#include <list>
#include <cstdlib>  // for srand, rand
#include <fstream> // ifstream
#include <ctime> // time
#include <algorithm>

class NumberGenerator
{
public:
    static std::list<Point> generate_numbers(const int count, const int mode = 1)
    {
        if (mode == 1)
        {
            return get_random_numbers(count);
        }
        else if (mode == 2)
        {
            return NumberGenerator::get_rectangle_numbers(count);
        }
        else if (mode == 3)
        {
            return NumberGenerator::get_circle_numbers(count);
        }
        else if (mode == 4)
        {
            return NumberGenerator::get_diagonal_numbers(count);
        }
        else throw "unspecified rng Mode"; // TODO: could handle in parse args
    }

    static std::list<Point> read_numbers(const std::string &fileRnd)
    {
        std::list<Point> points;
        std::ifstream in(fileRnd.c_str());
        if (in.is_open())
        {
            std::string line;
            std::getline(in, line); // get first line for explizit valueCount
            int valCount = std::stoi(line);
            float x = 0;
            float y = 0;
            for (int i = 0; i < valCount; ++i)
            {
                getline(in, line);
                //getline(in, line, ','); // could also be used slightly different but includes newlines :/
                size_t pos = line.find(',');
                if (pos != std::string::npos)
                {
                    x = std::stof(line.substr(0, pos));
                    y = std::stof(line.substr(pos + 1));
                    points.push_back(Point(x, y));
                }
                else
                {
                    throw "invalid format!";
                }
            }
        }
        return points;
    }

    static std::list<Point> get_random_numbers (const int valCount)
    {
        std::list<Point> points;

#ifdef _DEBUG
        srand(static_cast <unsigned> (0)); // fixed seed for testing
#else
        srand(static_cast <unsigned> (time(0)));
#endif

        float x = 0;
        float y = 0;
        for (int i = 0; i < valCount; ++i)
        {
            x = OFFSET + static_cast <float> (rand()) / (static_cast <float> (RAND_MAX / (WIDTH - 2*OFFSET)));
            y = OFFSET + static_cast <float> (rand()) / (static_cast <float> (RAND_MAX / (HEIGHT - 2*OFFSET)));

            points.push_back(Point(x, y));
        }

        return points;
    }

    static std::list<Point> get_rectangle_numbers (const int valCount)
    {
        std::list<Point> points;

        float diff = (2.f * HEIGHT/valCount);

        float x = 0;
        float y = 0;
        for (int i = 0; i < valCount; ++i)
        {
            x = (i%2 == 0) ? OFFSET : WIDTH - OFFSET;
            y = diff/2 + (i/2) * diff;
            /*if (i % 4 == 0)
            {
                x = OFFSET;
            }
            else
            {
                x = (i % 4) * WIDTH / 4;
            }
            y = diff / 4 + (i / 4) * diff;*/

            points.push_back(Point(x, y));
        }

        return points;
    }

    static std::list<Point> get_circle_numbers (const int valCount)
    {
        std::list<Point> points;

        float rad = HEIGHT/2;
        float deg = (float)(2 * 3.14159 / valCount);

        float x = 0;
        float y = 0;
        for (int i = 0; i < valCount; ++i)
        {
            x = WIDTH/2 + rad * cosf(i * deg);
            y = HEIGHT/2 + rad * sinf(i * deg);

            points.push_back(Point(x, y));
        }
        return points;
    }

    static std::list<Point> get_diagonal_numbers(const int valCount)
    {
        std::list<Point> points;

        float x = 0;
        float y = 0;
        for (int i = 0; i < valCount; ++i)
        {
            x = OFFSET + static_cast <float> (rand()) / (static_cast <float> (RAND_MAX / (std::min(WIDTH, HEIGHT) - 2 * OFFSET)));
            points.push_back(Point(x, HEIGHT - x)); // ascending
            //points.push_back(Point(x, HEIGHT - x)); // descending
        }
        return points;
    }
};