#!/usr/bin/python3

# Copyright (c) 2022-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
#
# See LICENSE for license information.

import argparse
import datetime
import os
import sys
from functools import wraps
import math

import torch
from torch import nn
import torch.distributed as dist
import transformer_engine.pytorch as te
import transformer_engine_torch as tex
from transformer_engine.common.recipe import (
    MXFP8BlockScaling,
    DelayedScaling,
    Float8CurrentScaling,
    Float8BlockScaling,
    NVFP4BlockScaling,
    Format,
    Recipe,
    QParams,
)
from transformer_engine.pytorch import Float8CurrentScalingQuantizer, NVFP4Quantizer
from transformer_engine.pytorch.constants import NVFP4_BLOCK_SCALING_SIZE
from transformer_engine.pytorch.distributed import gather_along_first_dim
from run_layer_with_overlap import _compare_tensors
from torch.utils.cpp_extension import IS_HIP_EXTENSION

SEQ_LEN, BATCH_SIZE = 16, 16
HIDDEN_SIZE = 64
NR_HEADS = 4
WORLD_RANK, WORLD_SIZE = None, None
NCCL_WORLD = None
LOSS_FN = nn.MSELoss()
QUANTIZATION = None
NVTE_TEST_NVINSPECT_ENABLED = int(os.environ.get("NVTE_TEST_NVINSPECT_ENABLED") or "0")

if NVTE_TEST_NVINSPECT_ENABLED:
    # The numerics of all the layers should work the same,
    # when debug=True. I fed them with dummy feature
    # to prevent switching off debug, which can happen if
    # no feature is active.
    import nvdlfw_inspect.api as debug_api

    debug_api.initialize(
        os.environ["NVTE_TEST_NVINSPECT_CONFIG_FILE"],
        feature_dirs=os.environ["NVTE_TEST_NVINSPECT_FEATURE_DIRS"],
    )


def nvfp4_vanilla():
    nvfp4_recipe = NVFP4BlockScaling()
    nvfp4_recipe.fp4_quant_fwd_inp = QParams()
    nvfp4_recipe.fp4_quant_fwd_weight = QParams()
    nvfp4_recipe.fp4_quant_bwd_grad = QParams()
    return nvfp4_recipe


# Quantization recipe setup
def quantization_recipe() -> Recipe:
    if QUANTIZATION == "fp8":
        return DelayedScaling(
            fp8_format=Format.HYBRID, amax_history_len=32, amax_compute_algo="max"
        )
    if QUANTIZATION == "mxfp8":
        return MXFP8BlockScaling()
    if QUANTIZATION == "fp8_cs":
        return Float8CurrentScaling()
    if QUANTIZATION == "fp8_block_scaling":
        return Float8BlockScaling()
    if QUANTIZATION == "nvfp4":
        return nvfp4_vanilla()
    return te.quantization.get_default_fp8_recipe()


def main(argv=None, namespace=None):
    global WORLD_RANK, WORLD_SIZE, NCCL_WORLD, QUANTIZATION

    WORLD_RANK = int(os.getenv("RANK", "0"))
    WORLD_SIZE = int(os.getenv("WORLD_SIZE", "1"))
    LOCAL_RANK = int(os.getenv("LOCAL_RANK", "0"))
    LOCAL_SIZE = int(os.getenv("LOCAL_WORLD_SIZE", "1"))

    assert WORLD_SIZE == LOCAL_SIZE  # this test supports only 1 node
    assert LOCAL_SIZE <= torch.cuda.device_count()
    dist_init_kwargs = {
        "backend": "nccl",
        "rank": WORLD_RANK,
        "world_size": WORLD_SIZE,
        "timeout": datetime.timedelta(seconds=30),
    }
    dist_init_kwargs["init_method"] = "env://"
    dist_init_kwargs["device_id"] = torch.device(f"cuda:{LOCAL_RANK}")
    assert dist.is_nccl_available()
    torch.cuda.set_device(LOCAL_RANK)
    dist.init_process_group(**dist_init_kwargs)

    NCCL_WORLD = dist.new_group(backend="nccl")

    WORLD_SIZE = dist.get_world_size()

    parser = argparse.ArgumentParser()
    parser.add_argument("-l", "--layer-type", type=str)
    parser.add_argument("--quantization", type=str, default=None)
    args = parser.parse_args(argv, namespace)

    # Quantization scheme
    QUANTIZATION = args.quantization
    global SEQ_LEN, BATCH_SIZE, HIDDEN_SIZE
    if QUANTIZATION in ("fp8", "mxfp8", "nvfp4"):
        SEQ_LEN = 32
        BATCH_SIZE = 32
        HIDDEN_SIZE = 128
    # For fp8 block scaling, block size is 128,
    # and to make low precision TP work, input tensor
    # must be 128x128 divisible to be eligible for
    # low precision All-Gather when needed
    elif QUANTIZATION == "fp8_block_scaling":
        SEQ_LEN = 128
        BATCH_SIZE = 128
        HIDDEN_SIZE = 512

    test_dict = [
        test_quantizer,
        test_quantized_all_gather,
        test_linear,
        test_layernorm,
        test_layernorm_linear,
        test_layernorm_mlp,
        test_transformer_layer,
    ]

    for test in test_dict:
        test()
    dist.destroy_process_group()
    return 0


def run_distributed_test(test_name=None):
    def decorator(func):
        @wraps(func)
        def wrapper(*args, **kwargs):
            name = test_name if test_name is not None else func.__name__

            dist_print(f"Starting test {name} with args {args} and {kwargs}")
            torch.cuda.set_device(WORLD_RANK)
            torch.manual_seed(12345)
            torch.cuda.manual_seed(12345)
            func(*args, **kwargs)

            dist.barrier()
            dist_print(f"Passed test {name}")

        return wrapper

    return decorator


def _gather(tensor, dim=0):
    """
    Gathers tensors and concats them. Since torch.distributed.nn.functional.all_gather
    multiplies gradients by WORLD_SIZE, those gradiedts are rescaled.
    """

    class HalfGradient(torch.autograd.Function):
        @staticmethod
        def forward(ctx, input):
            return input  # forward pass (identity)

