/*
 *  2ooM: The Master of Orion II Reverse Engineering Project
 *  Simple command-line tool to convert an LBX image to a set of PNGs.
 *  Copyright (C) 2006-2008 Nick Bowler
 *
 *  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 <http://www.gnu.org/licenses/>.
 */
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <assert.h>
#include <getopt.h>
#include <errno.h>

#include <png.h>

#include "tools.h"
#include "image.h"
#include "lbx.h"

/* Global flags */
static int verbose = 0;
static char *outname = "out";
static int usepalette = 1;

static void printusage(void)
{
	puts("usage: lbximg [-i|-d] [-v] [-p palette_file] [-O override_file]"
	                  " [-f path]");
	puts("              [frameno ...]");
}

static void printhelp(void)
{
	printusage();
	puts("For now, see the man page for detailed help.");
}

static const char *progname;
#define errmsg(fmt, ...) (\
	fprintf(stderr, "%s: " fmt, progname, __VA_ARGS__)\
)

enum {
	MODE_NONE,
	MODE_DECODE,
	MODE_IDENT,
};

int parserange(struct lbx_imginfo *info, char *str, unsigned char *bits)
{
	unsigned long start, end;
	unsigned int i;
	char *endptr;

	start = strtoul(str, &endptr, 0);
	if (start >= info->nframes) {
		errmsg("frame %lu out of range.\n", start);
		return -1;
	}

	if (endptr == str) {
		errmsg("invalid frame range: %s.\n", str);
		return -1;
	}

	switch (*endptr) {
	case '\0':
		end = start;
		break;
	case '-':
		end = strtoul(endptr+1, &endptr, 0);
		if (end >= info->nframes) {
			errmsg("frame %lu out of range.\n", end);
			return -1;
		}

		if (endptr == str)
			end = info->nframes - 1;
		break;
	default:
		errmsg("invalid frame range: %s.\n", str);
		return -1;
	}

	if (end < start) {
		errmsg("invalid frame range: %s.\n", str);
		return -1;
	}

	for (i = start; i <= end; i++) {
		bits[i / CHAR_BIT] |= 1 << (i % CHAR_BIT);
	}

	return 0;
}

static int ismasked(unsigned char **mask, unsigned width, unsigned height)
{
	unsigned y, x;
	for (y = 0; y < height; y++) {
		for (x = 0; x < width; x++) {
			if (mask[y][x] == 0) return 1;
		}
	}

	return 0;
}

int outpng(unsigned int frameno,
           unsigned char **framedata, unsigned char **mask,
           unsigned int width, unsigned int height,
           struct lbx_colour palette[static 256])
{
	char name[strlen(outname) + sizeof ".65535.png"];
	unsigned char *row;
	unsigned int x, y;
	FILE *of;

	png_structp png;
	png_infop   info;

	assert(frameno < 65536);
	snprintf(name, sizeof name, "%s.%03d.png", outname, frameno);

	row = malloc(4 * width);
	if (!row) {
		errmsg("failed to allocate row buffer: %s\n", strerror(errno));
		return -1;
	}

	of = fopen(name, "wb");
	if (!of) {
		errmsg("failed to open %s: %s.\n", name, strerror(errno));
		free(row);
		return -1;
	}

	png = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
	if (!png) {
		errmsg("failed to init libpng.\n", 0);
		goto err;
	}

	info = png_create_info_struct(png);
	if (!info) {
		errmsg("failed to init libpng.\n", 0);
		png_destroy_write_struct(&png, NULL);
		goto err;
	}

	if (setjmp(png_jmpbuf(png))) {
		free(row);
		png_destroy_write_struct(&png, &info);
		goto err;
	}

	png_init_io(png, of);

	if (!ismasked(mask, width, height)) {
		/*
		 * This case is easy; we can just feed the palette and pixel
		 * data to libpng and let it do its magic.
		 */

		png_color png_palette[256];
		for (unsigned i = 0; i < 256; i++) {
			png_palette[i].red   = palette[i].red;
			png_palette[i].green = palette[i].green;
			png_palette[i].blue  = palette[i].blue;
		}

