Start the LibreOffice (FlatPak) in a virtual environment.

office.py

"""
This module is used to start the LibreOffice (FlatPak) in a virtual environment.
When this script is run, it will start the LibreOffice (FlatPak) and include
the virtual environment's site-packages directory in the PYTHONPATH.

In short when this module is included in the root of a project with a virtual environment
then the LibreOffice (FlatPak) will be able to import the project's modules installed with pip.

Usage:
    python office.py [options] [app]

Examples:
    python office.py --nologo writer

Known Issues:
    The --minimized option does not work (at least not when I tested).

See:
    https://gist.github.com/Amourspirit/1540a52f21c020a8190b468a3e9efc16
"""
from __future__ import annotations
from typing import List, Union
import argparse
import os
import sys
from pathlib import Path
from subprocess import Popen


# region Get Virtual Environment Location
def _get_root_dir() -> Path:
    return Path(_get_virtual_env()).parent

def _get_virtual_env() -> Path:
    """
    Gets the Virtual Environment for current python environment.

    Raises:
        FileNotFoundError: If no virtual environment is found.

    Returns:
        Path: Viruatl Environment path such as ``/home/user/my_project/.venv``.
    """
    env = os.getenv("VIRTUAL_ENV", "")
    if env:
        return Path(env)

    current_dir = Path(__file__).parent
    if (current_dir / ".venv").exists():
        return current_dir / ".venv"
    if (current_dir / "venv").exists():
        return current_dir / "venv"
    if (current_dir / "env").exists():
        return current_dir / "env"
    raise FileNotFoundError("No Virtual Environment Found")


def _get_site_packages_dir() -> Union[Path, None]:
    """
    Gets the ``site-packages`` directory for current python environment.

    Returns:
        Union[Path, None]: site-packages dir if found; Otherwise, None.
    """
    v_path = _get_virtual_env()
    p_site = v_path / "Lib" / "site-packages"
    if p_site.exists() and p_site.is_dir():
        return p_site

    ver = f"{sys.version_info[0]}.{sys.version_info[1]}"
    p_site = v_path / "lib" / f"python{ver}" / "site-packages"
    if p_site.exists() and p_site.is_dir():
        return p_site
    return None


# endregion Get Virtual Environment Location

# region Manage Arguments
def _add_args(parser: argparse.ArgumentParser) -> None:
    parser.add_argument(
        "--invisible",
        action="store_true",
        default=False,
        help="""Starts in invisible mode. Neither the start-up logo nor 
                       the initial program window will be visible. Application 
                       can be controlled, and documents and dialogs can be
                       controlled and opened via the API. Using the parameter, 
                       the process can only be ended using the taskmanager
                       (Windows) or the kill command (UNIX-like systems). It
                       cannot be used in conjunction with --quickstart. """,
    )
    parser.add_argument(
        "--nologo", action="store_true", default=False, help="Disables the splash screen at program start."
    )
    parser.add_argument(
        "--minimized", action="store_true", default=False, help="Starts minimized. The splash screen is not displayed."
    )
    parser.add_argument(
        "--norestore",
        action="store_true",
        default=False,
        help="enables restart and file recovery after a system crash.",
    )
    parser.add_argument(
        "--headless",
        action="store_true",
        default=False,
        help="""Starts in "headless mode" which allows using the
                       application without GUI. This special mode can be used
                       when the application is controlled by external clients
                       via the API.""",
    )
    parser.add_argument("app", choices=["writer", "calc", "draw", "impress", "math", "base", 'global", "web', "none"])
    parser.add_argument(
        "--path-no-root", action="store_true", default=False, help="If set then the root path is not included in PYTHONPATH."
    )


def _update_args(args: argparse.Namespace, args_lst: List[str]) -> None:
    if args.invisible:
        args_lst.append("--invisible")
    if args.norestore:
        args_lst.append("--norestore")
    if args.nologo:
        args_lst.append("--nologo")
    if args.minimized:
        args_lst.append("--minimized")
    if args.headless:
        args_lst.append("--headless")
    if args.app != "none":
        args_lst.append(f"--{args.app}")

# endregion Manage Arguments

def main() -> None:
    parser = argparse.ArgumentParser(description="Office")
    _add_args(parser)
    args = parser.parse_args()
    if len(sys.argv) == 1:
        parser.print_help(sys.stderr)
        sys.exit(1)

    python_path = str(_get_site_packages_dir())
    if args.path_no_root is False:
        python_path += f":{_get_root_dir()}"

    open_args = [
        "flatpak",
        f'--env=PYTHONPATH="{python_path}"',
        "run",
        "org.libreoffice.LibreOffice/x86_64/stable",
        "--nofirststartwizard",
    ]

    _update_args(args, open_args)

    # display is included because of this issue when it is omitted:
    #     Set DISPLAY environment variable, use -display option
    #    or check permissions of your X-Server
    #    (See "man X" resp. "man xhost" for details)
    open_args.append(f"--display {os.getenv('DISPLAY', ':0')}")

    # print(" ".join(open_args))

    Popen(" ".join(open_args), shell=True)


if __name__ == "__main__":
    main()