package net.minecraft.world.level.block.entity;

import net.minecraft.commands.CommandSource;
import net.minecraft.commands.CommandSourceStack;
import net.minecraft.core.BlockPos;
import net.minecraft.core.HolderLookup;
import net.minecraft.core.component.DataComponents;
import net.minecraft.nbt.CompoundTag;
import net.minecraft.network.chat.Component;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.util.Mth;
import net.minecraft.world.Clearable;
import net.minecraft.world.Container;
import net.minecraft.world.MenuProvider;
import net.minecraft.world.entity.player.Inventory;
import net.minecraft.world.entity.player.Player;
import net.minecraft.world.inventory.AbstractContainerMenu;
import net.minecraft.world.inventory.ContainerData;
import net.minecraft.world.inventory.LecternMenu;
import net.minecraft.world.item.ItemStack;
import net.minecraft.world.item.WrittenBookItem;
import net.minecraft.world.item.component.WritableBookContent;
import net.minecraft.world.item.component.WrittenBookContent;
import net.minecraft.world.level.block.LecternBlock;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.phys.Vec2;
import net.minecraft.world.phys.Vec3;
import org.jetbrains.annotations.Nullable;

public class LecternBlockEntity extends BlockEntity implements Clearable, MenuProvider {
	public static final int DATA_PAGE = 0;
	public static final int NUM_DATA = 1;
	public static final int SLOT_BOOK = 0;
	public static final int NUM_SLOTS = 1;
	private final Container bookAccess = new Container() {
		@Override
		public int getContainerSize() {
			return 1;
		}

		@Override
		public boolean isEmpty() {
			return LecternBlockEntity.this.book.isEmpty();
		}

		@Override
		public ItemStack getItem(int slot) {
			return slot == 0 ? LecternBlockEntity.this.book : ItemStack.EMPTY;
		}

		@Override
		public ItemStack removeItem(int slot, int amount) {
			if (slot == 0) {
				ItemStack itemStack = LecternBlockEntity.this.book.split(amount);
				if (LecternBlockEntity.this.book.isEmpty()) {
					LecternBlockEntity.this.onBookItemRemove();
				}

				return itemStack;
			} else {
				return ItemStack.EMPTY;
			}
		}

		@Override
		public ItemStack removeItemNoUpdate(int slot) {
			if (slot == 0) {
				ItemStack itemStack = LecternBlockEntity.this.book;
				LecternBlockEntity.this.book = ItemStack.EMPTY;
				LecternBlockEntity.this.onBookItemRemove();
				return itemStack;
			} else {
				return ItemStack.EMPTY;
			}
		}

		@Override
		public void setItem(int slot, ItemStack stack) {
		}

		@Override
		public int getMaxStackSize() {
			return 1;
		}

		@Override
		public void setChanged() {
			LecternBlockEntity.this.setChanged();
		}

		@Override
		public boolean stillValid(Player player) {
			return Container.stillValidBlockEntity(LecternBlockEntity.this, player) && LecternBlockEntity.this.hasBook();
		}

		@Override
		public boolean canPlaceItem(int slot, ItemStack stack) {
			return false;
		}

		@Override
		public void clearContent() {
		}
	};
	private final ContainerData dataAccess = new ContainerData() {
		@Override
		public int get(int index) {
			return index == 0 ? LecternBlockEntity.this.page : 0;
		}

		@Override
		public void set(int index, int value) {
			if (index == 0) {
				LecternBlockEntity.this.setPage(value);
			}
		}

		@Override
		public int getCount() {
			return 1;
		}
	};
	ItemStack book = ItemStack.EMPTY;
	int page;
	private int pageCount;

	public LecternBlockEntity(BlockPos pos, BlockState blockState) {
		super(BlockEntityType.LECTERN, pos, blockState);
	}

	public ItemStack getBook() {
		return this.book;
	}

	/**
	 * @return whether the ItemStack in this lectern is a book or written book
	 */
	public boolean hasBook() {
		return this.book.has(DataComponents.WRITABLE_BOOK_CONTENT) || this.book.has(DataComponents.WRITTEN_BOOK_CONTENT);
	}