		png_set_IHDR(png, info, width, height, 8,
		             PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
			     PNG_COMPRESSION_TYPE_DEFAULT,
			     PNG_FILTER_TYPE_DEFAULT);
		
		png_set_PLTE(png, info, png_palette, 256);
		png_set_rows(png, info, framedata);
		png_write_png(png, info, PNG_TRANSFORM_IDENTITY, NULL);
	} else {
		/*
		 * Unfortunately, LBX doesn't translate nicely to PNG here.
		 * LBX has a 256 colour palette _plus_ transparency.
		 * We'll form an RGBA PNG to deal with this.
		 */

		png_set_IHDR(png, info, width, height, 8,
		             PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE,
		             PNG_COMPRESSION_TYPE_DEFAULT,
		             PNG_FILTER_TYPE_DEFAULT);
	
		png_write_info(png, info);
	
		for (y = 0; y < height; y++) {
			for (x = 0; x < width; x++) {
				row[4*x+0] = palette[framedata[y][x]].red;
				row[4*x+1] = palette[framedata[y][x]].green;
				row[4*x+2] = palette[framedata[y][x]].blue;
				row[4*x+3] = (mask[y][x]) ? -1 : 0;
			}
	
			png_write_row(png, row);
		}
	
		png_write_end(png, NULL);
	}

	png_destroy_write_struct(&png, &info);
	fclose(of);

	if (verbose)
		printf("wrote %s\n", name);

	return 0;

err:
	fclose(of);
	remove(name);
	free(row);
	return -1;
}

static int loadoverride(FILE *f, struct lbx_colour palette[static 256])
{
	LBX_IMG *overimg = lbximg_fopen(f);
	struct lbx_imginfo info;

	if (!overimg) {
		errmsg("failed to open override image: %s\n", lbx_strerror());
		return -1;
	}
	lbximg_getinfo(overimg, &info);

	if (!info.palettesz) {
		errmsg("override image has no palette.\n", 0);
		lbximg_close(overimg);
		return -1;
	}

	if (lbximg_getpalette(overimg, palette) == -1) {
		errmsg("error reading override palette: %s\n", lbx_strerror());
		lbximg_close(overimg);
		return -1;
	}

	lbximg_close(overimg);
	return 0;
}

static int loadpalette(LBX_IMG *img, struct lbx_imginfo *info,
                       FILE *palf, FILE *override,
                       struct lbx_colour palette[static 256])
{
	int i;

	/* In no-palette mode, use palette indices for colour. */
	if (!usepalette) {
		for (i = 0; i < 256; i++) {
			palette[i] = (struct lbx_colour){i,i,i};
		}

		return 0;
	}

	/* For sanity. */
	if (!palf && !info->palettesz && !override) {
		errmsg("no palette available.\n", 0);
		return -1;
	}

	/* Default the palette to a wonderful pink. */
	for (i = 0; i < 256; i++) {
		palette[i] = (struct lbx_colour){0xff, 0x00, 0xff};
	}

	/* Read the external palette, if any. */
	if (palf && lbximg_loadpalette(palf, &lbx_default_fops, palette) != 0) {
		errmsg("error reading external palette: %s\n", lbx_strerror());
		return -1;
	}

	/* Read the embedded palette, if any. */
	if (info->palettesz && lbximg_getpalette(img, palette) == -1) {
		errmsg("error reading embedded palette: %s\n", lbx_strerror());
		return -1;
	}

	/* Read the override palette, if any. */
	if (override && loadoverride(override, palette) == -1) {
		return -1;
	}

	return 0;
}

int decode(LBX_IMG *img, FILE *palf, FILE *override, char **argv)
{
	unsigned char *framebits;
	struct lbx_colour palette[256];
	struct lbx_imginfo info;
	int extracted = 0;
	unsigned int i;

	lbximg_getinfo(img, &info);

	framebits = malloc(info.nframes / CHAR_BIT + 1);
	if (!framebits) {
		return EXIT_FAILURE;
	}

