#include "svg.h"
#include <algorithm>
#include <string>

using namespace std;

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

    void end(ostream& out) {
        out << "</svg>\n";
    }

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

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

    void show_histogram_svg(ostream& out, const vector<size_t>& bins) {
        begin(out, IMAGE_WIDTH, IMAGE_HEIGHT);

        if (bins.empty()) {
            end(out);
            return;
        }


        size_t max_count = *max_element(bins.begin(), bins.end());
        double scale = (max_count > 0) ? (IMAGE_WIDTH - TEXT_WIDTH) / static_cast<double>(max_count) : 1.0;

        double top = 0;
        for (size_t bin : bins) {
            const double bin_width = bin * scale;
            text(out, TEXT_LEFT, top + TEXT_BASELINE, to_string(bin));


            string fill_color = (static_cast<int>(top / BIN_HEIGHT) % 2 == 0) ? "#aaffaa" : "#aaaaff";
            rect(out, TEXT_WIDTH, top, bin_width, BIN_HEIGHT, "black", fill_color);

            top += BIN_HEIGHT;
        }

        end(out);
    }
}