package me.xmrvizzy.skyblocker.utils;

import com.mojang.brigadier.Command;
import me.xmrvizzy.skyblocker.SkyblockerMod;
import net.fabricmc.fabric.api.client.command.v2.FabricClientCommandSource;
import net.minecraft.client.MinecraftClient;
import net.minecraft.client.gui.screen.Screen;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.PriorityQueue;
import java.util.function.Supplier;

/**
 * A scheduler for running tasks at a later time. Tasks will be run synchronously on the main client thread. Use the instance stored in {@link SkyblockerMod#scheduler}. Do not instantiate this class.
 */
public class Scheduler {
    private static final Logger LOGGER = LoggerFactory.getLogger(Scheduler.class);
    private int currentTick = 0;
    private final PriorityQueue<ScheduledTask> tasks = new PriorityQueue<>();

    /**
     * Do not instantiate this class. Use {@link SkyblockerMod#scheduler} instead.
     */
    @SuppressWarnings("DeprecatedIsStillUsed")
    @Deprecated
    public Scheduler() {
    }

    /**
     * Schedules a task to run after a delay.
     *
     * @param task  the task to run
     * @param delay the delay in ticks
     */
    public void schedule(Runnable task, int delay) {
        if (delay < 0) {
            LOGGER.warn("Scheduled a task with negative delay");
        }
        ScheduledTask tmp = new ScheduledTask(task, currentTick + delay);
        tasks.add(tmp);
    }

    /**
     * Schedules a task to run every period ticks.
     *
     * @param task   the task to run
     * @param period the period in ticks
     */
    public void scheduleCyclic(Runnable task, int period) {
        if (period <= 0) {
            LOGGER.error("Attempted to schedule a cyclic task with period lower than 1");
        } else {
            new CyclicTask(task, period).run();
        }
    }

    public static Command<FabricClientCommandSource> queueOpenScreenCommand(Supplier<Screen> screenSupplier) {
        return context -> SkyblockerMod.getInstance().scheduler.queueOpenScreen(screenSupplier);
    }

    /**
     * Schedules a screen to open in the next tick. Used in commands to avoid screen immediately closing after the command is executed.
     *
     * @param screenSupplier the supplier of the screen to open
     * @see #queueOpenScreenCommand(Supplier)
     */
    public int queueOpenScreen(Supplier<Screen> screenSupplier) {
        MinecraftClient.getInstance().send(() -> MinecraftClient.getInstance().setScreen(screenSupplier.get()));
        return Command.SINGLE_SUCCESS;
    }

    public void tick() {
        currentTick += 1;
        ScheduledTask task;
        while ((task = tasks.peek()) != null && task.schedule <= currentTick && runTask(task)) {
            tasks.poll();
        }
    }

    /**
     * Runs the task if able.
     *
     * @param task the task to run
     * @return {@code true} if the task is run, and {@link false} if task is not run.
     */
    protected boolean runTask(Runnable task) {
        task.run();
        return true;
    }

    /**
     * A task that runs every period ticks. More specifically, this task reschedules itself to run again after period ticks every time it runs.
     *
     * @param inner  the task to run
     * @param period the period in ticks
     */
    protected record CyclicTask(Runnable inner, int period) implements Runnable {
        @Override
        public void run() {
            SkyblockerMod.getInstance().scheduler.schedule(this, period);
            inner.run();
        }
    }

    /**
     * A task that runs at a specific tick, relative to {@link #currentTick}.
     *
     * @param inner    the task to run
     * @param schedule the tick to run at
     */
    protected record ScheduledTask(Runnable inner, int schedule) implements Comparable<ScheduledTask>, Runnable {
        @Override
        public int compareTo(ScheduledTask o) {
            return schedule - o.schedule;
        }

        @Override
        public void run() {
            inner.run();
        }
    }
}