package net.minecraft.client.gui.screens.inventory;

import com.mojang.blaze3d.platform.cursor.CursorTypes;
import java.util.Objects;
import net.minecraft.client.gui.GuiGraphicsExtractor;
import net.minecraft.client.gui.components.Button.OnPress;
import net.minecraft.client.gui.components.Button.Plain;
import net.minecraft.client.input.MouseButtonEvent;
import net.minecraft.client.renderer.RenderPipelines;
import net.minecraft.network.chat.CommonComponents;
import net.minecraft.network.chat.Component;
import net.minecraft.network.protocol.game.ServerboundSelectTradePacket;
import net.minecraft.resources.Identifier;
import net.minecraft.util.Mth;
import net.minecraft.world.entity.npc.villager.VillagerData;
import net.minecraft.world.entity.player.Inventory;
import net.minecraft.world.inventory.MerchantMenu;
import net.minecraft.world.item.ItemStack;
import net.minecraft.world.item.trading.MerchantOffer;
import net.minecraft.world.item.trading.MerchantOffers;

public class MerchantScreen extends AbstractContainerScreen<MerchantMenu> {
	private static final Identifier OUT_OF_STOCK_SPRITE = Identifier.withDefaultNamespace("container/villager/out_of_stock");
	private static final Identifier EXPERIENCE_BAR_BACKGROUND_SPRITE = Identifier.withDefaultNamespace("container/villager/experience_bar_background");
	private static final Identifier EXPERIENCE_BAR_CURRENT_SPRITE = Identifier.withDefaultNamespace("container/villager/experience_bar_current");
	private static final Identifier EXPERIENCE_BAR_RESULT_SPRITE = Identifier.withDefaultNamespace("container/villager/experience_bar_result");
	private static final Identifier SCROLLER_SPRITE = Identifier.withDefaultNamespace("container/villager/scroller");
	private static final Identifier SCROLLER_DISABLED_SPRITE = Identifier.withDefaultNamespace("container/villager/scroller_disabled");
	private static final Identifier TRADE_ARROW_OUT_OF_STOCK_SPRITE = Identifier.withDefaultNamespace("container/villager/trade_arrow_out_of_stock");
	private static final Identifier TRADE_ARROW_SPRITE = Identifier.withDefaultNamespace("container/villager/trade_arrow");
	private static final Identifier DISCOUNT_STRIKETHRUOGH_SPRITE = Identifier.withDefaultNamespace("container/villager/discount_strikethrough");
	private static final Identifier VILLAGER_LOCATION = Identifier.withDefaultNamespace("textures/gui/container/villager.png");
	private static final int TEXTURE_WIDTH = 512;
	private static final int TEXTURE_HEIGHT = 256;
	private static final int MERCHANT_MENU_PART_X = 99;
	private static final int PROGRESS_BAR_X = 136;
	private static final int PROGRESS_BAR_Y = 16;
	private static final int SELL_ITEM_1_X = 5;
	private static final int SELL_ITEM_2_X = 35;
	private static final int BUY_ITEM_X = 68;
	private static final int LABEL_Y = 6;
	private static final int NUMBER_OF_OFFER_BUTTONS = 7;
	private static final int TRADE_BUTTON_X = 5;
	private static final int TRADE_BUTTON_HEIGHT = 20;
	private static final int TRADE_BUTTON_WIDTH = 88;
	private static final int SCROLLER_HEIGHT = 27;
	private static final int SCROLLER_WIDTH = 6;
	private static final int SCROLL_BAR_HEIGHT = 139;
	private static final int SCROLL_BAR_TOP_POS_Y = 18;
	private static final int SCROLL_BAR_START_X = 94;
	private static final Component TRADES_LABEL = Component.translatable("merchant.trades");
	private static final Component DEPRECATED_TOOLTIP = Component.translatable("merchant.deprecated");
	private int shopItem;
	private final MerchantScreen.TradeOfferButton[] tradeOfferButtons = new MerchantScreen.TradeOfferButton[7];
	private int scrollOff;
	private boolean isDragging;

	public MerchantScreen(final MerchantMenu menu, final Inventory inventory, final Component title) {
		super(menu, inventory, title, 276, 166);
		this.inventoryLabelX = 107;
	}

	private void postButtonClick() {
		this.menu.setSelectionHint(this.shopItem);
		this.menu.tryMoveItems(this.shopItem);
		this.minecraft.getConnection().send(new ServerboundSelectTradePacket(this.shopItem));
	}