        @staticmethod
        def backward(ctx, grad_output):
            return grad_output / WORLD_SIZE  # gradient division by WORLD_SIZE

    tensor = HalfGradient.apply(tensor)
    gathered = torch.distributed.nn.functional.all_gather(tensor, group=NCCL_WORLD)
    return torch.cat(gathered, dim=dim)


def _constant(tensor):
    return nn.init.constant_(tensor, 0.05)


def dist_print(msg, src=None, end="\n", error=False):
    stream = sys.stderr if error else sys.stdout
    if WORLD_RANK == (0 if src is None else src):
        stream.write(f"[rank{WORLD_RANK}] {msg}{end}\n")


def _get_tolerances(dtype):
    # loose tolerances for fp8_cs because of sequence parallel & amax reduction
    # so that each rank has a different scale_inv for computing Y when we have
    # row parallel & sequence parallel, because we do the all_gather in backward pass
    if QUANTIZATION == "fp8_cs":
        return {"rtol": 0.4, "atol": 0.25}
    elif QUANTIZATION == "nvfp4":
        # TODO(zhongboz): investigate why the tolerance is so large
        return {"rtol": 0.125, "atol": 0.12}
    elif QUANTIZATION is not None:
        return {"rtol": 0.125, "atol": 0.0625}

    if dtype == torch.float16:
        return {"rtol": 1e-3, "atol": 1e-5}
    if dtype == torch.bfloat16:
        return {"rtol": 1.6e-2, "atol": 1e-5}
    if dtype == torch.float32:
        # TF32 has same mantissa bits as FP16
        return {"rtol": 1e-3, "atol": 1e-5}
    raise ValueError(f"Unsupported dtype ({dtype})")


def _check_outputs(output_single_node, output_distributed):
    numerics_failed = torch.tensor([0], dtype=torch.uint8, device="cuda")

    output_failed, output_info = _compare_tensors(
        "outputs",
        output_distributed,
        output_single_node,
        **_get_tolerances(output_single_node.dtype),
    )
    if output_failed:
        dist_print(output_info, src=WORLD_RANK, error=output_failed)
    numerics_failed[0] = int(output_failed)
    dist.all_reduce(numerics_failed, dist.ReduceOp.MAX, NCCL_WORLD)
    assert not bool(numerics_failed.item())


def _match_param_sizes(dist_param, single_param):
    """
    Adjust single_param to match the shape of dist_param
    by slicing along dimensions where the shapes differ.
    This function is typically used in a distributed setting
    where single_param is a larger tensor that needs
    to be partitioned among multiple processes.

    Args:
        dist_param: Tensor representing the distributed output
        with the desired shape for the current process.
        single_param: Tensor representing the non-distributed output,
        possibly larger than dist_param.

    Returns:
        Tensor: Sliced version of single_param matching
        the shape of dist_param for the current process.
    """
    # Initialize indices for slicing with full slices for each dimension
    indices = [slice(None)] * len(single_param.shape)

    # Iterate over each dimension to identify where shapes differ
    for i in range(len(dist_param.shape)):
        if dist_param.shape[i] != single_param.shape[i]:
            # Calculate the start and end indices for slicing based on the world rank
            start = WORLD_RANK * dist_param.shape[i]
            end = (WORLD_RANK + 1) * dist_param.shape[i]
            src_slice = slice(start, end)

            # Update the slicing indices for the current dimension
            indices[i] = src_slice

    # Slice single_param to obtain the output matching dist_param's shape
    to_output = single_param[tuple(indices)]

    return to_output


def _check_gradients(model_distributed, model_single, main_grad_check=False):
    for i, ((name, param_d), param_s) in enumerate(
        zip(model_distributed.named_parameters(), model_single.parameters())
    ):
        numerics_failed = torch.tensor([0], dtype=torch.uint8, device="cuda")
        grad_failed, grad_info = None, None
        if main_grad_check:
            param_s_grad = _match_param_sizes(param_d.main_grad, param_s.main_grad)
            grad_failed, grad_info = _compare_tensors(
                str(i), param_d.main_grad, param_s_grad, **_get_tolerances(param_s_grad.dtype)
            )
        else:
            param_s_grad = _match_param_sizes(param_d.grad, param_s.grad)
            grad_failed, grad_info = _compare_tensors(
                str(i), param_d.grad, param_s_grad, **_get_tolerances(param_s_grad.dtype)
            )

        if grad_failed:
            dist_print(i, src=WORLD_RANK)
            dist_print(name, src=WORLD_RANK)
            dist_print(grad_info, src=WORLD_RANK, error=grad_failed)
        numerics_failed[0] = int(grad_failed)
        dist.all_reduce(numerics_failed, dist.ReduceOp.MAX, NCCL_WORLD)
        assert not bool(numerics_failed.item())


