#!/usr/bin/python3

from gi.repository import Gio, GLib
from xapp.SettingsWidgets import *

CAN_BACKEND = ["Switch", "SpinButton", "Entry", "TextView", "FontButton", "Range", "ComboBox",
               "ColorChooser", "FileChooser", "IconChooser"]

# Monkey patch Gio.Settings object
def __setitem__(self, key, value):
    # set_value() aborts the program on an unknown key
    if key not in self:
        raise KeyError('unknown key: %r' % (key,))

    # determine type string of this key
    range = self.get_range(key)
    type_ = range.get_child_value(0).get_string()
    v = range.get_child_value(1)
    if type_ == 'type':
        # v is boxed empty array, type of its elements is the allowed value type
        assert v.get_child_value(0).get_type_string().startswith('a')
        type_str = v.get_child_value(0).get_type_string()[1:]
    elif type_ == 'enum':
        # v is an array with the allowed values
        assert v.get_child_value(0).get_type_string().startswith('a')
        type_str = v.get_child_value(0).get_child_value(0).get_type_string()
    elif type_ == 'flags':
        # v is an array with the allowed values
        assert v.get_child_value(0).get_type_string().startswith('a')
        type_str = v.get_child_value(0).get_type_string()
    elif type_ == 'range':
        # type_str is a tuple giving the range
        assert v.get_child_value(0).get_type_string().startswith('(')
        type_str = v.get_child_value(0).get_type_string()[1]

    if not self.set_value(key, GLib.Variant(type_str, value)):
        raise ValueError("value '%s' for key '%s' is outside of valid range" % (value, key))

def bind_with_mapping(self, key, widget, prop, flags, key_to_prop, prop_to_key):
    self._ignore_key_changed = False

    def key_changed(settings, key):
        if self._ignore_key_changed:
            return
        self._ignore_prop_changed = True
        widget.set_property(prop, key_to_prop(self[key]))
        self._ignore_prop_changed = False

    def prop_changed(widget, param):
        if self._ignore_prop_changed:
            return
        self._ignore_key_changed = True
        self[key] = prop_to_key(widget.get_property(prop))
        self._ignore_key_changed = False

    if not (flags & (Gio.SettingsBindFlags.SET | Gio.SettingsBindFlags.GET)): # ie Gio.SettingsBindFlags.DEFAULT
        flags |= Gio.SettingsBindFlags.SET | Gio.SettingsBindFlags.GET
    if flags & Gio.SettingsBindFlags.GET:
        key_changed(self, key)
        if not (flags & Gio.SettingsBindFlags.GET_NO_CHANGES):
            self.connect('changed::' + key, key_changed)
    if flags & Gio.SettingsBindFlags.SET:
        widget.connect('notify::' + prop, prop_changed)
    if not (flags & Gio.SettingsBindFlags.NO_SENSITIVITY):
        self.bind_writable(key, widget, "sensitive", False)

Gio.Settings.bind_with_mapping = bind_with_mapping
Gio.Settings.__setitem__ = __setitem__

class BinFileMonitor(GObject.GObject):
    __gsignals__ = {
        'changed': (GObject.SignalFlags.RUN_LAST, None, ()),
    }
    def __init__(self):
        super(BinFileMonitor, self).__init__()

        self.changed_id = 0

        env = GLib.getenv("PATH")

        if env == None:
            env = "/bin:/usr/bin:."

        self.paths = env.split(":")

        self.monitors = []

        for path in self.paths:
            file = Gio.File.new_for_path(path)
            mon = file.monitor_directory(Gio.FileMonitorFlags.SEND_MOVED, None)
            mon.connect("changed", self.queue_emit_changed)
            self.monitors.append(mon)

    def _emit_changed(self):
        self.emit("changed")
        self.changed_id = 0
        return False

    def queue_emit_changed(self, file, other, event_type, data=None):
        if self.changed_id > 0:
            GLib.source_remove(self.changed_id)
            self.changed_id = 0

        self.changed_id = GLib.idle_add(self._emit_changed)

file_monitor = None

def get_file_monitor():
    global file_monitor

    if file_monitor == None:
        file_monitor = BinFileMonitor()

    return file_monitor

# This class is not meant to be used directly - it is only a backend for the
# settings widgets to enable them to bind attributes to gsettings keys. To use
# the gesttings backend, simply add the "GSettings" prefix to the beginning
# of the widget class name. The arguments of the backended class will be
# (label, schema, key, any additional widget-specific args and keyword args).
# (Note: this only works for classes that are gsettings compatible.)
#
# If you wish to make a new widget available to be backended, place it in the
# CAN_BACKEND list. In addition, you will need to add the following attributes
# to the widget class:
#
# bind_dir - (Gio.SettingsBindFlags) flags to define the binding direction or
#            None if you don't want the setting bound (for example if the
#            setting effects multiple attributes)
# bind_prop - (string) the attribute in the widget that will be bound to the
#             setting. This property may be omitted if bind_dir is None
# bind_object - (optional) the object to which to bind to (only needed if the
#               attribute to be bound is not a property of self.content_widget)
# map_get, map_set - (function, optional) a function to map between setting and
#                    bound attribute. May also be passed as a keyword arg during
#                    instantiation. These will be ignored if bind_dir=None
# set_rounding - (function, optional) To be used to set the digits to round to
#                if the setting is an integer
class PXGSettingsBackend(object):
    def bind_settings(self):
        if hasattr(self, "set_rounding"):
            vtype = self.settings.get_value(self.key).get_type_string()
            if vtype in ["i", "u"]:
                self.set_rounding(0)
        if hasattr(self, "bind_object"):
            bind_object = self.bind_object
        else:
            bind_object = self.content_widget
        if hasattr(self, "map_get") or hasattr(self, "map_set"):
            self.settings.bind_with_mapping(self.key, bind_object, self.bind_prop, self.bind_dir, self.map_get, self.map_set)
        elif self.bind_dir != None:
            self.settings.bind(self.key, bind_object, self.bind_prop, self.bind_dir)
        else:
            self.settings.connect("changed::"+self.key, self.on_setting_changed)
            self.settings.bind_writable(self.key, bind_object, "sensitive", False)
            self.on_setting_changed()
            self.connect_widget_handlers()

    def set_value(self, value):
        self.settings[self.key] = value

    def get_value(self):
        return self.settings[self.key]

    def get_range(self):
        range = self.settings.get_range(self.key)
        if range[0] == "range":
            return [range[1][0], range[1][1]]
        else:
            return None

    def on_setting_changed(self, *args):
        raise NotImplementedError("SettingsWidget class must implement on_setting_changed().")

    def connect_widget_handlers(self, *args):
        if self.bind_dir == None:
            raise NotImplementedError("SettingsWidget classes with no .bind_dir must implement connect_widget_handlers().")

def g_settings_factory(subclass):
    class NewClass(globals()[subclass], PXGSettingsBackend):
        def __init__(self, label, schema, key, *args, **kwargs):
            self.key = key
            if schema not in settings_objects:
                settings_objects[schema] = Gio.Settings.new(schema)
            self.settings = settings_objects[schema]

            if "map_get" in kwargs:
                self.map_get = kwargs["map_get"]
                del kwargs["map_get"]
            if "map_set" in kwargs:
                self.map_set = kwargs["map_set"]
                del kwargs["map_set"]

            super(NewClass, self).__init__(label, *args, **kwargs)
            self.bind_settings()
    return NewClass

for widget in CAN_BACKEND:
    globals()["GSettings"+widget] = g_settings_factory(widget)