// Camera.hpp
#pragma once
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>

namespace vapp{
    enum Camera_Movement{
        FORWARD,
        BACKWARD,
        LEFT,
        RIGHT,
        UP,
        DOWN,
    };

    class Camera{
    public:
        float Yaw = -90.0f, Pitch = 0.0f;
        float MovementSpeed = 2.5f;
        float MouseSensitivity = 0.1f;
        float Zoom = 45.0f;

        glm::vec3 Position, Front, Up, Right, WorldUp;

        Camera(glm::vec3 pos = {0, 0, 3}, glm::vec3 up = {0, 1, 0})
            : Position(pos), WorldUp(up), Front({0, 0, -1}){ updateCameraVectors(); }

        glm::mat4 GetViewMatrix(){
            return glm::lookAt(Position, Position + Front, Up);
        }

        void ProcessKeyboard(Camera_Movement dir, float dt){
            float v = MovementSpeed * dt;
            if(dir == FORWARD) Position += Front * v;
            if(dir == BACKWARD) Position -= Front * v;
            if(dir == LEFT) Position -= Right * v;
            if(dir == RIGHT) Position += Right * v;
            if(dir == UP) Position += Up * v;
            if(dir == DOWN) Position -= Up * v;
        }

        void ProcessMouseMovement(float xoff, float yoff, bool constrainPitch = true){
            xoff *= MouseSensitivity;
            yoff *= MouseSensitivity;
            Yaw += xoff;
            Pitch += yoff;
            if(constrainPitch){
                if(Pitch > 89.0f) Pitch = 89.0f;
                if(Pitch < -89.0f) Pitch = -89.0f;
            }
            updateCameraVectors();
        }

        void ProcessMouseScroll(float yoff){
            Zoom -= yoff;
            if(Zoom < 1.0f) Zoom = 1.0f;
            if(Zoom > 45.0f) Zoom = 45.0f;
        }

    private:
        void updateCameraVectors(){
            glm::vec3 f;
            f.x = cos(glm::radians(Yaw)) * cos(glm::radians(Pitch));
            f.y = sin(glm::radians(Pitch));
            f.z = sin(glm::radians(Yaw)) * cos(glm::radians(Pitch));
            Front = glm::normalize(f);
            Right = glm::normalize(glm::cross(Front, WorldUp));
            Up = glm::normalize(glm::cross(Right, Front));
        }
    };
}