def _copy_params(model_distributed, model_single):
    for dist_param, single_param in zip(model_distributed.parameters(), model_single.parameters()):
        with torch.no_grad():
            to_copy = single_param
            for dim, _ in enumerate(dist_param.shape):
                if dist_param.shape[dim] != single_param.shape[dim]:
                    src_slice = slice(
                        WORLD_RANK * dist_param.shape[dim], (WORLD_RANK + 1) * dist_param.shape[dim]
                    )
                    indices = [slice(None)] * max(min(dim, len(dist_param.shape) - 1), 0)
                    indices.append(src_slice)
                    if dim < len(dist_param.shape) - 1:
                        indices.append(slice(None))
                    to_copy = single_param[tuple(indices)]
            dist_param.copy_(to_copy)


def _apply_models(
    model_single_node, model_distributed, input_single_node, input_distributed, **kwargs
):
    _alloc_main_grad(model_single_node, model_distributed)  # for fuse_wgrad_accumulation=True
    input_single_node.requires_grad_()
    input_distributed.requires_grad_()
    with te.autocast(
        enabled=QUANTIZATION is not None,
        recipe=quantization_recipe(),
    ):
        output_single_node = model_single_node(input_single_node, **kwargs)
    with te.autocast(
        enabled=QUANTIZATION is not None,
        recipe=quantization_recipe(),
        amax_reduction_group=NCCL_WORLD,
    ):
        output_distributed = model_distributed(input_distributed, **kwargs)
    return output_single_node, output_distributed


def _loss_backward(output_single_node, output_distributed):
    target = torch.randn_like(output_single_node)
    LOSS_FN(output_single_node, target).backward()
    LOSS_FN(output_distributed, target).backward()


def _loss_backward_dw(model_single_node, model_distributed):
    model_single_node.backward_dw()
    model_distributed.backward_dw()


def _alloc_main_grad(model_single_node, model_distributed):
    for model in [model_single_node, model_distributed]:
        for param in model.parameters():
            param.main_grad = torch.zeros_like(param, dtype=torch.float32)


###############################################
#                   Quantizer                 #
###############################################
def _construct_quantizer(quantizer_class, low_precision_dtype, device, tp_group, tp_size):
    """
    quantizer is the reference quantizer on a single GPU.
    quantizer_dist is the distributed quantizer to be tested on multiple GPUs.
    """
    if quantizer_class == Float8CurrentScalingQuantizer:
        quantizer_dist = quantizer_class(
            fp8_dtype=low_precision_dtype,
            device=device,
            with_amax_reduction=True,
            amax_reduction_group=tp_group,
        )
        quantizer = quantizer_class(
            fp8_dtype=low_precision_dtype,
            device=device,
            with_amax_reduction=False,
        )
        return quantizer, quantizer_dist
    elif quantizer_class == NVFP4Quantizer:
        quantizer_dist = quantizer_class(
            fp4_dtype=low_precision_dtype,
            with_amax_reduction=True,
            amax_reduction_group=tp_group,
        )
        quantizer = quantizer_class(
            fp4_dtype=low_precision_dtype,
            with_amax_reduction=False,
            amax_reduction_group=None,
        )
        return quantizer, quantizer_dist
    else:
        raise ValueError(f"Unsupported quantizer class: {quantizer_class}")


def _shard_tensor(x, world_size, axis):
    split_size = x.size()[axis] // world_size
    split_tensor = torch.split(x, split_size, axis)
    out = []
    for tensor in split_tensor:
        out.append(tensor.detach().clone().requires_grad_(x.requires_grad).cuda())
    return out


@run_distributed_test()
def _test_quantizer(input_dtype, fp8_dtype):
    """Test the quantizer under distributed settings.

    Args:
        input_dtype (torch.dtype): The data type of the input.
        fp8_dtype (tex.DType): The data type of the fp8.
    """

    M, N = WORLD_SIZE * BATCH_SIZE, HIDDEN_SIZE

    # high precision input
    x_hp_cpu = torch.randn((M, N), device="cpu").to(input_dtype)
    # set one element of the input to a very large value, which doesn't live in rank 0 after the split
    # to test the amax reduction on purpose
    x_hp_cpu[M - 1, N - 1] = 1e4
    # rank 0 takes the full copy and quantize with GPU 0 for verification
    if WORLD_RANK == 0:
        x_hp_rank0 = x_hp_cpu.clone().detach().requires_grad_(True).to("cuda")
    x_hp_local_rank = _shard_tensor(x_hp_cpu, WORLD_SIZE, 0)[WORLD_RANK]

    # Create quantizers
    quantizer, quantizer_dist = _construct_quantizer(
        Float8CurrentScalingQuantizer, fp8_dtype, x_hp_local_rank.device, NCCL_WORLD, WORLD_SIZE
    )

    # quantize the input
    if WORLD_RANK == 0:
        x_fp8_single = quantizer(x_hp_rank0)

    # multi-GPU quantizer
    x_fp8_dist = quantizer_dist(x_hp_local_rank)

    # check scale_inv with zero tolerance
    if WORLD_RANK == 0:
        torch.testing.assert_close(
            x_fp8_single._scale_inv, x_fp8_dist._scale_inv, rtol=0.0, atol=0.0
        )


def test_quantizer():
    """
    Run quantizer tests with various configurations.
    Currently only check fp8_cs because it needs to do amax reduction in the quantizer.
    """
    # skip this test for other quantization schemes
    if QUANTIZATION != "fp8_cs":
        return

    input_dtypes = [torch.float32, torch.bfloat16]
    fp8_dtypes = [tex.DType.kFloat8E4M3, tex.DType.kFloat8E5M2]

    for input_dtype in input_dtypes:
        for fp8_dtype in fp8_dtypes:
            _test_quantizer(input_dtype, fp8_dtype)


