package net.minecraft.world.item.crafting;

import com.google.common.annotations.VisibleForTesting;
import com.mojang.serialization.Codec;
import com.mojang.serialization.DataResult;
import com.mojang.serialization.MapCodec;
import com.mojang.serialization.codecs.RecordCodecBuilder;
import it.unimi.dsi.fastutil.chars.CharArraySet;
import it.unimi.dsi.fastutil.chars.CharSet;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.function.Function;
import net.minecraft.Util;
import net.minecraft.core.NonNullList;
import net.minecraft.network.RegistryFriendlyByteBuf;
import net.minecraft.network.codec.StreamCodec;
import net.minecraft.util.ExtraCodecs;
import net.minecraft.world.item.ItemStack;

public final class ShapedRecipePattern {
	private static final int MAX_SIZE = 3;
	public static final MapCodec<ShapedRecipePattern> MAP_CODEC = ShapedRecipePattern.Data.MAP_CODEC
		.flatXmap(
			ShapedRecipePattern::unpack,
			shapedRecipePattern -> (DataResult)shapedRecipePattern.data
				.map(DataResult::success)
				.orElseGet(() -> DataResult.error(() -> "Cannot encode unpacked recipe"))
		);
	public static final StreamCodec<RegistryFriendlyByteBuf, ShapedRecipePattern> STREAM_CODEC = StreamCodec.ofMember(
		ShapedRecipePattern::toNetwork, ShapedRecipePattern::fromNetwork
	);
	private final int width;
	private final int height;
	private final NonNullList<Ingredient> ingredients;
	private final Optional<ShapedRecipePattern.Data> data;
	private final int ingredientCount;
	private final boolean symmetrical;

	public ShapedRecipePattern(int width, int height, NonNullList<Ingredient> ingredients, Optional<ShapedRecipePattern.Data> data) {
		this.width = width;
		this.height = height;
		this.ingredients = ingredients;
		this.data = data;
		int i = 0;

		for (Ingredient ingredient : ingredients) {
			if (!ingredient.isEmpty()) {
				i++;
			}
		}

		this.ingredientCount = i;
		this.symmetrical = Util.isSymmetrical(width, height, ingredients);
	}

	public static ShapedRecipePattern of(Map<Character, Ingredient> key, String... pattern) {
		return of(key, List.of(pattern));
	}

	public static ShapedRecipePattern of(Map<Character, Ingredient> key, List<String> pattern) {
		ShapedRecipePattern.Data data = new ShapedRecipePattern.Data(key, pattern);
		return unpack(data).getOrThrow();
	}

	private static DataResult<ShapedRecipePattern> unpack(ShapedRecipePattern.Data data) {
		String[] strings = shrink(data.pattern);
		int i = strings[0].length();
		int j = strings.length;
		NonNullList<Ingredient> nonNullList = NonNullList.withSize(i * j, Ingredient.EMPTY);
		CharSet charSet = new CharArraySet(data.key.keySet());

		for (int k = 0; k < strings.length; k++) {
			String string = strings[k];

			for (int l = 0; l < string.length(); l++) {
				char c = string.charAt(l);
				Ingredient ingredient = c == ' ' ? Ingredient.EMPTY : (Ingredient)data.key.get(c);
				if (ingredient == null) {
					return DataResult.error(() -> "Pattern references symbol '" + c + "' but it's not defined in the key");
				}

				charSet.remove(c);
				nonNullList.set(l + i * k, ingredient);
			}
		}

		return !charSet.isEmpty()
			? DataResult.error(() -> "Key defines symbols that aren't used in pattern: " + charSet)
			: DataResult.success(new ShapedRecipePattern(i, j, nonNullList, Optional.of(data)));
	}

