# Copyright (c) Microsoft Corporation.
# SPDX-License-Identifier: Apache-2.0

# DeepSpeed Team
import importlib
import inspect

from .abstract_accelerator import DeepSpeedAccelerator
# During setup stage torch may not be installed, pass on no torch will
# allow op builder related API to be executed.
try:
    import torch.npu
except ImportError:
    pass


class NPU_Accelerator(DeepSpeedAccelerator):

    def __init__(self):
        super().__init__()
        self._name = 'npu'
        self._communication_backend_name = 'hccl'
        # dict that holds class name <--> class type mapping i.e.
        # 'AsyncIOBuilder': <class 'op_builder.async_io.AsyncIOBuilder'>
        # this dict will be filled at init stage
        self.class_dict = None

    def is_synchronized_device(self):
        return False

    def use_host_timers(self):
        return self.is_synchronized_device()

    def resolves_data_dependency(self):
        return self.is_synchronized_device()

    def handles_memory_backpressure(self):
        return self.is_synchronized_device()

    # Device APIs
    def device_name(self, device_index=None):
        if device_index is None:
            return 'npu'
        return 'npu:{}'.format(device_index)

    def device(self, device_index=None):
        return torch.npu.device(device_index)

    def set_device(self, device_index):
        torch.npu.set_device(device_index)

    def current_device(self):
        return torch.npu.current_device()

    def current_device_name(self):
        return 'npu:{}'.format(torch.npu.current_device())

    def device_count(self):
        return torch.npu.device_count()

    def synchronize(self, device_index=None):
        return torch.npu.synchronize(device_index)

    # RNG APIs
    def random(self):
        return torch.random

    def set_rng_state(self, new_state, device_index=None):
        if device_index is None:
            return torch.npu.set_rng_state(new_state)

        return torch.npu.set_rng_state(new_state, device_index)

    def get_rng_state(self, device_index=None):
        if device_index is None:
            return torch.npu.get_rng_state()

        return torch.npu.get_rng_state(device_index)

    def manual_seed(self, seed):
        return torch.npu.manual_seed(seed)

    def manual_seed_all(self, seed):
        return torch.npu.manual_seed_all(seed)

    def initial_seed(self, seed):
        return torch.npu.initial_seed(seed)

    def default_generator(self, device_index):
        return torch.npu.default_generators[device_index]

    # Streams/Events
    @property
    def Stream(self):
        return torch.npu.Stream

    def stream(self, stream):
        return torch.npu.stream(stream)

    def current_stream(self, device_index=None):
        return torch.npu.current_stream(device_index)

    def default_stream(self, device_index=None):
        return torch.npu.default_stream(device_index)

    @property
    def Event(self):
        return torch.npu.Event

    # Memory management
    def empty_cache(self):
        return torch.npu.empty_cache()

    def memory_allocated(self, device_index=None):
        return torch.npu.memory_allocated(device_index)

    def max_memory_allocated(self, device_index=None):
        return torch.npu.max_memory_allocated(device_index)

    def reset_max_memory_allocated(self, device_index=None):
        return torch.npu.reset_max_memory_allocated(device_index)

    def memory_cached(self, device_index=None):
        return torch.npu.memory_cached(device_index)

    def max_memory_cached(self, device_index=None):
        return torch.npu.max_memory_cached(device_index)

    def reset_max_memory_cached(self, device_index=None):
        return torch.npu.reset_max_memory_cached(device_index)

    def memory_stats(self, device_index=None):
        if hasattr(torch.npu, 'memory_stats'):
            return torch.npu.memory_stats(device_index)

    def reset_peak_memory_stats(self, device_index=None):
        if hasattr(torch.npu, 'reset_peak_memory_stats'):
            return torch.npu.reset_peak_memory_stats(device_index)

    def memory_reserved(self, device_index=None):
        if hasattr(torch.npu, 'memory_reserved'):
            return torch.npu.memory_reserved(device_index)

    def max_memory_reserved(self, device_index=None):
        if hasattr(torch.npu, 'max_memory_reserved'):
            return torch.npu.max_memory_reserved(device_index)

    def total_memory(self, device_index=None):
        return torch.npu.get_device_properties(device_index).total_memory

    def available_memory(self, device_index=None):
        return self.total_memory(device_index) - self.memory_allocated(device_index)

    # Data types
    def is_bf16_supported(self):
        return torch.npu.is_bf16_supported()

    def is_fp16_supported(self):
        return True

    def supported_dtypes(self):
        return [torch.float, torch.half, torch.bfloat16]

    # Misc
    def amp(self):
        if hasattr(torch.npu, 'amp'):
            return torch.npu.amp
        return None

    def is_available(self):
        return torch.npu.is_available()

    def range_push(self, msg):
        return

    def range_pop(self):
        return

    def lazy_call(self, callback):
        return torch.npu._lazy_call(callback)

    def communication_backend_name(self):
        return self._communication_backend_name

    def is_triton_supported(self):
        return False

    # Graph operations
    def create_graph(self):
        return None

    def capture_to_graph(self, graph, pool=None, stream=None):
        from deepspeed.runtime.utils import noop_context
        return noop_context()

    def replay_graph(self, graph):
        return

    # Tensor operations

    @property
    def BFloat16Tensor(self):
        return torch.npu.BFloat16Tensor

    @property
    def ByteTensor(self):
        return torch.npu.ByteTensor

    @property
    def DoubleTensor(self):
        return torch.npu.DoubleTensor

    @property
    def FloatTensor(self):
        return torch.npu.FloatTensor

    @property
    def HalfTensor(self):
        return torch.npu.HalfTensor

    @property
    def IntTensor(self):
        return torch.npu.IntTensor

    @property
    def LongTensor(self):
        return torch.npu.LongTensor

    def pin_memory(self, tensor, align_bytes=1):
        return tensor.pin_memory()

    def is_pinned(self, tensor):
        return tensor.is_pinned()

    def on_accelerator(self, tensor):
        device_str = str(tensor.device)
        if device_str.startswith('npu:'):
            return True
        else:
            return False

    def op_builder_dir(self):
        try:
            # is op_builder from deepspeed or a 3p version? this should only succeed if it's deepspeed
            # if successful this also means we're doing a local install and not JIT compile path
            from op_builder import __deepspeed__  # noqa: F401 # type: ignore
            return "op_builder.npu"
        except ImportError:
            return "deepspeed.ops.op_builder.npu"

    def _lazy_init_class_dict(self):
        if self.class_dict:
            return

        op_builder_module = importlib.import_module(self.op_builder_dir())

        # get op builder class from op_builder/npu/__init__.py
        self.class_dict = {}
        for class_name, class_obj in inspect.getmembers(op_builder_module, inspect.isclass):
            self.class_dict[class_name] = class_obj

    # create an instance of op builder and return, name specified by class_name
    def create_op_builder(self, class_name):
        builder_class = self.get_op_builder(class_name)
        return None if builder_class is None else builder_class()

    # return an op builder class, name specified by class_name
    def get_op_builder(self, class_name):
        self._lazy_init_class_dict()
        if class_name in self.class_dict:
            return self.class_dict[class_name]
        else:
            return self.class_dict['NotImplementedBuilder'] if 'NotImplementedBuilder' in self.class_dict else None

    def build_extension(self):
        from torch.utils.cpp_extension import BuildExtension
        return BuildExtension

    def export_envs(self):
        return ['ASCEND', 'HCCL', 'LD_LIBRARY', 'PATH']