package net.minecraft.client.renderer.feature;

import com.mojang.blaze3d.vertex.VertexConsumer;
import java.util.List;
import net.fabricmc.api.EnvType;
import net.fabricmc.api.Environment;
import net.minecraft.client.renderer.entity.state.EntityRenderState;
import net.minecraft.client.renderer.feature.submit.SubmitNode;
import net.minecraft.client.renderer.rendertype.RenderType;
import net.minecraft.client.renderer.rendertype.RenderTypes;
import net.minecraft.client.renderer.texture.OverlayTexture;
import net.minecraft.resources.Identifier;
import net.minecraft.util.ARGB;
import net.minecraft.world.phys.AABB;
import org.joml.Matrix4fc;
import org.joml.Vector3f;

@Environment(EnvType.CLIENT)
public class ShadowFeatureRenderer extends RenderTypeFeatureRenderer<ShadowFeatureRenderer.Submit> {
	public static final FeatureRendererType<ShadowFeatureRenderer.Submit> TYPE = FeatureRendererType.create("Shadow");
	private static final RenderType SHADOW_RENDER_TYPE = RenderTypes.entityShadow(Identifier.withDefaultNamespace("textures/misc/shadow.png"));

	@Override
	protected void buildGroup(final FeatureFrameContext context, final List<ShadowFeatureRenderer.Submit> submits) {
		VertexConsumer builder = this.getVertexBuilder(SHADOW_RENDER_TYPE);

		for (ShadowFeatureRenderer.Submit submit : submits) {
			this.prepare(submit, builder);
		}
	}

	private void prepare(final ShadowFeatureRenderer.Submit submit, final VertexConsumer builder) {
		for (EntityRenderState.ShadowPiece piece : submit.pieces()) {
			AABB aabb = piece.shapeBelow().bounds();
			float x01 = piece.relativeX() + (float)aabb.minX;
			float x11 = piece.relativeX() + (float)aabb.maxX;
			float y01 = piece.relativeY() + (float)aabb.minY;
			float z01 = piece.relativeZ() + (float)aabb.minZ;
			float z11 = piece.relativeZ() + (float)aabb.maxZ;
			float radius = submit.radius();
			float u0 = -x01 / 2.0F / radius + 0.5F;
			float u1 = -x11 / 2.0F / radius + 0.5F;
			float v0 = -z01 / 2.0F / radius + 0.5F;
			float v1 = -z11 / 2.0F / radius + 0.5F;
			int color = ARGB.white(piece.alpha());
			shadowVertex(submit.pose(), builder, color, x01, y01, z01, u0, v0);
			shadowVertex(submit.pose(), builder, color, x01, y01, z11, u0, v1);
			shadowVertex(submit.pose(), builder, color, x11, y01, z11, u1, v1);
			shadowVertex(submit.pose(), builder, color, x11, y01, z01, u1, v0);
		}
	}

	private static void shadowVertex(
		final Matrix4fc pose, final VertexConsumer buffer, final int color, final float x, final float y, final float z, final float u, final float v
	) {
		Vector3f position = pose.transformPosition(x, y, z, new Vector3f());
		buffer.addVertex(position.x(), position.y(), position.z(), color, u, v, OverlayTexture.NO_OVERLAY, 15728880, 0.0F, 1.0F, 0.0F);
	}

	@Environment(EnvType.CLIENT)
	public record Submit(Matrix4fc pose, float radius, List<EntityRenderState.ShadowPiece> pieces) implements SubmitNode {
		@Override
		public FeatureRendererType<ShadowFeatureRenderer.Submit> featureType() {
			return ShadowFeatureRenderer.TYPE;
		}
	}
}