#ifndef WIN32
    #include "dirent.h"
#endif

#include "errno.h"
#include "nse_macros.h"
#include "nse_fs.h"
#include "nmap.h"
#include "nmap_error.h"
#include "NmapOps.h"

extern NmapOps o;

static bool filename_is_absolute(const char *file) {
	if (file[0] == '/')
		return true;
#ifdef WIN32
	if ((file[0] != '\0' && file[1] == ':') || file[0] == '\\')
		return true;
#endif
	return false;
}

/* This is simply the most portable way to check
 * if a file has a given extension.
 * The portability comes at the price of reduced
 * flexibility.
 */
int nse_check_extension (const char* ext, const char* path)
{
  int pathlen = strlen(path);
  int extlen = strlen(ext);
  if (extlen > pathlen || pathlen > MAX_FILENAME_LEN)
    return 0;
  else
    return strcmp(path + pathlen - extlen, ext) == 0;
}

int nse_fetchfile(char *path, size_t path_len, const char *file) {
	int type = nmap_fetchfile(path, path_len, file);

	// lets look in <nmap>/scripts too
	if(type == 0) {
        std::string alt_path = std::string(SCRIPT_ENGINE_LUA_DIR) + std::string(file);
		type = nmap_fetchfile(path, path_len, alt_path.c_str());
	}

	return type;
}

/* This is a modification of nse_fetchfile that first looks for an
 * absolute file name.
 */
int nse_fetchfile_absolute(char *path, size_t path_len, const char *file) {
	if (filename_is_absolute(file)) {
		if (o.debugging > 1)
			log_write(LOG_STDOUT, "%s: Trying absolute path %s\n", SCRIPT_ENGINE, file);
		Strncpy(path, file, path_len);
		return nmap_fileexistsandisreadable(file);
	}

	return nse_fetchfile(path, path_len, file);
}

#ifdef WIN32

int nse_scandir (lua_State *L) {
	HANDLE dir;
	WIN32_FIND_DATA entry;
	std::string path;
	BOOL morefiles = FALSE;
    const char *dirname = luaL_checkstring(L, 1);
    int files_or_dirs = luaL_checkint(L, 2);

    lua_createtable(L, 100, 0); // 100 files average

	dir = FindFirstFile((std::string(dirname) + "\\*").c_str(), &entry);

	if (dir == INVALID_HANDLE_VALUE)
    	{ 
		error("%s: No files in '%s\\*'", SCRIPT_ENGINE, dirname);
		return SCRIPT_ENGINE_ERROR;
	}

	while(!(morefiles == FALSE && GetLastError() == ERROR_NO_MORE_FILES)) {
		// if we are looking for files and this file doesn't end with .nse or
		// is a directory, then we don't look further at it
		if(files_or_dirs == FILES) {
			if(!(
						(nse_check_extension(SCRIPT_ENGINE_EXTENSION, entry.cFileName)) 
						&& !(entry.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
			    )) { 
				morefiles = FindNextFile(dir, &entry);
				continue;
			}

		// if we are looking for dirs and this dir
		// isn't a directory, then we don't look further at it
		} else if(files_or_dirs == DIRS) {
			if(!(
						(entry.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
			    )) {
				morefiles = FindNextFile(dir, &entry);
				continue;
			}
		
		// they have passed an invalid value for files_or_dirs 
		} else {
			fatal("%s: In: %s:%i This should never happen.", 
					SCRIPT_ENGINE, __FILE__, __LINE__);
		}

		// otherwise we add it to the results
		// we assume that dirname ends with a directory separator of some kind
		path = std::string(dirname) + "\\" + std::string(entry.cFileName);
        lua_pushstring(L, path.c_str());
        lua_rawseti(L, -2, lua_objlen(L, -2) + 1);
		morefiles = FindNextFile(dir, &entry);
	}


	return 1;
}

#else

int nse_scandir (lua_State *L) {
	DIR* dir;
	struct dirent* entry;
	struct stat stat_entry;
    const char *dirname = luaL_checkstring(L, 1);
    int files_or_dirs = luaL_checkint(L, 2);

    lua_createtable(L, 100, 0); // 100 files average

	dir = opendir(dirname);
	if(dir == NULL) {
		error("%s: Could not open directory '%s'.", SCRIPT_ENGINE, dirname);
		return SCRIPT_ENGINE_ERROR;
	}
	
	// note that if there is a symlink in the dir, we have to rely on
	// the .nse extension
	// if they provide a symlink to a dir which ends with .nse, things
	// break :/
	while((entry = readdir(dir)) != NULL) {
        std::string path = std::string(dirname) + "/" + std::string(entry->d_name);
		
		if(stat(path.c_str(), &stat_entry) != 0)
			fatal("%s: In: %s:%i This should never happen.", 
					SCRIPT_ENGINE, __FILE__, __LINE__);

		// if we are looking for files and this file doesn't end with .nse and
		// isn't a file or a link, then we don't look further at it
		if(files_or_dirs == FILES) {
			if(!(
						(nse_check_extension(SCRIPT_ENGINE_EXTENSION, entry->d_name)) 
						&& (S_ISREG(stat_entry.st_mode) 
							|| S_ISLNK(stat_entry.st_mode))
			    )) { 
				continue;
			}

			// if we are looking for dirs and this dir
			// isn't a dir or a link, then we don't look further at it
		} else if(files_or_dirs == DIRS) {
			if(!(
						(S_ISDIR(stat_entry.st_mode) 
						 || S_ISLNK(stat_entry.st_mode))
			    )) {
				continue;
			}

			// they have passed an invalid value for files_or_dirs 
		} else {
			fatal("%s: In: %s:%i This should never happen.", 
					SCRIPT_ENGINE, __FILE__, __LINE__);
		}

		// otherwise we add it to the results
        lua_pushstring(L, path.c_str());
        lua_rawseti(L, -2, lua_objlen(L, -2) + 1);
	}
	
	closedir(dir);

	return 1;
}

#endif