package com.mojang.blaze3d.platform;

import com.mojang.blaze3d.systems.RenderSystem;
import com.mojang.logging.LogUtils;
import it.unimi.dsi.fastutil.longs.Long2ObjectMap;
import it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap;
import net.fabricmc.api.EnvType;
import net.fabricmc.api.Environment;
import org.jetbrains.annotations.Nullable;
import org.lwjgl.PointerBuffer;
import org.lwjgl.glfw.GLFW;
import org.lwjgl.glfw.GLFWMonitorCallback;
import org.slf4j.Logger;

@Environment(EnvType.CLIENT)
public class ScreenManager {
	private static final Logger LOGGER = LogUtils.getLogger();
	private final Long2ObjectMap<Monitor> monitors = new Long2ObjectOpenHashMap<>();
	private final MonitorCreator monitorCreator;

	public ScreenManager(MonitorCreator monitorCreator) {
		this.monitorCreator = monitorCreator;
		GLFW.glfwSetMonitorCallback(this::onMonitorChange);
		PointerBuffer pointerBuffer = GLFW.glfwGetMonitors();
		if (pointerBuffer != null) {
			for (int i = 0; i < pointerBuffer.limit(); i++) {
				long l = pointerBuffer.get(i);
				this.monitors.put(l, monitorCreator.createMonitor(l));
			}
		}
	}

	private void onMonitorChange(long monitorID, int opCode) {
		RenderSystem.assertOnRenderThread();
		if (opCode == 262145) {
			this.monitors.put(monitorID, this.monitorCreator.createMonitor(monitorID));
			LOGGER.debug("Monitor {} connected. Current monitors: {}", monitorID, this.monitors);
		} else if (opCode == 262146) {
			this.monitors.remove(monitorID);
			LOGGER.debug("Monitor {} disconnected. Current monitors: {}", monitorID, this.monitors);
		}
	}

	@Nullable
	public Monitor getMonitor(long monitorID) {
		return this.monitors.get(monitorID);
	}

	@Nullable
	public Monitor findBestMonitor(Window window) {
		long l = GLFW.glfwGetWindowMonitor(window.getWindow());
		if (l != 0L) {
			return this.getMonitor(l);
		} else {
			int i = window.getX();
			int j = i + window.getScreenWidth();
			int k = window.getY();
			int m = k + window.getScreenHeight();
			int n = -1;
			Monitor monitor = null;
			long o = GLFW.glfwGetPrimaryMonitor();
			LOGGER.debug("Selecting monitor - primary: {}, current monitors: {}", o, this.monitors);

			for (Monitor monitor2 : this.monitors.values()) {
				int p = monitor2.getX();
				int q = p + monitor2.getCurrentMode().getWidth();
				int r = monitor2.getY();
				int s = r + monitor2.getCurrentMode().getHeight();
				int t = clamp(i, p, q);
				int u = clamp(j, p, q);
				int v = clamp(k, r, s);
				int w = clamp(m, r, s);
				int x = Math.max(0, u - t);
				int y = Math.max(0, w - v);
				int z = x * y;
				if (z > n) {
					monitor = monitor2;
					n = z;
				} else if (z == n && o == monitor2.getMonitor()) {
					LOGGER.debug("Primary monitor {} is preferred to monitor {}", monitor2, monitor);
					monitor = monitor2;
				}
			}

			LOGGER.debug("Selected monitor: {}", monitor);
			return monitor;
		}
	}

	public static int clamp(int value, int min, int max) {
		if (value < min) {
			return min;
		} else {
			return value > max ? max : value;
		}
	}

	public void shutdown() {
		RenderSystem.assertOnRenderThread();
		GLFWMonitorCallback gLFWMonitorCallback = GLFW.glfwSetMonitorCallback(null);
		if (gLFWMonitorCallback != null) {
			gLFWMonitorCallback.free();
		}
	}
}