# Copyright (c) 2021 The Regents of the University of California
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from ...utils.override import overrides
from ..boards.mem_mode import MemMode
from ..processors.simple_core import SimpleCore

from m5.util import warn

from .abstract_processor import AbstractProcessor
from .cpu_types import CPUTypes
from ...isas import ISA
from ..boards.abstract_board import AbstractBoard

from typing import Optional


class SimpleProcessor(AbstractProcessor):
    """
    A SimpeProcessor contains a number of cores of a a single CPUType.
    """

    def __init__(
        self,
        cpu_type: CPUTypes,
        num_cores: int,
        isa: Optional[ISA] = None,
    ) -> None:
        """
        param cpu_type: The CPU type for each type in the processor.
:
        :param num_cores: The number of CPU cores in the processor.

        :param isa: The ISA of the processor. This argument is optional. If not
        set the `runtime.get_runtime_isa` is used to determine the ISA at
        runtime. **WARNING**: This functionality is deprecated. It is
        recommended you explicitly set your ISA via SimpleProcessor
        construction.
        """
        super().__init__(
            cores=self._create_cores(
                cpu_type=cpu_type,
                num_cores=num_cores,
                isa = isa,
            )
        )

        self._cpu_type = cpu_type
        if self._cpu_type == CPUTypes.KVM:
            from m5.objects import KvmVM

            self.kvm_vm = KvmVM()

    def _create_cores(
        self,
        cpu_type: CPUTypes,
        num_cores: int,
        isa: Optional[ISA]
    ):
        return [
            SimpleCore(cpu_type=cpu_type, core_id=i, isa=isa,) \
                for i in range(num_cores)
        ]

    @overrides(AbstractProcessor)
    def incorporate_processor(self, board: AbstractBoard) -> None:
        if self._cpu_type == CPUTypes.KVM:
            board.kvm_vm = self.kvm_vm

        # Set the memory mode.
        if self._cpu_type in (CPUTypes.TIMING, CPUTypes.O3, CPUTypes.MINOR):
            board.set_mem_mode(MemMode.TIMING)
        elif self._cpu_type == CPUTypes.KVM:
            board.set_mem_mode(MemMode.ATOMIC_NONCACHING)
        elif self._cpu_type == CPUTypes.ATOMIC:
            if board.get_cache_hierarchy().is_ruby():
                warn(
                    "Using an atomic core with Ruby will result in "
                    "'atomic_noncaching' memory mode. This will skip caching "
                    "completely."
                )
            else:
                board.set_mem_mode(MemMode.ATOMIC)
        else:
            raise NotImplementedError

        if self._cpu_type == CPUTypes.KVM:
            # To get the KVM CPUs to run on different host CPUs
            # Specify a different event queue for each CPU
            for i, core in enumerate(self.cores):
                for obj in core.get_simobject().descendants():
                    obj.eventq_index = 0
                core.get_simobject().eventq_index = i + 1