	@Override
	protected void init() {
		super.init();
		int xo = (this.width - this.imageWidth) / 2;
		int yo = (this.height - this.imageHeight) / 2;
		int buttonY = yo + 16 + 2;

		for (int i = 0; i < 7; i++) {
			this.tradeOfferButtons[i] = this.addRenderableWidget(new MerchantScreen.TradeOfferButton(xo + 5, buttonY, i, button -> {
				if (button instanceof MerchantScreen.TradeOfferButton tradeOfferButton) {
					this.shopItem = tradeOfferButton.getIndex() + this.scrollOff;
					this.postButtonClick();
				}
			}));
			buttonY += 20;
		}
	}

	@Override
	protected void extractLabels(final GuiGraphicsExtractor graphics, final int xm, final int ym) {
		int traderLevel = this.menu.getTraderLevel();
		if (traderLevel > 0 && traderLevel <= 5 && this.menu.showProgressBar()) {
			Component titleAndLevel = Component.translatable("merchant.title", new Object[]{this.title, Component.translatable("merchant.level." + traderLevel)});
			int totalWidth = this.font.width(titleAndLevel);
			int startX = 49 + this.imageWidth / 2 - totalWidth / 2;
			graphics.text(this.font, titleAndLevel, startX, 6, -12566464, false);
		} else {
			graphics.text(this.font, this.title, 49 + this.imageWidth / 2 - this.font.width(this.title) / 2, 6, -12566464, false);
		}

		graphics.text(this.font, this.playerInventoryTitle, this.inventoryLabelX, this.inventoryLabelY, -12566464, false);
		int textWidth = this.font.width(TRADES_LABEL);
		graphics.text(this.font, TRADES_LABEL, 5 - textWidth / 2 + 48, 6, -12566464, false);
	}

	@Override
	public void extractBackground(final GuiGraphicsExtractor graphics, final int mouseX, final int mouseY, final float a) {
		super.extractBackground(graphics, mouseX, mouseY, a);
		int xo = (this.width - this.imageWidth) / 2;
		int yo = (this.height - this.imageHeight) / 2;
		graphics.blit(RenderPipelines.GUI_TEXTURED, VILLAGER_LOCATION, xo, yo, 0.0F, 0.0F, this.imageWidth, this.imageHeight, 512, 256);
		MerchantOffers offers = this.menu.getOffers();
		if (!offers.isEmpty()) {
			int itemIndex = this.shopItem;
			if (itemIndex < 0 || itemIndex >= offers.size()) {
				return;
			}

			MerchantOffer offer = (MerchantOffer)offers.get(itemIndex);
			if (offer.isOutOfStock()) {
				graphics.blitSprite(RenderPipelines.GUI_TEXTURED, OUT_OF_STOCK_SPRITE, this.leftPos + 83 + 99, this.topPos + 35, 28, 21);
			}
		}
	}

	private void extractProgressBar(final GuiGraphicsExtractor graphics, final int xo, final int yo, final MerchantOffer offer) {
		int traderLevel = this.menu.getTraderLevel();
		int traderXp = this.menu.getTraderXp();
		if (traderLevel < 5) {
			graphics.blitSprite(RenderPipelines.GUI_TEXTURED, EXPERIENCE_BAR_BACKGROUND_SPRITE, xo + 136, yo + 16, 102, 5);
			int minXp = VillagerData.getMinXpPerLevel(traderLevel);
			if (traderXp >= minXp && VillagerData.canLevelUp(traderLevel)) {
				int progressLength = 102;
				float multiplier = 102.0F / (VillagerData.getMaxXpPerLevel(traderLevel) - minXp);
				int w = Math.min(Mth.floor(multiplier * (traderXp - minXp)), 102);
				graphics.blitSprite(RenderPipelines.GUI_TEXTURED, EXPERIENCE_BAR_CURRENT_SPRITE, 102, 5, 0, 0, xo + 136, yo + 16, w, 5);
				int futureXp = this.menu.getFutureTraderXp();
				if (futureXp > 0) {
					int futureXpWidth = Math.min(Mth.floor(futureXp * multiplier), 102 - w);
					graphics.blitSprite(RenderPipelines.GUI_TEXTURED, EXPERIENCE_BAR_RESULT_SPRITE, 102, 5, w, 0, xo + 136 + w, yo + 16, futureXpWidth, 5);
				}
			}
		}
	}

