"""

Copyright (c) 2014 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 *

skip_asserts = False

class AXIStreamFrame(object):
    def __init__(self, data=b'', keep=None, user=None):
        self.B = 0
        self.N = 8
        self.M = 1
        self.WL = 8
        self.data = b''
        self.keep = None
        self.user = None

        if type(data) is bytes or type(data) is bytearray:
            self.data = bytearray(data)
        elif type(data) is AXIStreamFrame:
            self.N = data.N
            self.WL = data.WL
            if type(data.data) is bytearray:
                self.data = bytearray(data.data)
            else:
                self.data = list(data.data)
            if data.keep is not None:
                self.keep = list(data.keep)
            if data.user is not None:
                if type(data.user) is int or type(data.user) is bool:
                    self.user = data.user
                else:
                    self.user = list(data.user)
        else:
            self.data = list(data)

    def build(self):
        if self.data is None:
            return

        f = list(self.data)
        tdata = []
        tkeep = []
        tuser = []
        i = 0

        assert_tuser = False
        if (type(self.user) is int or type(self.user) is bool) and self.user:
            assert_tuser = True
            self.user = None

        if self.B == 0:
            while len(f) > 0:
                data = 0
                keep = 0
                for j in range(self.M):
                    data = data | (f.pop(0) << (j*self.WL))
                    keep = keep | (1 << j)
                    if len(f) == 0: break
                tdata.append(data)
                if self.keep is None:
                    tkeep.append(keep)
                else:
                    tkeep.append(self.keep[i])
                if self.user is None:
                    tuser.append(0)
                else:
                    tuser.append(self.user[i])
                i += 1
        else:
            # multiple tdata signals
            while len(f) > 0:
                data = 0
                tdata.append(f.pop(0))
                tkeep.append(0)
                if self.user is None:
                    tuser.append(0)
                else:
                    tuser.append(self.user[i])
                i += 1

        if assert_tuser:
            tuser[-1] = 1
            self.user = 1

        return tdata, tkeep, tuser

    def parse(self, tdata, tkeep, tuser):
        if tdata is None or tkeep is None or tuser is None:
            return
        if len(tdata) != len(tkeep) or len(tdata) != len(tuser):
            raise Exception("Invalid data")

        self.data = []
        self.keep = []
        self.user = []

        if self.B == 0:
            mask = 2**self.WL-1

            for i in range(len(tdata)):
                for j in range(self.M):
                    if tkeep[i] & (1 << j):
                        self.data.append((tdata[i] >> (j*self.WL)) & mask)
                self.keep.append(tkeep[i])
                self.user.append(tuser[i])
        else:
            for i in range(len(tdata)):
                self.data.append(tdata[i])
                self.keep.append(tkeep[i])
                self.user.append(tuser[i])

        if self.WL == 8:
            self.data = bytearray(self.data)

    def __eq__(self, other):
        if type(other) is AXIStreamFrame:
            return self.data == other.data

    def __repr__(self):
        return 'AXIStreamFrame(data=%s, keep=%s, user=%s)' % (repr(self.data), repr(self.keep), repr(self.user))

    def __iter__(self):
        return self.data.__iter__()

def AXIStreamSource(clk, rst,
                    tdata=None,
                    tkeep=Signal(bool(True)),
                    tvalid=Signal(bool(False)),
                    tready=Signal(bool(True)),
                    tlast=Signal(bool(False)),
                    tuser=Signal(bool(False)),
                    fifo=None,
                    pause=0,
                    name=None):

    tready_int = Signal(bool(False))
    tvalid_int = Signal(bool(False))

    @always_comb
    def pause_logic():
        tready_int.next = tready and not pause
        tvalid.next = tvalid_int and not pause

