from migen import *


class OInterface:
    def __init__(self, data_width, address_width=0,
                 fine_ts_width=0, suppress_nop=True):
        self.stb = Signal()
        self.busy = Signal()

        if data_width:
            self.data = Signal(data_width)
        if address_width:
            self.address = Signal(address_width)
        if fine_ts_width:
            self.fine_ts = Signal(fine_ts_width)

        self.suppress_nop = suppress_nop

    @classmethod
    def like(cls, other):
        return cls(get_data_width(other),
                   get_address_width(other),
                   get_fine_ts_width(other),
                   other.suppress_nop)


class IInterface:
    def __init__(self, data_width,
                 timestamped=True, fine_ts_width=0):
        self.stb = Signal()

        if data_width:
            self.data = Signal(data_width)
        if fine_ts_width:
            self.fine_ts = Signal(fine_ts_width)

        self.timestamped = timestamped
        assert(not fine_ts_width or timestamped)

    @classmethod
    def like(cls, other):
        return cls(get_data_width(other),
                   other.timestamped,
                   get_fine_ts_width(other))


class Interface:
    def __init__(self, o, i=None):
        self.o = o
        self.i = i

    @classmethod
    def like(cls, other):
        if self.i is None:
            return cls(OInterface.like(self.o))
        else:
            return cls(OInterface.like(self.o),
                       IInterface.like(self.i))


def _get_or_zero(interface, attr):
    if isinstance(interface, Interface):
        return max(_get_or_zero(interface.i, attr),
                   _get_or_zero(interface.o, attr))
    else:
        if hasattr(interface, attr):
            return len(getattr(interface, attr))
        else:
            return 0


def get_data_width(interface):
    return _get_or_zero(interface, "data")


def get_address_width(interface):
    return _get_or_zero(interface, "address")


def get_fine_ts_width(interface):
    return _get_or_zero(interface, "fine_ts")
