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

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

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

	@Nullable
	public Monitor findBestMonitor(final Window window) {
		long windowMonitor = GLFW.glfwGetWindowMonitor(window.handle());
		if (windowMonitor != 0L) {
			return this.getMonitor(windowMonitor);
		} else {
			int winMinX = window.getX();
			int winMaxX = winMinX + window.getScreenWidth();
			int winMinY = window.getY();
			int winMaxY = winMinY + window.getScreenHeight();
			int maxArea = -1;
			Monitor result = null;
			long primaryMonitor = GLFW.glfwGetPrimaryMonitor();
			LOGGER.debug("Selecting monitor - primary: {}, current monitors: {}", primaryMonitor, this.monitors);

			for (Monitor monitor : this.monitors.values()) {
				int monMinX = monitor.getX();
				int monMaxX = monMinX + monitor.getCurrentMode().getWidth();
				int monMinY = monitor.getY();
				int monMaxY = monMinY + monitor.getCurrentMode().getHeight();
				int minX = clamp(winMinX, monMinX, monMaxX);
				int maxX = clamp(winMaxX, monMinX, monMaxX);
				int minY = clamp(winMinY, monMinY, monMaxY);
				int maxY = clamp(winMaxY, monMinY, monMaxY);
				int sx = Math.max(0, maxX - minX);
				int sy = Math.max(0, maxY - minY);
				int area = sx * sy;
				if (area > maxArea) {
					result = monitor;
					maxArea = area;
				} else if (area == maxArea && primaryMonitor == monitor.getMonitor()) {
					LOGGER.debug("Primary monitor {} is preferred to monitor {}", monitor, result);
					result = monitor;
				}
			}

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

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

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