############################################
#            Quantized All-Gather          #
############################################


def _ref_zero_padding_scale_inv(scale_inv, unpadded_shape):
    """
    Zero padding the scale_inv.
    scale_inv shape is the padded shape, but not zero padded
    unpadded_shape is the original shape before padding
    """
    dim0, dim1 = scale_inv.shape
    unpadded_dim0, unpadded_dim1 = unpadded_shape
    pad_dim0 = (128 - unpadded_dim0 % 128) % 128
    pad_dim1 = (4 - unpadded_dim1 % 4) % 4
    new_dim0 = unpadded_dim0 + pad_dim0
    new_dim1 = unpadded_dim1 + pad_dim1

    assert dim0 == new_dim0
    assert dim1 == new_dim1

    # return input if no padding is needed
    if pad_dim0 == 0 and pad_dim1 == 0:
        return scale_inv

    # unpad first to remove random bits from torch empty
    scale_inv = scale_inv[:unpadded_dim0, :unpadded_dim1].contiguous()
    # using torch padding
    new_scale_inv = torch.nn.functional.pad(
        scale_inv, (0, pad_dim1, 0, pad_dim0), mode="constant", value=0
    )

    assert new_scale_inv.shape == (new_dim0, new_dim1)

    return new_scale_inv


def _get_unpadded_scale_inv_shape(input_shape, quantizer_cls, columnwise):
    """
    Calculate the unpadded shape of the scale_inv tensor.
    """
    M, K = 1, 1
    M = math.prod(input_shape[:-1])
    K = input_shape[-1]

    if quantizer_cls == NVFP4Quantizer:
        if columnwise:
            outer = K
            inner = math.ceil(M / NVFP4_BLOCK_SCALING_SIZE)
            return (outer, inner)
        else:
            outer = M
            inner = math.ceil(K / NVFP4_BLOCK_SCALING_SIZE)
            return (outer, inner)
    else:
        raise ValueError(f"Unsupported quantizer class: {quantizer_cls}")


@run_distributed_test()
def _test_quantized_all_gather(input_dtype, low_precision_dtype, quantizer_cls):
    """Test the quantizer under distributed settings.

    Args:
        input_dtype (torch.dtype): The data type of the input.
        low_precision_dtype (tex.DType): The data type of the low precision, can be fp4 or fp8.
    """

    M, N = WORLD_SIZE * BATCH_SIZE, HIDDEN_SIZE // 2

    # high precision input
    x_hp_cpu = torch.randn((M, N), device="cpu").to(input_dtype)
    # set one element of the input to a very large value, which doesn't live in rank 0 after the split
    # to test the amax reduction on purpose
    # x_hp_cpu[M - 1, N - 1] = 1e4

    # get the unpadded shapes
    unpadded_rowwise_scale_inv_shape = _get_unpadded_scale_inv_shape((M, N), quantizer_cls, False)
    unpadded_columnwise_scale_inv_shape = _get_unpadded_scale_inv_shape((M, N), quantizer_cls, True)

    # rank 0 takes the full copy and quantize with GPU 0 for verification
    if WORLD_RANK == 0:
        x_hp_rank0 = x_hp_cpu.clone().detach().requires_grad_(True).to("cuda")
    x_hp_local_rank = _shard_tensor(x_hp_cpu, WORLD_SIZE, 0)[WORLD_RANK]

    # Create quantizers
    quantizer, quantizer_dist = _construct_quantizer(
        quantizer_cls, low_precision_dtype, x_hp_local_rank.device, NCCL_WORLD, WORLD_SIZE
    )

    # quantize the entire input
    if WORLD_RANK == 0:
        x_low_precision_single = quantizer(x_hp_rank0)

    # run all-gather with a quantizer as input for quantized all-gather
    x_low_precision_total, _ = gather_along_first_dim(
        x_hp_local_rank, NCCL_WORLD, async_op=False, quantizer=quantizer_dist
    )

    # check the outputs
    if WORLD_RANK == 0:
        # assert all data and scale_inv are the same
        torch.testing.assert_close(
            x_low_precision_single._rowwise_data,
            x_low_precision_total._rowwise_data,
            rtol=0.0,
            atol=0.0,
        )
        # check the rowwise scale without any padding
        unpad_dim0, unpad_dim1 = unpadded_rowwise_scale_inv_shape
        unpadded_rowwise_scale_inv_ref = x_low_precision_single._rowwise_scale_inv[
            :unpad_dim0, :unpad_dim1
        ]
        unpadded_rowwise_scale_inv = x_low_precision_total._rowwise_scale_inv[
            :unpad_dim0, :unpad_dim1
        ]
        torch.testing.assert_close(
            unpadded_rowwise_scale_inv_ref,
            unpadded_rowwise_scale_inv,
            rtol=0.0,
            atol=0.0,
        )
        torch.testing.assert_close(
            _ref_zero_padding_scale_inv(
                x_low_precision_single._rowwise_scale_inv, unpadded_rowwise_scale_inv_shape
            ),
            _ref_zero_padding_scale_inv(
                x_low_precision_total._rowwise_scale_inv, unpadded_rowwise_scale_inv_shape
            ),
            rtol=0.0,
            atol=0.0,
        )
        torch.testing.assert_close(
            x_low_precision_single._columnwise_data,
            x_low_precision_total._columnwise_data,
            rtol=0.0,
            atol=0.0,
        )
        unpad_dim0, unpad_dim1 = unpadded_columnwise_scale_inv_shape
        unpadded_columnwise_scale_inv_ref = x_low_precision_single._columnwise_scale_inv[
            :unpad_dim0, :unpad_dim1
        ]
        unpadded_columnwise_scale_inv = x_low_precision_total._columnwise_scale_inv[
            :unpad_dim0, :unpad_dim1
        ]
        torch.testing.assert_close(
            unpadded_columnwise_scale_inv_ref,
            unpadded_columnwise_scale_inv,
            rtol=0.0,
            atol=0.0,
        )
        torch.testing.assert_close(
            _ref_zero_padding_scale_inv(
                x_low_precision_single._columnwise_scale_inv, unpadded_columnwise_scale_inv_shape
            ),
            _ref_zero_padding_scale_inv(
                x_low_precision_total._columnwise_scale_inv, unpadded_columnwise_scale_inv_shape
            ),
            rtol=0.0,
            atol=0.0,
        )


