from abc import ABCMeta, abstractmethod
from pathlib import Path

from power_fv.build import sby


__all__ = ["PowerFVCheck"]


class PowerFVCheckMeta(ABCMeta):
    all_checks = {}

    def __new__(metacls, clsname, bases, namespace, name=None, **kwargs):
        if name is not None:
            if name in metacls.all_checks:
                raise NameError("Check {!r} already exists".format(name))
            namespace["name"] = name

        cls = ABCMeta.__new__(metacls, clsname, bases, namespace, **kwargs)
        if name is not None:
            metacls.all_checks[name] = cls
            cls.name = name
        return cls

    @classmethod
    def find(cls, *name):
        for check_name, check_cls in cls.all_checks.items():
            assert isinstance(check_name, tuple)
            if len(name) > len(check_name):
                continue
            if name == check_name[:len(name)]:
                yield check_name, check_cls


class PowerFVCheck(metaclass=PowerFVCheckMeta):
    @classmethod
    def add_check_arguments(cls, parser):
        parser.add_argument(
            "name", metavar="NAME", type=str, help="name of the check")
        parser.add_argument(
            "--depth", type=int, default=15,
            help="depth of the BMC, in clock cycles (default: %(default)s)")
        parser.add_argument(
            "--skip", type=int, default=None,
            help="skip the specified number of clock cycles (default: DEPTH-1))")

    @classmethod
    def add_build_arguments(cls, parser):
        parser.add_argument(
            "--build-dir", type=Path, default=Path("./build"),
            help="output directory (default: %(default)s)")

    def __init__(self, *, depth, skip, core, **kwargs):
        self.depth = depth
        self.skip  = skip if skip is not None else depth - 1
        self.core  = core
        self.dut   = core.wrapper(**kwargs)

    @abstractmethod
    def testbench(self):
        raise NotImplementedError

    def build(self, *, build_dir, **kwargs):
        platform = sby.SymbiYosysPlatform()
        self.core.add_files(platform, self.dut, **kwargs)

        top = self.testbench()
        build_dir = build_dir / top.name
        overrides = {key: str(value) for key, value in kwargs.items()}
        overrides["depth"] = str(self.depth)
        overrides["skip"] = str(self.skip)

        return platform.build(top, name=top.name, build_dir=build_dir, **overrides)