package net.minecraft.client.renderer.debug;

import net.fabricmc.api.EnvType;
import net.fabricmc.api.Environment;
import net.minecraft.client.Minecraft;
import net.minecraft.client.gui.components.debug.DebugScreenEntries;
import net.minecraft.client.renderer.LevelRenderer;
import net.minecraft.client.renderer.SectionOcclusionGraph;
import net.minecraft.client.renderer.chunk.SectionRenderDispatcher;
import net.minecraft.client.renderer.culling.Frustum;
import net.minecraft.core.BlockPos;
import net.minecraft.core.Direction;
import net.minecraft.gizmos.GizmoStyle;
import net.minecraft.gizmos.Gizmos;
import net.minecraft.util.ARGB;
import net.minecraft.util.Mth;
import net.minecraft.util.debug.DebugValueAccess;
import net.minecraft.world.phys.Vec3;
import org.joml.Vector4f;

@Environment(EnvType.CLIENT)
public class ChunkCullingDebugRenderer implements DebugRenderer.SimpleDebugRenderer {
	public static final Direction[] DIRECTIONS = Direction.values();
	private final Minecraft minecraft;

	public ChunkCullingDebugRenderer(final Minecraft minecraft) {
		this.minecraft = minecraft;
	}

	@Override
	public void emitGizmos(
		final double camX, final double camY, final double camZ, final DebugValueAccess debugValues, final Frustum frustum, final float partialTicks
	) {
		LevelRenderer levelRenderer = this.minecraft.levelRenderer;
		boolean sectionPath = this.minecraft.debugEntries.isCurrentlyEnabled(DebugScreenEntries.CHUNK_SECTION_PATHS);
		boolean sectionVisibility = this.minecraft.debugEntries.isCurrentlyEnabled(DebugScreenEntries.CHUNK_SECTION_VISIBILITY);
		if (sectionPath || sectionVisibility) {
			SectionOcclusionGraph sectionOcclusionGraph = levelRenderer.sectionOcclusionGraph();

			for (SectionRenderDispatcher.RenderSection section : levelRenderer.visibleSections()) {
				SectionOcclusionGraph.Node node = sectionOcclusionGraph.getNode(section);
				if (node != null) {
					BlockPos renderOffset = section.getRenderOrigin();
					if (sectionPath) {
						int color = node.step == 0 ? 0 : Mth.hsvToRgb(node.step / 50.0F, 0.9F, 0.9F);

						for (int i = 0; i < DIRECTIONS.length; i++) {
							if (node.hasSourceDirection(i)) {
								Direction direction = DIRECTIONS[i];
								Gizmos.line(
									Vec3.atLowerCornerWithOffset(renderOffset, 8.0, 8.0, 8.0),
									Vec3.atLowerCornerWithOffset(renderOffset, 8 - 16 * direction.getStepX(), 8 - 16 * direction.getStepY(), 8 - 16 * direction.getStepZ()),
									ARGB.opaque(color)
								);
							}
						}
					}

					if (sectionVisibility && section.getSectionMesh().hasRenderableLayers()) {
						int c = 0;

						for (Direction direction1 : DIRECTIONS) {
							for (Direction direction2 : DIRECTIONS) {
								boolean b = section.getSectionMesh().facesCanSeeEachother(direction1, direction2);
								if (!b) {
									c++;
									Gizmos.line(
										Vec3.atLowerCornerWithOffset(renderOffset, 8 + 8 * direction1.getStepX(), 8 + 8 * direction1.getStepY(), 8 + 8 * direction1.getStepZ()),
										Vec3.atLowerCornerWithOffset(renderOffset, 8 + 8 * direction2.getStepX(), 8 + 8 * direction2.getStepY(), 8 + 8 * direction2.getStepZ()),
										ARGB.color(255, 255, 0, 0)
									);
								}
							}
						}

						if (c > 0) {
							float delta = 0.5F;
							float a = 0.2F;
							Gizmos.cuboid(section.getBoundingBox().deflate(0.5), GizmoStyle.fill(ARGB.colorFromFloat(0.2F, 0.9F, 0.9F, 0.0F)));
						}
					}
				}
			}
		}

		Frustum capturedFrustum = this.minecraft.gameRenderer.mainCamera().getCapturedFrustum();
		if (capturedFrustum != null) {
			Vec3 offset = new Vec3(capturedFrustum.getCamX(), capturedFrustum.getCamY(), capturedFrustum.getCamZ());
			Vector4f[] frustumPoints = capturedFrustum.getFrustumPoints();
			this.addFrustumQuad(offset, frustumPoints, 0, 1, 2, 3, 0, 1, 1);
			this.addFrustumQuad(offset, frustumPoints, 4, 5, 6, 7, 1, 0, 0);
			this.addFrustumQuad(offset, frustumPoints, 0, 1, 5, 4, 1, 1, 0);
			this.addFrustumQuad(offset, frustumPoints, 2, 3, 7, 6, 0, 0, 1);
			this.addFrustumQuad(offset, frustumPoints, 0, 4, 7, 3, 0, 1, 0);
			this.addFrustumQuad(offset, frustumPoints, 1, 5, 6, 2, 1, 0, 1);
			this.addFrustumLine(offset, frustumPoints[0], frustumPoints[1]);
			this.addFrustumLine(offset, frustumPoints[1], frustumPoints[2]);
			this.addFrustumLine(offset, frustumPoints[2], frustumPoints[3]);
			this.addFrustumLine(offset, frustumPoints[3], frustumPoints[0]);
			this.addFrustumLine(offset, frustumPoints[4], frustumPoints[5]);
			this.addFrustumLine(offset, frustumPoints[5], frustumPoints[6]);
			this.addFrustumLine(offset, frustumPoints[6], frustumPoints[7]);
			this.addFrustumLine(offset, frustumPoints[7], frustumPoints[4]);
			this.addFrustumLine(offset, frustumPoints[0], frustumPoints[4]);
			this.addFrustumLine(offset, frustumPoints[1], frustumPoints[5]);
			this.addFrustumLine(offset, frustumPoints[2], frustumPoints[6]);
			this.addFrustumLine(offset, frustumPoints[3], frustumPoints[7]);
		}
	}

	private void addFrustumLine(final Vec3 offset, final Vector4f a, final Vector4f b) {
		Gizmos.line(new Vec3(offset.x + a.x, offset.y + a.y, offset.z + a.z), new Vec3(offset.x + b.x, offset.y + b.y, offset.z + b.z), -16777216);
	}

	private void addFrustumQuad(
		final Vec3 offset, final Vector4f[] frustumPoints, final int i0, final int i1, final int i2, final int i3, final int r, final int g, final int b
	) {
		float a = 0.25F;
		Gizmos.rect(
			new Vec3(frustumPoints[i0].x(), frustumPoints[i0].y(), frustumPoints[i0].z()).add(offset),
			new Vec3(frustumPoints[i1].x(), frustumPoints[i1].y(), frustumPoints[i1].z()).add(offset),
			new Vec3(frustumPoints[i2].x(), frustumPoints[i2].y(), frustumPoints[i2].z()).add(offset),
			new Vec3(frustumPoints[i3].x(), frustumPoints[i3].y(), frustumPoints[i3].z()).add(offset),
			GizmoStyle.fill(ARGB.colorFromFloat(0.25F, r, g, b))
		);
	}
}