import com.jme3.asset.AssetManager;
import com.jme3.export.InputCapsule;
import com.jme3.export.JmeExporter;
import com.jme3.export.JmeImporter;
import com.jme3.export.OutputCapsule;
import com.jme3.light.Light;
import com.jme3.light.LightList;
import com.jme3.light.PointLight;
import com.jme3.material.MatParam;
import com.jme3.material.Material;
import com.jme3.material.Technique;
import com.jme3.math.Vector2f;
import com.jme3.math.Vector3f;
import com.jme3.renderer.Camera;
import com.jme3.renderer.Caps;
import com.jme3.renderer.RenderManager;
import com.jme3.renderer.ViewPort;
import com.jme3.renderer.queue.GeometryList;
import com.jme3.renderer.queue.RenderQueue.ShadowMode;
import com.jme3.scene.Geometry;
import com.jme3.scene.Node;
import com.jme3.shader.Shader;
import com.jme3.shader.Uniform;
import com.jme3.shader.VarType;
import com.jme3.shadow.AbstractShadowRenderer;
import com.jme3.shadow.CompareMode;
import com.jme3.shadow.PointLightShadowRenderer;
import com.jme3.shadow.ShadowUtil;
import com.jme3.texture.FrameBuffer;

import java.io.IOException;
import java.util.ArrayList;


public class MultiPointLightShadowRenderer extends MyAbstractShadowRenderer
{

    public static final int CAM_NUMBER = 6;
    protected PointLight light;
    protected Camera[] shadowCams;
    private Geometry[] frustums = null;

    private Node _lightNode;

    /**
     * Used for serialization use
     * PointLightShadowRenderer"PointLightShadowRenderer(AssetManager
     * assetManager, int shadowMapSize)
     */
    public MultiPointLightShadowRenderer()
    {
        super();
        //_lights = new ArrayList<PointLight>();
    }

    /**
     * Creates a PointLightShadowRenderer
     *
     * @param assetManager the application asset manager
     * @param shadowMapSize the size of the rendered shadowmaps (512,1024,2048,
     * etc...)
     */
    public MultiPointLightShadowRenderer(AssetManager assetManager, int shadowMapSize, Node lightNode)
    {
        super(assetManager, shadowMapSize, CAM_NUMBER);

        //_lights = new ArrayList<PointLight>();
        //Material mat = new Material(assetManager, "MatDefs/Shadow/PostShadowMS.j3md");
        //setPostShadowMaterial(mat);

        _lightNode = lightNode;

        init(shadowMapSize);


    }

    private void init(int shadowMapSize)
    {
        shadowCams = new Camera[CAM_NUMBER];
        for (int i = 0; i < CAM_NUMBER; i++) {
            shadowCams[i] = new Camera(shadowMapSize, shadowMapSize);
        }
    }

    @Override
    protected void updateShadowCams(Camera viewCam) {

        if (light == null)
        {
            throw new IllegalStateException("The light can't be null for a " + this.getClass().getName());
        }

        //bottom
        shadowCams[0].setAxes(Vector3f.UNIT_X.mult(-1f), Vector3f.UNIT_Z.mult(-1f), Vector3f.UNIT_Y.mult(-1f));

        //top
        shadowCams[1].setAxes(Vector3f.UNIT_X.mult(-1f), Vector3f.UNIT_Z, Vector3f.UNIT_Y);

        //forward
        shadowCams[2].setAxes(Vector3f.UNIT_X.mult(-1f), Vector3f.UNIT_Y, Vector3f.UNIT_Z.mult(-1f));

        //backward
        shadowCams[3].setAxes(Vector3f.UNIT_X, Vector3f.UNIT_Y, Vector3f.UNIT_Z);

        //left
        shadowCams[4].setAxes(Vector3f.UNIT_Z, Vector3f.UNIT_Y, Vector3f.UNIT_X.mult(-1f));

        //right
        shadowCams[5].setAxes(Vector3f.UNIT_Z.mult(-1f), Vector3f.UNIT_Y, Vector3f.UNIT_X);

        for (int i = 0; i < CAM_NUMBER; i++)
        {
            shadowCams[i].setFrustumPerspective(90f, 1f, 0.1f, light.getRadius());
            shadowCams[i].setLocation(light.getPosition());
            shadowCams[i].update();
            shadowCams[i].updateViewProjection();
        }