	/**
	 * Sets the ItemStack in this lectern. Note that this does not update the block state, use {@link net.minecraft.world.level.block.LecternBlock#tryPlaceBook} for that.
	 */
	public void setBook(ItemStack stack) {
		this.setBook(stack, null);
	}

	void onBookItemRemove() {
		this.page = 0;
		this.pageCount = 0;
		LecternBlock.resetBookState(null, this.getLevel(), this.getBlockPos(), this.getBlockState(), false);
	}

	/**
	 * Sets the ItemStack in this lectern. Note that this does not update the block state, use {@link net.minecraft.world.level.block.LecternBlock#tryPlaceBook} for that.
	 * 
	 * @param player the player used for resolving the components within the book
	 */
	public void setBook(ItemStack stack, @Nullable Player player) {
		this.book = this.resolveBook(stack, player);
		this.page = 0;
		this.pageCount = getPageCount(this.book);
		this.setChanged();
	}

	void setPage(int page) {
		int i = Mth.clamp(page, 0, this.pageCount - 1);
		if (i != this.page) {
			this.page = i;
			this.setChanged();
			LecternBlock.signalPageChange(this.getLevel(), this.getBlockPos(), this.getBlockState());
		}
	}

	public int getPage() {
		return this.page;
	}

	public int getRedstoneSignal() {
		float f = this.pageCount > 1 ? this.getPage() / (this.pageCount - 1.0F) : 1.0F;
		return Mth.floor(f * 14.0F) + (this.hasBook() ? 1 : 0);
	}

	/**
	 * Resolves the contents of the passed ItemStack, if it is a book
	 */
	private ItemStack resolveBook(ItemStack stack, @Nullable Player player) {
		if (this.level instanceof ServerLevel serverLevel) {
			WrittenBookItem.resolveBookComponents(stack, this.createCommandSourceStack(player, serverLevel), player);
		}

		return stack;
	}

	private CommandSourceStack createCommandSourceStack(@Nullable Player player, ServerLevel serverLevel) {
		String string;
		Component component;
		if (player == null) {
			string = "Lectern";
			component = Component.literal("Lectern");
		} else {
			string = player.getName().getString();
			component = player.getDisplayName();
		}

		Vec3 vec3 = Vec3.atCenterOf(this.worldPosition);
		return new CommandSourceStack(CommandSource.NULL, vec3, Vec2.ZERO, serverLevel, 2, string, component, serverLevel.getServer(), player);
	}

	@Override
	public boolean onlyOpCanSetNbt() {
		return true;
	}

	@Override
	protected void loadAdditional(CompoundTag tag, HolderLookup.Provider registries) {
		super.loadAdditional(tag, registries);
		if (tag.contains("Book", 10)) {
			this.book = this.resolveBook((ItemStack)ItemStack.parse(registries, tag.getCompound("Book")).orElse(ItemStack.EMPTY), null);
		} else {
			this.book = ItemStack.EMPTY;
		}

		this.pageCount = getPageCount(this.book);
		this.page = Mth.clamp(tag.getInt("Page"), 0, this.pageCount - 1);
	}

	@Override
	protected void saveAdditional(CompoundTag tag, HolderLookup.Provider registries) {
		super.saveAdditional(tag, registries);
		if (!this.getBook().isEmpty()) {
			tag.put("Book", this.getBook().save(registries));
			tag.putInt("Page", this.page);
		}
	}

	@Override
	public void clearContent() {
		this.setBook(ItemStack.EMPTY);
	}

	@Override
	public AbstractContainerMenu createMenu(int i, Inventory inventory, Player player) {
		return new LecternMenu(i, this.bookAccess, this.dataAccess);
	}

	@Override
	public Component getDisplayName() {
		return Component.translatable("container.lectern");
	}

	private static int getPageCount(ItemStack stack) {
		WrittenBookContent writtenBookContent = stack.get(DataComponents.WRITTEN_BOOK_CONTENT);
		if (writtenBookContent != null) {
			return writtenBookContent.pages().size();
		} else {
			WritableBookContent writableBookContent = stack.get(DataComponents.WRITABLE_BOOK_CONTENT);
			return writableBookContent != null ? writableBookContent.pages().size() : 0;
		}
	}
}