/*
 *  2ooM: The Master of Orion II Reverse Engineering Project
 *  Simple command-line tool to convert an LBX image to a set of PNGs.
 *  Copyright © 2006-2011, 2013 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 "tools.h"
#include "image.h"
#include "error.h"
#include "lbx.h"

#include "imgoutput.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.");
}

enum {
	MODE_NONE,
	MODE_DECODE,
	MODE_IDENT,
};

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

	start = strtoul(str, &endptr, 0);
	if (start >= frames) {
		tool_err(-1, "frame %lu out of range.", start);
		return -1;
	}

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

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

		if (endptr == str)
			end = frames - 1;
		break;
	default:
		tool_err(-1, "invalid frame range: %s.", str);
		return -1;
	}

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

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

	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"];
	FILE *of;
	int rc;

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

	of = fopen(name, "wb");
	if (!of) {
		tool_err(0, "failed to open %s", name);
		return -1;
	}

	rc = img_output_png(of, name, width, height, framedata, mask, palette);
	if (rc < 0) {
		fclose(of);
		return -1;
	}

	if (fclose(of) == EOF) {
		tool_err(0, "error writing %s", name);
		return -1;
	}
		
	if (verbose)
		printf("wrote %s\n", name);

	return 0;
}

static int loadoverride(FILE *f, struct lbx_colour palette[static 256])
{
	struct lbx_image *overimg = lbx_img_open(f, &lbx_default_fops, NULL);
	struct lbx_imginfo info;

	if (!overimg) {
		tool_err(-1, "failed to open override image: %s", lbx_errmsg());
		return -1;
	}
	lbx_img_getinfo(overimg, &info);

	if (!info.palettesz) {
		tool_err(-1, "override image has no palette.");
		lbx_img_close(overimg);
		return -1;
	}

	if (lbx_img_getpalette(overimg, palette) == -1) {
		tool_err(-1, "error reading override palette: %s", lbx_errmsg());
		lbx_img_close(overimg);
		return -1;
	}

	lbx_img_close(overimg);
	return 0;
}

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

	/* For sanity. */
	if (!palf && !info->palettesz && !override) {
		tool_err(-1, "no palette available.");
		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 && lbx_img_loadpalette(palf, &lbx_default_fops, palette) != 0) {
		tool_err(-1, "error reading external palette: %s", lbx_errmsg());
		return -1;
	}

	/* Read the embedded palette, if any. */
	if (info->palettesz && lbx_img_getpalette(img, palette) == -1) {
		tool_err(-1, "error reading embedded palette: %s", lbx_errmsg());
		return -1;
	}

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

	return 0;
}

int decode(struct lbx_image *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;

	lbx_img_getinfo(img, &info);

	framebits = calloc(1, img->frames / 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, img->frames / CHAR_BIT + 1);
	} else {
		for (i = 0; argv[i]; i++) {
			parserange(img->frames, argv[i], framebits);
		}
	}

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

	/* Extract the images, in order. */
	for (i = 0; i < img->frames; i++) {
		unsigned char **data;
		unsigned char **mask;

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

		data = lbx_img_getframe(img, i);
		if (!data) {
			tool_err(-1, "error in frame %u: %s", i, lbx_errmsg());
			continue;
		}

		mask = lbx_img_getmask(img);

		if (!outpng(i, data, mask, img->width, img->height,
			    usepalette ? palette : NULL)) {
			extracted = 1;
		}
	}

	if (!extracted) {
		tool_err(-1, "no frames extracted.");
		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 stdin_handle = { .f = stdin };
	FILE *palf = NULL, *overf = NULL;
	const char *file = NULL;
	struct lbx_image *img;

	static const char *sopts = "idnvf: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' },

		{ "no-palette", 0, NULL, 'n' },

		{ 0 }
	};

	tool_init("lbximg", argc, argv);
	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':
			file = optarg;
			break;
		case 'n':
			usepalette = 0;
			break;
		case 'p':
			palf = fopen(optarg, "rb");
			if (!palf) {
				tool_err(0, "failed to open %s", optarg);
				return EXIT_FAILURE;
			}

			break;
		case 'O':
			overf = fopen(optarg, "rb");
			if (!overf) {
				tool_err(0, "failed to open %s", optarg);
				return EXIT_FAILURE;
			}
			break;
		case 'V':
			tool_version();
			return EXIT_SUCCESS;
		case 'U':
			printusage();
			return EXIT_SUCCESS;
		case 'H':
			printhelp();
			return EXIT_SUCCESS;
		case '?':
		case ':':
			return EXIT_FAILURE;
		}
	}

	if (mode == MODE_NONE) {
		tool_err(-1, "you must specify a mode.");
		return EXIT_FAILURE;
	}

	if (file)
		img = lbx_img_fopen(file);
	else
		img = lbx_img_open(&stdin_handle, &lbx_pipe_fops, NULL);

	if (!img) {
		tool_err(-1, "failed to open image: %s.", lbx_errmsg());
		return EXIT_FAILURE;
	}

	if (verbose || mode == MODE_IDENT) {
		struct lbx_imginfo info;

		if (!file)
			file = "stdin";

		lbx_img_getinfo(img, &info);
		printf("%s is %ux%u LBX image, %u frame(s)%s%s\n",
		       file, img->width, img->height, img->frames,
		       info.palettesz ? ", embedded palette" : "",
		       img->chunk     ? ", chunked" : "",
		       info.looping   ? ", loops" : "");
	}

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

	lbx_img_close(img);
	return rc;
}