package com.mojang.blaze3d.platform;

import net.fabricmc.api.EnvType;
import net.fabricmc.api.Environment;
import net.minecraft.Util;
import net.minecraft.client.InactivityFpsLimit;
import net.minecraft.client.Minecraft;
import net.minecraft.client.Options;

@Environment(EnvType.CLIENT)
public class FramerateLimitTracker {
	private static final int OUT_OF_LEVEL_MENU_LIMIT = 60;
	private static final int ICONIFIED_WINDOW_LIMIT = 10;
	private static final int AFK_LIMIT = 30;
	private static final int LONG_AFK_LIMIT = 10;
	private static final long AFK_THRESHOLD_MS = 60000L;
	private static final long LONG_AFK_THRESHOLD_MS = 600000L;
	private final Options options;
	private final Minecraft minecraft;
	private int framerateLimit;
	private long latestInputTime;

	public FramerateLimitTracker(Options options, Minecraft minecraft) {
		this.options = options;
		this.minecraft = minecraft;
		this.framerateLimit = options.framerateLimit().get();
	}

	public int getFramerateLimit() {
		return switch (this.getThrottleReason()) {
			case NONE -> this.framerateLimit;
			case WINDOW_ICONIFIED -> 10;
			case LONG_AFK -> 10;
			case SHORT_AFK -> Math.min(this.framerateLimit, 30);
			case OUT_OF_LEVEL_MENU -> 60;
		};
	}

	public FramerateLimitTracker.FramerateThrottleReason getThrottleReason() {
		InactivityFpsLimit inactivityFpsLimit = this.options.inactivityFpsLimit().get();
		if (this.minecraft.getWindow().isIconified()) {
			return FramerateLimitTracker.FramerateThrottleReason.WINDOW_ICONIFIED;
		} else {
			if (inactivityFpsLimit == InactivityFpsLimit.AFK) {
				long l = Util.getMillis() - this.latestInputTime;
				if (l > 600000L) {
					return FramerateLimitTracker.FramerateThrottleReason.LONG_AFK;
				}

				if (l > 60000L) {
					return FramerateLimitTracker.FramerateThrottleReason.SHORT_AFK;
				}
			}

			return this.minecraft.level != null || this.minecraft.screen == null && this.minecraft.getOverlay() == null
				? FramerateLimitTracker.FramerateThrottleReason.NONE
				: FramerateLimitTracker.FramerateThrottleReason.OUT_OF_LEVEL_MENU;
		}
	}

	public boolean isHeavilyThrottled() {
		FramerateLimitTracker.FramerateThrottleReason framerateThrottleReason = this.getThrottleReason();
		return framerateThrottleReason == FramerateLimitTracker.FramerateThrottleReason.WINDOW_ICONIFIED
			|| framerateThrottleReason == FramerateLimitTracker.FramerateThrottleReason.LONG_AFK;
	}

	public void setFramerateLimit(int framerateLimit) {
		this.framerateLimit = framerateLimit;
	}

	public void onInputReceived() {
		this.latestInputTime = Util.getMillis();
	}

	@Environment(EnvType.CLIENT)
	public static enum FramerateThrottleReason {
		NONE,
		WINDOW_ICONIFIED,
		LONG_AFK,
		SHORT_AFK,
		OUT_OF_LEVEL_MENU;
	}
}