/* Pepy by @ohsqueezy [ohsqueezy.itch.io] */

#ifndef PEPY_H_
#define PEPY_H_

/* Enable swizzling in GLM */
#define GLM_ENABLE_EXPERIMENTAL
#include <glm/glm.hpp>
#include <glm/gtx/compatibility.hpp>

/* [SPACE BOX] headers */
#include "Game.hpp"
#include "VBO.hpp"

/* Project headers */
#include "Model.hpp"

class angle_sort
{
    glm::vec2 m_origin;
    glm::vec2 m_dreference;

    // z-coordinate of cross-product, aka determinant
    static double xp(glm::vec2 a, glm::vec2 b) { return a.x * b.y - a.y * b.x; }

public:

    angle_sort(const glm::vec2 origin, const glm::vec2 reference) : m_origin(origin), m_dreference(reference - origin) {}

    bool operator()(const glm::vec2 a, const glm::vec2 b) const
    {
        const glm::vec2 da = a - m_origin, db = b - m_origin;
        const double detb = xp(m_dreference, db);

        // nothing is less than zero degrees
        if (detb == 0 && db.x * m_dreference.x + db.y * m_dreference.y >= 0) return false;

        const double deta = xp(m_dreference, da);

        // zero degrees is less than anything else
        if (deta == 0 && da.x * m_dreference.x + da.y * m_dreference.y >= 0) return true;

        if (deta * detb >= 0) {
            // both on same side of reference, compare to each other
            return xp(da, db) > 0;
        }

        // vectors "less than" zero degrees are actually large, near 2 pi
        return deta > 0;
    }
};

class Pepy : public Game
{

private:

    /* Convention for calling parent class in a consistent way across classes */
    typedef Game super;

    bool shaking = true, flying = false, stopped = false;
    sb::VAO cuckoo_vao, wad_vao;
    sb::VBO vbo;
    GLuint shader;
    Model cuckoo;
    std::vector<std::pair<Plane, glm::vec2>> wad;
    std::map<std::string, GLuint> uniform;
    float hue_offset = 0.0f, time_seconds = 0.0f, aspect_ratio = 1.0f, return_speed = 0.0075f, cuckoo_speed = 0.0f, countdown = 10.0f;
    glm::mat4 orthographic_projection {1};
    glm::vec3 cuckoo_offset {0.0f, 0.0f, 0.0f};
    bool grabbed = false;
    glm::ivec2 mouse_pixel = {0, 0};
    Plane background;

    void load_gl_context();
    void update();

public:

    Pepy();
    void respond(SDL_Event&);

};

#endif