/**
 * Copyright (c) 2006-2022 LOVE Development Team
 *
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would be
 *    appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 **/

#include "MouseJoint.h"

// Module
#include "Body.h"
#include "World.h"
#include "Physics.h"

#include <float.h>

namespace love
{
namespace physics
{
namespace box2d
{

love::Type MouseJoint::type("MouseJoint", &Joint::type);

MouseJoint::MouseJoint(Body *body1, float x, float y)
	: Joint(body1)
	, joint(NULL)
{
	if (body1->getType() == Body::BODY_KINEMATIC)
		throw love::Exception("Cannot attach a MouseJoint to a kinematic body");

	b2MouseJointDef def;

	def.bodyA = body1->world->getGroundBody();
	def.bodyB = body1->body;
	def.maxForce = 1000.0f * body1->body->GetMass();
	def.target = Physics::scaleDown(b2Vec2(x,y));
	b2LinearStiffness(def.stiffness, def.damping, 5.0f, 0.7f, def.bodyA, def.bodyB);
	joint = (b2MouseJoint *)createJoint(&def);
}

MouseJoint::~MouseJoint()
{
}

void MouseJoint::setTarget(float x, float y)
{
	joint->SetTarget(Physics::scaleDown(b2Vec2(x, y)));
}

int MouseJoint::getTarget(lua_State *L)
{
	lua_pushnumber(L, Physics::scaleUp(joint->GetTarget().x));
	lua_pushnumber(L, Physics::scaleUp(joint->GetTarget().y));
	return 2;
}

void MouseJoint::setMaxForce(float force)
{
	joint->SetMaxForce(Physics::scaleDown(force));
}

float MouseJoint::getMaxForce() const
{
	return Physics::scaleUp(joint->GetMaxForce());
}

void MouseJoint::setFrequency(float hz)
{
	// This is kind of a crappy check. The Stiffness is used in an internal
	// box2d calculation whose result must be > FLT_EPSILON, but other variables
	// go into that calculation...
	if (hz <= FLT_EPSILON * 2)
		throw love::Exception("MouseJoint Stiffness must be a positive number.");

	float stiffness, damping;
	b2LinearStiffness(stiffness, damping, hz, getDampingRatio(), joint->GetBodyA(), joint->GetBodyB());
	joint->SetStiffness(stiffness);
}

float MouseJoint::getFrequency() const
{
	float frequency, ratio;
	Physics::b2LinearFrequency(frequency, ratio, joint->GetStiffness(), joint->GetDamping(), joint->GetBodyA(), joint->GetBodyB());
	return frequency;
}

void MouseJoint::setDampingRatio(float ratio)
{
	float stiffness, damping;
	b2LinearStiffness(stiffness, damping, getFrequency(), ratio, joint->GetBodyA(), joint->GetBodyB());
	joint->SetDamping(damping);
}

float MouseJoint::getDampingRatio() const
{
	float frequency, ratio;
	Physics::b2LinearFrequency(frequency, ratio, joint->GetStiffness(), joint->GetDamping(), joint->GetBodyA(), joint->GetBodyB());
	return ratio;
}

void MouseJoint::setStiffness(float k)
{
	// This is kind of a crappy check. The Stiffness is used in an internal
	// box2d calculation whose result must be > FLT_EPSILON, but other variables
	// go into that calculation...
	if (k <= FLT_EPSILON * 2)
		throw love::Exception("MouseJoint Stiffness must be a positive number.");

	joint->SetStiffness(k);
}

float MouseJoint::getStiffness() const
{
	return joint->GetStiffness();
}

void MouseJoint::setDamping(float d)
{
	joint->SetDamping(d);
}

float MouseJoint::getDamping() const
{
	return joint->GetDamping();
}

Body *MouseJoint::getBodyA() const
{
	return Joint::getBodyB();
}

Body *MouseJoint::getBodyB() const
{
	return nullptr;
}

} // box2d
} // physics
} // love