package net.minecraft.commands.arguments;

import com.mojang.brigadier.StringReader;
import com.mojang.brigadier.arguments.ArgumentType;
import com.mojang.brigadier.context.CommandContext;
import com.mojang.brigadier.exceptions.CommandSyntaxException;
import com.mojang.brigadier.exceptions.SimpleCommandExceptionType;
import com.mojang.brigadier.suggestion.Suggestions;
import com.mojang.brigadier.suggestion.SuggestionsBuilder;
import java.util.Arrays;
import java.util.Collection;
import java.util.concurrent.CompletableFuture;
import net.minecraft.commands.CommandSourceStack;
import net.minecraft.commands.SharedSuggestionProvider;
import net.minecraft.network.chat.Component;
import net.minecraft.util.Mth;
import net.minecraft.world.scores.ScoreAccess;

public class OperationArgument implements ArgumentType<OperationArgument.Operation> {
	private static final Collection<String> EXAMPLES = Arrays.asList("=", ">", "<");
	private static final SimpleCommandExceptionType ERROR_INVALID_OPERATION = new SimpleCommandExceptionType(Component.translatable("arguments.operation.invalid"));
	private static final SimpleCommandExceptionType ERROR_DIVIDE_BY_ZERO = new SimpleCommandExceptionType(Component.translatable("arguments.operation.div0"));

	public static OperationArgument operation() {
		return new OperationArgument();
	}

	public static OperationArgument.Operation getOperation(CommandContext<CommandSourceStack> context, String name) {
		return context.getArgument(name, OperationArgument.Operation.class);
	}

	public OperationArgument.Operation parse(StringReader reader) throws CommandSyntaxException {
		if (!reader.canRead()) {
			throw ERROR_INVALID_OPERATION.createWithContext(reader);
		} else {
			int i = reader.getCursor();

			while (reader.canRead() && reader.peek() != ' ') {
				reader.skip();
			}

			return getOperation(reader.getString().substring(i, reader.getCursor()));
		}
	}

	@Override
	public <S> CompletableFuture<Suggestions> listSuggestions(CommandContext<S> commandContext, SuggestionsBuilder suggestionsBuilder) {
		return SharedSuggestionProvider.suggest(new String[]{"=", "+=", "-=", "*=", "/=", "%=", "<", ">", "><"}, suggestionsBuilder);
	}

	@Override
	public Collection<String> getExamples() {
		return EXAMPLES;
	}

	/**
	 * Makes an {@link net.minecraft.commands.arguments.OperationArgument.Operation} instance based on the given name. This method handles all operations.
	 */
	private static OperationArgument.Operation getOperation(String name) throws CommandSyntaxException {
		return (OperationArgument.Operation)(name.equals("><") ? (scoreAccess, scoreAccess2) -> {
			int i = scoreAccess.get();
			scoreAccess.set(scoreAccess2.get());
			scoreAccess2.set(i);
		} : getSimpleOperation(name));
	}

	/**
	 * Makes an {@link net.minecraft.commands.arguments.OperationArgument.Operation} instance based on the given name. This method actually returns {@link net.minecraft.commands.arguments.OperationArgument.SimpleOperation}, which is used as a functional interface target with 2 ints. It handles all operations other than swap (><).
	 */
	private static OperationArgument.SimpleOperation getSimpleOperation(String name) throws CommandSyntaxException {
		return switch (name) {
			case "=" -> (i, j) -> j;
			case "+=" -> Integer::sum;
			case "-=" -> (i, j) -> i - j;
			case "*=" -> (i, j) -> i * j;
			case "/=" -> (i, j) -> {
				if (j == 0) {
					throw ERROR_DIVIDE_BY_ZERO.create();
				} else {
					return Mth.floorDiv(i, j);
				}
			};
			case "%=" -> (i, j) -> {
				if (j == 0) {
					throw ERROR_DIVIDE_BY_ZERO.create();
				} else {
					return Mth.positiveModulo(i, j);
				}
			};
			case "<" -> Math::min;
			case ">" -> Math::max;
			default -> throw ERROR_INVALID_OPERATION.create();
		};
	}

	@FunctionalInterface
	public interface Operation {
		void apply(ScoreAccess scoreAccess, ScoreAccess scoreAccess2) throws CommandSyntaxException;
	}

	@FunctionalInterface
	interface SimpleOperation extends OperationArgument.Operation {
		int apply(int i, int j) throws CommandSyntaxException;

		@Override
		default void apply(ScoreAccess scoreAccess, ScoreAccess scoreAccess2) throws CommandSyntaxException {
			scoreAccess.set(this.apply(scoreAccess.get(), scoreAccess2.get()));
		}
	}
}