package com.julian.ogl.main;

import org.joml.Matrix4f;
import org.joml.Vector3f;

public class Camera {

    enum Camera_Movement{
        FORWARD,
        BACKWARD,
        LEFT,
        RIGHT
    };

    //defaults
    Vector3f POSITION = new Vector3f(0.0f, 0.0f, 0.0f);
    Vector3f UP = new Vector3f(0.0f, 1.0f, 0.0f);
    Vector3f FRONT = new Vector3f(0.0f, 0.0f, -1.0f);
    float YAW = -90.0f;
    float PITCH = 0.0f;
    float SPEED = 2.5f;
    float SENSITIVITY = 0.1f;
    float ZOOM = 90.0f;

    //attributes
    Vector3f Position;
    Vector3f Front;
    Vector3f Up;
    Vector3f Right;
    Vector3f WorldUp;

    //euler angles
    float Yaw;
    float Pitch;

    //camera options
    float MovementSpeed;
    float MouseSensitivity;
    float Zoom;

    public void printVectorData() {
        System.out.println("Position: " + Position);
        System.out.println("Front: " + Front);
        System.out.println("Up: " + Up);
        System.out.println("Right: " + Right);
        System.out.println("WorldUp: " + WorldUp);
    }

    private void updateCameraVectors() {
        Vector3f front = new Vector3f(0.0f, 0.0f, 0.0f);
        front.x = (float) (Math.cos(Yaw) * Math.cos(Pitch));
        front.y = (float) Math.sin(Pitch);
        front.z = (float) (Math.sin(Yaw) * Math.cos(Pitch));
        Front = front.normalize(new Vector3f());

        Right = Front.cross(WorldUp, new Vector3f()).normalize(new Vector3f());
        Up = Right.cross(Front, new Vector3f()).normalize(new Vector3f());
    }

    public Matrix4f getViewMatrix() {
        return new Matrix4f().lookAt(Position, Position.add(Front, new Vector3f()), Up);
    }

    public void ProcessMouseScroll(float yoffset) {
        Zoom -= yoffset;
        if(Zoom < 1.0f)
            Zoom = 1.0f;
        if(Zoom > 90.0f)
            Zoom = 90.0f;
    }

    public void ProcessMouseMovement(float xoffset, float yoffset, boolean constrainPitch) {
        xoffset *= MouseSensitivity;
        yoffset *= MouseSensitivity;

        Yaw += xoffset;
        Pitch += yoffset;

        //make sure screen doesnt get flipped when out of bounds
        if(constrainPitch) {
            if(Pitch > 89.0f)
                Pitch = 89.0f;
            if(Pitch < -89.0f)
                Pitch = -89.0f;
        }

        updateCameraVectors();
    }

    public void ProcessKeyboard(Camera_Movement direction, float delta) {
        float velocity = MovementSpeed * delta;
        if (direction == Camera_Movement.FORWARD)
            Position = Position.add(Front.mul(velocity, new Vector3f()), new Vector3f());
        if (direction == Camera_Movement.BACKWARD)
            Position = Position.sub(Front.mul(velocity, new Vector3f()), new Vector3f());
        if (direction == Camera_Movement.LEFT)
            Position = Position.sub(Right.mul(velocity, new Vector3f()), new Vector3f());
        if (direction == Camera_Movement.RIGHT)
            Position = Position.add(Right.mul(velocity, new Vector3f()), new Vector3f());
    }

    public Camera(Vector3f position) {
        Position = position;
        Front = FRONT;
        WorldUp = UP;
        Yaw = YAW;
        Pitch = PITCH;
        MovementSpeed = SPEED;
        Zoom = ZOOM;

        updateCameraVectors();
    }

    public Camera() {
        Position = POSITION;
        Front = FRONT;
        WorldUp = UP;
        Yaw = YAW;
        Pitch = PITCH;
        MovementSpeed = SPEED;
        Zoom = ZOOM;

        updateCameraVectors();
    }

    public Camera(Vector3f position, Vector3f up, float yaw, float pitch) {
        Position = position;
        WorldUp = up;
        Yaw = yaw;
        Pitch = pitch;
        updateCameraVectors();
    }

}