import os
from pathlib import Path
import sys
import subprocess

def get_desktop_environment() -> str:
    """
    Returns the name of the current desktop environment.
    """
    # From https://stackoverflow.com/a/21213358/2624876
    # which takes from:
    # http://stackoverflow.com/questions/2035657/what-is-my-current-desktop-environment
    # and http://ubuntuforums.org/showthread.php?t=652320
    # and http://ubuntuforums.org/showthread.php?t=1139057
    if sys.platform in ["win32", "cygwin"]:
        return "windows"
    elif sys.platform == "darwin":
        return "mac"
    else: # Most likely either a POSIX system or something not much common
        desktop_session = os.environ.get("DESKTOP_SESSION")
        if desktop_session is not None: # easier to match if we doesn't have to deal with character cases
            desktop_session = desktop_session.lower()
            if desktop_session in [
                "gnome", "unity", "cinnamon", "mate", "xfce4", "lxde", "fluxbox", 
                "blackbox", "openbox", "icewm", "jwm", "afterstep", "trinity", "kde"
            ]:
                return desktop_session
            ## Special cases ##
            # Canonical sets $DESKTOP_SESSION to Lubuntu rather than LXDE if using LXDE.
            # There is no guarantee that they will not do the same with the other desktop environments.
            elif "xfce" in desktop_session or desktop_session.startswith("xubuntu"):
                return "xfce4"
            elif desktop_session.startswith("ubuntustudio"):
                return "kde"
            elif desktop_session.startswith("ubuntu"):
                return "gnome"     
            elif desktop_session.startswith("lubuntu"):
                return "lxde" 
            elif desktop_session.startswith("kubuntu"): 
                return "kde" 
            elif desktop_session.startswith("razor"): # e.g. razorkwin
                return "razor-qt"
            elif desktop_session.startswith("wmaker"): # e.g. wmaker-common
                return "windowmaker"
        gnome_desktop_session_id = os.environ.get("GNOME_DESKTOP_SESSION_ID")
        if os.environ.get("KDE_FULL_SESSION") == "true":
            return "kde"
        elif gnome_desktop_session_id:
            if not "deprecated" in gnome_desktop_session_id:
                return "gnome2"
        # From http://ubuntuforums.org/showthread.php?t=652320
        elif is_running("xfce-mcs-manage"):
            return "xfce4"
        elif is_running("ksmserver"):
            return "kde"
    return "unknown"

def is_running(process: str) -> bool:
    """Returns whether a process with the given name is (likely) currently running.

    Uses a basic text search, and so may have false positives.
    """
    # From http://www.bloggerpolis.com/2011/05/how-to-check-if-a-process-is-running-using-python/
    # and http://richarddingwall.name/2009/06/18/windows-equivalents-of-ps-and-kill-commands/
    try: # Linux/Unix
        s = subprocess.Popen(["ps", "axw"], stdout=subprocess.PIPE)
    except: # Windows
        s = subprocess.Popen(["tasklist", "/v"], stdout=subprocess.PIPE)
    assert s.stdout is not None
    for x in s.stdout:
        # if re.search(process, x):
        if process in str(x):
            return True
    return False


def set_wallpaper(file_loc: str, first_run: bool = True):
    """Sets the wallpaper to the given file location."""
    # From https://stackoverflow.com/a/21213504/2624876
    # I have not personally tested most of this. -- @1j01
    # -----------------------------------------

