"""
A number of function that enhance IDLE on MacOSX when it used as a normal
GUI application (as opposed to an X11 application).
"""
import sys
import tkinter
from os import path


_appbundle = None

def runningAsOSXApp():
    """
    Returns True if Python is running from within an app on OSX.
    If so, the various OS X customizations will be triggered later (menu
    fixup, et al).  (Originally, this test was supposed to condition
    behavior on whether IDLE was running under Aqua Tk rather than
    under X11 Tk but that does not work since a framework build
    could be linked with X11.  For several releases, this test actually
    differentiates between whether IDLE is running from a framework or
    not.  As a future enhancement, it should be considered whether there
    should be a difference based on framework and any needed X11 adaptions
    should be made dependent on a new function that actually tests for X11.)
    """
    global _appbundle
    if _appbundle is None:
        _appbundle = sys.platform == 'darwin'
        if _appbundle:
            import sysconfig
            _appbundle = bool(sysconfig.get_config_var('PYTHONFRAMEWORK'))
    return _appbundle

_carbonaquatk = None

def isCarbonAquaTk(root):
    """
    Returns True if IDLE is using a Carbon Aqua Tk (instead of the
    newer Cocoa Aqua Tk).
    """
    global _carbonaquatk
    if _carbonaquatk is None:
        _carbonaquatk = (runningAsOSXApp() and
                         'aqua' in root.tk.call('tk', 'windowingsystem') and
                         'AppKit' not in root.tk.call('winfo', 'server', '.'))
    return _carbonaquatk

def tkVersionWarning(root):
    """
    Returns a string warning message if the Tk version in use appears to
    be one known to cause problems with IDLE.
    1. Apple Cocoa-based Tk 8.5.7 shipped with Mac OS X 10.6 is unusable.
    2. Apple Cocoa-based Tk 8.5.9 in OS X 10.7 and 10.8 is better but
        can still crash unexpectedly.
    """

    if (runningAsOSXApp() and
            ('AppKit' in root.tk.call('winfo', 'server', '.')) ):
        patchlevel = root.tk.call('info', 'patchlevel')
        if patchlevel not in ('8.5.7', '8.5.9'):
            return False
        return (r"WARNING: The version of Tcl/Tk ({0}) in use may"
                r" be unstable.\n"
                r"Visit http://www.python.org/download/mac/tcltk/"
                r" for current information.".format(patchlevel))
    else:
        return False

def addOpenEventSupport(root, flist):
    """
    This ensures that the application will respond to open AppleEvents, which
    makes is feasible to use IDLE as the default application for python files.
    """
    def doOpenFile(*args):
        for fn in args:
            flist.open(fn)

    # The command below is a hook in aquatk that is called whenever the app
    # receives a file open event. The callback can have multiple arguments,
    # one for every file that should be opened.
    root.createcommand("::tk::mac::OpenDocument", doOpenFile)

def hideTkConsole(root):
    try:
        root.tk.call('console', 'hide')
    except tkinter.TclError:
        # Some versions of the Tk framework don't have a console object
        pass

def overrideRootMenu(root, flist):
    """
    Replace the Tk root menu by something that's more appropriate for
    IDLE.
    """
    # The menu that is attached to the Tk root (".") is also used by AquaTk for
    # all windows that don't specify a menu of their own. The default menubar
    # contains a number of menus, none of which are appropriate for IDLE. The
    # Most annoying of those is an 'About Tck/Tk...' menu in the application
    # menu.
    #
    # This function replaces the default menubar by a mostly empty one, it
    # should only contain the correct application menu and the window menu.
    #
    # Due to a (mis-)feature of TkAqua the user will also see an empty Help
    # menu.
    from tkinter import Menu, Text, Text
    from idlelib.EditorWindow import prepstr, get_accelerator
    from idlelib import Bindings
    from idlelib import WindowList
    from idlelib.MultiCall import MultiCallCreator

    menubar = Menu(root)
    root.configure(menu=menubar)
    menudict = {}

    menudict['windows'] = menu = Menu(menubar, name='windows')
    menubar.add_cascade(label='Window', menu=menu, underline=0)

    def postwindowsmenu(menu=menu):
        end = menu.index('end')
        if end is None:
            end = -1

        if end > 0:
            menu.delete(0, end)
        WindowList.add_windows_to_menu(menu)
    WindowList.register_callback(postwindowsmenu)

    def about_dialog(event=None):
        from idlelib import aboutDialog
        aboutDialog.AboutDialog(root, 'About IDLE')

    def config_dialog(event=None):
        from idlelib import configDialog

        # Ensure that the root object has an instance_dict attribute,
        # mirrors code in EditorWindow (although that sets the attribute
        # on an EditorWindow instance that is then passed as the first
        # argument to ConfigDialog)
        root.instance_dict = flist.inversedict
        root.instance_dict = flist.inversedict
        configDialog.ConfigDialog(root, 'Settings')

    def help_dialog(event=None):
        from idlelib import textView
        fn = path.join(path.abspath(path.dirname(__file__)), 'help.txt')
        textView.view_file(root, 'Help', fn)

    root.bind('<<about-idle>>', about_dialog)
    root.bind('<<open-config-dialog>>', config_dialog)
    root.createcommand('::tk::mac::ShowPreferences', config_dialog)
    if flist:
        root.bind('<<close-all-windows>>', flist.close_all_callback)

        # The binding above doesn't reliably work on all versions of Tk
        # on MacOSX. Adding command definition below does seem to do the
        # right thing for now.
        root.createcommand('exit', flist.close_all_callback)

    if isCarbonAquaTk(root):
        # for Carbon AquaTk, replace the default Tk apple menu
        menudict['application'] = menu = Menu(menubar, name='apple')
        menubar.add_cascade(label='IDLE', menu=menu)
        Bindings.menudefs.insert(0,
            ('application', [
                ('About IDLE', '<<about-idle>>'),
                    None,
                ]))
        tkversion = root.tk.eval('info patchlevel')
        if tuple(map(int, tkversion.split('.'))) < (8, 4, 14):
            # for earlier AquaTk versions, supply a Preferences menu item
            Bindings.menudefs[0][1].append(
                    ('_Preferences....', '<<open-config-dialog>>'),
                )
    else:
        # assume Cocoa AquaTk
        # replace default About dialog with About IDLE one
        root.createcommand('tkAboutDialog', about_dialog)
        # replace default "Help" item in Help menu
        root.createcommand('::tk::mac::ShowHelp', help_dialog)
        # remove redundant "IDLE Help" from menu
        del Bindings.menudefs[-1][1][0]

def setupApp(root, flist):
    """
    Perform setup for the OSX application bundle.
    """
    if not runningAsOSXApp(): return

    hideTkConsole(root)
    overrideRootMenu(root, flist)
    addOpenEventSupport(root, flist)