def test_quantized_all_gather():
    """
    Run quantized all-gather tests with various configurations.
    """
    # skip this test for other quantization schemes
    is_nvfp4 = QUANTIZATION == "nvfp4"
    # add other recipes for testing if needed
    if not is_nvfp4:
        return

    input_dtypes = [torch.bfloat16]
    fp4_dtype = [tex.DType.kFloat4E2M1]
    fp8_dtype = [tex.DType.kFloat8E4M3, tex.DType.kFloat8E5M2]
    quantizer_cls_nvfp4 = [NVFP4Quantizer]
    # add FP8 quantizers if needed
    quantizer_cls_fp8 = []

    low_precisio_dtypes = fp4_dtype if is_nvfp4 else fp8_dtype
    quantizer_cls_list = quantizer_cls_nvfp4 if is_nvfp4 else quantizer_cls_fp8

    for quantizer_cls in quantizer_cls_list:
        for input_dtype in input_dtypes:
            for low_precision_dtype in low_precisio_dtypes:
                _test_quantized_all_gather(input_dtype, low_precision_dtype, quantizer_cls)


############################################
#                   Linear                 #
############################################
@run_distributed_test()
def _test_linear(parallel_mode=None, sequence_parallel=False, **kwargs):
    """Test the linear layer with specified parallel mode and sequence parallelization.

    Args:
        parallel_mode (str): 'row' or 'column' parallelism.
        sequence_parallel (bool): Enable sequence parallelism if True.
        kwargs (dict): Additional arguments for the linear layer.
    """
    # Set parameter data type
    params_dtype = kwargs.get("params_dtype", torch.float32)

    # Create models
    model_single_node = te.Linear(HIDDEN_SIZE, HIDDEN_SIZE, **kwargs)
    model_distributed = te.Linear(
        HIDDEN_SIZE,
        HIDDEN_SIZE,
        tp_size=WORLD_SIZE,
        tp_group=NCCL_WORLD,
        parallel_mode=parallel_mode,
        sequence_parallel=sequence_parallel,
        **kwargs,
    )

    # Synchronize parameters between models
    _copy_params(model_distributed, model_single_node)

    # Prepare input tensors
    input_single_node = torch.randn((BATCH_SIZE, HIDDEN_SIZE)).cuda().to(params_dtype)

    if parallel_mode == "row":
        # Split input across GPUs for row parallelism
        split_size = HIDDEN_SIZE // WORLD_SIZE
        input_distributed = input_single_node[
            :, WORLD_RANK * split_size : (WORLD_RANK + 1) * split_size
        ].clone()
    elif parallel_mode == "column":
        if sequence_parallel:
            # Duplicate input for sequence parallelism
            input_single_node = (
                torch.empty((WORLD_SIZE * BATCH_SIZE, HIDDEN_SIZE)).cuda().to(params_dtype)
            )
            input_distributed = torch.randn((BATCH_SIZE, HIDDEN_SIZE)).cuda().to(params_dtype)
            # when quantization is fp8_cs, we need to trigger corner cases to see if amax reduction is working
            if QUANTIZATION == "fp8_cs":
                input_distributed = torch.clamp(input_distributed, min=-10, max=10)
                if WORLD_RANK == WORLD_SIZE - 1:
                    input_distributed[BATCH_SIZE - 1, HIDDEN_SIZE - 1] = 11
            input_single_node = _gather(input_distributed, dim=0).detach()
        else:
            input_distributed = input_single_node.clone()
    else:
        raise ValueError(f"Invalid parallel_mode: {parallel_mode}")

    # Apply models
    output_single_node, output_distributed = _apply_models(
        model_single_node, model_distributed, input_single_node, input_distributed
    )

    if "return_bias" in kwargs:
        output_single_node, bias_s = output_single_node
        output_distributed, bias_d = output_distributed
        if parallel_mode == "column":
            bias_d = _gather(bias_d)
        _check_outputs(bias_s, bias_d)

    # Gather outputs if necessary
    if parallel_mode == "column" or (sequence_parallel and parallel_mode == "row"):
        output_distributed = _gather(output_distributed, dim=1 if parallel_mode == "column" else 0)

    # Compute loss and backpropagate
    _loss_backward(output_single_node, output_distributed)

    # Compute delayed weight gradient
    if "delay_wgrad_compute" in kwargs:
        _loss_backward_dw(model_single_node, model_distributed)