    @instance
    def logic():
        frame = AXIStreamFrame()
        data = []
        keep = []
        user = []
        B = 0
        N = len(tdata)
        M = len(tkeep)
        WL = int((len(tdata)+M-1)/M)

        if type(tdata) is list or type(tdata) is tuple:
            # multiple tdata signals
            B = len(tdata)
            N = [len(b) for b in tdata]
            M = 1
            WL = [1]*B

        while True:
            yield clk.posedge, rst.posedge

            if rst:
                if B > 0:
                    for s in tdata:
                        s.next = 0
                else:
                    tdata.next = 0
                tkeep.next = 0
                tvalid_int.next = False
                tlast.next = False
            else:
                if tready_int and tvalid:
                    if len(data) > 0:
                        if B > 0:
                            l = data.pop(0)
                            for i in range(B):
                                tdata[i].next = l[i]
                        else:
                            tdata.next = data.pop(0)
                        tkeep.next = keep.pop(0)
                        tuser.next = user.pop(0)
                        tvalid_int.next = True
                        tlast.next = len(data) == 0
                    else:
                        tvalid_int.next = False
                        tlast.next = False
                if (tlast and tready_int and tvalid) or not tvalid_int:
                    if not fifo.empty():
                        frame = fifo.get()
                        frame = AXIStreamFrame(frame)
                        frame.B = B
                        frame.N = N
                        frame.M = M
                        frame.WL = WL
                        data, keep, user = frame.build()
                        if name is not None:
                            print("[%s] Sending frame %s" % (name, repr(frame)))
                        if B > 0:
                            l = data.pop(0)
                            for i in range(B):
                                tdata[i].next = l[i]
                        else:
                            tdata.next = data.pop(0)
                        tkeep.next = keep.pop(0)
                        tuser.next = user.pop(0)
                        tvalid_int.next = True
                        tlast.next = len(data) == 0

    return logic, pause_logic


def AXIStreamSink(clk, rst,
                  tdata=None,
                  tkeep=Signal(bool(True)),
                  tvalid=Signal(bool(True)),
                  tready=Signal(bool(True)),
                  tlast=Signal(bool(True)),
                  tuser=Signal(bool(False)),
                  fifo=None,
                  pause=0,
                  name=None):

    tready_int = Signal(bool(False))
    tvalid_int = Signal(bool(False))

    @always_comb
    def pause_logic():
        tready.next = tready_int and not pause
        tvalid_int.next = tvalid and not pause

    @instance
    def logic():
        frame = AXIStreamFrame()
        data = []
        keep = []
        user = []
        B = 0
        N = len(tdata)
        M = len(tkeep)
        WL = int((len(tdata)+M-1)/M)
        first = True

        if type(tdata) is list or type(tdata) is tuple:
            # multiple tdata signals
            B = len(tdata)
            N = [len(b) for b in tdata]
            M = 1
            WL = [1]*B

        while True:
            yield clk.posedge, rst.posedge

            if rst:
                tready_int.next = False
                frame = AXIStreamFrame()
                data = []
                keep = []
                user = []
                first = True
            else:
                tready_int.next = True

                if tvalid_int:

                    if not skip_asserts:
                        # zero tkeep not allowed
                        assert int(tkeep) != 0
                        # tkeep must be contiguous
                        # i.e. 0b00011110 allowed, but 0b00011010 not allowed
                        b = int(tkeep)
                        while b & 1 == 0:
                            b = b >> 1
                        while b & 1 == 1:
                            b = b >> 1
                        assert b == 0
                        # tkeep must not have gaps across cycles
                        if not first:
                            # not first cycle; lowest bit must be set
                            assert int(tkeep) & 1
                        if not tlast:
                            # not last cycle; highest bit must be set
                            assert int(tkeep) & (1 << len(tkeep)-1)

                    if B > 0:
                        l = []
                        for i in range(B):
                            l.append(int(tdata[i]))
                        data.append(l)
                    else:
                        data.append(int(tdata))
                    keep.append(int(tkeep))
                    user.append(int(tuser))
                    first = False
                    if tlast:
                        frame.B = B
                        frame.N = N
                        frame.M = M
                        frame.WL = WL
                        frame.parse(data, keep, user)
                        if fifo is not None:
                            fifo.put(frame)
                        if name is not None:
                            print("[%s] Got frame %s" % (name, repr(frame)))
                        frame = AXIStreamFrame()
                        data = []
                        keep = []
                        user = []
                        first = True

    return logic, pause_logic