package chess.render;

import org.lwjgl.*;
import org.lwjgl.glfw.*;
import org.lwjgl.opengl.*;
import org.lwjgl.system.*;

import java.nio.*;

import static org.lwjgl.glfw.Callbacks.*;
import static org.lwjgl.glfw.GLFW.*;
import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.system.MemoryStack.*;
import static org.lwjgl.system.MemoryUtil.*;

public class Window {

	// The window handle
	private long window;

	private Renderer renderer;
	private Camera cam;

	public Window() {
		this.renderer = new Renderer();
		this.cam = new Camera();
	}

	public void run() {
		System.out.println("LWJGL " + Version.getVersion() + "!");

		init();
		loop();

		// Free the window callbacks and destroy the window
		glfwFreeCallbacks(window);
		glfwDestroyWindow(window);

		// Terminate GLFW and free the error callback
		glfwTerminate();
		glfwSetErrorCallback(null).free();
	}

	private void init() {
		// Setup an error callback. The default implementation
		// will print the error message in System.err.
		GLFWErrorCallback.createPrint(System.err).set();

		// Initialize GLFW. Most GLFW functions will not work before doing this.
		if (!glfwInit())
			throw new IllegalStateException("Unable to initialize GLFW");

		// Configure GLFW
		glfwDefaultWindowHints(); // optional, the current window hints are already the default
		glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE); // the window will stay hidden after creation
		glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE); // the window will be resizable

		// Create the window
		window = glfwCreateWindow(1000, 1000, "Chess4J", NULL, NULL);
		if (window == NULL)
			throw new RuntimeException("Failed to create the GLFW window");

		// Get the thread stack and push a new frame
		try (MemoryStack stack = stackPush()) {
			IntBuffer pWidth = stack.mallocInt(1); // int*
			IntBuffer pHeight = stack.mallocInt(1); // int*

			// Get the window size passed to glfwCreateWindow
			glfwGetWindowSize(window, pWidth, pHeight);

			// Get the resolution of the primary monitor
			GLFWVidMode vidmode = glfwGetVideoMode(glfwGetPrimaryMonitor());

			// Center the window
			glfwSetWindowPos(
					window,
					(vidmode.width() - pWidth.get(0)) / 2,
					(vidmode.height() - pHeight.get(0)) / 2);
		} // the stack frame is popped automatically

		// Make the OpenGL context current
		glfwMakeContextCurrent(window);
		// Enable v-sync
		glfwSwapInterval(1);

		// Make the window visible
		glfwShowWindow(window);
	}

	private void render() {
		cam.rotate(0.01f, 0.01f);
		renderer.Render(cam);
	}

	private void loop() {
		// This line is critical for LWJGL's interoperation with GLFW's
		// OpenGL context, or any context that is managed externally.
		// LWJGL detects the context that is current in the current thread,
		// creates the GLCapabilities instance and makes the OpenGL
		// bindings available for use.
		GL.createCapabilities();

		renderer.Init();

		// Set the clear color
		glClearColor(0.0f, 0.0f, 0.0f, 0.0f);

		glColor4f(1.0f, 0.0f, 0.0f, 1.0f);

		// Run the rendering loop until the user has attempted to close
		// the window or has pressed the ESCAPE key.
		while (!glfwWindowShouldClose(window)) {
			glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // clear the framebuffer

			render();

			glfwSwapBuffers(window); // swap the color buffers

			// Poll for window events. The key callback above will only be
			// invoked during this call.
			glfwPollEvents();

			try (MemoryStack stack = stackPush()) {
				IntBuffer pWidth = stack.mallocInt(1); // int*
				IntBuffer pHeight = stack.mallocInt(1); // int*

				// Get the window size passed to glfwCreateWindow
				glfwGetWindowSize(window, pWidth, pHeight);

				glViewport(0, 0, pWidth.get(), pHeight.get());
			} // the stack frame is popped automatically
		}
	}

}