    # Validate outputs and gradients
    _check_outputs(output_single_node, output_distributed)

    # gradients in other cases need additional synchronization
    if (parallel_mode == "column" or not sequence_parallel) and "return_bias" not in kwargs:
        _check_gradients(
            model_distributed,
            model_single_node,
            main_grad_check=("fuse_wgrad_accumulation" in kwargs),
        )


def test_linear():
    """Run linear layer tests with various configurations."""
    base_kwargs_list = [
        {},
        {"bias": False},
        {"init_method": _constant},
        {"fuse_wgrad_accumulation": True},
        {"return_bias": True},
        {"params_dtype": torch.float16 if QUANTIZATION != "nvfp4" else torch.bfloat16},
        {"delay_wgrad_compute": True},
        {"save_original_input": True},
    ]
    #TODO:The blockwise recipe does not currently support calculations with bias set to true.
    """
    For AMD platforms, when the quantization recipe is fp8_block_scaling, iterate through base_kwargs_list,
    and if the bias value is not set in kwargs or the bias value is true, set bias to false.
    """
    if IS_HIP_EXTENSION and QUANTIZATION == "fp8_block_scaling":
        kwargs_list = [kwargs for kwargs in base_kwargs_list if kwargs.get("bias", True) is False]
    else:
        kwargs_list = base_kwargs_list
    for kwargs in kwargs_list:
        if kwargs.get("save_original_input", False) and QUANTIZATION == "fp8":
            continue
        if kwargs.get("delay_wgrad_compute", False) and NVTE_TEST_NVINSPECT_ENABLED:
            continue
        for parallel_mode in ["column", "row"]:
            for sequence_parallel in [False, True]:
                _test_linear(parallel_mode, sequence_parallel, **kwargs)


############################################
#                 LayerNorm                #
############################################


@run_distributed_test()
def _test_layernorm(kwargs):
    """Test LayerNorm and RMSNorm with given arguments.

    Args:
        kwargs (dict): Contains 'norm', 'basic_args', and 'distributed_args'.
    """
    # Extract parameters
    norm = kwargs["norm"]
    basic_args = kwargs["basic_args"]
    distributed_args = kwargs["distributed_args"]
    params_dtype = basic_args.get("params_dtype", torch.float32)

    # Create models
    model_single_node = norm(HIDDEN_SIZE, **basic_args)
    model_distributed = norm(HIDDEN_SIZE, **{**basic_args, **distributed_args})

    # Synchronize parameters between models
    _copy_params(model_distributed, model_single_node)

    # Prepare input tensors
    input_single_node = torch.randn((BATCH_SIZE, HIDDEN_SIZE), dtype=params_dtype).cuda()
    input_distributed = input_single_node.clone()

    # Apply models
    output_single_node, output_distributed = _apply_models(
        model_single_node, model_distributed, input_single_node, input_distributed
    )

    # Compute loss and backpropagate
    _loss_backward(output_single_node, output_distributed)

    # Validate outputs and gradients
    _check_outputs(output_single_node, output_distributed)
    _check_gradients(model_distributed, model_single_node)


def test_layernorm():
    """Run LayerNorm and RMSNorm tests with various configurations."""
    norms = [te.LayerNorm, te.RMSNorm]

    # Define basic arguments for the models
    basic_args_list = [
        {"zero_centered_gamma": True},
        {"params_dtype": torch.float16},
    ]

    # Define distributed arguments
    distributed_args_list = [
        {},
        {"sequence_parallel": True},
    ]

    # Generate combinations of norms and arguments
    for norm in norms:
        for basic_args in basic_args_list:
            for distributed_args in distributed_args_list:
                kwargs = {
                    "norm": norm,
                    "basic_args": basic_args,
                    "distributed_args": distributed_args,
                }
                _test_layernorm(kwargs)


############################################
#              LayerNormLinear             #
############################################


@run_distributed_test()
def _test_layernorm_linear(parallel_mode=None, sequence_parallel=False, **kwargs):
    """Test the linear layer with specified parallel mode and sequence parallelization.

    Args:
        parallel_mode (str): 'row' or 'column' parallelism.
        sequence_parallel (bool): Enable sequence parallelism if True.
        kwargs (dict): Additional arguments for the linear layer.
    """
    # Set parameter data type
    params_dtype = kwargs.get("params_dtype", torch.float32)

    # Create models
    model_single_node = te.LayerNormLinear(HIDDEN_SIZE, HIDDEN_SIZE, **kwargs)
    model_distributed = te.LayerNormLinear(
        HIDDEN_SIZE,
        HIDDEN_SIZE,
        tp_size=WORLD_SIZE,
        tp_group=NCCL_WORLD,
        parallel_mode=parallel_mode,
        sequence_parallel=sequence_parallel,
        **kwargs,
    )

    # Synchronize parameters between models
    _copy_params(model_distributed, model_single_node)

    # Prepare input tensors
    input_single_node = torch.randn((SEQ_LEN, HIDDEN_SIZE)).cuda().to(params_dtype)

    if sequence_parallel:
        # Duplicate input for sequence parallelism
        input_single_node = torch.empty((WORLD_SIZE * SEQ_LEN, HIDDEN_SIZE)).cuda().to(params_dtype)
        input_distributed = torch.randn((SEQ_LEN, HIDDEN_SIZE)).cuda().to(params_dtype)
        # make the last element of the input a large value to test the amax reduction on purpose
        # when quantization is fp8_cs, we need to trigger corner cases to see if amax reduction is working
        if QUANTIZATION == "fp8_cs":
            input_distributed = torch.clamp(input_distributed, min=-10, max=10)
            if WORLD_RANK == WORLD_SIZE - 1:
                input_distributed[SEQ_LEN - 1, HIDDEN_SIZE - 1] = 11
        input_single_node = _gather(input_distributed).detach()
    else:
        input_distributed = input_single_node.clone()
    # Apply models
    output_single_node, output_distributed = _apply_models(
        model_single_node, model_distributed, input_single_node, input_distributed
    )

    if "return_layernorm_output" in kwargs:
        output_single_node, norm_s = output_single_node
        output_distributed, norm_d = output_distributed
        if sequence_parallel and not kwargs.get("return_layernorm_output_gathered", False):
            norm_d = _gather(norm_d)
        _check_outputs(norm_s, norm_d)

    if "return_bias" in kwargs:
        output_single_node, bias_s = output_single_node
        output_distributed, bias_d = output_distributed
        if parallel_mode == "column":
            bias_d = _gather(bias_d)
        _check_outputs(bias_s, bias_d)