    # Note: There are two common Linux desktop environments where
    # I have not been able to set the desktop background from
    # command line: KDE, Enlightenment
    desktop_env = get_desktop_environment()
    if desktop_env in ["gnome", "unity", "cinnamon"]:
        # Tested on Ubuntu 22 -- @1j01
        uri = Path(file_loc).as_uri()
        SCHEMA = "org.gnome.desktop.background"
        KEY = "picture-uri"
        # Needed for Ubuntu 22 in dark mode
        # Might be better to set only one or the other, depending on the current theme
        # In the settings it will say "This background selection only applies to the dark style"
        # even if it's set for both, arguably referring to the selection that you can make on that page.
        # -- @1j01
        KEY_DARK = "picture-uri-dark"
        try:
            from gi.repository import Gio  # type: ignore
            gsettings = Gio.Settings.new(SCHEMA)  # type: ignore
            gsettings.set_string(KEY, uri)
            gsettings.set_string(KEY_DARK, uri)
        except Exception:
            # Fallback tested on Ubuntu 22 -- @1j01
            args = ["gsettings", "set", SCHEMA, KEY, uri]
            subprocess.Popen(args)
            args = ["gsettings", "set", SCHEMA, KEY_DARK, uri]
            subprocess.Popen(args)
    elif desktop_env == "mate":
        try: # MATE >= 1.6
            # info from http://wiki.mate-desktop.org/docs:gsettings
            args = ["gsettings", "set", "org.mate.background", "picture-filename", file_loc]
            subprocess.Popen(args)
        except Exception: # MATE < 1.6
            # From https://bugs.launchpad.net/variety/+bug/1033918
            args = ["mateconftool-2", "-t", "string", "--set", "/desktop/mate/background/picture_filename", file_loc]
            subprocess.Popen(args)
    elif desktop_env == "gnome2": # Not tested
        # From https://bugs.launchpad.net/variety/+bug/1033918
        args = ["gconftool-2", "-t", "string", "--set", "/desktop/gnome/background/picture_filename", file_loc]
        subprocess.Popen(args)
    ## KDE4 is difficult
    ## see http://blog.zx2c4.com/699 for a solution that might work
    elif desktop_env in ["kde3", "trinity"]:
        # From http://ubuntuforums.org/archive/index.php/t-803417.html
        args = ["dcop", "kdesktop", "KBackgroundIface", "setWallpaper", "0", file_loc, "6"]
        subprocess.Popen(args)
    elif desktop_env == "xfce4":
        # From http://www.commandlinefu.com/commands/view/2055/change-wallpaper-for-xfce4-4.6.0
        if first_run:
            args0 = ["xfconf-query", "-c", "xfce4-desktop", "-p", "/backdrop/screen0/monitor0/image-path", "-s", file_loc]
            args1 = ["xfconf-query", "-c", "xfce4-desktop", "-p", "/backdrop/screen0/monitor0/image-style", "-s", "3"]
            args2 = ["xfconf-query", "-c", "xfce4-desktop", "-p", "/backdrop/screen0/monitor0/image-show", "-s", "true"]
            subprocess.Popen(args0)
            subprocess.Popen(args1)
            subprocess.Popen(args2)
        args = ["xfdesktop", "--reload"]
        subprocess.Popen(args)
    elif desktop_env == "razor-qt": # TODO: implement reload of desktop when possible
        if first_run:
            import configparser
            desktop_conf = configparser.ConfigParser()
            # Development version
            desktop_conf_file = os.path.join(get_config_dir("razor"), "desktop.conf") 
            if os.path.isfile(desktop_conf_file):
                config_option = R"screens\1\desktops\1\wallpaper"
            else:
                desktop_conf_file = os.path.join(get_home_dir(), ".razor/desktop.conf")
                config_option = R"desktops\1\wallpaper"
            desktop_conf.read(os.path.join(desktop_conf_file))
            try:
                if desktop_conf.has_option("razor", config_option): # only replacing a value
                    desktop_conf.set("razor", config_option, file_loc)
                    with open(desktop_conf_file, "w", encoding="utf-8", errors="replace") as f:
                        desktop_conf.write(f)
            except Exception:
                pass
        else:
            # TODO: reload desktop when possible
            pass 
    elif desktop_env in ["fluxbox", "jwm", "openbox", "afterstep"]:
        # http://fluxbox-wiki.org/index.php/Howto_set_the_background
        # used fbsetbg on jwm too since I am too lazy to edit the XML configuration 
        # now where fbsetbg does the job excellent anyway. 
        # and I have not figured out how else it can be set on Openbox and AfterSTep
        # but fbsetbg works excellent here too.
        try:
            args = ["fbsetbg", file_loc]
            subprocess.Popen(args)
        except Exception:
            sys.stderr.write("ERROR: Failed to set wallpaper with fbsetbg!\n")
            sys.stderr.write("Please make sre that You have fbsetbg installed.\n")
    elif desktop_env == "icewm":
        # command found at http://urukrama.wordpress.com/2007/12/05/desktop-backgrounds-in-window-managers/
        args = ["icewmbg", file_loc]
        subprocess.Popen(args)
    elif desktop_env == "blackbox":
        # command found at http://blackboxwm.sourceforge.net/BlackboxDocumentation/BlackboxBackground
        args = ["bsetbg", "-full", file_loc]
        subprocess.Popen(args)
    elif desktop_env == "lxde":
        args = ["pcmanfm", "--set-wallpaper", file_loc, "--wallpaper-mode=scaled"]
        subprocess.Popen(args)
    elif desktop_env == "windowmaker":
        # From http://www.commandlinefu.com/commands/view/3857/set-wallpaper-on-windowmaker-in-one-line
        args = ["wmsetbg", "-s", "-u", file_loc]
        subprocess.Popen(args)
    # elif desktop_env == "enlightenment": # I have not been able to make it work on e17. On e16 it would have been something in this direction
    #     args = ["enlightenment_remote", "-desktop-bg-add", "0", "0", "0", "0", file_loc]
    #     subprocess.Popen(args)
    elif desktop_env == "windows":
        # From https://stackoverflow.com/questions/1977694/change-desktop-background
        # Tested on Windows 10. -- @1j01
        import ctypes
        SPI_SETDESKWALLPAPER = 20
        ctypes.windll.user32.SystemParametersInfoW(SPI_SETDESKWALLPAPER, 0, file_loc, 0)  # type: ignore
    elif desktop_env == "mac":
        # From https://stackoverflow.com/questions/431205/how-can-i-programatically-change-the-background-in-mac-os-x
        try:
            # Tested on macOS 10.14.6 (Mojave) -- @1j01
            assert sys.platform == "darwin" # ignore `Import "appscript" could not be resolved` for other platforms
            from appscript import app, mactypes
            app("Finder").desktop_picture.set(mactypes.File(file_loc))
        except ImportError:
            # Tested on macOS 10.14.6 (Mojave) -- @1j01
            # import subprocess
            # SCRIPT = f"""/usr/bin/osascript<<END
            # tell application "Finder" to set desktop picture to POSIX file "{file_loc}"
            # END"""
            # subprocess.Popen(SCRIPT, shell=True)

