// Copyright (C) 2009-present, Panagiotis Christopoulos Charitos and contributors.
// All rights reserved.
// Code licensed under the BSD License.
// http://www.anki3d.org/LICENSE

#pragma once

#include <AnKi/Physics/Common.h>
#include <AnKi/Util/ClassWrapper.h>

namespace anki {

/// @addtogroup physics
/// @{

/// An interface to process contacts.
/// @memberof PhysicsBody
class PhysicsTriggerCallbacks
{
public:
	/// Will be called whenever a contact first touches a trigger.
	virtual void onTriggerEnter([[maybe_unused]] const PhysicsBody& trigger, [[maybe_unused]] const PhysicsObjectBase& obj)
	{
	}

	/// Will be called whenever a contact stops touching a trigger.
	virtual void onTriggerExit([[maybe_unused]] const PhysicsBody& trigger, [[maybe_unused]] const PhysicsObjectBase& obj)
	{
	}
};

/// An interface to process contacts.
/// @memberof PhysicsBody
class PhysicsCollisionFilterCallback
{
public:
	virtual Bool collidesWith(const PhysicsBody& body1, const PhysicsBody& body2) = 0;
};

/// Init info for PhysicsBody.
class PhysicsBodyInitInfo
{
public:
	PhysicsCollisionShape* m_shape = nullptr;

	F32 m_mass = 0.0f; ///< Zero mass means static object.

	Transform m_transform = Transform::getIdentity();

	F32 m_friction = 0.5f;

	PhysicsLayer m_layer = PhysicsLayer::kStatic;

	Bool m_isTrigger = false;

	void* m_userData = nullptr;
};

/// Rigid body.
class PhysicsBody : public PhysicsObjectBase
{
	ANKI_PHYSICS_COMMON_FRIENDS
	friend class PhysicsBodyPtrDeleter;

public:
	const Transform& getTransform(U32* version = nullptr) const
	{
		if(version)
		{
			*version = m_worldTrfVersion;
		}
		return m_worldTrf;
	}

	void setPositionAndRotation(Vec3 position, const Mat3& rotation);

	/// @param force In Newton and in world space.
	/// @param relPos The position to apply the force. It's in the local space of the body.
	void applyForce(const Vec3& force, const Vec3& relPos);

	/// Apply force to the center of mass.
	void applyForce(const Vec3& force);

	void activate(Bool activate);

	/// Zero means no gravity, 1 means normal gravity.
	void setGravityFactor(F32 factor);

	void setLinearVelocity(Vec3 v);

	void setAngularVelocity(Vec3 v);

	void clearForcesAndTorque();

	void setPhysicsTriggerCallbacks(PhysicsTriggerCallbacks* callbacks)
	{
		ANKI_ASSERT(m_isTrigger);
		m_triggerCallbacks = callbacks;
	}

	void setCollisionFilterCallback(PhysicsCollisionFilterCallback* callback);

	F32 getMass() const
	{
		return m_mass;
	}

private:
	class MyGroupFilter final : public JPH::GroupFilter
	{
	public:
		Bool CanCollide(const JPH::CollisionGroup& inGroup1, const JPH::CollisionGroup& inGroup2) const override;
	};

	static MyGroupFilter m_groupFilter;

	JPH::Body* m_jphBody = nullptr;
	PhysicsCollisionShapePtr m_primaryShape;
	PhysicsCollisionShapePtr m_scaledShape;

	PhysicsTriggerCallbacks* m_triggerCallbacks = nullptr;
	PhysicsCollisionFilterCallback* m_collisionFilterCallback = nullptr;

	F32 m_mass = 0.0f;

	U32 m_worldTrfVersion : 30 = 1;
	U32 m_activated : 1 = false;
	U32 m_isTrigger : 1 = false;

	Transform m_worldTrf;

	PhysicsBody();

	~PhysicsBody();

	void init(const PhysicsBodyInitInfo& init);

	void postPhysicsUpdate();
};
/// @}

} // end namespace anki