	/* Figure out what images we're extracting. */
	if (!argv[0]) {
		/* extract all images by default. */
		memset(framebits, -1, info.nframes / CHAR_BIT + 1);
	} else {
		for (i = 0; argv[i]; i++) {
			parserange(&info, argv[i], framebits);
		}
	}

	if (loadpalette(img, &info, palf, override, palette) == -1) {
		goto err;
	}

	/* Extract the images, in order. */
	for (i = 0; i < info.nframes; i++) {
		unsigned char **data;
		unsigned char **mask;

		if (!(framebits[i / CHAR_BIT] & (1 << (i % CHAR_BIT))))
			continue;

		data = lbximg_getframe(img, i);
		if (!data) {
			errmsg("error in frame %u: %s\n", i, lbx_strerror());
			continue;
		}

		mask = lbximg_getmask(img);

		if (!outpng(i, data, mask, info.width, info.height, palette)) {
			extracted = 1;
		}
	}

	if (!extracted) {
		errmsg("no frames extracted.\n", 0);
		goto err;
	}

	free(framebits);
	return EXIT_SUCCESS;
err:
	free(framebits);
	return EXIT_FAILURE;
}

int main(int argc, char **argv)
{
	int mode = MODE_NONE, opt, rc = EXIT_FAILURE;
	struct lbx_pipe_state state = { .f = stdin };
	FILE *palf = NULL, *overf = NULL;
	const char *name = "stdin";
	LBX_IMG *img;

	static const char *sopts = "idvf:p:O:V";
	static const struct option lopts[] = {
		{ "ident",    0, NULL, 'i' },
		{ "decode",   0, NULL, 'd' },
		{ "verbose",  0, NULL, 'v' },
		{ "file",     1, NULL, 'f' },
		{ "palette",  1, NULL, 'p' },
		{ "override", 1, NULL, 'p' },

		{ "version",  0, NULL, 'V' },
		{ "usage",    0, NULL, 'U' },
		{ "help",     0, NULL, 'H' },

		{ "nopalette", 0, &usepalette, 0 },

		{ 0 }
	};

	progname = "lbximg"; /* argv[0]; */
	while ((opt = getopt_long(argc, argv, sopts, lopts, NULL)) != -1) {
		switch(opt) {
		case 'i':
			mode = MODE_IDENT;
			break;
		case 'd':
			mode = MODE_DECODE;
			break;
		case 'v':
			verbose = 1;
			break;
		case 'f':
			name = strrchr(optarg, '/');
			name = name ? name+1 : optarg;

			if (!freopen(optarg, "rb", state.f)) {
				errmsg("failed to open %s: %m\n", optarg);
				return EXIT_FAILURE;
			}
			break;
		case 'p':
			palf = fopen(optarg, "rb");
			if (!palf) {
				errmsg("failed to open %s: %m\n", optarg);
				return EXIT_FAILURE;
			}

			break;
		case 'O':
			overf = fopen(optarg, "rb");
			if (!overf) {
				errmsg("failed to open %s: %m\n", optarg);
				return EXIT_FAILURE;
			}
			break;
		case 'V':
			puts(VERSION_BOILERPLATE("lbximg"));
			return EXIT_SUCCESS;
		case 'U':
			printusage();
			return EXIT_SUCCESS;
		case 'H':
			printhelp();
			return EXIT_SUCCESS;
		case '?':
		case ':':
			return EXIT_FAILURE;
		}
	}

	if (mode == MODE_NONE) {
		errmsg("you must specify a mode.\n", 0);
		return EXIT_FAILURE;
	}

	if (fseek(state.f, 0, SEEK_CUR) == 0)
		img = lbximg_open(state.f, &lbx_default_fops, NULL);
	else
		img = lbximg_open(&state, &lbx_pipe_fops, NULL);

	if (!img) {
		errmsg("failed to open image: %s.\n", lbx_strerror());
		return EXIT_FAILURE;
	}

	if (verbose || mode == MODE_IDENT) {
		struct lbx_imginfo info;
		lbximg_getinfo(img, &info);

		printf("%s is %ux%u LBX image, %u frame(s)%s%s\n",
		       name, info.width, info.height, info.nframes,
		       info.palettesz ? ", embedded palette" : "",
		       info.chunk     ? ", chunked" : "",
		       info.looping   ? ", loops" : "");
	}

	switch (mode) {
	case MODE_DECODE:
		rc = decode(img, palf, overf, &argv[optind]);
		break;
	}

	lbximg_close(img);
	return rc;
}