+int GetZipFileTreeType(char *zip_filename)
+{
+ static char *top_dir_path = NULL;
+ static char *top_dir_conf_filename[NUM_BASE_TREE_TYPES] = { NULL };
+ static char *conf_basename[NUM_BASE_TREE_TYPES] =
+ {
+ GRAPHICSINFO_FILENAME,
+ SOUNDSINFO_FILENAME,
+ MUSICINFO_FILENAME,
+ LEVELINFO_FILENAME
+ };
+ int j;
+
+ checked_free(top_dir_path);
+ top_dir_path = NULL;
+
+ for (j = 0; j < NUM_BASE_TREE_TYPES; j++)
+ {
+ checked_free(top_dir_conf_filename[j]);
+ top_dir_conf_filename[j] = NULL;
+ }
+
+ char **zip_entries = zip_list(zip_filename);
+
+ // check if zip file successfully opened
+ if (zip_entries == NULL || zip_entries[0] == NULL)
+ return TREE_TYPE_UNDEFINED;
+
+ // first zip file entry is expected to be top level directory
+ char *top_dir = zip_entries[0];
+
+ // check if valid top level directory found in zip file
+ if (!strSuffix(top_dir, "/"))
+ return TREE_TYPE_UNDEFINED;
+
+ // get filenames of valid configuration files in top level directory
+ for (j = 0; j < NUM_BASE_TREE_TYPES; j++)
+ top_dir_conf_filename[j] = getStringCat2(top_dir, conf_basename[j]);
+
+ int tree_type = TREE_TYPE_UNDEFINED;
+ int e = 0;
+
+ while (zip_entries[e] != NULL)
+ {
+ // check if every zip file entry is below top level directory
+ if (!strPrefix(zip_entries[e], top_dir))
+ return TREE_TYPE_UNDEFINED;
+
+ // check if this zip file entry is a valid configuration filename
+ for (j = 0; j < NUM_BASE_TREE_TYPES; j++)
+ {
+ if (strEqual(zip_entries[e], top_dir_conf_filename[j]))
+ {
+ // only exactly one valid configuration file allowed
+ if (tree_type != TREE_TYPE_UNDEFINED)
+ return TREE_TYPE_UNDEFINED;
+
+ tree_type = j;
+ }
+ }
+
+ e++;
+ }
+
+ return tree_type;
+}
+