package net.minecraft.client.gui.components;

import net.fabricmc.api.EnvType;
import net.fabricmc.api.Environment;
import net.minecraft.client.gui.GuiGraphics;
import net.minecraft.client.renderer.RenderType;
import net.minecraft.network.chat.Component;
import net.minecraft.resources.ResourceLocation;
import net.minecraft.util.Mth;

@Environment(EnvType.CLIENT)
public abstract class AbstractScrollArea extends AbstractWidget {
	public static final int SCROLLBAR_WIDTH = 6;
	private double scrollAmount;
	private static final ResourceLocation SCROLLER_SPRITE = ResourceLocation.withDefaultNamespace("widget/scroller");
	private static final ResourceLocation SCROLLER_BACKGROUND_SPRITE = ResourceLocation.withDefaultNamespace("widget/scroller_background");
	private boolean scrolling;

	public AbstractScrollArea(int i, int j, int k, int l, Component component) {
		super(i, j, k, l, component);
	}

	@Override
	public boolean mouseScrolled(double mouseX, double mouseY, double scrollX, double scrollY) {
		if (!this.visible) {
			return false;
		} else {
			this.setScrollAmount(this.scrollAmount() - scrollY * this.scrollRate());
			return true;
		}
	}

	@Override
	public boolean mouseDragged(double mouseX, double mouseY, int button, double dragX, double dragY) {
		if (this.scrolling) {
			if (mouseY < this.getY()) {
				this.setScrollAmount(0.0);
			} else if (mouseY > this.getBottom()) {
				this.setScrollAmount(this.maxScrollAmount());
			} else {
				double d = Math.max(1, this.maxScrollAmount());
				int i = this.scrollerHeight();
				double e = Math.max(1.0, d / (this.height - i));
				this.setScrollAmount(this.scrollAmount() + dragY * e);
			}

			return true;
		} else {
			return super.mouseDragged(mouseX, mouseY, button, dragX, dragY);
		}
	}

	@Override
	public void onRelease(double mouseX, double mouseY) {
		this.scrolling = false;
	}

	public double scrollAmount() {
		return this.scrollAmount;
	}

	public void setScrollAmount(double scrollAmount) {
		this.scrollAmount = Mth.clamp(scrollAmount, 0.0, (double)this.maxScrollAmount());
	}

	public boolean updateScrolling(double mouseX, double mouseY, int button) {
		this.scrolling = this.scrollbarVisible()
			&& this.isValidClickButton(button)
			&& mouseX >= this.scrollBarX()
			&& mouseX <= this.scrollBarX() + 6
			&& mouseY >= this.getY()
			&& mouseY < this.getBottom();
		return this.scrolling;
	}

	public void refreshScrollAmount() {
		this.setScrollAmount(this.scrollAmount);
	}

	public int maxScrollAmount() {
		return Math.max(0, this.contentHeight() - this.height);
	}

	protected boolean scrollbarVisible() {
		return this.maxScrollAmount() > 0;
	}

	protected int scrollerHeight() {
		return Mth.clamp((int)((float)(this.height * this.height) / this.contentHeight()), 32, this.height - 8);
	}

	protected int scrollBarX() {
		return this.getRight() - 6;
	}

	protected int scrollBarY() {
		return Math.max(this.getY(), (int)this.scrollAmount * (this.height - this.scrollerHeight()) / this.maxScrollAmount() + this.getY());
	}

	protected void renderScrollbar(GuiGraphics guiGraphics) {
		if (this.scrollbarVisible()) {
			int i = this.scrollBarX();
			int j = this.scrollerHeight();
			int k = this.scrollBarY();
			guiGraphics.blitSprite(RenderType::guiTextured, SCROLLER_BACKGROUND_SPRITE, i, this.getY(), 6, this.getHeight());
			guiGraphics.blitSprite(RenderType::guiTextured, SCROLLER_SPRITE, i, k, 6, j);
		}
	}

	protected abstract int contentHeight();

	protected abstract double scrollRate();
}