""" SG Backup Doku

Automagically document the windows backup process
"""

__version__ = "0.0.1"


from datetime import datetime
from pathlib import Path

import Evtx.Evtx as evtx
import Evtx.Views as e_views


SCHEMA = "{http://schemas.microsoft.com/win/2004/08/events/event}"

LEFT_TO_RIGHT_MARK = "\u200e"

LOG_TIME_FORMAT = "%d/%m/%Y %H:%M"
DOC_DATE_FORMAT = "%Y-%m-%d"
DOC_DATE_TIME_FORMAT = DOC_DATE_FORMAT + " %H:%M"


def _get_backup_time(record):
    """ extract the raw date from an log entry record """
    node = record.lxml()
    for item in node.iter(f"{SCHEMA}Data"):
        if item.attrib.get("Name") == "ProtectedUpToTime":
            if item.text in (None, "NULL"):
                return None
            raw = item.text.replace(LEFT_TO_RIGHT_MARK, "")
            return datetime.strptime(raw, LOG_TIME_FORMAT)


def get_last_backup_time(path):
    with evtx.Evtx(path) as log:
        time_entries = (_get_backup_time(record) for record in log.records())
        backup_times = (entry for entry in time_entries if entry)
        return max(backup_times)


def document_last_backup_time(path, last_backup_time):
    with open(path, "a") as fh:
        now = datetime.now()
        now_text = now.strftime(DOC_DATE_FORMAT)
        last_backup_text = last_backup_time.strftime(DOC_DATE_TIME_FORMAT)
        line = f"{now_text}\tLast successful backup on {last_backup_text}"
        fh.write(f"{line}\n")


def windows():
    LOG_FILE_PATH = r"C:\Windows\System32\winevt\Logs\Microsoft-Windows-FileHistory-Core%4WHC.evtx"
    OUT_FILE_PATH = r"C:\Users\Holgi\Documents\safeguard_backup_documentation.txt"
    
    last_backup = get_last_backup_time(Path(LOG_FILE_PATH))
    document_last_backup_time(Path(OUT_FILE_PATH), last_backup)