#!/usr/bin/python3

# Copyright 2021, Robert Maupin

# Copying and distribution of this file, with or without modification, are

# permitted in any medium without royalty, provided the copyright notice and

# this notice are preserved. This file is offered as-is, without any warranty.

import io

import os

import lz4.block

import math

import sys

from glob import glob

FILE_PATH = os.path.dirname(os.path.realpath(__file__))

def uint32(data: bytes) -> int:

"""Convert 4 bytes to a little endian unsigned integer."""

return int.from_bytes(data, byteorder='little', signed=False) & 0xffffffff

def byte4(data: int):

"""Convert unsigned 32 bit integer to 4 bytes."""

return data.to_bytes(4, byteorder='little', signed=False)

# The important part

def decompress(data):

"""Decompresses the given save bytes."""

size = len(data)

din = io.BytesIO(data)

out = bytearray()

while din.tell() < size:

magic = uint32(din.read(4))

if magic != 0xfeeda1e5:

print("Invalid Block, bad file")

return bytes() # some unsupported format

compressedSize = uint32(din.read(4))

uncompressedSize = uint32(din.read(4))

din.seek(4, 1) # skip 4 bytes

out += lz4.block.decompress(din.read(compressedSize), uncompressed_size=uncompressedSize)

return out

# The important part, part 2

def compress(data):

"""Compresses the given save bytes."""

size = len(data)

din = io.BytesIO(data)

out = bytearray()

while din.tell() < size:

uncompressedSize = min([0x80000, size - din.tell()])

block = lz4.block.compress(din.read(uncompressedSize), store_size=False)

out += byte4(0xfeeda1e5)

out += byte4(len(block))

out += byte4(uncompressedSize)

out += byte4(0)

out += block

return out

def readFile(path):

fin = open(path, "rb")

data = fin.read()

fin.close()

return data

def writeFile(path, data):

fout = open(path, "wb")

fout.write(data)

fout.close()

def findSaveGames():

"""Finds all saves on windows."""

return glob("C:\\Users\\*\\AppData\\Roaming\\HelloGames\\NMS\\*\\save*.hg")

def usage(name):

print("No Man's Sky Save Tool v0.1")

print("Copyright (c) 2021 Robert Maupin. Permissive License.")

print("Usage: %s compress <input> <output>" % os.path.basename(name))

print("Usage: %s decompress <input> <output>" % os.path.basename(name))

print("Usage: %s list" % os.path.basename(name))

print(" compress Decompress a given 'No Man's Sky' save file.")

print(" decompress Compress a given 'No Man's Sky' save file.")

print(" list Searchs for save files and outputs what files were found.")

def main():

args = sys.argv

if len(args) == 2:

if args[1] == "l" or args[1] == "list":

for file in findSaveGames():

print(file)

return

if len(args) == 4:

if args[1] == "c" or args[1] == "compress":

writeFile(args[3], compress(readFile(args[2])))

print("done")

return

if args[1] == "d" or args[1] == "decompress":

writeFile(args[3], decompress(readFile(args[2])))

print("done")

return

usage(args[0])

main()