#include "svg.h"
#include <string>
using namespace std;

void svg_begin(double width, double height) {
    cout << "<?xml version='1.0' encoding='UTF-8'?>\n";
    cout << "<svg "
        << "width='" << width << "' "
        << "height='" << height << "' "
        << "viewBox='0 0 " << width << " " << height << "' "
        << "xmlns='http://www.w3.org/2000/svg'>\n";
}

void svg_end() {
    cout << "</svg>\n";
}

void svg_text(double left, double baseline, const string& text) {
    cout << "<text x='" << left
        << "' y='" << baseline
        << "'>" << text
        << "</text>\n";
}

void svg_rect(double x, double y, double width, double height,
    const string& stroke, const string& fill) {
    cout << "<rect x='" << x
        << "' y='" << y
        << "' width='" << width
        << "' height='" << height
        << "' stroke='" << stroke
        << "' fill='" << fill
        << "' />\n";
}

void show_histogram_svg(const std::vector<size_t>& bins, double bin_size, double min_val) {
    const double IMAGE_WIDTH = 400;
    const double IMAGE_HEIGHT = 300;
    const double TEXT_LEFT = 20;
    const double TEXT_BASELINE = 20;
    const double TEXT_WIDTH = 50;
    const double BIN_HEIGHT = 30;
    const double VSPACE = BIN_HEIGHT + TEXT_BASELINE * 2 + 5;

    svg_begin(IMAGE_WIDTH, IMAGE_HEIGHT);

    size_t max_count = 0;
    for (size_t c : bins)
        if (c > max_count)
            max_count = c;
    double max_width = IMAGE_WIDTH - TEXT_WIDTH - 100;

    for (size_t j = 0; j < bins.size(); ++j) {
        size_t count = bins[j];
        double y = j * VSPACE;

        double width;
        if (max_count > 0) {
            width = static_cast<double>(count) / max_count * max_width;
        }
        else {
            width = 0.0;
        }

        svg_text(TEXT_LEFT, y + TEXT_BASELINE, to_string(count));
        svg_rect(TEXT_WIDTH, y, width, BIN_HEIGHT, "blue", "blue");
        double boundary = min_val + bin_size * (j + 1);
        svg_text(TEXT_WIDTH,y + BIN_HEIGHT + TEXT_BASELINE,to_string(boundary)
        );
    }

    svg_end();
}