from typing import Callable, Dict, List, Tuple, Union

import torch

from colossalai.auto_parallel.tensor_shard.sharding_strategy import (
    MemoryCost,
    OperationData,
    OperationDataType,
    ShardingStrategy,
    StrategiesVector,
    TrainCycleItem,
)
from colossalai.fx.profiler.memory_utils import activation_size
from colossalai.fx.profiler.opcount import flop_mapping
from colossalai.tensor.sharding_spec import ShardingSpec

from ..registry import meta_register

__all__ = ['linear_meta_info']


@meta_register.register(torch.nn.Linear)
def linear_meta_info(*args) -> Tuple[TrainCycleItem, TrainCycleItem, List[torch.Tensor]]:
    """torch.nn.Linear meta info generator
    The atens graph of torch.nn.Linear with bias is
    graph():
    %input_2 : [#users=2] = placeholder[target=placeholder](default=)
    %addmm_default : [#users=1] = call_function[target=torch.ops.aten.addmm.default](args = (None, %input_2, None), kwargs = {})
    %zeros_like_default : [#users=3] = call_function[target=torch.ops.aten.zeros_like.default](args = (%addmm_default,), kwargs = {dtype: None, layout: None, device: None, pin_memory: None})
    %detach_default : [#users=1] = call_function[target=torch.ops.aten.detach.default](args = (%input_2,), kwargs = {})
    %mm_default : [#users=1] = call_function[target=torch.ops.aten.mm.default](args = (%zeros_like_default, None), kwargs = {})
    %t_default : [#users=1] = call_function[target=torch.ops.aten.t.default](args = (%zeros_like_default,), kwargs = {})
    %mm_default_1 : [#users=1] = call_function[target=torch.ops.aten.mm.default](args = (%t_default, %detach_default), kwargs = {})
    %t_default_1 : [#users=1] = call_function[target=torch.ops.aten.t.default](args = (%mm_default_1,), kwargs = {})
    %sum_dim_int_list : [#users=1] = call_function[target=torch.ops.aten.sum.dim_IntList](args = (%zeros_like_default, [None], None), kwargs = {})
    %view_default : [#users=1] = call_function[target=torch.ops.aten.view.default](args = (%sum_dim_int_list, [None]), kwargs = {})
    %detach_default_1 : [#users=1] = call_function[target=torch.ops.aten.detach.default](args = (%view_default,), kwargs = {})
    %detach_default_2 : [#users=0] = call_function[target=torch.ops.aten.detach.default](args = (%detach_default_1,), kwargs = {})
    %detach_default_3 : [#users=1] = call_function[target=torch.ops.aten.detach.default](args = (%mm_default,), kwargs = {})
    %detach_default_4 : [#users=0] = call_function[target=torch.ops.aten.detach.default](args = (%detach_default_3,), kwargs = {})
    %t_default_2 : [#users=1] = call_function[target=torch.ops.aten.t.default](args = (%t_default_1,), kwargs = {})
    %detach_default_5 : [#users=1] = call_function[target=torch.ops.aten.detach.default](args = (%t_default_2,), kwargs = {})
    %detach_default_6 : [#users=0] = call_function[target=torch.ops.aten.detach.default](args = (%detach_default_5,), kwargs = {})

    The one without bias is
    graph():
    %input_2 : [#users=2] = placeholder[target=placeholder](default=)
    %mm_default : [#users=1] = call_function[target=torch.ops.aten.mm.default](args = (%input_2, None), kwargs = {})
    %zeros_like_default : [#users=2] = call_function[target=torch.ops.aten.zeros_like.default](args = (%mm_default,), kwargs = {dtype: None, layout: None, device: None, pin_memory: None})
    %detach_default : [#users=1] = call_function[target=torch.ops.aten.detach.default](args = (%input_2,), kwargs = {})
    %t_default : [#users=1] = call_function[target=torch.ops.aten.t.default](args = (%zeros_like_default,), kwargs = {})
    %mm_default_1 : [#users=1] = call_function[target=torch.ops.aten.mm.default](args = (%t_default, %detach_default), kwargs = {})
    %t_default_1 : [#users=1] = call_function[target=torch.ops.aten.t.default](args = (%mm_default_1,), kwargs = {})
    %mm_default_2 : [#users=1] = call_function[target=torch.ops.aten.mm.default](args = (%zeros_like_default, None), kwargs = {})
    %detach_default_1 : [#users=1] = call_function[target=torch.ops.aten.detach.default](args = (%mm_default_2,), kwargs = {})
    %detach_default_2 : [#users=0] = call_function[target=torch.ops.aten.detach.default](args = (%detach_default_1,), kwargs = {})
    %t_default_2 : [#users=1] = call_function[target=torch.ops.aten.t.default](args = (%t_default_1,), kwargs = {})
    %detach_default_3 : [#users=1] = call_function[target=torch.ops.aten.detach.default](args = (%t_default_2,), kwargs = {})
    %detach_default_4 : [#users=0] = call_function[target=torch.ops.aten.detach.default](args = (%detach_default_3,), kwargs = {})

