#include <iostream>
#include <chrono>
#include <thread>

#include "Display.h"
#include "Point.h"
#include "Utility.h"

#define RADIUS 10.f

Display::Display()
{
    if (!m_font.loadFromFile("arial.ttf"))
    {
        std::cerr << "font arial.ttf could not be loaded!" << std::endl;
    }

    m_textStatus.setPosition(OFFSET, HEIGHT - 2*OFFSET);
    m_textStatus.setFont(m_font);
    m_textStatus.setString("initializing...");
    m_textStatus.setCharacterSize(12);
    m_textStatus.setFillColor(sf::Color::Black);
}

void Display::drawPoint(sf::RenderWindow& window, size_t index)
{
    Point &pt = m_points[index];
    sf::CircleShape shape(RADIUS);
    //shape.setOrigin(RADIUS, RADIUS); // handle with origin or manually calc position
    shape.setPosition(pt.x() - RADIUS, pt.y() - RADIUS);
    shape.setFillColor(sf::Color::Green);
    shape.setOutlineThickness(1.f);
    shape.setOutlineColor(sf::Color::Black);
    window.draw(shape);

    sf::Text label;
    label.setPosition(pt.x() - RADIUS/2, pt.y() - RADIUS/2 - 3);
    label.setFont(m_font);
    label.setString(std::to_string(index));
    label.setCharacterSize(12);
    label.setFillColor(sf::Color::Black);
    window.draw(label);
}

// multiple options possible:
// a) draw every frame, using elapsed time for updates
//      --> not really needed because we have no animations... also uses a lot of performance
// b) checking every frame if elapsed time since last tick is larger than a specified offset, then draw the field
//      --> mostly doing nothing but still uses a lot of performance O_o
// c) just start a simple (c++11 <3) non-busy sleep
//      --> may delay user input / events but don't care atm :p
void Display::show()
{
    sf::ContextSettings settings;
    settings.antialiasingLevel = 4;

    sf::RenderWindow window(sf::VideoMode(WIDTH, HEIGHT), "ALGO Prog2: Quickhull - visualization", sf::Style::Default, settings);
    // b)
    //window.setFramerateLimit(0.2);

    //sf::Clock clock;
    //sf::Time timeSinceLastUpdate = sf::Time::Zero;
    //sf::Time frameTime = sf::seconds(2); //sf::seconds(1.f / 60.f)
    while (window.isOpen())
    {
        sf::Event event;
        while (window.pollEvent(event))
        {
            if (event.type == sf::Event::Closed)
                window.close();
        }

        std::cout << "entering gameloop" << std::endl;

        /* b)
        timeSinceLastUpdate += clock.restart();
        // only handle every few seconds because we need no animations
        if (timeSinceLastUpdate > frameTime)
        {
            // start by getting the most left and right point
            timeSinceLastUpdate -= frameTime;
        }*/

        // a)
        //update(elapsed);
        update();

        window.clear(sf::Color::White);

        // TODO: refactor -> parse into sf::Vertices or Shapes
        // always print remaining points
        size_t points = m_points.size();
        for (size_t i = 0; i < points; ++i)
        {
            drawPoint(window, i);
        }

        // draw already calculated hull
        //if (step >= 1)
        {
            //window.draw(&m_hull[0], m_hull.size(), sf::Lines);
            window.draw(&m_hull[0], m_hull.getVertexCount(), m_hull.getPrimitiveType());
        }

        window.draw(m_textStatus);

        window.display();

        // c)
        // choose a simple sleep 
        std::this_thread::sleep_for(std::chrono::milliseconds(2000));
    }
}

void Display::update()
{
    // TODO: maybe include Akl–Toussaint heuristic first?
    // https://en.wikipedia.org/wiki/Convex_hull_algorithms#Akl%E2%80%93Toussaint_heuristic
    if (m_curStep == 1)
    {
        // first step: select min - max x coordinates
        m_textStatus.setString("step " + std::to_string(m_curStep) + ": select min - max x coordinates...");
        std::pair<Point, Point> minmax = getMinMaxX(m_points);
        std::cout << "min: " << minmax.first.x() << ", " << minmax.first.y() <<
            ", max: " << minmax.second.x() << ", " << minmax.second.y() << std::endl;

        m_hull.setPrimitiveType(sf::Lines);
        m_hull.append(sf::Vertex(sf::Vector2f(minmax.first.x(), minmax.first.y()), sf::Color::Blue));
        m_hull.append(sf::Vertex(sf::Vector2f(minmax.second.x(), minmax.second.y()), sf::Color::Blue));
    }
    else if (m_curStep == 2)
    {
        // second step: split board and find furthest point
        m_textStatus.setString("step " + std::to_string(m_curStep) + ": split board and find furthest point...");
    }
    else if (m_curStep == 3)
    {
        // third step: draw triangle, remove inner points
        m_textStatus.setString("step " + std::to_string(m_curStep) + ": draw triangle, remove inner points...");
    }
    else if (m_curStep == 4)
    {
        // fourth step: remove inner points
        m_textStatus.setString("step " + std::to_string(m_curStep) + ": remove inner points...");
    }
    else if (m_curStep == 5)
    {
        // fourth step: remove inner points
        m_textStatus.setString("step " + std::to_string(m_curStep) + ": finished calculating convex hull");
    }

    m_curStep++;
    // if finished removing inner points and there are still points left -> repeat from step 2
    // TODO: 
    if (m_curStep == 5 && m_points.size() > 0)
    {
        m_curStep = 2;
    }

}

void Display::setData(std::vector<Point> pts)
{
    m_points = pts;
}