/*
 * Test app for _NET_WM_ICON formatting.
 * Copyright © 2022 Nick Bowler
 *
 * Use a fake colour scheme to generate an icon of the chosen size (16x16,
 * 24x24, 32x32 or 48x48) and display the pixels as characters.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <getopt.h>

#include "ewmhicon.h"
#include "colour.h"
#include "help.h"

static const char *progname = "ewmhicon";
static const char sopts[] = "c:VH";
static const struct option lopts[] = {
	{ "colourseq", 1, NULL, 'c' },
	{ "version",   0, NULL, 'V' },
	{ "help",      0, NULL, 'H' },
	{ 0 }
};

#define PASTE(a, b) a ## b
#define INDIR(a) a

#define S8TO16(x) ((x) * 0xfffful / 0xff)

#define RGB8_(r, g, b) { \
	0xff000000 | (r << 16) | (g << 8) | b, \
	S8TO16(r), S8TO16(g), S8TO16(b) }

#define RGB8(r, g, b) RGB8_(0x ## r ## ul, 0x ## g ## ul, 0x ## b ## ul)

#define COLOURTAB(n) { \
	INDIR(RGB8 PASTE(COLOUR ## n, _PRIMARY_RGB_)), \
	INDIR(RGB8 PASTE(COLOUR ## n, _DARK_RGB_)), \
	INDIR(RGB8 PASTE(COLOUR ## n, _LIGHT_RGB_)) }

static const XColor colours[7][3] = {
	{
		{ 0xffff0000, 0xffff },
		{ 0xff00ff00, 0, 0xffff },
		{ 0xff0000ff, 0, 0, 0xffff }
	},
	COLOURTAB(0), COLOURTAB(1), COLOURTAB(2),
	COLOURTAB(3), COLOURTAB(4), COLOURTAB(5)
};

static void print_usage(FILE *f)
{
	fprintf(f, "Usage: %s size\n", progname);
	if (f != stdout)
		fprintf(f, "Try %s --help for more information.\n", progname);
}

static void print_help(void)
{
	const struct option *opt;

	print_usage(stdout);
	putchar('\n');
	puts("Options:");
	for (opt = lopts; opt->name; opt++) {
		if (help_print_optstring(opt, "ARG", 20))
			putchar('\n');
	}
	putchar('\n');

	printf("Report bugs to <%s>.\n", PACKAGE_BUGREPORT);
}

static void print_version(void)
{
	printf("ewmhicon (%s) %s\n", PACKAGE, PACKAGE_VERSION);
	printf("Copyright (C) 2022 Nick Bowler\n");
	puts("License GPLv3+: GNU GPL version 3 or any later version");
	puts("This is free software: you are free to change and redistribute it.");
	puts("There is NO WARRANTY, to the extent permitted by law.");
}

static const char sizes[][6] = {
	"16x16", "24x24", "32x32", "48x48"
};

static int to_size_enum(const char *arg)
{
	char buf[8];
	unsigned i;

	if (!strchr(arg, 'x')) {
		sprintf(buf, "%.3sx%.3s", arg, arg);
		arg = buf;
	}

	for (i = 0; i < sizeof sizes / sizeof sizes[0]; i++) {
		if (!strcmp(arg, sizes[i]))
			return i;
	}

	return -1;
}

static void gen_icon(int size, const char *colourseq)
{
	void (*tilefunc)(unsigned long *, const XColor *, int, int);
	static unsigned long icon_buf[48*48];
	const char colourchars[21] = ".%+"",Rr""-Oo""'Yy"":Gg"";Bb"" Ww";
	unsigned i, j, x, y, w, h, n;

	switch (size) {
	case ICON_16x16: tilefunc = ewmh_tile16; w = h = 16; break;
	case ICON_24x24: tilefunc = ewmh_tile24; w = h = 24; break;
	case ICON_32x32: tilefunc = ewmh_tile32; w = h = 32; break;
	case ICON_48x48: tilefunc = ewmh_tile48; w = h = 48; break;
	default: assert(0);
	}

	for (i = 0; i < 9; i++) {
		const XColor *c;

		assert(colourseq[i] >= '0' && colourseq[i] <= '6');
		c = colours[colourseq[i]-'0'];

		tilefunc(icon_buf, c, i%3, i/3);
	}

	n = 7;
	for (i = 0; i < 7; i++)
		n -= !strchr(colourseq, '0'+i);

	puts("/* XPM */");
	puts("static char *icon[] = {");
	printf("\"%u %u %u 1\",\n", w, h, 3*n);
	for (i = 0; i < 7; i++) {
		if (!strchr(colourseq, '0'+i))
			continue;

		for (j = 0; j < 3; j++) {
			printf("\"%c c #%.6lx\",\n", colourchars[3*i+j],
			               colours[i][j].pixel & 0xffffff);
		}
	}

	for (y = 0; y < h; y++) {
		putchar('"');
		for (x = 0; x < w; x++) {
			unsigned long val = icon_buf[y*h+x];
			int c = '#';

			for (i = 0; i < sizeof colourchars; i++) {
				if (colours[i/3][i%3].pixel == val) {
					c = colourchars[i];
					break;
				}
			}

			putchar(c);
		}
		printf("\"%.*s\n", y+1<h, ",");
	}
	printf("};\n");
}

int decode_colourseq(char *out, const char *arg)
{
	int i;

	for (i = 0; i < 9; i++) {
		switch (arg[i]) {
		case 0: return 0;
		case 'R': case 'r': out[i] = '1'; break;
		case 'O': case 'o': out[i] = '2'; break;
		case 'Y': case 'y': out[i] = '3'; break;
		case 'G': case 'g': out[i] = '4'; break;
		case 'B': case 'b': out[i] = '5'; break;
		case 'W': case 'w': out[i] = '6'; break;
		case '1': case '2': case '3': case '4': case '5': case '6':
			case '0': out[i] = arg[i]; break;
		default: goto err;
		}
	}

	if (arg[i]) {
err:
		fprintf(stderr, "%s: error: invalid colour sequence '%s'\n",
		                progname, arg);
		return -1;
	}

	return 0;
}

int main(int argc, char **argv)
{
	char colourseq[9] = "000000000";
	int opt, size;

	if (argc > 0)
		progname = argv[0];

	while ((opt = getopt_long(argc, argv, sopts, lopts, 0)) != -1) {
		switch (opt) {
		case 'c':
			if (decode_colourseq(colourseq, optarg) != 0)
				return EXIT_FAILURE;
			break;
		case 'H':
			print_help();
			return EXIT_SUCCESS;
		case 'V':
			print_version();
			return EXIT_SUCCESS;
		default:
			print_usage(stderr);
			return EXIT_FAILURE;
		}
	}

	if (argc != optind+1) {
		printf("%s: error: size not specified\n", progname);
		print_usage(stderr);
		return EXIT_FAILURE;
	}

	size = to_size_enum(argv[optind]);
	if (size < 0) {
		printf("%s: error: invalid size %s\n", progname, argv[optind]);
		print_usage(stderr);
		return EXIT_FAILURE;
	}

	gen_icon(size, colourseq);
	return 0;
}