# Copyright (c) 2023, NVIDIA CORPORATION. All rights reserved.

import pytest

import torch

from megatron.core.transformer.parallel_mlp import ParallelMLP


@pytest.fixture
def mlp(transformer_config):
    return ParallelMLP(transformer_config)


class TestParallelMLP:
    def test_constructor(self, mlp):
        assert isinstance(mlp, ParallelMLP)

        num_weights = sum([p.numel() for p in mlp.parameters()])
        assert num_weights == 1212

    def test_cpu_forward(self, mlp):
        # [sequence length, micro batch size, hidden size]
        hidden_states = torch.ones((32, 2, mlp.config.hidden_size))
        output, output_bias = mlp(hidden_states)
        assert output.shape[0] == 32
        assert output.shape[1] == 2
        assert output.shape[2] == mlp.config.hidden_size
        assert output_bias.shape[0] == mlp.config.hidden_size
        assert output.dtype == torch.float32

    @pytest.mark.skipif(not torch.cuda.is_available(), reason="CUDA not available")
    def test_gpu_forward(self, mlp):
        mlp.cuda()
        # [sequence length, batch size, hidden size]
        hidden_states = torch.ones((32, 2, mlp.config.hidden_size))
        hidden_states = hidden_states.cuda()
        output, output_bias = mlp(hidden_states)
        assert output.shape[0] == 32
        assert output.shape[1] == 2
        assert output.shape[2] == mlp.config.hidden_size
        assert output_bias.shape[0] == mlp.config.hidden_size
        assert output.dtype == torch.float32
        assert output.device.type == 'cuda'
        assert output_bias.device.type == 'cuda'