#!/usr/bin/python
# -*- coding: utf-8 -*-

# Cagou: desktop/mobile frontend for Salut à Toi XMPP client
# Copyright (C) 2016-2018 Jérôme Poisson (goffi@goffi.org)

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 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 Affero General Public License for more details.

# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.


from sat.core import log as logging
log = logging.getLogger(__name__)
from sat_frontends.quick_frontend import quick_widgets
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.uix.carousel import Carousel
from kivy.metrics import dp
from kivy import properties
from cagou import G


CAROUSEL_SCROLL_DISTANCE = dp(50)
CAROUSEL_SCROLL_TIMEOUT = 80
NEW_WIDGET_DIST = 10
REMOVE_WIDGET_DIST = NEW_WIDGET_DIST


class WHSplitter(Button):
    horizontal=properties.BooleanProperty(True)
    thickness=properties.NumericProperty(dp(20))
    split_move = None # we handle one split at a time, so we use a class attribute

    def __init__(self, handler, **kwargs):
        super(WHSplitter, self).__init__(**kwargs)
        self.handler = handler

    def getPos(self, touch):
        if self.horizontal:
            relative_y = self.handler.to_local(*touch.pos, relative=True)[1]
            return self.handler.height - relative_y
        else:
            return touch.x

    def on_touch_move(self, touch):
        if self.split_move is None and self.collide_point(*touch.opos):
            WHSplitter.split_move = self

        if self.split_move is self:
            pos = self.getPos(touch)
            if pos > NEW_WIDGET_DIST:
                # we are above minimal distance, we resize the widget
                self.handler.setWidgetSize(self.horizontal, pos)

    def on_touch_up(self, touch):
        if self.split_move is self:
            pos = self.getPos(touch)
            if pos <= REMOVE_WIDGET_DIST:
                # if we go under minimal distance, the widget is not wanted anymore
                self.handler.removeWidget(self.horizontal)
            WHSplitter.split_move=None
        return super(WHSplitter, self).on_touch_up(touch)


class HandlerCarousel(Carousel):

    def __init__(self, *args, **kwargs):
        super(HandlerCarousel, self).__init__(
            *args,
            direction='right',
            loop=True,
            **kwargs)
        self._former_slide = None
        self.bind(current_slide=self.onSlideChange)
        self._slides_update_lock = False

    def changeWidget(self, new_widget):
        """Change currently displayed widget

        slides widgets will be updated
        """
        # slides update need to be blocked to avoid the update in onSlideChange
        # which would mess the removal of current widgets
        self._slides_update_lock = True
        current = self.current_slide
        for w in self.slides:
            if w == current or w == new_widget:
                continue
            if isinstance(w, quick_widgets.QuickWidget):
                G.host.widgets.deleteWidget(w)
        self.clear_widgets()
        self.add_widget(new_widget)
        self._slides_update_lock = False
        self.updateHiddenSlides()

    def onSlideChange(self, handler, new_slide):
        if isinstance(self._former_slide, quick_widgets.QuickWidget):
            G.host.removeVisibleWidget(self._former_slide)
        self._former_slide = new_slide
        if isinstance(new_slide, quick_widgets.QuickWidget):
            G.host.addVisibleWidget(new_slide)
            self.updateHiddenSlides()

    def hiddenList(self, visible_list):
        """return widgets of same class as holded one which are hidden

