package net.minecraft.client.gui.components;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Objects;
import java.util.function.Consumer;
import net.minecraft.client.Minecraft;
import net.minecraft.client.gui.GuiGraphicsExtractor;
import net.minecraft.client.gui.components.events.GuiEventListener;
import net.minecraft.client.gui.layouts.Layout;
import net.minecraft.client.gui.layouts.LayoutElement;
import net.minecraft.client.gui.narration.NarratableEntry;
import net.minecraft.client.gui.narration.NarrationElementOutput;
import net.minecraft.client.gui.navigation.ScreenDirection;
import net.minecraft.client.gui.navigation.ScreenRectangle;
import net.minecraft.network.chat.CommonComponents;
import org.jspecify.annotations.Nullable;

public class ScrollableLayout implements Layout {
	private static final int DEFAULT_SCROLLBAR_SPACING = 4;
	private final Layout content;
	private final ScrollableLayout.Container container;
	private final ScrollableLayout.ReserveStrategy reserveStrategy;
	private final int scrollbarSpacing;
	private int minWidth;
	private int minHeight;
	private int maxHeight;

	public ScrollableLayout(final Minecraft minecraft, final Layout content, final int maxHeight) {
		this(minecraft, content, maxHeight, ScrollableLayout.ReserveStrategy.BOTH);
	}

	public ScrollableLayout(final Minecraft minecraft, final Layout content, final int maxHeight, final ScrollableLayout.ReserveStrategy reserveStrategy) {
		this.content = content;
		this.maxHeight = maxHeight;
		this.reserveStrategy = reserveStrategy;
		this.scrollbarSpacing = 4;
		this.container = new ScrollableLayout.Container(minecraft, 0, maxHeight, AbstractScrollArea.defaultSettings(10));
	}

	public void setMinWidth(final int minWidth) {
		this.minWidth = minWidth;
		this.container.setWidth(Math.max(this.content.getWidth(), minWidth));
	}

	public void setMinHeight(final int minHeight) {
		this.minHeight = minHeight;
		this.container.setHeight(Math.max(this.content.getHeight(), minHeight));
	}

	public void setMaxHeight(final int maxHeight) {
		this.maxHeight = maxHeight;
		this.container.setHeight(Math.min(this.content.getHeight(), maxHeight));
		this.container.refreshScrollAmount();
	}

	@Override
	public void arrangeElements() {
		this.content.arrangeElements();
		int contentWidth = this.content.getWidth();

		int scrollbarReserve = switch (this.reserveStrategy) {
			case RIGHT -> this.container.scrollbarReserve();
			case BOTH -> 2 * this.container.scrollbarReserve();
		};
		this.container.setWidth(Math.max(contentWidth, this.minWidth) + scrollbarReserve);
		this.container.setHeight(Math.clamp(this.container.getHeight(), this.minHeight, this.maxHeight));
		this.container.refreshChildren();
		this.container.refreshScrollAmount();
	}

	@Override
	public void visitChildren(final Consumer<LayoutElement> layoutElementVisitor) {
		layoutElementVisitor.accept(this.container);
	}

	@Override
	public void removeChildren() {
		this.container.children().clear();
		this.content.removeChildren();
	}

	@Override
	public void setX(final int x) {
		this.container.setX(x);
	}

	@Override
	public void setY(final int y) {
		this.container.setY(y);
	}

	@Override
	public int getX() {
		return this.container.getX();
	}

	@Override
	public int getY() {
		return this.container.getY();
	}

	@Override
	public int getWidth() {
		return this.container.getWidth();
	}

	@Override
	public int getHeight() {
		return this.container.getHeight();
	}

	private class Container extends AbstractContainerWidget {
		private final Minecraft minecraft;
		private final List<AbstractWidget> children;

		public Container(final Minecraft minecraft, final int width, final int height, final AbstractScrollArea.ScrollbarSettings scrollbarSettings) {
			Objects.requireNonNull(ScrollableLayout.this);
			super(0, 0, width, height, CommonComponents.EMPTY, scrollbarSettings);
			this.children = new ArrayList();
			this.minecraft = minecraft;
			this.refreshChildren();
		}

		public void refreshChildren() {
			this.children.clear();
			ScrollableLayout.this.content.visitWidgets(this.children::add);
		}

		@Override
		protected int contentHeight() {
			return ScrollableLayout.this.content.getHeight();
		}

		@Override
		protected void extractWidgetRenderState(final GuiGraphicsExtractor graphics, final int mouseX, final int mouseY, final float a) {
			graphics.enableScissor(this.getX(), this.getY(), this.getX() + this.width, this.getY() + this.height);

			for (AbstractWidget child : this.children) {
				child.extractRenderState(graphics, mouseX, mouseY, a);
			}

			graphics.disableScissor();
			this.extractScrollbar(graphics, mouseX, mouseY);
		}

		@Override
		protected void updateWidgetNarration(final NarrationElementOutput output) {
		}

		@Override
		public ScreenRectangle getBorderForArrowNavigation(final ScreenDirection opposite) {
			GuiEventListener focused = this.getFocused();
			return focused != null
				? focused.getBorderForArrowNavigation(opposite)
				: new ScreenRectangle(this.getX(), this.getY(), this.width, this.contentHeight()).getBorder(opposite);
		}

		@Override
		public void setFocused(@Nullable final GuiEventListener focused) {
			super.setFocused(focused);
			if (focused != null && this.minecraft.getLastInputType().isKeyboard()) {
				ScreenRectangle area = this.getRectangle();
				ScreenRectangle focusedRect = focused.getRectangle();
				int topDelta = focusedRect.top() - area.top();
				int bottomDelta = focusedRect.bottom() - area.bottom();
				double scrollRate = this.scrollRate();
				if (topDelta < 0) {
					this.setScrollAmount(this.scrollAmount() + topDelta - scrollRate);
				} else if (bottomDelta > 0) {
					this.setScrollAmount(this.scrollAmount() + bottomDelta + scrollRate);
				}
			}
		}

		@Override
		public void setX(final int x) {
			super.setX(x);
			ScrollableLayout.this.content.setX(x + (ScrollableLayout.this.reserveStrategy == ScrollableLayout.ReserveStrategy.BOTH ? this.scrollbarReserve() : 0));
		}

		@Override
		public void setY(final int y) {
			super.setY(y);
			ScrollableLayout.this.content.setY(y - (int)this.scrollAmount());
		}

		private int scrollbarReserve() {
			return ScrollableLayout.this.scrollbarSpacing + this.scrollbarWidth();
		}

		@Override
		public void setScrollAmount(final double scrollAmount) {
			super.setScrollAmount(scrollAmount);
			ScrollableLayout.this.content.setY(this.getRectangle().top() - (int)this.scrollAmount());
		}

		@Override
		public List<? extends GuiEventListener> children() {
			return this.children;
		}

		@Override
		public Collection<? extends NarratableEntry> getNarratables() {
			return this.children;
		}
	}

	public static enum ReserveStrategy {
		RIGHT,
		BOTH;
	}
}