/***************************************************************************
 resource_patch.c  Copyright (C) 2001 Christoph Reichenbach


 This program may be modified and copied freely according to the terms of
 the GNU general public license (GPL), as long as the above copyright
 notice and the licensing information contained herein are preserved.

 Please refer to www.gnu.org for licensing details.

 This work is provided AS IS, without warranty of any kind, expressed or
 implied, including but not limited to the warranties of merchantibility,
 noninfringement, and fitness for a specific purpose. The author will not
 be held liable for any damage caused by this work or derivatives of it.

 By using this source code, you agree to the licensing terms as stated
 above.


 Please contact the maintainer for bug reports or inquiries.

 Current Maintainer:

    Christoph Reichenbach (CR) <jameson@linuxgames.com>

***************************************************************************/


#include "sci/include/sciresource.h"
#include "sci/include/sci_memory.h"

void
sci0_sprintf_patch_file_name(char *string, resource_t *res) {
	sprintf(string, "%s.%03i", sci_resource_types[res->type], res->number);
}

void
sci1_sprintf_patch_file_name(char *string, resource_t *res) {
	sprintf(string, "%d.%s", res->number, sci_resource_type_suffixes[res->type]);
}

/* version-agnostic patch application */
static void
process_patch(resource_source_t *source,
              char *entry, int restype, int resnumber, resource_t **resource_p, int *resource_nr_p) {
	int fsize;
	char filename[MAXPATHLEN];

	if (restype == sci_invalid_resource)
		return;

	printf("Patching \"%s\": ", entry);

	sprintf(filename, "%s%s", source->location.dir.name, entry);
	fsize = sci_file_size(filename);
	if (fsize < 0)
		perror("""__FILE__"": (""__LINE__""): sci_file_size()");
	else {
		int file;
		guint8 filehdr[2];
		resource_t *newrsc = _scir_find_resource_unsorted(*resource_p,
		                     *resource_nr_p,
		                     restype,
		                     resnumber);

		if (fsize < 3) {
			printf("File too small\n");
			return;
		}

		file = open(entry, O_RDONLY);
		if (!IS_VALID_FD(file))
			perror("""__FILE__"": (""__LINE__""): open()");
		else {
			int patch_data_offset;

			read(file, filehdr, 2);

			patch_data_offset = filehdr[1];

			if ((filehdr[0] & 0x7f) != restype) {
				printf("Failed; resource type mismatch\n");
				close(file);
			} else if (patch_data_offset + 2 >= fsize) {
				printf("Failed; patch starting at offset %d can't be in file of size %d\n", filehdr[1] + 2, fsize);
				close(file);
			} else {
				/* Adjust for file offset */
				fsize -= patch_data_offset;

				/* Prepare destination, if neccessary */
				if (!newrsc) {
					/* Completely new resource! */
					++(*resource_nr_p);
					*resource_p = (resource_t*)sci_realloc(*resource_p,
					                                       *resource_nr_p
					                                       * sizeof(resource_t));
					newrsc = (*resource_p - 1) + *resource_nr_p;
					newrsc->alt_sources = NULL;
				}

				/* Overwrite everything, because we're patching */
				newrsc->size = fsize - 2;
				newrsc->id = restype << 11 | resnumber;
				newrsc->number = resnumber;
				newrsc->status = SCI_STATUS_NOMALLOC;
				newrsc->type = restype;
				newrsc->source = source;
				newrsc->file_offset = 2 + patch_data_offset;

				_scir_add_altsource(newrsc, source, 2);

				close(file);

				printf("OK\n");

			}
		}
	}
}


int
sci0_read_resource_patches(resource_source_t *source, resource_t **resource_p, int *resource_nr_p) {
	sci_dir_t dir;
	char *entry;
	char *caller_cwd = sci_getcwd();

	chdir(source->location.dir.name);
	sci_init_dir(&dir);
	entry = sci_find_first(&dir, "*.???");
	while (entry) {
		int restype = sci_invalid_resource;
		int resnumber = -1;
		int i;
		unsigned int resname_len;
		char *endptr;

		for (i = sci_view; i < sci_invalid_resource; i++)
			if (scumm_strnicmp(sci_resource_types[i], entry,
			                strlen(sci_resource_types[i])) == 0)
				restype = i;

		if (restype != sci_invalid_resource) {

			resname_len = strlen(sci_resource_types[restype]);
			if (entry[resname_len] != '.')
				restype = sci_invalid_resource;
			else {
				resnumber = strtol(entry + 1 + resname_len,
				                   &endptr, 10); /* Get resource number */
				if ((*endptr != '\0') || (resname_len + 1 == strlen(entry)))
					restype = sci_invalid_resource;

				if ((resnumber < 0) || (resnumber > 1000))
					restype = sci_invalid_resource;
			}
		}

		process_patch(source, entry, restype, resnumber, resource_p, resource_nr_p);

		entry = sci_find_next(&dir);
	}

	chdir(caller_cwd);
	free(caller_cwd);
	return 0;
}

int
sci1_read_resource_patches(resource_source_t *source, resource_t **resource_p, int *resource_nr_p) {
	sci_dir_t dir;
	char *entry;
	char *caller_cwd = sci_getcwd();

	chdir(source->location.dir.name);
	sci_init_dir(&dir);
	entry = sci_find_first(&dir, "*.*");
	while (entry) {
		int restype = sci_invalid_resource;
		int resnumber = -1;
		int i;
		char *endptr;
		char *dot = strchr(entry, '.');

		for (i = sci_view; i < sci_invalid_resource; i++) {
			if (dot != NULL) {
				if (scumm_strnicmp(sci_resource_type_suffixes[i], dot + 1, 3) == 0) {
					restype = i;
				}
			}
		}

		if (restype != sci_invalid_resource) {

			resnumber = strtol(entry,
			                   &endptr, 10); /* Get resource number */

			if (endptr != dot)
				restype = sci_invalid_resource;

			if (*(dot + 4) != '\0')
				restype = sci_invalid_resource;

			if ((resnumber < 0) || (resnumber > 8192))
				restype = sci_invalid_resource;
		}

		process_patch(source, entry, restype, resnumber, resource_p, resource_nr_p);

		entry = sci_find_next(&dir);
	}

	chdir(caller_cwd);
	free(caller_cwd);
	return 0;
}