	@VisibleForTesting
	static String[] shrink(List<String> pattern) {
		int i = Integer.MAX_VALUE;
		int j = 0;
		int k = 0;
		int l = 0;

		for (int m = 0; m < pattern.size(); m++) {
			String string = (String)pattern.get(m);
			i = Math.min(i, firstNonSpace(string));
			int n = lastNonSpace(string);
			j = Math.max(j, n);
			if (n < 0) {
				if (k == m) {
					k++;
				}

				l++;
			} else {
				l = 0;
			}
		}

		if (pattern.size() == l) {
			return new String[0];
		} else {
			String[] strings = new String[pattern.size() - l - k];

			for (int o = 0; o < strings.length; o++) {
				strings[o] = ((String)pattern.get(o + k)).substring(i, j + 1);
			}

			return strings;
		}
	}

	private static int firstNonSpace(String row) {
		int i = 0;

		while (i < row.length() && row.charAt(i) == ' ') {
			i++;
		}

		return i;
	}

	private static int lastNonSpace(String row) {
		int i = row.length() - 1;

		while (i >= 0 && row.charAt(i) == ' ') {
			i--;
		}

		return i;
	}

	public boolean matches(CraftingInput input) {
		if (input.ingredientCount() != this.ingredientCount) {
			return false;
		} else {
			if (input.width() == this.width && input.height() == this.height) {
				if (!this.symmetrical && this.matches(input, true)) {
					return true;
				}

				if (this.matches(input, false)) {
					return true;
				}
			}

			return false;
		}
	}

	private boolean matches(CraftingInput input, boolean symmetrical) {
		for (int i = 0; i < this.height; i++) {
			for (int j = 0; j < this.width; j++) {
				Ingredient ingredient;
				if (symmetrical) {
					ingredient = this.ingredients.get(this.width - j - 1 + i * this.width);
				} else {
					ingredient = this.ingredients.get(j + i * this.width);
				}

				ItemStack itemStack = input.getItem(j, i);
				if (!ingredient.test(itemStack)) {
					return false;
				}
			}
		}

		return true;
	}

	private void toNetwork(RegistryFriendlyByteBuf buffer) {
		buffer.writeVarInt(this.width);
		buffer.writeVarInt(this.height);

		for (Ingredient ingredient : this.ingredients) {
			Ingredient.CONTENTS_STREAM_CODEC.encode(buffer, ingredient);
		}
	}

	private static ShapedRecipePattern fromNetwork(RegistryFriendlyByteBuf buffer) {
		int i = buffer.readVarInt();
		int j = buffer.readVarInt();
		NonNullList<Ingredient> nonNullList = NonNullList.withSize(i * j, Ingredient.EMPTY);
		nonNullList.replaceAll(ingredient -> Ingredient.CONTENTS_STREAM_CODEC.decode(buffer));
		return new ShapedRecipePattern(i, j, nonNullList, Optional.empty());
	}

	public int width() {
		return this.width;
	}

	public int height() {
		return this.height;
	}

	public NonNullList<Ingredient> ingredients() {
		return this.ingredients;
	}

	public record Data(Map<Character, Ingredient> key, List<String> pattern) {
		private static final Codec<List<String>> PATTERN_CODEC = Codec.STRING.listOf().comapFlatMap(list -> {
			if (list.size() > 3) {
				return DataResult.error(() -> "Invalid pattern: too many rows, 3 is maximum");
			} else if (list.isEmpty()) {
				return DataResult.error(() -> "Invalid pattern: empty pattern not allowed");
			} else {
				int i = ((String)list.getFirst()).length();

				for (String string : list) {
					if (string.length() > 3) {
						return DataResult.error(() -> "Invalid pattern: too many columns, 3 is maximum");
					}

					if (i != string.length()) {
						return DataResult.error(() -> "Invalid pattern: each row must be the same width");
					}
				}

				return DataResult.success(list);
			}
		}, Function.identity());
		private static final Codec<Character> SYMBOL_CODEC = Codec.STRING.comapFlatMap(string -> {
			if (string.length() != 1) {
				return DataResult.error(() -> "Invalid key entry: '" + string + "' is an invalid symbol (must be 1 character only).");
			} else {
				return " ".equals(string) ? DataResult.error(() -> "Invalid key entry: ' ' is a reserved symbol.") : DataResult.success(string.charAt(0));
			}
		}, String::valueOf);
		public static final MapCodec<ShapedRecipePattern.Data> MAP_CODEC = RecordCodecBuilder.mapCodec(
			instance -> instance.group(
					ExtraCodecs.strictUnboundedMap(SYMBOL_CODEC, Ingredient.CODEC_NONEMPTY).fieldOf("key").forGetter(data -> data.key),
					PATTERN_CODEC.fieldOf("pattern").forGetter(data -> data.pattern)
				)
				.apply(instance, ShapedRecipePattern.Data::new)
		);
	}
}