#include "SpikeGeneration2DManyIP.h"

#include <omp.h>
#include <stdio.h>
#include <string.h>

#include <algorithm>
#include <cassert>
#include <iostream>


SpikeGeneration2DManyIP::SpikeGeneration2DManyIP()
{

};

SpikeGeneration2DManyIP::~SpikeGeneration2DManyIP()
{

};

bool SpikeGeneration2DManyIP::spike_generation_entrypoint(
    int64_t input_pointer_addr, int64_t input_dim_0,
    int64_t input_dim_1, int64_t input_dim_2, int64_t input_dim_3,
    int64_t random_values_pointer_addr, int64_t random_values_dim_0,
    int64_t random_values_dim_1, int64_t random_values_dim_2,
    int64_t random_values_dim_3, int64_t output_pointer_addr,
    int64_t output_dim_0, int64_t output_dim_1, int64_t output_dim_2,
    int64_t output_dim_3, int64_t number_of_cpu_processes)
{

    float* input_pointer = (float*)input_pointer_addr;
    float* random_values_pointer = (float*)random_values_pointer_addr;
    int64_t* output_pointer = (int64_t*)output_pointer_addr;

    // Input
    assert((input_pointer != nullptr));
    assert((input_dim_0 > 0));
    assert((input_dim_1 > 0));
    assert((input_dim_2 > 0));
    assert((input_dim_3 > 0));

    // Random
    assert((random_values_pointer != nullptr));
    assert((random_values_dim_0 > 0));
    assert((random_values_dim_1 > 0));
    assert((random_values_dim_2 > 0));
    assert((random_values_dim_3 > 0));

    // Output
    assert((output_pointer != nullptr));
    assert((output_dim_0 > 0));
    assert((output_dim_1 > 0));
    assert((output_dim_2 > 0));
    assert((output_dim_3 > 0));

    // Input
    size_t input_dim_c0 = input_dim_1 * input_dim_2 * input_dim_3;
    size_t input_dim_c1 = input_dim_2 * input_dim_3;
    size_t input_dim_c2 = input_dim_3;

    // Random
    size_t random_values_dim_c0 =
        random_values_dim_1 * random_values_dim_2 * random_values_dim_3;
    size_t random_values_dim_c1 =
        random_values_dim_2 * random_values_dim_3;
    size_t random_values_dim_c2 = random_values_dim_3;

    // Output
    size_t output_dim_c0 =
        output_dim_1 * output_dim_2 * output_dim_3;
    size_t output_dim_c1 = output_dim_2 * output_dim_3;
    size_t output_dim_c2 = output_dim_3;

    size_t number_of_pattern = input_dim_0;
    size_t h_dim = input_dim_1;
    size_t spike_dim = output_dim_1;
    size_t x_dim = output_dim_2;
    size_t y_dim = output_dim_2;

    if (number_of_cpu_processes > 0)
    {

        omp_set_num_threads(number_of_cpu_processes);
        // DEBUG:
        // omp_set_num_threads(1);

        size_t pattern_id;

#pragma omp parallel for
        for (pattern_id = 0; pattern_id < number_of_pattern; pattern_id++)
        {
            spike_generation(
                input_pointer,
                input_dim_c0,
                input_dim_c1,
                input_dim_c2,
                random_values_pointer,
                random_values_dim_c0,
                random_values_dim_c1,
                random_values_dim_c2,
                output_pointer,
                output_dim_c0,
                output_dim_c1,
                output_dim_c2,
                x_dim,
                y_dim,
                spike_dim,
                h_dim,
                pattern_id);
        }
    }
    else
    {
        std::cout << "Error: number_of_processes <= 0" << std::endl;
        return false;
    }

    return true;
};

bool SpikeGeneration2DManyIP::spike_generation(
    float* input_pointer,
    size_t input_dim_c0,
    size_t input_dim_c1,
    size_t input_dim_c2,
    float* random_values_pointer,
    size_t random_values_dim_c0,
    size_t random_values_dim_c1,
    size_t random_values_dim_c2,
    int64_t* output_pointer,
    size_t output_dim_c0,
    size_t output_dim_c1,
    size_t output_dim_c2,
    size_t x_dim,
    size_t y_dim,
    size_t spike_dim,
    size_t h_dim,
    size_t pattern_id)
{

    size_t counter;
    size_t counter_x = 0;
    size_t counter_y = 0;

    float* p_ptr = nullptr;
    int64_t* out_ptr = nullptr;
    float* rand_ptr = nullptr;

    for (counter_x = 0; counter_x < x_dim; counter_x++)
    {
        for (counter_y = 0; counter_y < y_dim; counter_y++)
        {
            p_ptr = input_pointer + pattern_id * input_dim_c0 +
                counter_x * input_dim_c2 + counter_y;
            // + counter * input_dim_c1

            out_ptr = output_pointer + pattern_id * output_dim_c0 +
                counter_x * output_dim_c2 + counter_y;
            // + counter * output_dim_c1

            rand_ptr = random_values_pointer +
                pattern_id * random_values_dim_c0 +
                counter_x * random_values_dim_c2 + counter_y;
            // + counter * random_values_dim_c1

            for (counter = 0; counter < spike_dim; counter++)
            {
                out_ptr[counter * output_dim_c1] = lower_bound(p_ptr,
                    h_dim,
                    input_dim_c1,
                    rand_ptr[counter * random_values_dim_c1]);
            }
        }
    }

    return true;
};

// algorithmic idea stolen from libc++
size_t SpikeGeneration2DManyIP::lower_bound(float* data_ptr,
    size_t data_length,
    size_t data_ptr_stride,
    float compare_to_value)
{

    size_t start_of_range = 0;
    size_t length_of_range = data_length;

    while (length_of_range != 0)
    {
        size_t half_length = length_of_range >> 1;
        size_t actual_position = start_of_range + half_length;

        if (data_ptr[actual_position * data_ptr_stride] < compare_to_value)
        {
            start_of_range = ++actual_position;
            length_of_range -= half_length + 1;
        }
        else
            length_of_range = half_length;
    }
    return start_of_range;
};