    # Gather outputs if necessary
    if parallel_mode == "column" or (sequence_parallel and parallel_mode == "row"):
        output_distributed = _gather(output_distributed, dim=1 if parallel_mode == "column" else 0)

    # Compute loss and backpropagate
    _loss_backward(output_single_node, output_distributed)

    # Compute delayed weight gradient
    if "delay_wgrad_compute" in kwargs:
        _loss_backward_dw(model_single_node, model_distributed)

    # Validate outputs and gradients
    _check_outputs(output_single_node, output_distributed)

    # gradients in other cases need additional synchronization
    if parallel_mode == "column" and not sequence_parallel and "return_bias" not in kwargs:
        _check_gradients(
            model_distributed,
            model_single_node,
            main_grad_check=("fuse_wgrad_accumulation" in kwargs),
        )


def test_layernorm_linear():
    base_kwargs_list = [
        {},
        {"bias": False},
        {"init_method": _constant},
        {"fuse_wgrad_accumulation": True},
        {"return_bias": True},
        {"params_dtype": torch.float16 if QUANTIZATION != "nvfp4" else torch.bfloat16},
        {"zero_centered_gamma": False},
        {"return_layernorm_output": True},
        {"delay_wgrad_compute": True},
    ]
    #TODO:The blockwise recipe does not currently support calculations with bias set to true.
    """
    For AMD platforms, when the quantization recipe is fp8_block_scaling, iterate through base_kwargs_list,
    and if the bias value is not set in kwargs or the bias value is true, set bias to false.
    """
    if IS_HIP_EXTENSION and QUANTIZATION == "fp8_block_scaling":
        kwargs_list = [kwargs for kwargs in base_kwargs_list if kwargs.get("bias", True) is False]
    else:
        kwargs_list = base_kwargs_list
    for kwargs in kwargs_list:
        if kwargs.get("delay_wgrad_compute", False) and NVTE_TEST_NVINSPECT_ENABLED:
            continue
        for parallel_mode in ["column"]:
            for sequence_parallel in [False, True]:
                _test_layernorm_linear(parallel_mode, sequence_parallel, **kwargs)


############################################
#               LayerNormMLP               #
############################################


@run_distributed_test()
def _test_layernorm_mlp(set_parallel_mode=None, sequence_parallel=False, **kwargs):
    """Test the LayerNormMLP with specified parallel mode and sequence parallelization.

    Args:
        set_parallel_mode (bool): Enable parallel mode.
        sequence_parallel (bool): Enable sequence parallelism if True.
        kwargs (dict): Additional arguments for the linear layer.
    """
    # Set parameter data type
    params_dtype = kwargs.get("params_dtype", torch.float32)
    FFN_HIDDEN_SIZE = 32 if QUANTIZATION is None else 128

    # Create models
    model_single_node = te.LayerNormMLP(HIDDEN_SIZE, FFN_HIDDEN_SIZE, **kwargs)
    model_distributed = te.LayerNormMLP(
        HIDDEN_SIZE,
        FFN_HIDDEN_SIZE,
        tp_size=WORLD_SIZE,
        tp_group=NCCL_WORLD,
        set_parallel_mode=set_parallel_mode,
        sequence_parallel=sequence_parallel,
        **kwargs,
    )

    # Synchronize parameters between models
    _copy_params(model_distributed, model_single_node)

    # Prepare input tensors
    input_single_node = torch.randn((SEQ_LEN, HIDDEN_SIZE)).cuda().to(params_dtype)

    if sequence_parallel:
        # Duplicate input for sequence parallelism
        input_single_node = torch.empty((WORLD_SIZE * SEQ_LEN, HIDDEN_SIZE)).cuda().to(params_dtype)
        input_distributed = torch.randn((SEQ_LEN, HIDDEN_SIZE)).cuda().to(params_dtype)
        # make the last element of the input a large value to test the amax reduction on purpose
        # when quantization is fp8_cs, we need to trigger corner cases to see if amax reduction is working
        if QUANTIZATION == "fp8_cs":
            input_distributed = torch.clamp(input_distributed, min=-10, max=10)
            if WORLD_RANK == WORLD_SIZE - 1:
                input_distributed[SEQ_LEN - 1, HIDDEN_SIZE - 1] = 11
        input_single_node = _gather(input_distributed).detach()
    else:
        input_distributed = input_single_node.clone()
    # Apply models
    output_single_node, output_distributed = _apply_models(
        model_single_node, model_distributed, input_single_node, input_distributed
    )

    if "return_layernorm_output" in kwargs:
        output_single_node, norm_s = output_single_node
        output_distributed, norm_d = output_distributed
        if sequence_parallel and not kwargs.get("return_layernorm_output_gathered", False):
            norm_d = _gather(norm_d)
        _check_outputs(norm_s, norm_d)

    if "return_bias" in kwargs:
        output_single_node, bias_s = output_single_node
        output_distributed, bias_d = output_distributed
        _check_outputs(bias_s, bias_d)

    if sequence_parallel:
        output_distributed = _gather(output_distributed)

    # Compute loss and backpropagate
    _loss_backward(output_single_node, output_distributed)

    if "delay_wgrad_compute" in kwargs:
        _loss_backward_dw(model_single_node, model_distributed)

