#pragma once

#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>

#define _USE_MATH_DEFINES
#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif

namespace Donut
{
    enum class CameraMode
    {
        FPS,
        Orbital
    };

    class Camera
    {
    public:
        Camera(float fov = 45.0f, float aspect_ratio = 16.0f / 9.0f, 
               float near_plane = 0.1f, float far_plane = 100.0f);
        ~Camera() = default;

        void set_position(const glm::vec3& position) { m_position = position; recalculate_view_matrix(); }
        void set_rotation(const glm::vec3& rotation) { m_rotation = rotation; recalculate_view_matrix(); }
        
        const glm::vec3& get_position() const { return m_position; }
        const glm::vec3& get_rotation() const { return m_rotation; }
        
        glm::vec3 get_forward_direction() const;
        glm::vec3 get_right_direction()   const;
        glm::vec3 get_up_direction()      const;

        const glm::mat4& get_projection_matrix()     const { return m_projection_matrix; }
        const glm::mat4& get_view_matrix()           const { return m_view_matrix; }
        const glm::mat4& get_view_projection_matrix() const { return m_view_projection_matrix; }

        void set_projection(float fov, float aspect_ratio, float near_plane, float far_plane);
        void on_mouse_move(float x_offset, float y_offset, bool constrain_pitch = true);
        
        void move_forward(float delta_time);
        void move_backward(float delta_time);
        void move_right(float delta_time);
        void move_left(float delta_time);
        void move_up(float delta_time);
        void move_down(float delta_time);

        void set_mouse_sensitivity(float sensitivity) { m_mouse_sensitivity = sensitivity; }
        float get_mouse_sensitivity() const  { return m_mouse_sensitivity; }

        void set_movement_speed(float speed) { m_movement_speed = speed;   }
        float get_movement_speed()    const  { return m_movement_speed;    }

        void set_orbital_target(const glm::vec3& target) { m_orbital_target = target; }
        const glm::vec3& get_orbital_target()      const { return m_orbital_target;   }
        
        void set_orbital_radius(double radius) { m_orbital_radius = radius; }
        double get_orbital_radius() const { return m_orbital_radius; }
        
        void set_orbital_limits(double min_radius, double max_radius) 
        { 
            m_orbital_min_radius = min_radius; 
            m_orbital_max_radius = max_radius; 
        }
        
        void set_orbital_speed(float speed) { m_orbital_speed = speed; }
        float get_orbital_speed() const { return m_orbital_speed; }
        
        void set_zoom_speed(double speed) { m_zoom_speed = speed; }
        double get_zoom_speed() const { return m_zoom_speed; }
        
        void set_azimuth(float azimuth) { m_azimuth = azimuth; }
        float get_azimuth() const { return m_azimuth; }
        
        void set_elevation(float elevation) { m_elevation = elevation; }
        float get_elevation() const { return m_elevation; }
        
        glm::vec3 get_orbital_position() const;
        void update_orbital();
        void process_orbital_mouse_move(double x, double y);
        void process_orbital_mouse_button(int button, int action, int mods);
        void process_orbital_scroll(double x_offset, double y_offset);
        
        void       set_camera_mode(CameraMode mode) { m_camera_mode = mode; }
        CameraMode get_camera_mode()          const { return m_camera_mode; }
        
        bool  is_dragging() const { return m_dragging; }
        bool  is_panning()  const { return m_panning;  }
        bool  is_moving()   const { return m_moving;   }
        double get_last_x()  const { return m_last_x;    }
        double get_last_y()  const { return m_last_y;    }

    private:
        void recalculate_view_matrix();
        void recalculate_projection_matrix();
    private:
        CameraMode m_camera_mode = CameraMode::FPS;
        
        glm::mat4 m_projection_matrix;
        glm::mat4 m_view_matrix;
        glm::mat4 m_view_projection_matrix;

        glm::vec3 m_position = { 0.0f, 0.0f, 3.0f };
        glm::vec3 m_rotation = { 0.0f, 0.0f, 0.0f };

        float m_fov         = 45.0f;
        float m_aspect_ratio = 16.0f / 9.0f;
        float m_near_plane   = 0.1f;
        float m_far_plane    = 100.0f;

        float m_mouse_sensitivity = 0.1f;
        float m_movement_speed    = 5.0f;
        bool  m_first_mouse       = true;
        float m_last_x            = 0.0f;
        float m_last_y            = 0.0f;
        
        glm::vec3 m_orbital_target    = glm::vec3(0.0f, 0.0f, 0.0f);
        double    m_orbital_radius    = 6.34194e10;
        double    m_orbital_min_radius = 1e10;
        double    m_orbital_max_radius = 1e12;
        float     m_azimuth          = 0.0f;
        float     m_elevation        = static_cast<float>(M_PI) / 2.0f;
        float     m_orbital_speed     = 0.01f;
        double    m_zoom_speed        = 25e9f;
        bool      m_dragging         = false;
        bool      m_panning          = false;
        bool      m_moving           = false;
        double    m_last_x_orbital    = 0.0;
        double    m_last_y_orbital    = 0.0;
    };
}