/*
 * Copyright (C) 2013  Patrick "P. J." McDermott
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/>.
 */

#include <stdio.h>
#include <SDL.h>
#include <config.h>
#include "../logging.h"
#include "palette.h"
#include "resource.h"

struct resource_table pal_res;

static void palette_gpl_parse(const char *, SDL_Palette *);

struct palette *
palette_get(const char *path)
{
	struct palette *pal;

	pal = (struct palette *) resource_get(&pal_res, path);
	if (pal != NULL) {
		resource_use((struct resource *) pal);
		return pal;
	}

	pal = resource_alloc(path, sizeof(*pal));
	pal->palette = malloc(sizeof(*pal->palette));
	if (pal->palette == NULL) {
		err(1, "Failed to load palette \"%s\" (out of memory)", path);
	}
	pal->palette->colors = malloc(sizeof(*pal->palette->colors) * 240);
	if (pal->palette->colors == NULL) {
		err(1, "Failed to load palette \"%s\" (out of memory)", path);
	}

	palette_gpl_parse(path, pal->palette);

#ifdef DEBUG_PALETTES
	{
		int col_i;

		debug("Palette \"%s\"", path);
		for (col_i = 0; col_i < pal->palette->ncolors; ++col_i) {
			debug("    Color %3.3d: 0x%2.2x%2.2x%2.2x",
					col_i,
					pal->palette->colors[col_i].r,
					pal->palette->colors[col_i].g,
					pal->palette->colors[col_i].b);
		}
	}
#endif

	resource_use((struct resource *) pal);
	resource_add(&pal_res, path, (struct resource *) pal);

	return pal;

}

static void
palette_gpl_parse(const char *path, SDL_Palette *palette)
{
	FILE *fp;
	char str[1024];
	int i;
	char *tok;

	/*
	 * See also:
	 *   * gimp_palette_load()
	 *     GIMP 2.8.2, app/core/gimppalette-load.c:53
	 */

	fp = fopen(path, "rb");
	if (fp == NULL) {
		err(1, "Failed to load palette \"%s\" (cannot open file)",
				path);
	}

	/* GIMP Palette */
	if (fgets(str, sizeof(str), fp) == NULL) {
		err(1, "Failed to load palette \"%s\" (cannot read line)",
				path);
	}
	if (strncmp(str, "GIMP Palette", 12) != 0) {
		err(1, "Failed to load palette \"%s\" (bad magic header)",
				path);
	}

	/* Name: ... */
	if (fgets(str, sizeof(str), fp) == NULL) {
		err(1, "Failed to load palette \"%s\" (cannot read line)",
				path);
	}
	if (strncmp(str, "Name: ", 6) == 0) {
		/* Columns: ... */
		if (fgets(str, sizeof(str), fp) == NULL) {
			err(1, "Failed to load palette \"%s\" "
					"(cannot read line)", path);
		}
		if (strncmp(str, "Columns: ", 9) == 0) {
			if (fgets(str, sizeof(str), fp) == NULL) {
				err(1, "Failed to load palette \"%s\" "
						"(cannot read line)", path);
			}
		}
	}

	i = 0;
	while (!feof(fp)) {
		if (str[0] != '#' && str[0] != '\n') {
			if (i >= 240) {
				warn("Ignoring extra colors in palette \"%s\"",
						path);
				break;
			}

			tok = strtok(str, " \t");
			if (tok != NULL) {
				palette->colors[i].r = atoi(tok);
			} else {
				warn("Bad color definition in palette \"%s\"",
						path);
			}

			tok = strtok(NULL, " \t");
			if (tok != NULL) {
				palette->colors[i].g = atoi(tok);
			} else {
				warn("Bad color definition in palette \"%s\"",
						path);
			}

			tok = strtok(NULL, " \t");
			if (tok != NULL) {
				palette->colors[i].b = atoi(tok);
			} else {
				warn("Bad color definition in palette \"%s\"",
						path);
			}

			++i;
		}

		if (fgets(str, sizeof(str), fp) == NULL) {
			if (feof(fp)) {
				break;
			}
			err(1, "Failed to load palette \"%s\" "
					"(cannot read line)", path);
		}
	}

	palette->ncolors = i;
	fclose(fp);
}

void
palette_free(struct palette *palette)
{
	SDL_Palette *data;

	if (palette == NULL) {
		return;
	}

	data = palette->palette;
	if (resource_free(&pal_res, (struct resource *) palette)) {
		free(data->colors);
		free(data);
	}
}