#include <cuda_runtime_api.h>
#include <gtest/gtest.h>

#include <iostream>

#include "conv2d.cuh"

class Conv2dTest : public ::testing::Test {
  protected:
    Layers::Conv2d commonTestSetup(
        int                 inputSize,
        int                 inputChannels,
        int                 kernelSize,
        int                 stride,
        std::string         padding,
        int                 numFilters,
        Activation          activation,
        std::vector<float>& input,
        std::vector<float>& kernels,
        float*&             d_input,
        float*&             d_output
    ) {
        // Create Conv2d layer
        Layers::Conv2d conv2d(
            inputSize, inputChannels, kernelSize, stride, padding, numFilters,
            activation
        );

        conv2d.setKernels(kernels);

        // Allocate device memory
        cudaStatus = cudaMalloc(
            (void**)&d_input, sizeof(float) * inputSize * inputSize * inputChannels
        );
        EXPECT_EQ(cudaStatus, cudaSuccess);

        cudaStatus = cudaMalloc(
            (void**)&d_output, sizeof(float) * conv2d.outputSize * conv2d.outputSize * numFilters
        );
        EXPECT_EQ(cudaStatus, cudaSuccess);

        // // Copy input to device
        cudaStatus = cudaMemcpy(
            d_input, input.data(), sizeof(float) * input.size(),
            cudaMemcpyHostToDevice
        );
        EXPECT_EQ(cudaStatus, cudaSuccess);


        return conv2d;
    }

    void commonTestTeardown(float* d_input, float* d_output) {
        // Free device memory
        cudaFree(d_input);
        cudaFree(d_output);
    }

    cudaError_t cudaStatus;
};

TEST_F(Conv2dTest, SimpleTest) {
    int         inputSize     = 4;
    int         inputChannels = 1;
    int         kernelSize    = 2;
    int         stride        = 1;
    std::string padding       = "VALID";
    int         numFilters    = 1;
    Activation  activation    = LINEAR;

    std::vector<float> input   = {1.0f,  2.0f,  3.0f,  4.0f,  5.0f,  6.0f,
                                  7.0f,  8.0f,  9.0f,  10.0f, 11.0f, 12.0f,
                                  13.0f, 14.0f, 15.0f, 16.0f};
    std::vector<float> kernels = {
        1.0f,
        2.0f,
        3.0f,
        4.0f,
    };

    float* d_input;
    float* d_output;

    Layers::Conv2d conv2d = commonTestSetup(
        inputSize, inputChannels, kernelSize, stride, padding, numFilters,
        activation, input, kernels, d_input, d_output
    );

    int outputSize = (inputSize - kernelSize) / stride + 1;
    EXPECT_EQ(outputSize, conv2d.outputSize);

    conv2d.forward(d_input, d_output);

    std::vector<float> expected = {44.0f,  54.0f,  64.0f,  84.0f, 94.0f,
                                   104.0f, 124.0f, 134.0f, 144.0f};
    std::vector<float> output(outputSize * outputSize * numFilters);

    cudaStatus = cudaMemcpy(
        output.data(), d_output, sizeof(float) * output.size(),
        cudaMemcpyDeviceToHost
    );
    EXPECT_EQ(cudaStatus, cudaSuccess);

    for (int i = 0; i < output.size(); ++i) {
        EXPECT_FLOAT_EQ(expected[i], output[i]);
    }

    commonTestTeardown(d_input, d_output);
}

TEST_F(Conv2dTest, ComplexTest) {
    int         inputSize     = 5;
    int         inputChannels = 3;
    int         kernelSize    = 3;
    int         stride        = 1;
    std::string padding       = "SAME";
    int         numFilters    = 2;
    Activation  activation    = LINEAR;

    std::vector<float> input = {
        // Channel 1
        0.823f, 0.217f, 0.435f, 0.981f, 0.742f,
        0.109f, 0.518f, 0.374f, 0.681f, 0.147f,
        0.956f, 0.729f, 0.654f, 0.087f, 0.392f,
        0.784f, 0.921f, 0.543f, 0.231f, 0.816f,
        0.472f, 0.614f, 0.102f, 0.987f, 0.398f,
        // Channel 2
        0.051f, 0.756f, 0.841f, 0.293f, 0.128f,
        0.417f, 0.632f, 0.095f, 0.184f, 0.529f,
        0.871f, 0.958f, 0.213f, 0.347f, 0.725f,
        0.461f, 0.012f, 0.278f, 0.195f, 0.649f,
        0.853f, 0.707f, 0.988f, 0.988f, 0.322f,
        // Channel 3
        0.345f, 0.123f, 0.789f, 0.123f, 0.456f,
        0.456f, 0.789f, 0.123f, 0.345f, 0.123f,
        0.789f, 0.123f, 0.345f, 0.123f, 0.456f,
        0.123f, 0.345f, 0.123f, 0.789f, 0.123f,
        0.345f, 0.123f, 0.789f, 0.123f, 0.456f
    };

    std::vector<float> kernels = {
        // Filter 1 Channel 1
        0.128f, 0.754f, 0.987f,
        0.321f, 0.412f, 0.635f,
        0.298f, 0.017f, 0.845f,
        // Filter 1 Channel 2
        0.514f, 0.729f, 0.952f,
        0.684f, 0.378f, 0.159f,
        0.823f, 0.547f, 0.216f,
        // Filter 1 Channel 3
        0.456f, 0.123f, 0.789f,
        0.123f, 0.345f, 0.123f,
        0.789f, 0.123f, 0.345f,
        // Filter 2 Channel 1
        0.123f, 0.345f, 0.123f,
        0.789f, 0.123f, 0.345f,
        0.123f, 0.345f, 0.123f,
        // Filter 2 Channel 2
        0.146f, 0.789f, 0.123f,
        0.345f, 0.123f, 0.789f,
        0.123f, 0.345f, 0.123f,
        // Filter 2 Channel 3
        0.123f, 0.345f, 0.123f,
        0.789f, 0.123f, 0.345f,
        0.123f, 0.345f, 0.123f


    };

    float* d_input;
    float* d_output;

    Layers::Conv2d conv2d = commonTestSetup(
        inputSize, inputChannels, kernelSize, stride, padding, numFilters,
        activation, input, kernels, d_input, d_output
    );

    EXPECT_EQ(inputSize, conv2d.outputSize);

    conv2d.forward(d_input, d_output);
}