	private void extractScroller(final GuiGraphicsExtractor graphics, final int xo, final int yo, final int mouseX, final int mouseY, final MerchantOffers offers) {
		int steps = offers.size() + 1 - 7;
		if (steps > 1) {
			int leftOver = 139 - (27 + (steps - 1) * 139 / steps);
			int stepHeight = 1 + leftOver / steps + 139 / steps;
			int maxScrollerOff = 113;
			int scrollerYOff = Math.min(113, this.scrollOff * stepHeight);
			if (this.scrollOff == steps - 1) {
				scrollerYOff = 113;
			}

			int scrollerX = xo + 94;
			int scrollerY = yo + 18 + scrollerYOff;
			graphics.blitSprite(RenderPipelines.GUI_TEXTURED, SCROLLER_SPRITE, scrollerX, scrollerY, 6, 27);
			if (mouseX >= scrollerX && mouseX < xo + 94 + 6 && mouseY >= scrollerY && mouseY <= scrollerY + 27) {
				graphics.requestCursor(this.isDragging ? CursorTypes.RESIZE_NS : CursorTypes.POINTING_HAND);
			}
		} else {
			graphics.blitSprite(RenderPipelines.GUI_TEXTURED, SCROLLER_DISABLED_SPRITE, xo + 94, yo + 18, 6, 27);
		}
	}

	@Override
	public void extractContents(final GuiGraphicsExtractor graphics, final int mouseX, final int mouseY, final float a) {
		super.extractContents(graphics, mouseX, mouseY, a);
		MerchantOffers offers = this.menu.getOffers();
		if (!offers.isEmpty()) {
			int xo = (this.width - this.imageWidth) / 2;
			int yo = (this.height - this.imageHeight) / 2;
			int offerY = yo + 16 + 1;
			int sellItem1X = xo + 5 + 5;
			this.extractScroller(graphics, xo, yo, mouseX, mouseY, offers);
			int currentOfferIndex = 0;

			for (MerchantOffer offer : offers) {
				if (!this.canScroll(offers.size()) || currentOfferIndex >= this.scrollOff && currentOfferIndex < 7 + this.scrollOff) {
					ItemStack baseCostA = offer.getBaseCostA();
					ItemStack costA = offer.getCostA();
					ItemStack costB = offer.getCostB();
					ItemStack result = offer.getResult();
					int decorHeight = offerY + 2;
					this.extractAndDecorateCostA(graphics, costA, baseCostA, sellItem1X, decorHeight);
					if (!costB.isEmpty()) {
						graphics.fakeItem(costB, xo + 5 + 35, decorHeight);
						graphics.itemDecorations(this.font, costB, xo + 5 + 35, decorHeight);
					}

					this.extractButtonArrows(graphics, offer, xo, decorHeight);
					graphics.fakeItem(result, xo + 5 + 68, decorHeight);
					graphics.itemDecorations(this.font, result, xo + 5 + 68, decorHeight);
					offerY += 20;
					currentOfferIndex++;
				} else {
					currentOfferIndex++;
				}
			}

			int itemIndex = this.shopItem;
			MerchantOffer selectedOffer = (MerchantOffer)offers.get(itemIndex);
			if (this.menu.showProgressBar()) {
				this.extractProgressBar(graphics, xo, yo, selectedOffer);
			}

			if (selectedOffer.isOutOfStock() && this.isHovering(186, 35, 22, 21, mouseX, mouseY) && this.menu.canRestock()) {
				graphics.setTooltipForNextFrame(this.font, DEPRECATED_TOOLTIP, mouseX, mouseY);
			}

			for (MerchantScreen.TradeOfferButton button : this.tradeOfferButtons) {
				if (button.isHoveredOrFocused()) {
					button.extractToolTip(graphics, mouseX, mouseY);
				}

				button.visible = button.index < this.menu.getOffers().size();
			}
		}
	}

	private void extractButtonArrows(final GuiGraphicsExtractor graphics, final MerchantOffer offer, final int xo, final int decorHeight) {
		if (offer.isOutOfStock()) {
			graphics.blitSprite(RenderPipelines.GUI_TEXTURED, TRADE_ARROW_OUT_OF_STOCK_SPRITE, xo + 5 + 35 + 20, decorHeight + 3, 10, 9);
		} else {
			graphics.blitSprite(RenderPipelines.GUI_TEXTURED, TRADE_ARROW_SPRITE, xo + 5 + 35 + 20, decorHeight + 3, 10, 9);
		}
	}

