/* Copyright (c) 2012 Scott Lembcke and Howling Moon Software
 * Copyright (c) 2012 cocos2d-x.org
 * Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.
 * Copyright (c) 2021 @aismann; Peter Eismann, Germany; dreifrankensoft
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#include "CCPhysicsDebugNode.h"

#include "chipmunk/chipmunk_private.h"


#include "base/ccTypes.h"
#include "math/CCGeometry.h"


#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <limits.h>
#include <string.h>


NS_CC_EXT_BEGIN

Vec2 physicsDebugNodeOffset;

/*
 IMPORTANT - READ ME!
 
 This file sets pokes around in the private API a lot to provide efficient
 debug rendering given nothing more than reference to a Chipmunk space.
 It is not recommended to write rendering code like this in your own games
 as the private API may change with little or no warning.
 */

static const cpVect spring_verts[] = {
    {0.00f, 0.0f},
    {0.20f, 0.0f},
    {0.25f, 3.0f},
    {0.30f, -6.0f},
    {0.35f, 6.0f},
    {0.40f, -6.0f},
    {0.45f, 6.0f},
    {0.50f, -6.0f},
    {0.55f, 6.0f},
    {0.60f, -6.0f},
    {0.65f, 6.0f},
    {0.70f, -3.0f},
    {0.75f, 6.0f},
    {0.80f, 0.0f},
    {1.00f, 0.0f},
};
static const int spring_count = sizeof(spring_verts) / sizeof(cpVect);

static Color4F ColorForBody(cpBody *body)
{
    if (CP_BODY_TYPE_STATIC == cpBodyGetType(body) || cpBodyIsSleeping(body))
    {
        return Color4F(0.5f, 0.5f, 0.5f ,0.5f);
    }
    else if (body->sleeping.idleTime > cpBodyGetSpace(body)->sleepTimeThreshold)
    {
        return Color4F(0.33f, 0.33f, 0.33f, 0.5f);
    }
    else
    {
        return Color4F(1.0f, 0.0f, 0.0f, 0.5f);
    }
}

static Vec2 cpVert2Point(const cpVect &vert)
{
    return (Vec2(vert.x, vert.y) + physicsDebugNodeOffset);
}

static void DrawShape(cpShape *shape, DrawNode *renderer)
{
    cpBody *body = cpShapeGetBody(shape);
    Color4F color = ColorForBody(body);
    
    switch (shape->klass->type)
    {
        case CP_CIRCLE_SHAPE:
        {
            cpCircleShape *circle = (cpCircleShape *)shape;
            cpVect center = circle->tc;
            cpFloat radius = circle->r;
            renderer->drawDot(cpVert2Point(center), cpfmax(radius, 1.0), color);
            renderer->drawSegment(cpVert2Point(center), cpVert2Point(cpvadd(center, cpvmult(cpBodyGetRotation(body), radius))), 1.0, color);
        }
             break;
        case CP_SEGMENT_SHAPE:
        {
            cpSegmentShape *seg = (cpSegmentShape *)shape;
            renderer->drawSegment(cpVert2Point(seg->ta), cpVert2Point(seg->tb), cpfmax(seg->r, 1.0), color);
        }
            break;
        case CP_POLY_SHAPE:
        {
            cpPolyShape* poly = (cpPolyShape*)shape;     
            Color4F line = color;
            line.a = cpflerp(color.a, 1.0, 0.5);
            int num = poly->count;
            Vec2* pPoints = new (std::nothrow) Vec2[num];
            for(int i=0;i<num;++i)
                pPoints[i] = cpVert2Point(poly->planes[i].v0);
            if (cpfmax(poly->r, 1.0) > 1.0) {
                renderer->drawPolygon(pPoints, num, Color4F(0.5f, 0.5f, 0.5f, 0.0f), poly->r, color);
            } else {
                renderer->drawPolygon(pPoints, num, color, 1.0, line);
            }

          
            CC_SAFE_DELETE_ARRAY(pPoints);
        }
            break;
        default:
            cpAssertHard(false, "Bad assertion in DrawShape()");
    }
}

static Color4F CONSTRAINT_COLOR(0, 1, 0, 0.5);

static void DrawConstraint(cpConstraint *constraint, DrawNode *renderer)
{
    cpBody *body_a = cpConstraintGetBodyA(constraint);
    cpBody *body_b = cpConstraintGetBodyB(constraint);
    
    if(cpConstraintIsPinJoint(constraint))
    {
        cpVect a = cpvadd(cpBodyGetPosition(body_a), cpvrotate(cpPinJointGetAnchorA(constraint), cpBodyGetRotation(body_a)));
        cpVect b = cpvadd(cpBodyGetPosition(body_b), cpvrotate(cpPinJointGetAnchorB(constraint), cpBodyGetRotation(body_b)));
        
