#ifndef OS_H_
#define OS_H_

typedef enum {
	FS_NON_EXISTENT,
	FS_FILE,
	FS_DIRECTORY,
	FS_OTHER
} FsType;

enum {
	FS_PERMISSION_READ = 0x01,
	FS_PERMISSION_WRITE = 0x02,
};
typedef u8 FsPermission;

typedef struct {
	FsType type;
	char name[];
} FsDirectoryEntry;

// returns what kind of thing this is.
FsType fs_path_type(char const *path);
FsPermission fs_path_permission(char const *path);
// Does this file exist? Returns false for directories.
bool fs_file_exists(char const *path);
// Returns a NULL-terminated array of the files/directories in this directory, or NULL if the directory does not exist/out of memory.
// When you're done with the entries, call fs_dir_entries_free (or call free on each entry, then on the whole array).
// NOTE: The files/directories aren't returned in any particular order!
FsDirectoryEntry **fs_list_directory(char const *dirname);
// Create the directory specified by `path`
// Returns:
// 1  if the directory was created successfully
// 0  if the directory already exists
// -1 if the path already exists, but it's not a directory, or if there's another error (e.g. don't have permission to create directory).
int fs_mkdir(char const *path);
// Puts the current working directory into buf, including a null-terminator, writing at most buflen bytes.
// Returns:
// 1  if the working directory was inserted into buf successfully
// 0  if buf is too short to hold the cwd
// -1 if we can't get the cwd for whatever reason.
int fs_get_cwd(char *buf, size_t buflen);
struct timespec time_last_modified(char const *filename);
struct timespec time_get(void);
// sleep for a certain number of nanoseconds
void time_sleep_ns(u64 ns);


// free the entries generated by fs_list_directory.
static void fs_dir_entries_free(FsDirectoryEntry **entries) {
	for (int i = 0; entries[i]; ++i)
		free(entries[i]);
	free(entries);
}

static double time_get_seconds(void) {
	return timespec_to_seconds(time_get());
}



// sleep for microseconds
static void time_sleep_us(u64 us) {
	time_sleep_ns(us * 1000);
}

// sleep for milliseconds
static void time_sleep_ms(u64 ms) {
	time_sleep_ns(ms * 1000000);
}

// sleep for seconds
static void time_sleep_s(u64 s) {
	time_sleep_ns(s * 1000000000);
}


#endif // OS_H_