#include <iostream>
#include <fstream>
#include <cmath>
#include <bitset>
#include <string>
#include <stdio.h>
#include <getopt.h>

using namespace std;

#define SECTION_COUNT 6
#define LAYERS 4
#define OUTLINE 1

typedef struct point
{
	double x;
	double y;
} point;

void add_hex(char *data, ofstream& file, double height,
	int layer_order[4], int x_count = 0, int y_count = 0)
{
	point pts[LAYERS + 1][SECTION_COUNT];
	point center;
	double layer_mod[LAYERS + 1] = {1.0, 0.9, 0.5, 0.4, 0.0};
	double section_rad[SECTION_COUNT] = {90, 30, 330, 270, 210, 150};
	double offset;
	int layer;
	int section;
	bitset<LAYERS * SECTION_COUNT> bits;

	if (NULL == data)
	{
		return;
	}

	for (int i = 0; i < LAYERS * SECTION_COUNT / 8; ++i)
	{
		for (int j = 0; j < 8; ++j)
		{
			bits[i * 8 + j] = data[i] & (0x80 >> j);
		}
	}

	offset = height * 1.1;
	center.x = height / 2;
	center.y = height / 2;
	center.x += offset * x_count;
	center.y += offset * y_count;

	// Calculate Points
	for (layer = 0; layer < LAYERS + 1; ++layer)
	{
		for (section = 0; section < SECTION_COUNT; ++section)
		{
			pts[layer][section].x =	cos(section_rad[section] * M_PI / 180.0) *
				layer_mod[layer] * height / 2 + center.x;
			pts[layer][section].y = -sin(section_rad[section] * M_PI / 180.0) *
				layer_mod[layer] * height / 2 + center.y;
		}
	}

#if OUTLINE
	// Draw Outline
	file <<
		"\t<g id=\"hex\" fill=\"none\" stroke=\"#000000\" stroke-width=\"" <<
		height / 100 << "\">" << endl;
	for (layer = 0; layer < LAYERS; ++layer)
	{
		file << "\t\t<path d=\"M " << pts[layer][0].x << " " << pts[layer][0].y;
		for (section = 1; section < SECTION_COUNT; ++section)
		{
			file << " L " << pts[layer][section].x <<
				" " << pts[layer][section].y;
		}
		file << " Z\"/>" << endl;
	}

	for (section = 0; section < SECTION_COUNT / 2; ++section)
	{
		file << "\t\t<path d=\"M " << pts[0][section].x <<
			" " << pts[0][section].y <<
			" L " << pts[0][section + SECTION_COUNT / 2].x <<
			" " << pts[0][section + SECTION_COUNT / 2].y <<
			" Z\"/>" << endl;
	}

	file << "\t</g>" << endl;
#endif
	// Fill Hexes
	file << "\t<g id=\"fill\">" << endl;
	for (section = 0; section < SECTION_COUNT; ++section)
	{
		for (int i = 0; i < LAYERS; ++i)
		{
			layer = layer_order[i];
			if (bits.test(section * LAYERS + i))
			{
				file << "\t\t<path d=\"" <<
					"M " << pts[layer][section].x <<
					" " << pts[layer][section].y <<
					" L " << pts[layer][(section + 1) % SECTION_COUNT].x <<
					" " << pts[layer][(section + 1) % SECTION_COUNT].y <<
					" L " << pts[layer + 1][(section + 1) % SECTION_COUNT].x <<
					" " << pts[layer + 1][(section + 1) % SECTION_COUNT].y <<
					" L " << pts[layer + 1][section].x <<
					" " << pts[layer + 1][section].y <<
					" Z\" fill=\"#000000\"/>" << endl;
			}
		}
	}
	file << "\t</g>" << endl;
}

void print_usage(const char *name)
{
	printf("Usage: %s [options] <data>\n", name);
	printf("\t-o <output filename> (default - out.svg)\n");
	printf("\t-s <size> (default - 300)\n");
	printf("'data' must be at least 3 bytes in hex format.\n"
		"More than that will be ignored\n"
		"E.g. '97C1A3'\n");
}

int main(int argc, char **argv)
{
	int order[4] = {1,3,0,2};
	double height = 300;
	char data[3] = {0, 0, 0};
	string data_str;
	string filename = "out.svg";
	ofstream file;

	const char optstr[] = "o:s:";
	int opt;

	// Parse arguments
	opt = getopt(argc, argv, optstr);
	while (opt != -1)
	{
		switch (opt)
		{
		case 'o':
			if (NULL == optarg)
			{
				printf("'o' requires a filename\n");
				return -1;
			}
			filename = optarg;
			break;

		case 's':
			if (NULL == optarg)
			{
				printf("'s' requires a size\n");
				return -1;
			}
			height = stod(optarg);
			break;

		case '?':
			print_usage(argv[0]);
			return 0;
			break;

		default:
			printf("Unknown parameter '%c'\n", opt);
			print_usage(argv[0]);
			return -1;
			break;
		}
		opt = getopt(argc, argv, optstr);
	}

	if (optind >= argc)
	{
		printf("Missing 'data'\n");
		print_usage(argv[0]);
		return -1;
	}

	// Parse data
	data_str = argv[optind];
	if (data_str.size() < 6)
	{
		printf("Not enough data\n");
		print_usage(argv[0]);
		return -1;
	}

	for (int i = 0; i < 3; ++i)
	{
		try
		{
			data[i] = stoi(data_str.substr(i * 2, 2), NULL, 16);
		}
		catch (exception &e)
		{
			printf("Bad data for byte %d\n", i);
		}
	}

	// Write file
	file.open(filename, ios_base::out);
	file << "<svg xmlns=\"http://www.w3.org/2000/svg\" " <<
		"xmlns:xlink=\"http://www.w3.org/1999/xlink\" " <<
		"width=\"100%\" height=\"100%\" " <<
		"viewBox=\"" << -height * 0.05 << " " << -height * 0.05 << " " <<
			height * 1.1 << " " << height * 1.1 << "\">" << endl;

	add_hex(data, file, height, order);

	file << "</svg>" << endl;
	file.close();

	return 0;
}