#!/usr/bin/env python

# xdg-autostart runs things based on the XDG autostart specification
# Copyright (C) 2008       Dana Jansens
#
# XDG autostart specification can be found here:
# http://standards.freedesktop.org/autostart-spec/
#
#
#
# LICENSE:
#   This program is free software; you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation; either version 2 of the License, or
#   (at your option) any later version.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.

ME="xdg-autostart"
VERSION="1.0"

import os, glob, sys
try:
    from xdg import BaseDirectory
    from xdg.DesktopEntry import DesktopEntry
    from xdg.Exceptions import ParsingError
except ImportError:
    print
    print "ERROR:", ME, "requires PyXDG to be installed"
    print
    sys.exit(1)

def main(argv=sys.argv):
    if "--help" in argv[1:]:
        show_help()
        return 0
    if "--version" in argv[1:]:
        show_version()
        return 0

    # get the autostart directories
    autodirs = BaseDirectory.load_config_paths("autostart")

    # find all the autostart files
    files = []
    for dir in autodirs:
        for path in glob.glob(os.path.join(dir, '*.desktop')):
            try:
                autofile = AutostartFile(path)
            except ParsingError:
                print "Invalid .desktop file: " + path
            else:
                if not autofile in files:
                    files.append(autofile)

    list = False
    if "--list" in argv[1:]:
        list = True
        argv.remove("--list")

    # run them !
    environments = argv[1:]
    for autofile in files:
        if list: autofile.list(environments)
        else: autofile.run(environments)

class AutostartFile():
    def __init__(self, path):
        self.path = path
        self.filename = os.path.basename(path)
        self.dirname = os.path.dirname(path)
        self.de = DesktopEntry(path)

    def __eq__(self, other):
        return self.filename == other.filename

    def __str__(self):
        return self.path + " : " + self.de.getName()

    def isexecfile(path):
        return os.access(path, os.X_OK)

    def findFile(self, path, search, match_func):
        # check empty path
        if not path: return None
        # check absolute path
        if path[0] == '/':
            if match_func(path): return path
            else: return None
            # check relative path
            for dirname in search.split(os.pathsep):
                if dirname != "":
                    candidate = os.path.join(dirname, path)
                    if (match_func(candidate)): return candidate

    def alert(self, str, info=False):
        if info:
            print "\t ", str
        else:
            print "\t*", str

    def showInEnvironment(self, envs, verbose=False):
        default = not self.de.getOnlyShowIn()
        noshow = False
        force = False
        for i in self.de.getOnlyShowIn():
            if i in envs: force = True
        for i in self.de.getNotShowIn():
            if i in envs: noshow = True

        if verbose:
            if not default and not force:
                s = ""
                for i in self.de.getOnlyShowIn():
                    if s: s += ", "
                    s += i
                self.alert("Excluded by: OnlyShowIn (" + s + ")")
            if default and noshow and not force:
                s = ""
                for i in self.de.getOnlyShowIn():
                    if s: s += ", "
                    s += i
                self.alert("Excluded by: NotShowIn (" + s + ")")
        return (default and not noshow) or force

    def shouldRun(self, envs, verbose=False):
        if not self.de.getExec():
            if verbose: self.alert("Excluded by: Missing Exec field")
            return False
        if self.de.getHidden():
            if verbose: self.alert("Excluded by: Hidden")
            return False
        if self.de.getTryExec():
            if not self.findFile(self.de.getTryExec(), os.getenv("PATH"),
                                 self.isexecfile):
                if verbose: self.alert("Excluded by: TryExec (" +
                                          self.de.getTryExec() + ")")
                return False
        if not self.showInEnvironment(envs, verbose):
            return False
        return True

    def list(self, envs):
        running = False
        if self.shouldRun(envs):
            print "[*] " + self.de.getName()
        else:
            print "[ ] " + self.de.getName()
        self.alert("File: " + self.path, info=True)
        if self.de.getExec():
            self.alert("Executes: " + self.de.getExec(), info=True)
        self.shouldRun(envs, True)
        print

    def run(self, envs):
        here = os.getcwd()
        if self.de.getPath():
            os.chdir(self.de.getPath())
        if self.shouldRun(envs):
            args = ["/bin/sh", "-c", "exec " + self.de.getExec()]
            os.spawnv(os.P_NOWAIT, args[0], args);
        os.chdir(here)

def show_help():
    print "Usage:", ME, "[OPTION]... [ENVIRONMENT]..."
    print
    print "This tool will run xdg autostart .desktop files"
    print
    print "OPTIONS"
    print "  --list        Show a list of the files which would be run"
    print "                Files which would be run are marked with an asterix"
    print "                symbol [*].  For files which would not be run,"
    print "                information is given for why they are excluded"
    print "  --help        Show this help and exit"
    print "  --version     Show version and copyright information"
    print
    print "ENVIRONMENT specifies a list of environments for which to run autostart"
    print "applications for.  If none are specified, only applications which do not "
    print "limit themselves to certain environments will be run."
    print
    print "ENVIRONMENT can be one or more of:"
    print "  GNOME         Gnome Desktop"
    print "  KDE           KDE Desktop"
    print "  ROX           ROX Desktop"
    print "  XFCE          XFCE Desktop"
    print "  Old           Legacy systems"
    print

def show_version():
    print ME, VERSION
    print "Copyright (c) 2008        Dana Jansens"
    print

if __name__ == "__main__":
        sys.exit(main())