Breeze2

#!/usr/bin/env python3
# isort: skip
import os
import sys

# Python <3.4 does not have pathlib
from venv import EnvBuilder

if sys.version_info.major != 3 or sys.version_info.minor < 7:
    print("ERROR! Make sure you use Python 3.7+ !!")
    sys.exit(1)

import subprocess
from os import execv
from pathlib import Path

if getattr(sys, 'frozen', False):
    # If the application is run as a bundle, the PyInstaller bootloader
    # extends the sys module by a flag frozen=True and sets the temporary app
    # path into variable _MEIPASS' and sys.executable is Breeze's executable path.
    AIRFLOW_SOURCES_DIR = Path(sys.executable).parent.resolve()
else:
    AIRFLOW_SOURCES_DIR = Path(__file__).parent.resolve()
BUILD_DIR = AIRFLOW_SOURCES_DIR / ".build"
BUILD_BREEZE_DIR = BUILD_DIR / "breeze2"
BUILD_BREEZE_CFG_SAVED = BUILD_BREEZE_DIR / "setup.cfg.saved"
BUILD_BREEZE_VENV_DIR = BUILD_BREEZE_DIR / "venv"
BUILD_BREEZE_VENV_BIN_DIR = BUILD_BREEZE_VENV_DIR / ("Scripts" if os.name == 'nt' else "bin")
BUILD_BREEZE_VENV_PYTHON = BUILD_BREEZE_VENV_BIN_DIR / "python"
BUILD_BREEZE_VENV_BREEZE = BUILD_BREEZE_VENV_BIN_DIR / "Breeze2"

BREEZE_SOURCE_PATH = AIRFLOW_SOURCES_DIR / "dev" / "breeze"
BREEZE_SETUP_CFG_PATH = BREEZE_SOURCE_PATH / "setup.cfg"

BUILD_BREEZE_DIR.mkdir(parents=True, exist_ok=True)


def needs_installation() -> bool:
    """Returns true if Breeze's virtualenv needs (re)installation"""
    if not BUILD_BREEZE_VENV_DIR.exists() or not BUILD_BREEZE_CFG_SAVED.exists():
        return True
    return BREEZE_SETUP_CFG_PATH.read_text() != BUILD_BREEZE_CFG_SAVED.read_text()


def save_config():
    """Saves cfg file to virtualenv to check if there is a need for reinstallation of the virtualenv"""
    BUILD_BREEZE_CFG_SAVED.write_text(BREEZE_SETUP_CFG_PATH.read_text())


if needs_installation():
    print(f"(Re)Installing Breeze's virtualenv in {BUILD_BREEZE_VENV_DIR}")
    try:
        EnvBuilder(system_site_packages=False, upgrade=True, with_pip=True, prompt="breeze").create(
            str(BUILD_BREEZE_VENV_DIR)
        )
    except Exception as e:
        # in some cases (mis-configured python) the venv creation might not work via API
        # (ensurepip missing). This is the case in case of default MacOS Python and Python executable
        # Bundled in Windows executable, In this case we fallback to running venv as a tool using default
        # Python3 found on path (in case of Windows Bundled exe, you don't even have a current
        # interpreted executable available, because Python interpreter is executed through a library.
        # and sys.executable points to the Bundled exe file.
        BUILD_BREEZE_VENV_DIR.mkdir(parents=True, exist_ok=True)
        subprocess.run(["python3", "-m", "venv", f"{BUILD_BREEZE_VENV_DIR}"], check=True)
    if os.name == 'nt':
        subprocess.run(
            [f"{BUILD_BREEZE_VENV_PYTHON}", "-m", "pip", "install", "--upgrade", "-e", "."],
            cwd=BREEZE_SOURCE_PATH,
            check=True,
        )
    else:
        subprocess.run(
            [f"{BUILD_BREEZE_VENV_PYTHON}", "-m", "pip", "install", "--upgrade", "-e", "."],
            cwd=BREEZE_SOURCE_PATH,
            check=True,
        )
    save_config()

if os.name == 'nt':
    # This is the best way of running it on Windows, though it leaves the original process hanging around
    subprocess.run([f"{BUILD_BREEZE_VENV_BREEZE}"] + sys.argv[1:], check=True)
else:
    execv(f"{BUILD_BREEZE_VENV_BREEZE}", [f"{BUILD_BREEZE_VENV_BREEZE}"] + sys.argv[1:])