    }

    @Override
    protected GeometryList getOccludersToRender(int shadowMapIndex, GeometryList sceneOccluders, GeometryList sceneReceivers, GeometryList shadowMapOccluders) {
        ShadowUtil.getGeometriesInCamFrustum(sceneOccluders, shadowCams[shadowMapIndex], shadowMapOccluders);
        return shadowMapOccluders;
    }

    @Override
    GeometryList getReceivers(GeometryList sceneReceivers, GeometryList lightReceivers) {
        lightReceivers.clear();
        ShadowUtil.getGeometriesInLightRadius(sceneReceivers, shadowCams, lightReceivers);
        return lightReceivers;
    }

    @Override
    protected Camera getShadowCam(int shadowMapIndex) {
        return shadowCams[shadowMapIndex];
    }

    @Override
    protected void doDisplayFrustumDebug(int shadowMapIndex) {
        if (frustums == null) {
            frustums = new Geometry[CAM_NUMBER];
            Vector3f[] points = new Vector3f[8];
            for (int i = 0; i < 8; i++) {
                points[i] = new Vector3f();
            }
            for (int i = 0; i < CAM_NUMBER; i++) {
                ShadowUtil.updateFrustumPoints2(shadowCams[i], points);
                frustums[i] = createFrustum(points, i);
            }
        }
        if (frustums[shadowMapIndex].getParent() == null) {
            ((Node) viewPort.getScenes().get(0)).attachChild(frustums[shadowMapIndex]);
        }
    }

    @Override
    protected void setMaterialParameters(Material material)
    {
        material.setVector3("LightPos", light.getPosition());

        updatePostShadowMatParams(material);
    }

    protected void updatePostShadowMatParams(Material material)
    {
        Technique technique = material.getActiveTechnique();
        if (technique == null)
            return;

        LightList list = _lightNode.getLocalLightList(); // Node with lights.
        ArrayList<PointLight> arr = new ArrayList<PointLight>(list.size());

        Light l;
        float dist = 0;

        for (int i = 0; i < list.size(); i++)
        {
            l = list.get(i);
            if (l == light) continue;
            if (!(l instanceof PointLight)) continue;

            PointLight p = (PointLight)l;

            dist = p.getPosition().distance(light.getPosition());
            if (dist > p.getRadius() * 2) continue;

            arr.add(p);
        }

        if (arr.size() == 0) return;

        Uniform lightPos = null;
        Vector3f pos = null;
        PointLight pl = null;

        try
        {
            material.getMaterialDef().addMaterialParam(VarType.Int, "LightCount", arr.size(), null);
            material.setInt("LightCount", arr.size());
            material.getMaterialDef().addMaterialParam(VarType.Float, "LightRadius", light.getRadius(), null);
            material.setFloat("LightRadius", light.getRadius());
            //material.getMaterialDef().addMaterialParam(VarType.Vector3Array, "LightsPositions", null, null);


            Shader shader = technique.getShader();

            lightPos = shader.getUniform("g_LightsPositions");
            lightPos.setVector4Length(arr.size());
            //if (lightPos.getValue() == null) return;

            for (int i = 0; i < arr.size(); i++)
            {
                pl = arr.get(i);

                pos = pl.getPosition();
                float radius = pl.getInvRadius();
                lightPos.setVector4InArray(pos.getX(), pos.getY(), pos.getZ(), radius, i);

            }

            //Uniform lightPos = shader.getUniform("g_LightPosition");

        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
    }

    /**
     * gets the point light used to cast shadows with this processor
     *
     * @return the point light
     */
    public PointLight getLight() {
        return light;
    }

    /**
     * sets the light to use for casting shadows with this processor
     *
     * @param light the point light
     */
    public void setLight(PointLight light) {
        this.light = light;
    }

    @Override
    public void read(JmeImporter im) throws IOException {
        super.read(im);
        InputCapsule ic = (InputCapsule) im.getCapsule(this);
        light = (PointLight) ic.readSavable("light", null);
        init((int) shadowMapSize);
    }

    @Override
    public void write(JmeExporter ex) throws IOException {
        super.write(ex);
        OutputCapsule oc = (OutputCapsule) ex.getCapsule(this);
        oc.write(light, "light", null);
    }
}