        renderer->drawDot(cpVert2Point(a), 3.0, CONSTRAINT_COLOR);
        renderer->drawDot(cpVert2Point(b), 3.0, CONSTRAINT_COLOR);
        renderer->drawSegment(cpVert2Point(a), cpVert2Point(b), 1.0, CONSTRAINT_COLOR);
    }
    else if(cpConstraintIsSlideJoint(constraint))
    {
        cpVect a = cpvadd(cpBodyGetPosition(body_a), cpvrotate(cpSlideJointGetAnchorA(constraint), cpBodyGetRotation(body_a)));
        cpVect b = cpvadd(cpBodyGetPosition(body_b), cpvrotate(cpSlideJointGetAnchorB(constraint), cpBodyGetRotation(body_b)));
        
        renderer->drawDot(cpVert2Point(a), 3.0, CONSTRAINT_COLOR);
        renderer->drawDot(cpVert2Point(b), 3.0, CONSTRAINT_COLOR);
        renderer->drawSegment(cpVert2Point(a), cpVert2Point(b), 1.0, CONSTRAINT_COLOR);
    }
    else if(cpConstraintIsPivotJoint(constraint))
    {
        cpVect a = cpvadd(cpBodyGetPosition(body_a), cpvrotate(cpPivotJointGetAnchorA(constraint), cpBodyGetRotation(body_a)));
        cpVect b = cpvadd(cpBodyGetPosition(body_b), cpvrotate(cpPivotJointGetAnchorB(constraint), cpBodyGetRotation(body_b)));
        
        renderer->drawDot(cpVert2Point(a), 3.0, CONSTRAINT_COLOR);
        renderer->drawDot(cpVert2Point(b), 3.0, CONSTRAINT_COLOR);
    }
    else if(cpConstraintIsGrooveJoint(constraint))
    {
        cpVect a = cpvadd(cpBodyGetPosition(body_a), cpvrotate(cpGrooveJointGetGrooveA(constraint), cpBodyGetRotation(body_a)));
        cpVect b = cpvadd(cpBodyGetPosition(body_a), cpvrotate(cpGrooveJointGetGrooveB(constraint), cpBodyGetRotation(body_a)));
        cpVect c = cpvadd(cpBodyGetPosition(body_b), cpvrotate(cpGrooveJointGetAnchorB(constraint), cpBodyGetRotation(body_b)));
        
        renderer->drawDot(cpVert2Point(c), 3.0, CONSTRAINT_COLOR);
        renderer->drawSegment(cpVert2Point(a), cpVert2Point(b), 1.0, CONSTRAINT_COLOR);
    }
    else if(cpConstraintIsDampedSpring(constraint))
    {
        cpDampedSpring* spring  = (cpDampedSpring*) constraint;

        cpVect a = cpTransformPoint(body_a->transform, spring->anchorA);
        cpVect b = cpTransformPoint(body_b->transform, spring->anchorB);

        renderer->drawDot(cpVert2Point(a), 3.0, CONSTRAINT_COLOR);
        renderer->drawDot(cpVert2Point(b), 3.0, CONSTRAINT_COLOR);

        cpVect delta = cpvsub(b, a);
        cpFloat cos  = delta.x;
        cpFloat sin  = delta.y;
        cpFloat s    = 1.0f / cpvlength(delta);

        cpVect r1 = cpv(cos, -sin * s);
        cpVect r2 = cpv(sin, cos * s);

        cpVect* verts = (cpVect*) alloca(spring_count * sizeof(cpVect));
        for (int i = 0; i < spring_count; i++) {
            cpVect v = spring_verts[i];
            verts[i] = cpv(cpvdot(v, r1) + a.x, cpvdot(v, r2) + a.y);
        }

        for (int i = 0; i < spring_count - 1; i++) {
            renderer->drawSegment(cpVert2Point(verts[i]), cpVert2Point(verts[i+1]), 1.0, CONSTRAINT_COLOR);
        }
    }
    else
    {
        CCLOG("Cannot draw constraint");
    }
}


// implementation of PhysicsDebugNode

void PhysicsDebugNode::draw(Renderer *renderer, const Mat4 &transform, uint32_t flags)
{
    if (! _spacePtr)
    {
        return;
    }
    // clear the shapes information before draw current shapes.
    DrawNode::clear();

    cpSpaceEachShape(_spacePtr, (cpSpaceShapeIteratorFunc)DrawShape, this);
    cpSpaceEachConstraint(_spacePtr, (cpSpaceConstraintIteratorFunc)DrawConstraint, this);
    
    DrawNode::draw(renderer, transform, flags);
}

PhysicsDebugNode::PhysicsDebugNode()
: _spacePtr(nullptr)
{}

PhysicsDebugNode* PhysicsDebugNode::create(cpSpace *space)
{
    PhysicsDebugNode *node = new (std::nothrow) PhysicsDebugNode();
    if (node)
    {
        node->init();
        node->_spacePtr = space;
        node->autorelease();
    }
    else
    {
        CC_SAFE_DELETE(node);
    }
    
    return node;
}

PhysicsDebugNode::~PhysicsDebugNode()
{
}

cpSpace* PhysicsDebugNode::getSpace() const
{
    return _spacePtr;
}

void PhysicsDebugNode::setSpace(cpSpace *space)
{
    _spacePtr = space;
}

NS_CC_EXT_END