    Returns:
        Tuple[TrainCycleItem, TrainCycleItem, bool]: compute cost, memory cost and forward inputs
    """

    has_bias: bool = False
    input_tensor = next(filter(lambda x: x.type == OperationDataType.ARG, args)).data
    output_tensor = next(filter(lambda x: x.type == OperationDataType.OUTPUT, args)).data
    weight_tensor = next(filter(lambda x: x.name == 'weight', args)).data

    # process the dimension of input and output
    if len(input_tensor.shape) > 2:
        input_tensor: torch.Tensor
        input_tensor = input_tensor.view(-1, input_tensor.shape[-1])

    if len(output_tensor.shape) > 2:
        output_tensor: torch.Tensor
        output_tensor = output_tensor.view(-1, output_tensor.shape[-1])

    if len(args) == 4:
        bias_tensor = next(filter(lambda x: x.name == 'bias', args)).data
        has_bias = True

    if has_bias:
        # calculate cost with bias
        # the fwd op with compute cost is addmm
        # the bwd op with compute cost is mm * 2 and sum.dim_IntList

        # calculate compute cost
        fwd_compute_cost = flop_mapping[torch.ops.aten.addmm.default](
            [bias_tensor, input_tensor, torch.transpose(weight_tensor, 0, 1)], (output_tensor,))
        bwd_compute_cost = flop_mapping[torch.ops.aten.mm.default]([output_tensor, weight_tensor], (input_tensor,)) + \
                           flop_mapping[torch.ops.aten.mm.default]([torch.transpose(output_tensor, 0, 1), input_tensor], (weight_tensor,)) + \
                           flop_mapping[torch.ops.aten.sum.dim_IntList]([output_tensor], (bias_tensor,))
        compute_cost = TrainCycleItem(fwd=fwd_compute_cost,
                                      bwd=bwd_compute_cost,
                                      total=fwd_compute_cost + bwd_compute_cost)

        # calculate memory cost
        # NOTE: Linear don't have buffer and temp in forward and backward phase
        # the forward activation cost is the size of output_tensor, parameter cost is the size of weight_tensor and bias_tensor
        fwd_memory_cost = MemoryCost(activation=activation_size(output_tensor),
                                     parameter=activation_size(weight_tensor) + activation_size(bias_tensor),
                                     temp=0,
                                     buffer=0)

        # the backward activation cost is the size of input_tensor, weight_tensor and bias_tensor, parameter cost is 0
        bwd_memory_cost = MemoryCost(activation=activation_size(input_tensor) + activation_size(weight_tensor) +
                                     activation_size(bias_tensor),
                                     parameter=activation_size(weight_tensor) + activation_size(bias_tensor),
                                     temp=0,
                                     buffer=0)

        # total cost is to sum the forward and backward cost
        total_cost = MemoryCost(activation=fwd_memory_cost.activation + bwd_memory_cost.activation,
                                parameter=fwd_memory_cost.parameter + bwd_memory_cost.parameter)

        memory_cost = TrainCycleItem(fwd=fwd_memory_cost, bwd=bwd_memory_cost, total=total_cost)

    else:
        # calculate cost without bias
        # the fwd op with compute cost is mm
        # the bwd op with compute cost is mm * 2

        # calculate compute cost
        fwd_compute_cost = flop_mapping[torch.ops.aten.mm.default](
            [input_tensor, torch.transpose(weight_tensor, 0, 1)], (output_tensor,))
        bwd_compute_cost = flop_mapping[torch.ops.aten.mm.default]([output_tensor, weight_tensor], (input_tensor,)) + \
                           flop_mapping[torch.ops.aten.mm.default]([torch.transpose(output_tensor, 0, 1), input_tensor], (weight_tensor,))

        compute_cost = TrainCycleItem(fwd=fwd_compute_cost,
                                      bwd=bwd_compute_cost,
                                      total=fwd_compute_cost + bwd_compute_cost)

        # calculate memory cost
        # NOTE: Linear don't have buffer and temp in forward and backward phase
        # the forward activation cost is the size of output_tensor, parameter cost is the size of weight_tensor
        fwd_memory_cost = MemoryCost(activation=activation_size(output_tensor),
                                     parameter=activation_size(weight_tensor),
                                     temp=0,
                                     buffer=0)

        # the backward activation cost is the size of input_tensor and weight_tensor, parameter cost is 0
        bwd_memory_cost = MemoryCost(activation=activation_size(input_tensor) + activation_size(weight_tensor),
                                     parameter=activation_size(weight_tensor),
                                     temp=0,
                                     buffer=0)

        # total cost is to sum the forward and backward cost
        total_cost = MemoryCost(activation=fwd_memory_cost.activation + bwd_memory_cost.activation,
                                parameter=fwd_memory_cost.parameter + bwd_memory_cost.parameter)

        memory_cost = TrainCycleItem(fwd=fwd_memory_cost, bwd=bwd_memory_cost, total=total_cost)

    # store fwd_in
    fwd_in = [input_tensor]

    return compute_cost, memory_cost, fwd_in
