package net.minecraft.commands.execution.tasks;

import java.util.List;
import net.minecraft.commands.execution.CommandQueueEntry;
import net.minecraft.commands.execution.EntryAction;
import net.minecraft.commands.execution.ExecutionContext;
import net.minecraft.commands.execution.Frame;

public class ContinuationTask<T, P> implements EntryAction<T> {
	private final ContinuationTask.TaskProvider<T, P> taskFactory;
	private final List<P> arguments;
	private final CommandQueueEntry<T> selfEntry;
	private int index;

	private ContinuationTask(final ContinuationTask.TaskProvider<T, P> taskFactory, final List<P> arguments, final Frame frame) {
		this.taskFactory = taskFactory;
		this.arguments = arguments;
		this.selfEntry = new CommandQueueEntry<>(frame, this);
	}

	@Override
	public void execute(final ExecutionContext<T> context, final Frame frame) {
		P argument = (P)this.arguments.get(this.index);
		context.queueNext(this.taskFactory.create(frame, argument));
		if (++this.index < this.arguments.size()) {
			context.queueNext(this.selfEntry);
		}
	}

	public static <T, P> void schedule(
		final ExecutionContext<T> context, final Frame frame, final List<P> arguments, final ContinuationTask.TaskProvider<T, P> taskFactory
	) {
		int argumentCount = arguments.size();
		switch (argumentCount) {
			case 0:
				break;
			case 1:
				context.queueNext(taskFactory.create(frame, (P)arguments.get(0)));
				break;
			case 2:
				context.queueNext(taskFactory.create(frame, (P)arguments.get(0)));
				context.queueNext(taskFactory.create(frame, (P)arguments.get(1)));
				break;
			default:
				context.queueNext((new ContinuationTask<>(taskFactory, arguments, frame)).selfEntry);
		}
	}

	@FunctionalInterface
	public interface TaskProvider<T, P> {
		CommandQueueEntry<T> create(Frame frame, P argument);
	}
}