        @param visible_list(list[QuickWidget]): widgets visible
        @return (iter[QuickWidget]): widgets hidden
        """
        added = [(w.targets, w.profiles) for w in visible_list]  # we want to avoid recreated widgets
        for w in G.host.widgets.getWidgets(self.current_slide.__class__, profiles=self.current_slide.profiles):
            if w in visible_list or (w.targets, w.profiles) in added:
                continue
            yield w

    def widgets_sort(self, widget):
        """method used as key to sort the widgets

        order of the widgets when changing slide is affected
        @param widget(QuickWidget): widget to sort
        @return: a value which will be used for sorting
        """
        try:
            return unicode(widget.target).lower()
        except AttributeError:
            return unicode(list(widget.targets)[0]).lower()

    def updateHiddenSlides(self):
        """adjust carousel slides according to visible widgets"""
        if self._slides_update_lock:
            return
        if not isinstance(self.current_slide, quick_widgets.QuickWidget):
            return
        # lock must be used here to avoid recursions
        self._slides_update_lock = True
        visible_list = G.host.getVisibleList(self.current_slide.__class__)
        hidden = list(self.hiddenList(visible_list))
        slides_sorted =  sorted(hidden + [self.current_slide], key=self.widgets_sort)
        to_remove = set(self.slides).difference({self.current_slide})
        for w in to_remove:
            self.remove_widget(w)
        if hidden:
            # no need to add more than two widgets (next and previous),
            # as the list will be updated on each new visible widget
            current_idx = slides_sorted.index(self.current_slide)
            try:
                next_slide = slides_sorted[current_idx+1]
            except IndexError:
                next_slide = slides_sorted[0]
            self.add_widget(G.host.getOrClone(next_slide))
            if len(hidden)>1:
                previous_slide = slides_sorted[current_idx-1]
                self.add_widget(G.host.getOrClone(previous_slide))

        if len(self.slides) == 1:
            # we block carousel with high scroll_distance to avoid swiping
            # when the is not other instance of the widget
            self.scroll_distance=2**32
            self.scroll_timeout=0
        else:
            self.scroll_distance = CAROUSEL_SCROLL_DISTANCE
            self.scroll_timeout=CAROUSEL_SCROLL_TIMEOUT
        self._slides_update_lock = False


class WidgetsHandler(BoxLayout):

    def __init__(self, wid=None, **kw):
        if wid is None:
            wid=self.default_widget
        self.vert_wid = self.hor_wid = None
        BoxLayout.__init__(self, orientation="vertical", **kw)
        self.blh = BoxLayout(orientation="horizontal")
        self.blv = BoxLayout(orientation="vertical")
        self.blv.add_widget(WHSplitter(self))
        self.carousel = HandlerCarousel()
        self.blv.add_widget(self.carousel)
        self.blh.add_widget(WHSplitter(self, horizontal=False))
        self.blh.add_widget(self.blv)
        self.add_widget(self.blh)
        self.changeWidget(wid)

    @property
    def default_widget(self):
        return G.host.default_wid['factory'](G.host.default_wid, None, None)

    @property
    def cagou_widget(self):
        """get holded CagouWidget"""
        return self.carousel.current_slide

    def changeWidget(self, new_widget):
        self.carousel.changeWidget(new_widget)

    def removeWidget(self, vertical):
        if vertical and self.vert_wid is not None:
            self.remove_widget(self.vert_wid)
            self.vert_wid.onDelete()
            self.vert_wid = None
        elif self.hor_wid is not None:
            self.blh.remove_widget(self.hor_wid)
            self.hor_wid.onDelete()
            self.hor_wid = None

    def setWidgetSize(self, vertical, size):
        if vertical:
            if self.vert_wid is None:
                self.vert_wid = WidgetsHandler(self.default_widget, size_hint=(1, None))
                self.add_widget(self.vert_wid, len(self.children))
            self.vert_wid.height=size
        else:
            if self.hor_wid is None:
                self.hor_wid = WidgetsHandler(self.default_widget, size_hint=(None, 1))
                self.blh.add_widget(self.hor_wid, len(self.blh.children))
            self.hor_wid.width=size

    def onDelete(self):
        # when this handler is deleted, we need to delete the holded CagouWidget
        cagou_widget = self.cagou_widget
        if isinstance(cagou_widget, quick_widgets.QuickWidget):
            G.host.removeVisibleWidget(cagou_widget)