#pragma once

#include <glm/vec2.hpp>
#include <glm/vec3.hpp>
#include <glm/mat4x4.hpp>

/**
 *  Default camera values
 */
#define DEFAULT_CAMERA_YAW           (-90.0f)
#define DEFAULT_CAMERA_PITCH           (0.0f)
#define DEFAULT_CAMERA_ROLL            (0.0f)
#define DEFAULT_CAMERA_SPEED           (1.0f)
#define DEFAULT_CAMERA_SENSITIVITY     (1.0f)
#define DEFAULT_CAMERA_JOYSENSITIVITY  (1.0f)
#define DEFAULT_CAMERA_ZOOM           (45.0f)

/*
 * Decelerate at gravity speed (9.8 m/s) / ???
 */
#define DEFAULT_CAMERA_DECELERATIONSPEED       (0.98f)
#define DEFAULT_CAMERA_MOUSEDECELERATIONSPEED (0.098f)

class Camera
{
	/**
	 *  An abstract camera class that processes input and calculates the corresponding
	 */
	glm::vec3 Position;
	glm::vec3 Front;
	glm::vec3 Right;
	glm::vec3 Up;
	glm::vec3 WorldUp;

	/** Euler Angles, Vectors and Matrices for use in OpenGL. */
	glm::vec3 Angles;

	/* XXX Maybe we shouldn't let the camera move? */
	glm::vec3 Direction;		 /* Position movement */
	glm::vec2 ViewDirection;	 /* Yaw, Pitch movement */

	void updateCameraVectors (void);

	public:
		/**
		 * Defines several possible options for camera movement.
		 * Used as abstraction to stay away from window-system specific input methods
		 */
		enum Movement
		{
			FORWARD, BACKWARD, LEFT, RIGHT, UP, DOWN, CW, CCW, NONE
		};

		/** Camera options */
		float MovementSpeed, MouseSensitivity, Zoom;
		float DecelerationSpeed, ViewDecelerationSpeed, JoystickSensitivity;
		float zNear, zFar;

		Camera (
			  const glm::vec3 position = glm::vec3(0.0f, 0.0f, 1.0f)
			, const glm::vec3 up = glm::vec3(0.0f, 1.0f, 0.0f)
			, const float yaw = DEFAULT_CAMERA_YAW
			, const float pitch = DEFAULT_CAMERA_PITCH
			, const float roll = DEFAULT_CAMERA_ROLL);

		glm::mat4 GetViewMatrix           (const bool constrainPitch = true);
		void      ProcessJoystickMovement (const float xoffset, const float yoffset, const float deltaTime);
		void      ProcessKeyboard         (const Camera::Movement direction, const float deltaTime);
		void      ProcessMouseMovement    (const float xoffset, const float yoffset, const float deltaTime);
		void      ProcessMouseScroll      (const float xoffset, const float yoffset, const float deltaTime);
};