#include "camera/Camera.h"
#include "Xml.h"
#include "Track.h"

#include <GL/glut.h>

#include <experimental/filesystem>

#include <syslog.h>
#include <cstdlib>
#include <iostream>
#include <math.h> // fmod
#include <unistd.h>
#include <vector>

GLfloat light_diffuse[] = {1.0, 0.0, 0.0, 1.0};  /* Red diffuse light. */
GLfloat light_position[] = {1.0, 1.0, 1.0, 0.0};  /* Infinite light location. */

Camera camera;

// TODO(dev):
//  As per https://www.opengl.org/resources/libraries/glut/spec3/node11.html
//  "Therefore, GLUT programs should not assume the window was created at the specified size or position.
//   A GLUT program should use the window's reshape callback to determine the true size of the window."

void draw_origin()
{
	// X:
	glBegin(GL_LINE_STRIP);
	glColor3d(0, 0, 0);
	glVertex3f(-10.0f, 0.0f, 0.0f);
	glColor3d(255, 0, 0);
	glVertex3f(0.0f, 0.0f, 0.0f);
	glColor3d(0, 0, 0);
	glVertex3f(10.0f, 0.0f, 0.0f);
	glEnd();

	// Y:
	glBegin(GL_LINE_STRIP);
	glVertex3f(0.0f, -10.0f, 0.0f);
	glColor3d(0, 255, 0);
	glVertex3f(0.0f, 0.0f, 0.0f);
	glColor3d(0, 0, 0);
	glVertex3f(0.0f, 10.0f, 0.0f);
	glEnd();

	// Z:
	glBegin(GL_LINE_STRIP);
	glVertex3f(0.0f, 0.0f, -10.0f);
	glColor3d(0, 0, 255);
	glVertex3f(0.0f, 0.0f, 0.0f);
	glColor3d(0, 0, 0);
	glVertex3f(0.0f, 0.0f, 10.0f);
	glEnd();
}

void display()
{
	// RESET:
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glLoadIdentity();

	glLineWidth(1.0f);

	//camera.RotateYaw(0.01);

	static double asdf = -10.0;
	asdf += 0.02;
	if(asdf > 15.0)
		asdf = -15.0;
	gluLookAt(-15.0, 30.0, -asdf,  /* eye is at */
	          0.0, 5.0, 0.0,  /* center is at */
	          0.0, 1.0, 0.0);    /* up is in positive Y direction */

	draw_origin();

	// DRAW TRACKS:
	for(auto track : tracks)
		draw(track);

	glutSwapBuffers();
}

void init()
{
	// dvereb:
	srand(time(NULL));

	glColor3d(1.0, 1.0, 1.0);

	/* Enable a single OpenGL light. */
	// glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
	// glLightfv(GL_LIGHT0, GL_POSITION, light_position);
	// glEnable(GL_LIGHT0);
	// glEnable(GL_LIGHTING);

	/* Use depth buffering for hidden surface elimination. */
	glEnable(GL_DEPTH_TEST);

	/* Setup the view of the cube. */
	glMatrixMode(GL_PROJECTION);
	gluPerspective( /* field of view in degree */ 70.0,
	                /* aspect ratio */ 1.0,
	                /* Z near */ 1.0, /* Z far */ 1000.0);
	glMatrixMode(GL_MODELVIEW);
	gluLookAt(-10.0, 25.0, -10.0,  /* eye is at */
	          0.0, 0.0, 0.0,  /* center is at */
	          0.0, 1.0, 0.0);    /* up is in positive Y direction */
}

int main(int argc, char *argv[])
{
	if(argc != 2)
	{
		std::cerr << "You pust pass the folder which contains gpx files." << std::endl;
		return -1;
	}

	std::vector<std::string> files;
	for(const auto& entry : std::experimental::filesystem::directory_iterator(argv[1]))
	{
		auto extension = entry.path().extension();
		if(extension == ".gpx")
			files.push_back(entry.path().string());
	}

	for(auto file : files)
		ParseFile(tracks, file);

	// NORMALIZE TRACKS TO VIEWPORT:
	bool first = true;
	float min_lat, min_lon, min_ele, max_lat, max_lon, max_ele;
	for(auto &track : tracks)
	{
		for(auto &p : track.points)
		{
			if(first)
			{
				first = false;
				min_lat = max_lat = p.lat;
				min_lon = max_lon = p.lon;
				min_ele = max_ele = p.ele;
			}
			else
			{
				if(p.lat < min_lat)
					min_lat = p.lat;
				else if(p.lat > max_lat)
					max_lat = p.lat;
				if(p.lon < min_lon)
					min_lon = p.lon;
				else if(p.lon > max_lon)
					max_lon = p.lon;
				if(p.ele < min_ele)
					min_ele = p.ele;
				else if(p.ele > max_ele)
					max_ele = p.ele;
			}
		}
	}
	auto lat_diff = min_lat + ((max_lat - min_lat) / 2.0);
	auto lon_diff = min_lon + ((max_lon - min_lon) / 2.0);
	auto ele_diff = min_ele;
	for(auto &track : tracks)
	{
		for(auto &p : track.points)
		{
			p.lat -= lat_diff;
			p.lon -= lon_diff;
			p.ele -= ele_diff;
		}
	}

	glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH | GLUT_ALPHA | GLUT_MULTISAMPLE);
	glutInit(&argc, argv);
	glutCreateWindow("3D GPX Viewer");
	glutDisplayFunc(display);

	// NOTE(dev): lmfao:
	// glutSetCursor(GLUT_CURSOR_SPRAY);
	glutSetCursor(GLUT_CURSOR_FULL_CROSSHAIR);

	init();
	camera.Init();
	camera.Fly(50);
	camera.RotatePitch(-89 * M_PI / 180.0);
	glutMainLoop();

	return 0;
}