Save scummer for "Getting Over It with Bennett Foddy"

save_scumming_over_it.py

import winreg
from pprint import pprint
import codecs
import xml.etree.ElementTree as ET
import os
import json
from datetime import datetime
import traceback
import sys


LOCATION_REG_KEY = "SOFTWARE\\Bennett Foddy\\Getting Over It"
IMPORTANT_KEYS = ["SaveGame0_h1867918426",
                  "SaveGame1_h1867918427", "NumSaves_h765021473"]

SAVE_FOLDER = "GoI_Saves"
SAVE_EXTENTION = "goi-scum-json"

MENU_TEXT = (
    """ Type an Option:
    X = exit
    Q = exit
    S = Save Current State
    L = Load last save-file as Current State
    O = Open specific file and load as Current State

    * Current State is what is written in the windows registry.
      i.e. what the game will read.

    * Rember to close the game before saving and loading.
""")


def print_exception(ex, msg, do_print=True):
    tb = ''.join(traceback.format_exception(
        etype=type(ex), value=ex, tb=ex.__traceback__))
    out = "Exception:\n{}\n{}".format(msg, tb)
    if do_print:
        print(out, file=sys.stderr)
    else:
        return out


class CustomException(Exception):
    pass


class BadXMLValues(CustomException):
    pass


class NoSavesFound(CustomException):
    pass


class BadSaveFile(CustomException):
    pass


def read_registry_values(key_location, value_names):
    reg_con = winreg.ConnectRegistry(None, winreg.HKEY_CURRENT_USER)
    open_key = winreg.OpenKey(reg_con, key_location, 0, winreg.KEY_ALL_ACCESS)
    registry_dict = dict()
    for key_name in value_names:
        val, rtype = winreg.QueryValueEx(open_key, key_name)
        if rtype == 3:
            val = codecs.encode(val, 'hex').decode("utf-8")
        registry_dict[key_name] = (val, rtype)
    return registry_dict


def write_registry_values(key_location, values_dict):
    reg_con = winreg.ConnectRegistry(None, winreg.HKEY_CURRENT_USER)
    open_key = winreg.OpenKey(reg_con, key_location, 0, winreg.KEY_ALL_ACCESS)
    for key_name, vtuple in values_dict.items():
        val, rtype = vtuple
        if rtype == 3:
            val = codecs.decode(val, 'hex')
        winreg.SetValueEx(open_key, key_name, 0, rtype, val)


def read_and_check():
    registry_dict = read_registry_values(LOCATION_REG_KEY, IMPORTANT_KEYS)
    did_find_saves = False
    for key_name, val_n_type in registry_dict.items():
        value, rtype = val_n_type
        if not key_name.startswith('SaveGame'):
            continue
        else:
            did_find_saves = True

        try:
            xml_string = codecs.decode(value, 'hex').decode('utf-8')[:-1]
            ET.fromstring(xml_string)
        except Exception as ex:
            # print_exception(ex, "OH NOE!")
            raise BadXMLValues(
                "A saved game in registry is malformed, try agian later")
    if not did_find_saves:
        raise NoSavesFound(
            "Hey! You need to play the game first. There are no Saved Games")
    return registry_dict


def generate_save_name():
    ts = datetime.utcfromtimestamp(
        datetime.now().timestamp()).timestamp() * 1000.0
    tstr = [n for n in reversed(str(ts).split('.'))].pop()
    return "{}.{}".format(tstr, SAVE_EXTENTION)


def check_make_dir(dir):
    if not os.path.isdir(dir):
        os.mkdir(dir)


def do_save():
    check_make_dir(SAVE_FOLDER)
    filename = None
    try:
        save_json = json.dumps(read_and_check())
        filename = generate_save_name()
        filepath = os.path.join(SAVE_FOLDER, filename)
        with open(filepath, 'w') as fh:
            fh.write(save_json)

    except CustomException as ex:
        print(ex)

    else:
        print('Saved game to "{}"'.format(filename))


def checked_load(filepath):
    registry_dict = None
    with open(filepath, 'r') as fp:
        registry_dict = json.load(fp)
        # pprint(registry_dict)
    if registry_dict is None:
        raise BadSaveFile()
    if len(list(filter(lambda k: k in IMPORTANT_KEYS, registry_dict))) is not len(IMPORTANT_KEYS):
        raise BadSaveFile()
    write_registry_values(LOCATION_REG_KEY, registry_dict)


def do_load():
    check_make_dir(SAVE_FOLDER)
    files = os.listdir(SAVE_FOLDER)
    known_saves = filter(lambda fn: fn.endswith(SAVE_EXTENTION), files)
    last_save = sorted(known_saves).pop()

    print('Would you like to load "{}"?'.format(last_save))

    selection = input("Y/N > ").upper().lstrip().strip()
    if not selection.startswith("Y"):
        print("Will not load save, due to your selection.")
        return

    filepath = os.path.join(SAVE_FOLDER, last_save)
    try:
        checked_load(filepath)
    except BadSaveFile as ex:
        print_exception(ex, "Whoa, save file is bad.")


def do_open_and_load():
    print("Enter file name (including path):")
    filename = input("> ").lstrip().strip()
    if not os.path.isfile(filename):
        print("File doesnt exist!")
        return
    print('Are you sure you want to load "{}" into registry - making it the current save game?'.format(filename))
    selection = input("Y/N > ").upper().lstrip().strip()
    if not selection.startswith("Y"):
        print("Will not load save, due to your selection.")
        return
    try:
        checked_load(filename)
    except BadSaveFile as ex:
        print_exception(ex, "Whoa, save file is bad.")





def main():
    stay_running = True
    while stay_running:
        print()
        print()
        print(MENU_TEXT)
        selection = input("Enter option> ").upper().lstrip().strip()

        if selection.startswith("X") or selection.startswith("Q"):
            print('bye!')
            stay_running = False
        elif selection.startswith("S"):
            do_save()
        elif selection.startswith("L"):
            do_load()
        elif selection.startswith("O"):
            do_open_and_load()
        print("#################")
        continue


if __name__ == '__main__':
    main()