            # Safer version, avoiding string interpolation,
            # to protect against command injection (both in the shell and in AppleScript):
            OSASCRIPT = """
            on run (clp)
                if clp's length is not 1 then error "Incorrect Parameters"
                local file_loc
                set file_loc to clp's item 1
                tell application "Finder" to set desktop picture to POSIX file file_loc
            end run
            """
            subprocess.Popen(["osascript", "-e", OSASCRIPT, "--", file_loc])
    else:
        if first_run: # don't spam the user with the same message over and over again
            sys.stderr.write("Warning: Failed to set wallpaper. Your desktop environment is not supported.")
            sys.stderr.write(f"You can try manually to set your wallpaper to {file_loc}")
        return False
    return True

def get_config_dir(app_name: str) -> str:
    if "XDG_CONFIG_HOME" in os.environ:
        config_home = os.environ["XDG_CONFIG_HOME"] 
    elif "APPDATA" in os.environ: # On Windows
        config_home = os.environ["APPDATA"] 
    else:
        try:
            from xdg import BaseDirectory  # type: ignore
            config_home = BaseDirectory.xdg_config_home
        except ImportError: # Most likely a Linux/Unix system anyway
            config_home = os.path.join(get_home_dir(), ".config")
    config_dir = os.path.join(config_home, app_name)
    return config_dir

def get_home_dir() -> str:
    return os.path.expanduser("~")