import logging
import platform

from io import StringIO
from itertools import product
from os import environ
from pathlib import Path
from subprocess import CalledProcessError, run

logging.getLogger(__name__).propagate=True

def find_flatpak_browser():
    if platform.system() != "Linux":
        return
    
    for path_element in map(Path, environ["PATH"].split(":")):
        if (path_element/"flatpak").is_file():
            flatpak_bin = path_element/"flatpak"
            break
    else:
        # flatpak is not installed
        return
    
    flatpak_apps = ("com.google.Chrome", "com.microsoft.Edge", "com.brave.Browser", "org.chromium.Chromium")

    try:
        flatpak_process = run(
            [
                str(flatpak_bin),
                "list",
                "--app",
                "--columns=application"
            ],
            capture_output=True,
            check=True
        )
    except CalledProcessError as e:
        pass
    else:
        with StringIO(flatpak_process.stdout.decode()) as flatpak_output:
            installed_flatpaks = flatpak_output.readlines()[1:]
        
        for flatpak_app in flatpak_apps:
            if flatpak_app in [_.strip() for _ in installed_flatpaks]:
                return f"flatpak run --filesystem={Path.home()/'.local/share/jupyter/runtime'} {flatpak_app} --start-maximized --profile-directory=Default --app=%s"


def find_browser():
    # find a chromium-based browser on the system to use. 
    if platform.system() == "Windows":
        cmds = (
            "Google/Chrome/Application/chrome.exe",
            "BraveSoftware/Brave-Browser/Application/brave.exe",
            "Microsoft/Edge/Application/msedge.exe",
        )
        path_elements = map(Path, (environ["ProgramFiles"], environ["ProgramFiles(x86)"]))

    elif platform.system() == "Linux":
        # prefers Google Chrome on Linux due to popularity of the browser
        cmds = ("google-chrome", "microsoft-edge", "brave", "chromium")
        path_elements = map(Path, environ["PATH"].split(":"))

    elif platform.system() == "Darwin":
        # also prefers Google Chrome on MacOS due to popularity of the browser
        cmds = (
            "Contents/MacOS/Google Chrome", 
            "Contents/MacOS/Microsoft Edge", 
            "Contents/MacOS/Brave Browser",
            "Contents/MacOS/Chromium",
        )
        path_elements = [Path(f"/Applications/{Path(cmd).name}.app") for cmd in cmds]

    # use the first chromium-based browser found as the browser to run Jupyter in app mode
    for cmd, path_element in product(cmds, path_elements):
        browser = path_element / cmd
        if browser.exists():
             return f'"{browser}" --start-maximized --profile-directory=Default --app=%s'


# generated if you run `jupyter lab --generate-config`, used for additional configuration
DEFAULT_CONFIG_FILE = Path.home() / ".jupyter/jupyter_lab_config.py"

# user's home will be the root path of jupyter's file explorer
c.ServerApp.root_dir = str(Path.home())

browser_cmd = find_flatpak_browser() or find_browser()

if browser_cmd:
    c.ServerApp.browser = browser_cmd
else:
    logging.getLogger(__name__).warning(
        "No Chromium-based browser was found on this system, therefore Jupyter will run "
        + "in a new tab of the system-default browser"
    )

# read and exec default config file for additional config/overrides
if DEFAULT_CONFIG_FILE.exists():
    with open(DEFAULT_CONFIG_FILE, "r") as config_file:
        exec(config_file.read())