update.py

# exes from https://github.com/macchrome/winchrome/releases
# requires a valid installation of 7zip.
# also requires psutil and requests: pip3 install psutil requests
import os
import requests
import winreg
import re
from pathlib import Path
import subprocess
import shutil
import psutil
import platform
import sys
import json
##############################
## Choose Install Location: ##
##############################
# Install in ProgramData (old default)
CHROMIUM_PATH = Path(os.getenv('PROGRAMDATA'),'Ungoogled Chromium').resolve()
# Install in Program Files (recommended)
# CHROMIUM_PATH = Path(os.getenv('PROGRAMFILES'),'Ungoogled Chromium').resolve()
# Install in AppData (if installing for a single user only)
# CHROMIUM_PATH = Path(os.getenv('LOCALAPPDATA'),'Programs','Ungoogled Chromium').resolve()
##############################
##############################
VERSION_FROM_TAG = re.compile('M([\d\.]*)')
RELEASE_INFO_PATH = CHROMIUM_PATH.joinpath('github_asset_info')
IS_64_BIT = platform.machine().endswith('64')

class ChromiumUpdater:
    OWNER = 'macchrome'
    REPO = 'winchrome'
    def __init__(self):
        try:
            CHROMIUM_PATH.mkdir() # can use exist_ok=True if pathlib > 3.5
        except FileExistsError:
            pass
        sub_key_7zfm = r'SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\7zFM.exe'
        try:
            with winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, sub_key_7zfm) as key_handle:
                sevenzipfm_dir = winreg.QueryValueEx(key_handle, 'Path')[0]
        except OSError:
            raise Exception('Unable to locate 7-zip from the Windows Registry')
        self.SEVENZIP = Path(sevenzipfm_dir, '7z.exe')
        if not self.SEVENZIP.is_file():
            raise Exception(f'7z.exe not found at path from registry: {self.SEVENZIP}')
        self.sinfo = subprocess.STARTUPINFO()
        self.sinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
        
    def _get_latest_release(self):
        r = requests.get(f'https://api.github.com/repos/{self.OWNER}/{self.REPO}/releases')
        r.raise_for_status()
        for release in sorted([r for r in r.json() if 'ungoogled' in r['name'].lower()], key=lambda a:a['id'], reverse=True):
            version = VERSION_FROM_TAG.search(release['tag_name'])
            if not version:
                raise Exception('Release version number could not be parsed.')
            valid_assets = [a for a in sorted(release['assets'], key=lambda a:a['id'], reverse=True) if a['name'].lower().endswith(f"{'win64' if IS_64_BIT else 'win32'}.7z")]
            if not valid_assets:
                continue
            valid_assets[0]['release_version'] = version.group(1)
            return valid_assets[0]
        else:
            raise Exception('No ungoogled versions found in releases.')
            
    def _check_running(self):
        for proc in psutil.process_iter():
            try:
                exepath = Path(CHROMIUM_PATH,'chrome.exe')
                if proc.name() == exepath.name and proc.exe() == str(exepath):
                    raise Exception('Chromium is currently running.')
            except psutil.NoSuchProcess as err:
                pass
            except psutil.AccessDenied:
                pass
            
    def run_on_schedule_and_startup(self, enable = True, path = Path(__file__) ):
        startup_key = r'Software\Microsoft\Windows\CurrentVersion\Run'
        winreg.CreateKeyEx(winreg.HKEY_CURRENT_USER, startup_key)
        key = winreg.OpenKeyEx(winreg.HKEY_CURRENT_USER, startup_key, access=winreg.KEY_WRITE)
        if enable:
            winreg.SetValueEx(key, 'Ungoogled Chromium Updater', 0, winreg.REG_SZ, f'"{sys.executable.replace("python.exe","pythonw.exe")}" "{path}"')
        else:
            try:
                winreg.DeleteValue(key, 'Ungoogled Chromium Updater')
            except FileNotFoundError:
                pass
        winreg.CloseKey(key)
        if enable:
            os.system(fr'''SchTasks /Create /SC DAILY /TN "Ungoogled Chromium Updater" /TR "'{sys.executable.replace('python.exe','pythonw.exe')}' '{path.absolute()}'" /ST 00:00 /F''')
        else:
            os.system(fr'''SchTasks /Delete /TN "Ungoogled Chromium Updater" /F''')
        
    def verify_archive(self, zippath, expected_version):
        ''' returns name of chrome archive or None if not found.'''
        bytes = subprocess.check_output([str(self.SEVENZIP), 'l', str(zippath)], startupinfo=self.sinfo)
        paths = [split[-1] for split in [line.split() for line in bytes.decode('utf-8').splitlines()] if len(split) and split[-1].endswith('.manifest')]
        for filepath in paths:
            fp = Path(filepath)
            if fp.parent.name and fp.stem == expected_version:
                return fp.parent
        return None
        
    def update(self):
        self._check_running()
        if RELEASE_INFO_PATH.exists():
            with RELEASE_INFO_PATH.open('r') as f:
                current_release_id = json.load(f)['id']
        else:
            current_release_id = 0
        new_version_info = self._get_latest_release()
        if current_release_id != new_version_info['id']:
            print('New version found, updating...')
        else:
            print('Ungoogled Chromium is up to date.')
            return
        tmpzip = Path(CHROMIUM_PATH,'zipped_tmp.7z')
        try:
            tmpzip.unlink() # can use missing_ok=True if pathlib > 3.8
        except FileNotFoundError:
            pass
        r = requests.get(new_version_info['browser_download_url'])
        r.raise_for_status()
        tmpzip.write_bytes(r.content)
        
        archive_contents = self.verify_archive(tmpzip, new_version_info['release_version'])
        if not archive_contents:
            raise Exception('Unexpected contents of Chromium archive.')
        googledir = Path(CHROMIUM_PATH, archive_contents)
        try:
            output = subprocess.check_output([str(self.SEVENZIP), 'x', str(tmpzip), f'-o{CHROMIUM_PATH}','-y'], startupinfo=self.sinfo)
        except subprocess.CalledProcessError:
            raise Exception('7zip extraction failed.')
        
        # delete all files in directory:
        for path in CHROMIUM_PATH.iterdir():
            if path.is_dir():
                if path != googledir:
                    shutil.rmtree(path)
            elif path.name not in (tmpzip.name,os.path.basename(__file__)):
                path.unlink()

        # copy contents of folder.
        shutil.copytree(googledir, str(CHROMIUM_PATH), dirs_exist_ok = True)
        #cleanup
        with RELEASE_INFO_PATH.open('w') as f:
            json.dump(new_version_info, f)
        try:
            tmpzip.unlink() # can use missing_ok=True if pathlib > 3.8
        except FileNotFoundError:
            pass
        shutil.rmtree(googledir)
            
if __name__ == '__main__':
    import argparse
    parser = argparse.ArgumentParser(description='Update Ungoogled Chromium.')
    parser.add_argument('--install', action='store_true',
                        help='Automatically update on Windows login and daily at 00:00.')
    parser.add_argument('--uninstall', action='store_true',
                        help='Do not run automatically.')

    args = parser.parse_args()
    c = ChromiumUpdater()
    try:
        c.update()
    finally:
        if args.install or args.uninstall:
            shutil.copyfile(Path(__file__).absolute(),Path(CHROMIUM_PATH,os.path.basename(__file__)))
            c.run_on_schedule_and_startup(enable = args.install, path=Path(CHROMIUM_PATH,os.path.basename(__file__)))