#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 <cmath> // 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;

void (*passiveMouseFunc)(int x, int y) = [](int x, int y)
{
	static int last_x = x;
	static int last_y = y;

	const int diff_x = x - last_x;
	const int diff_y = y - last_y;
	last_x = x;
	last_y = y;

	const int distance = 5;
	static float angle_horizontal = 0.0;
	static float angle_vertical = 0.0;
	angle_horizontal += diff_x / 100.0f;
	angle_vertical += diff_y / 100.0f;

	angle_horizontal = fmod(angle_horizontal, 6.283185);
	angle_vertical = fmod(angle_vertical, 6.283185);

	float new_x = cos(angle_horizontal);
	float new_y = sin(angle_vertical);
	float new_z = sin(angle_horizontal);
	camera.SetPos(distance * new_x,
	              distance * 12.5 * new_y,
	              distance * new_z);
};

// 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.SetTarget(Camera::Target::POINT); // center
	//camera.RotateYaw(0.01);

	// static int a = 0;
	// if(a < 400)
	// {
	// 	camera.RotatePitch(0.03f);
	// 	camera.RotateYaw(0.01f);
	// 	camera.Move(-0.1f);
	// 	if(++a == 200)
	// 		camera.SetTarget(Camera::Target::POINT); // center
	// }
	// else if(a++ == 400) // ONCE
	// {
	// 	static float angle = 0;
	// 	const int distance = 5;
	// 	angle += 0.001f;
	// 	angle = fmod(angle, 360.0);

	// 	float new_x = cos(angle);
	// 	float new_z = sin(angle);
	// 	camera.SetPos(distance * new_x + 2,
	// 	              distance * 12.5,
	// 	              distance * new_z - 4);
	// }
	camera.Refresh();

	// draw_origin();

	// DRAW TRACKS:
	for(auto track : track_groups[random_group].second)
		draw(*track);

	glutPostRedisplay();
	glutSwapBuffers();
}

void init()
{
	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 */ 90.0,
	                /* 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 */

	camera.SetTarget(Camera::Target::POINT); // center

	// handle mouse input
	glutPassiveMotionFunc(passiveMouseFunc);
}

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

	// dvereb:
	srand(time(NULL));

	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;

	// NOTE(dev):
	//  We're trying to determine groups of tracks that overlap
	//  First, put all the tracks in their own group
	//  Second, keep checking to see if any groups overlap until there are no changes
	// std::vector<std::pair<Track, std::vector<const Track*>>> track_groups;
	for(auto &track : tracks)
	{
		// Build a header-only copy of each track
		Track header;
		header.min = track.min;
		header.max = track.max;
		std::vector<const Track*> vec;
		vec.push_back(&track);

		std::pair<Track, std::vector<const Track*>> p;
		p.first = header;
		p.second = vec;
		// Point to the actual Track with the header info
		track_groups.push_back(p);
	}

	for(bool no_changes = false; !no_changes; )
	{
		no_changes = true;
		for(auto i = 0; i < track_groups.size(); ++i)
		{
			for(auto j = 0; j < track_groups.size(); /* no increment here */)
			{
				if(j == i)
				{
					++j;
					continue;
				}
				bool lat_overlap = false;
				bool lon_overlap = false;
				if(track_groups[j].first.min.lat <= track_groups[i].first.max.lat
				   && track_groups[j].first.max.lat >= track_groups[i].first.min.lat)
					lat_overlap = true;
				if(track_groups[j].first.min.lon <= track_groups[i].first.max.lon
				   && track_groups[j].first.max.lon >= track_groups[i].first.min.lon)
					lon_overlap = true;
				if(lat_overlap && lon_overlap)
				{
					no_changes = false;
					track_groups[i].first.min.lat = fmin(track_groups[i].first.min.lat,
					                                     track_groups[j].first.min.lat);
					track_groups[i].first.min.lon = fmin(track_groups[i].first.min.lon,
					                                     track_groups[j].first.min.lon);
					track_groups[i].first.min.ele = fmin(track_groups[i].first.min.ele,
					                                     track_groups[j].first.min.ele);
					track_groups[i].first.max.lat = fmax(track_groups[i].first.max.lat,
					                                     track_groups[j].first.max.lat);
					track_groups[i].first.max.lon = fmax(track_groups[i].first.max.lon,
					                                     track_groups[j].first.max.lon);
					track_groups[i].first.max.ele = fmax(track_groups[i].first.max.ele,
					                                     track_groups[j].first.max.ele);

					// std::cout << "first.min.lat: " << track_groups[i].first.min.lat << ", "
					//           << "first.min.lon: " << track_groups[i].first.min.lon << ", "
					//           << "first.min.lon: " << track_groups[i].first.min.ele << ", "
					//           << "first.min.lon: " << track_groups[i].first.max.lat << ", "
					//           << "first.min.lon: " << track_groups[i].first.max.lon << ", "
					//           << "first.min.lon: " << track_groups[i].first.max.ele << ", "
					//           << std::endl;

					// Add tracks vector to make one big one
					track_groups[i].second.insert(track_groups[i].second.end(),
					                              track_groups[j].second.begin(),
					                              track_groups[j].second.end());

					track_groups.erase(track_groups.begin() + j);
					if(j < i)
						--i;
				}
				else
					++j;
			}
		}
	}

	std::cout << "Generated " << track_groups.size() << " track groups:" << std::endl;
	int count = 0;
	for(const auto &track_group : track_groups)
	{
		++count;
		std::cout << "Track #" << count << ", including " << track_group.second.size()
		          << " tracks:" << std::endl;
		std::cout << " lat"
		          << " " << track_group.first.min.lat
		          << "-" << track_group.first.max.lat << std::endl;
		std::cout << " lon"
		          << " " << track_group.first.min.lon
		          << "-" << track_group.first.max.lon << std::endl;
		std::cout << " ele"
		          << " " << track_group.first.min.ele
		          << "-" << track_group.first.max.ele << std::endl;
	}
	std::cout << std::endl;

	random_group = 0;
	float min_lat, max_lat, min_lon, max_lon, min_ele, max_ele;
	first = true; // reset!
	for(auto &track : track_groups[random_group].second)
	{
		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;
			}
		}
	}
	std::cout << "min_lat: " << min_lat << " max_lat: " << max_lat << ", "
	          << "min_lon: " << min_lon << " max_lon: " << max_lon << ", "
	          << "min_ele: " << min_ele << " max_ele: " << max_ele << std::endl;
	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;
	std::cout << "lat_diff: " << lat_diff << ", "
	          << "lon_diff: " << lon_diff << ", "
	          // << "ele_diff: " << ele_diff << ", "
	          << std::endl;
	// for(Track &track : track_groups[random_group].second)
	// {
		for(auto &track : tracks)
		{
			track.max.lat -= lat_diff;
			track.max.lon -= lon_diff;
			track.min.lat -= lat_diff;
			track.min.lon -= lon_diff;
			for(auto &p : track.points)
			{
				p.lat -= lat_diff;
				p.lon -= lon_diff;

				p.lat *= 500;
				p.lon *= 500;
				// p.ele *= 0.001;
				p.ele *= 0.01;
			}
		}
	// }

	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.Strafe(-15);
	// camera.RotatePitch(-89 * M_PI / 180.0);
	glutMainLoop();

	return 0;
}