	private void extractAndDecorateCostA(
		final GuiGraphicsExtractor graphics, final ItemStack costA, final ItemStack baseCostA, final int sellItem1X, final int decorHeight
	) {
		graphics.fakeItem(costA, sellItem1X, decorHeight);
		if (baseCostA.getCount() == costA.getCount()) {
			graphics.itemDecorations(this.font, costA, sellItem1X, decorHeight);
		} else {
			graphics.itemDecorations(this.font, baseCostA, sellItem1X, decorHeight, baseCostA.getCount() == 1 ? "1" : null);
			graphics.itemDecorations(this.font, costA, sellItem1X + 14, decorHeight, costA.getCount() == 1 ? "1" : null);
			graphics.blitSprite(RenderPipelines.GUI_TEXTURED, DISCOUNT_STRIKETHRUOGH_SPRITE, sellItem1X + 7, decorHeight + 12, 9, 2);
		}
	}

	private boolean canScroll(final int numberOfOffers) {
		return numberOfOffers > 7;
	}

	@Override
	public boolean mouseScrolled(final double x, final double y, final double scrollX, final double scrollY) {
		if (super.mouseScrolled(x, y, scrollX, scrollY)) {
			return true;
		} else {
			int numberOfOffers = this.menu.getOffers().size();
			if (this.canScroll(numberOfOffers)) {
				int maxScrollOff = numberOfOffers - 7;
				this.scrollOff = Mth.clamp((int)(this.scrollOff - scrollY), 0, maxScrollOff);
			}

			return true;
		}
	}

	@Override
	public boolean mouseDragged(final MouseButtonEvent event, final double dx, final double dy) {
		int numberOfOffers = this.menu.getOffers().size();
		if (this.isDragging) {
			int fullScrollTopPos = this.topPos + 18;
			int fullScrollBottomPos = fullScrollTopPos + 139;
			int maxScrollOff = numberOfOffers - 7;
			float scrolling = ((float)event.y() - fullScrollTopPos - 13.5F) / (fullScrollBottomPos - fullScrollTopPos - 27.0F);
			scrolling = scrolling * maxScrollOff + 0.5F;
			this.scrollOff = Mth.clamp((int)scrolling, 0, maxScrollOff);
			return true;
		} else {
			return super.mouseDragged(event, dx, dy);
		}
	}

	@Override
	public boolean mouseClicked(final MouseButtonEvent event, final boolean doubleClick) {
		int xo = (this.width - this.imageWidth) / 2;
		int yo = (this.height - this.imageHeight) / 2;
		if (this.canScroll(this.menu.getOffers().size()) && event.x() > xo + 94 && event.x() < xo + 94 + 6 && event.y() > yo + 18 && event.y() <= yo + 18 + 139 + 1) {
			this.isDragging = true;
		}

		return super.mouseClicked(event, doubleClick);
	}

	@Override
	public boolean mouseReleased(final MouseButtonEvent event) {
		this.isDragging = false;
		return super.mouseReleased(event);
	}

	private class TradeOfferButton extends Plain {
		private final int index;

		public TradeOfferButton(final int x, final int y, final int index, final OnPress onPress) {
			Objects.requireNonNull(MerchantScreen.this);
			super(x, y, 88, 20, CommonComponents.EMPTY, onPress, DEFAULT_NARRATION);
			this.index = index;
			this.visible = false;
		}

		public int getIndex() {
			return this.index;
		}

		public void extractToolTip(final GuiGraphicsExtractor graphics, final int xm, final int ym) {
			if (this.isHovered && MerchantScreen.this.menu.getOffers().size() > this.index + MerchantScreen.this.scrollOff) {
				if (xm < this.getX() + 20) {
					ItemStack item = ((MerchantOffer)MerchantScreen.this.menu.getOffers().get(this.index + MerchantScreen.this.scrollOff)).getCostA();
					graphics.setTooltipForNextFrame(MerchantScreen.this.font, item, xm, ym);
				} else if (xm < this.getX() + 50 && xm > this.getX() + 30) {
					ItemStack item = ((MerchantOffer)MerchantScreen.this.menu.getOffers().get(this.index + MerchantScreen.this.scrollOff)).getCostB();
					if (!item.isEmpty()) {
						graphics.setTooltipForNextFrame(MerchantScreen.this.font, item, xm, ym);
					}
				} else if (xm > this.getX() + 65) {
					ItemStack item = ((MerchantOffer)MerchantScreen.this.menu.getOffers().get(this.index + MerchantScreen.this.scrollOff)).getResult();
					graphics.setTooltipForNextFrame(MerchantScreen.this.font, item, xm, ym);
				}
			}
		}
	}
}