth_type and
                    self.arp_htype == other.arp_htype and
                    self.arp_ptype == other.arp_ptype and
                    self.arp_hlen == other.arp_hlen and
                    self.arp_plen == other.arp_plen and
                    self.arp_oper == other.arp_oper and
                    self.arp_sha == other.arp_sha and
                    self.arp_spa == other.arp_spa and
                    self.arp_tha == other.arp_tha and
                    self.arp_tpa == other.arp_tpa
                )
        return False

    def __repr__(self):
        return (
                ('ArpFrame(eth_dest_mac=0x%012x, ' % self.eth_dest_mac) +
                ('eth_src_mac=0x%012x, ' % self.eth_src_mac) +
                ('eth_type=0x%04x, ' % self.eth_type) +
                ('arp_htype=0x%04x, ' % self.arp_htype) +
                ('arp_ptype=0x%04x, ' % self.arp_ptype) +
                ('arp_hlen=%d, ' % self.arp_hlen) +
                ('arp_plen=%d, ' % self.arp_plen) +
                ('arp_oper=0x%04x, ' % self.arp_oper) +
                ('arp_sha=0x%012x, ' % self.arp_sha) +
                ('arp_spa=0x%08x, ' % self.arp_spa) +
                ('arp_tha=0x%012x, ' % self.arp_tha) +
                ('arp_tpa=0x%08x)' % self.arp_tpa)
            )


class ARPFrameSource():
    def __init__(self):
        self.has_logic = False
        self.queue = []

    def send(self, frame):
        self.queue.append(ARPFrame(frame))

    def count(self):
        return len(self.queue)

    def empty(self):
        return self.count() == 0

    def create_logic(self,
                clk,
                rst,
                frame_valid=None,
                frame_ready=None,
                eth_dest_mac=Signal(intbv(0)[48:]),
                eth_src_mac=Signal(intbv(0)[48:]),
                eth_type=Signal(intbv(0)[16:]),
                arp_htype=Signal(intbv(0)[16:]),
                arp_ptype=Signal(intbv(0)[16:]),
                arp_hlen=Signal(intbv(6)[8:]),
                arp_plen=Signal(intbv(4)[8:]),
                arp_oper=Signal(intbv(0)[16:]),
                arp_sha=Signal(intbv(0)[48:]),
                arp_spa=Signal(intbv(0)[32:]),
                arp_tha=Signal(intbv(0)[48:]),
                arp_tpa=Signal(intbv(0)[32:]),
                pause=0,
                name=None
            ):

        assert not self.has_logic

        self.has_logic = True

        frame_ready_int = Signal(bool(False))
        frame_valid_int = Signal(bool(False))

        @always_comb
        def pause_logic():
            frame_ready_int.next = frame_ready and not pause
            frame_valid.next = frame_valid_int and not pause

        @instance
        def logic():
            frame = dict()

            while True:
                yield clk.posedge, rst.posedge

                if rst:
                    frame_valid_int.next = False
                else:
                    if frame_ready_int:
                        frame_valid_int.next = False
                    if (frame_ready_int and frame_valid) or not frame_valid_int:
                        if len(self.queue) > 0:
                            frame = self.queue.pop(0)
                            eth_dest_mac.next = frame.eth_dest_mac
                            eth_src_mac.next = frame.eth_src_mac
                            eth_type.next = frame.eth_type
                            arp_htype.next = frame.arp_htype
                            arp_ptype.next = frame.arp_ptype
                            arp_hlen.next = frame.arp_hlen
                            arp_plen.next = frame.arp_plen
                            arp_oper.next = frame.arp_oper
                            arp_sha.next = frame.arp_sha
                            arp_spa.next = frame.arp_spa
                            arp_tha.next = frame.arp_tha
                            arp_tpa.next = frame.arp_tpa

                            if name is not None:
                                print("[%s] Sending frame %s" % (name, repr(frame)))

                            frame_valid_int.next = True

        return logic, pause_logic


class ARPFrameSink():
    def __init__(self):
        self.has_logic = False
        self.queue = []

    def recv(self):
        if len(self.queue) > 0:
            return self.queue.pop(0)

    def count(self):
        return len(self.queue)

    def empty(self):
        return self.count() == 0

    def create_logic(self,
                clk,
                rst,
                frame_valid=None,
                frame_ready=None,
                eth_dest_mac=Signal(intbv(0)[48:]),
                eth_src_mac=Signal(intbv(0)[48:]),
                eth_type=Signal(intbv(0)[16:]),
                arp_htype=Signal(intbv(0)[16:]),
                arp_ptype=Signal(intbv(0)[16:]),
                arp_hlen=Signal(intbv(6)[8:]),
                arp_plen=Signal(intbv(4)[8:]),
                arp_oper=Signal(intbv(0)[16:]),
                arp_sha=Signal(intbv(0)[48:]),
                arp_spa=Signal(intbv(0)[32:]),
                arp_tha=Signal(intbv(0)[48:]),
                arp_tpa=Signal(intbv(0)[32:]),
                pause=0,
                name=None
            ):

        assert not self.has_logic

        self.has_logic = True

        frame_ready_int = Signal(bool(False))
        frame_valid_int = Signal(bool(False))

        @always_comb
        def pause_logic():
            frame_ready.next = frame_ready_int and not pause
            frame_valid_int.next = frame_valid and not pause

        @instance
        def logic():
            while True:
                yield clk.posedge, rst.posedge

                if rst:
                    frame_ready_int.next = False
                else:
                    frame_ready_int.next = True

                    if frame_ready_int and frame_valid_int:
                        frame = ARPFrame()
                        frame.eth_dest_mac = int(eth_dest_mac)
                        frame.eth_src_mac = int(eth_src_mac)
                        frame.eth_type = int(eth_type)
                        frame.arp_htype = int(arp_htype)
                        frame.arp_ptype = int(arp_ptype)
                        frame.arp_hlen = int(arp_hlen)
                        frame.arp_plen = int(arp_plen)
                        frame.arp_oper = int(arp_oper)
                        frame.arp_sha = int(arp_sha)
                        frame.arp_spa = int(arp_spa)
                        frame.arp_tha = int(arp_tha)
                        frame.arp_tpa = int(arp_tpa)
                        self.queue.append(frame)

                        if name is not None:
                            print("[%s] Got frame %s" % (name, repr(frame)))

        return logic, pause_logic