#include "histogram.h"
#include <vector>
#include <algorithm>

size_t find_minmax(const std::vector<double>& numbers, double& min, double& max) {
    if (numbers.empty()) {
        min = max = 0;
        return 0;
    }
    min = numbers[0];
    max = numbers[0];
    for (double number : numbers) {
        if (number < min) {
            min = number;
        }
        if (number > max) {
            max = number;
        }
    }
    return 0;
}
std::vector<size_t> make_histogram(const std::vector<double>& numbers, size_t bin_count) {
    std::vector<size_t> bins(bin_count, 0);
    if (numbers.empty() || bin_count == 0) {
        return bins;
    }
    double min, max;
    find_minmax(numbers, min, max);
    if (max == min) {
        return bins; 
    }
    double bin_width = (max - min) / bin_count;
    for (double number : numbers) {
        size_t bin_index = static_cast<size_t>((number - min) / bin_width);
        if (bin_index >= bin_count) {
            bin_index = bin_count - 1; 
        }
        bins[bin_index]++;
    }
    return bins;
};

void show_histogram_svg(const std::vector<size_t>& bins) {
    const auto IMAGE_WIDTH = 400;
    const auto IMAGE_HEIGHT = 300;
    const auto TEXT_LEFT = 20;
    const auto TEXT_BASELINE = 20;
    const auto TEXT_WIDTH = 50;
    const auto BIN_HEIGHT = 30;
    const auto BLOCK_WIDTH = 10;

    svg_begin(IMAGE_WIDTH, IMAGE_HEIGHT);
    for (size_t i = 0; i < bins.size(); ++i) {
        const double bin_width = BLOCK_WIDTH * bins[i];
        const double top = i * BIN_HEIGHT;
        svg_text(TEXT_LEFT, top + TEXT_BASELINE, std::to_string(bins[i]));
        svg_rect(TEXT_WIDTH, top, bin_width, BIN_HEIGHT, "black", "#aaffaa"); 
    }
    svg_end();
}