    # Validate outputs and gradients
    _check_outputs(output_single_node, output_distributed)

    # gradients in other cases need additional synchronization
    if not sequence_parallel and "return_bias" not in kwargs:
        _check_gradients(
            model_distributed,
            model_single_node,
            main_grad_check=("fuse_wgrad_accumulation" in kwargs),
        )


def test_layernorm_mlp():
    base_kwargs_list = [
        {},
        {"init_method": _constant},
        {"output_layer_init_method": _constant},
        {"normalization": "RMSNorm"},
        {"zero_centered_gamma": True},
        {"bias": False},
        {"params_dtype": torch.float16 if QUANTIZATION != "nvfp4" else torch.bfloat16},
        {"activation": "relu"},
        {"fuse_wgrad_accumulation": True},
        {"return_bias": True},
        {"return_layernorm_output": True},
        {"delay_wgrad_compute": True},
        {"checkpoint": True},
    ]
    #TODO:The blockwise recipe does not currently support calculations with bias set to true.
    """
    For AMD platforms, when the quantization recipe is fp8_block_scaling, iterate through base_kwargs_list,
    and if the bias value is not set in kwargs or the bias value is true, set bias to false.
    """
    if IS_HIP_EXTENSION and QUANTIZATION == "fp8_block_scaling":
        kwargs_list = [kwargs for kwargs in base_kwargs_list if kwargs.get("bias", True) is False]
    else:
        kwargs_list = base_kwargs_list
    for kwargs in kwargs_list:
        if kwargs.get("delay_wgrad_compute", False) and NVTE_TEST_NVINSPECT_ENABLED:
            continue
        for set_parallel_mode in [True]:
            for sequence_parallel in [False, True]:
                _test_layernorm_mlp(set_parallel_mode, sequence_parallel, **kwargs)


############################################
#             TransformerLayer             #
############################################


@run_distributed_test()
def _test_transformer_layer_parallel(sequence_parallel=False, **kwargs):
    params_dtype = kwargs.get("params_dtype", torch.float32)
    FFN_HIDDEN_SIZE = 32 if QUANTIZATION is None else 128

    model_single_node = te.TransformerLayer(
        HIDDEN_SIZE, FFN_HIDDEN_SIZE, NR_HEADS, attention_dropout=0, hidden_dropout=0, **kwargs
    )
    model_distributed = te.TransformerLayer(
        HIDDEN_SIZE,
        FFN_HIDDEN_SIZE,
        NR_HEADS,
        tp_size=WORLD_SIZE,
        tp_group=NCCL_WORLD,
        set_parallel_mode=True,
        sequence_parallel=sequence_parallel,
        seq_length=WORLD_SIZE * SEQ_LEN if sequence_parallel else None,
        attention_dropout=0,
        hidden_dropout=0,
        **kwargs,
    )

    _copy_params(model_distributed, model_single_node)
    _alloc_main_grad(model_single_node, model_distributed)  # for fuse_wgrad_accumulation=True

    input_single_node = (
        torch.randn((WORLD_SIZE * SEQ_LEN, BATCH_SIZE, HIDDEN_SIZE)).cuda().to(params_dtype)
    )
    if sequence_parallel:
        input_distributed = input_single_node[
            WORLD_RANK * SEQ_LEN : (WORLD_RANK + 1) * SEQ_LEN, :, :
        ]
    else:
        input_distributed = input_single_node.clone().cuda()

    encoder_output = None
    if "layer_type" in kwargs:
        encoder_output = torch.randn((SEQ_LEN, BATCH_SIZE, HIDDEN_SIZE)).cuda()

    output_single_node, output_distributed = _apply_models(
        model_single_node,
        model_distributed,
        input_single_node,
        input_distributed,
        encoder_output=encoder_output,
    )

    if sequence_parallel:
        output_distributed = _gather(output_distributed)

    _loss_backward(output_single_node, output_distributed)
    _check_outputs(output_single_node, output_distributed)

    # gradients in other cases need additional synchronization
    if not sequence_parallel and "return_bias" not in kwargs:
        _check_gradients(
            model_distributed,
            model_single_node,
            main_grad_check=("fuse_wgrad_accumulation" in kwargs),
        )


def test_transformer_layer():
    base_kwargs_list = [
        {},
        {"num_gqa_groups": 4},
        {"init_method": _constant},
        {"output_layer_init_method": _constant},
        {"apply_residual_connection_post_layernorm": True},
        {"output_layernorm": True},
        {"parallel_attention_mlp": True},
        # {"layer_type": "decoder"},
        {"window_size": (2, 2)},
        {"normalization": "RMSNorm"},
        {"zero_centered_gamma": True},
        {"fuse_qkv_params": True},
        {"fuse_qkv_params": True, "fuse_wgrad_accumulation": True},
        {"qkv_weight_interleaved": False},
        {"bias": False},
        {"params_dtype": torch.float16 if QUANTIZATION != "nvfp4" else torch.bfloat16},
        {"fuse_qkv_params": True},
        {"activation": "relu"},
    ]
    #TODO:The blockwise recipe does not currently support calculations with bias set to true.
    """
    For AMD platforms, when the quantization recipe is fp8_block_scaling, iterate through base_kwargs_list,
    and if the bias value is not set in kwargs or the bias value is true, set bias to false.
    """
    if IS_HIP_EXTENSION and QUANTIZATION == "fp8_block_scaling":
        kwargs_list = [kwargs for kwargs in base_kwargs_list if kwargs.get("bias", True) is False]
    else:
        kwargs_list = base_kwargs_list

    for kwargs in kwargs_list:
        for sequence_parallel in [False, True]:
            _test_transformer_layer_parallel(sequence_parallel, **kwargs)


if __name__ == "__main__":
    sys.exit(main())
