
# Copyright 2010 Fabian Stanke
# Copyright 2011-2017 Jaap Karssenberg


from gi.repository import GObject
from gi.repository import Gtk
from gi.repository import Pango

import logging

from functools import partial

from zim.plugins import PluginClass
from zim.signals import ConnectorMixin
from zim.plugins.pageindex import PageTreeStore, PageTreeStoreBase, PageTreeView, \
	NAME_COL, PATH_COL, EXISTS_COL, STYLE_COL, WEIGHT_COL, N_CHILD_COL, TIP_COL
from zim.notebook import Path
from zim.notebook.index import IndexNotFoundError
from zim.notebook.index.pages import PageIndexRecord
from zim.notebook.index.tags import IS_PAGE, IS_TAG, \
	TagsView, TaggedPagesTreeModelMixin, TagsTreeModelMixin, IndexTag
from zim.utils import natural_sort_key

from zim.gui.pageview import PageViewExtension
from zim.gui.widgets import LEFT_PANE, PANE_POSITIONS, populate_popup_add_separator, ScrolledWindow, encode_markup_text, \
	WindowSidePaneWidget
from zim.gui.clipboard import pack_urilist, INTERNAL_PAGELIST_TARGET_NAME

import zim.gui.clipboard

logger = logging.getLogger('zim.plugins.tags')



class TagsPlugin(PluginClass):

	plugin_info = {
		'name': _('Tags'), # T: plugin name
		'description': _('''\
This plugin provides a page index filtered by means of selecting tags in a cloud.
'''), # T: plugin description
		'author': 'Fabian Stanke & Jaap Karssenberg',
		'help': 'Plugins:Tags',
	}

	plugin_preferences = (
		# key, type, label, default
		('pane', 'choice', _('Position in the window'), LEFT_PANE, PANE_POSITIONS),
			# T: option for plugin preferences
	)


class TagsPageViewExtension(PageViewExtension):

	def __init__(self, plugin, pageview):
		PageViewExtension.__init__(self, plugin, pageview)

		self.widget = TagsPluginWidget(
			pageview.notebook,
			self.navigation,
			self.uistate
		)

		self.add_sidepane_widget(self.widget, 'pane')

		self.uistate.setdefault('vpane_pos', 150)
		self.widget.set_position(self.uistate['vpane_pos'])
		def update_uistate(*a):
			self.uistate['vpane_pos'] = self.widget.get_position()
		self.widget.connect('notify::position', update_uistate)

		#self.connectto_all(ui, ( # XXX
		#	('start-index-update', lambda o: self.disconnect_model()),
		#	('end-index-update', lambda o: self.reconnect_model()),
		#))
		self.connectto(pageview, 'page-changed', lambda o, p: self.widget.set_page(p))


class TagsPluginWidget(Gtk.VPaned, WindowSidePaneWidget):
	'''Widget combining a tag cloud and a tag based page treeview'''

	title = _('Tags') # T: title for sidepane tab

	def __init__(self, notebook, navigation, uistate):
		GObject.GObject.__init__(self)
		self.notebook = notebook
		self.index = notebook.index
		self.uistate = uistate

		self.uistate.setdefault('treeview', 'tags', {'tagged', 'tags'})
		self.uistate.setdefault('tagcloud_sorting', 'score', {'alpha', 'score'})
		self.uistate.setdefault('show_full_page_name', True)

		self.tagcloud = TagCloudWidget(self.index, sorting=self.uistate['tagcloud_sorting'])
		self.pack1(ScrolledWindow(self.tagcloud), shrink=False)

		self.treeview = TagsPageTreeView(notebook, navigation)
		self.pack2(ScrolledWindow(self.treeview), shrink=False)

		self.treeview.connect('populate-popup', self.on_populate_popup)
		self.tagcloud.connect('selection-changed', self.on_cloud_selection_changed)
		self.tagcloud.connect('sorting-changed', self.on_cloud_sortin_changed)

		self.reload_model()

	def set_page(self, page):
		treepath = self.treeview.set_current_page(page, vivificate=True)
		if treepath:
			selected_path = self.treeview.get_selected_path()
			if page != selected_path:
				self.treeview.select_treepath(treepath)

	def toggle_treeview(self):
		'''Toggle the treeview type in the widget'''
		if self.uistate['treeview'] == 'tagged':
			self.uistate['treeview'] = 'tags'
		else:
			self.uistate['treeview'] = 'tagged'

		model = self.treeview.get_model()
		if not isinstance(model, TaggedPageTreeStore):
			self.reload_model()

	def toggle_show_full_page_name(self):
		self.uistate['show_full_page_name'] = not self.uistate['show_full_page_name']
		self.reload_model()

	def on_populate_popup(self, treeview, menu):
		# Add a popup menu item to switch the treeview mode
		populate_popup_add_separator(menu, prepend=True)

		item = Gtk.CheckMenuItem(_('Show full page name')) # T: menu option
		item.set_active(self.uistate['show_full_page_name'])
		item.connect_object('toggled', self.__class__.toggle_show_full_page_name, self)
		menu.prepend(item)

		item = Gtk.CheckMenuItem(_('Sort pages by tags')) # T: menu option
		item.set_active(self.uistate['treeview'] == 'tags')
		item.connect_object('toggled', self.__class__.toggle_treeview, self)
		model = self.treeview.get_model()
		if isinstance(model, TaggedPageTreeStore):
			item.set_sensitive(False) # with tag selection toggle does nothing
		menu.prepend(item)

		menu.show_all()

	def on_cloud_selection_changed(self, cloud):
		self.reload_model()
		# FIXME - allow updating selection, requires signals for all added / removed pages

	def on_cloud_sortin_changed(self, cloud, sorting):
		self.uistate['tagcloud_sorting'] = sorting

	def disconnect_model(self):
		'''Stop the model from listening to the index. Used to
		unhook the model before reloading the index. Typically
		should be followed by reload_model().
		'''
		self.treeview.disconnect_index()
		self.tagcloud.disconnect_index()

	def reconnect_model(self):
		self.tagcloud.connect_index(self.index)
		self.reload_model()

	def reload_model(self):
		'''Re-initialize the treeview model. This is called when
		reloading the index to get rid of out-of-sync model errors
		without need to close the app first.
		'''
		assert self.uistate['treeview'] in ('tagged', 'tags')
		self.treeview.disconnect_index()

		tags = [t.name for t in self.tagcloud.get_tag_filter()]
		if tags:
			model = TaggedPageTreeStore(self.index, tags, self.uistate['show_full_page_name'])
		elif self.uistate['treeview'] == 'tags':
			model = TagsPageTreeStore(self.index, (), self.uistate['show_full_page_name'])
		else:
			model = PageTreeStore(self.index)

		self.treeview.set_model(model)

		def handler(o, *a):
			signal = a[-1]
			path = a[0].to_string()
		for signal in ('row-inserted', 'row-changed', 'row-deleted', 'row-has-child-toggled'):
			model.connect(signal, handler, signal)


class DuplicatePageTreeStore(PageTreeStoreBase):
	'''Sub-class of PageTreeStore that allows for the same page appearing
	multiple times in the tree.
	'''

	def set_current_page(self, path):
		'''Since there may be duplicates of each page, highlight all of them'''
		oldpath = self.current_page
		self.current_page = path

		for mypath in (oldpath, path):
			if mypath:
				for treepath in self.find_all(mypath):
					if treepath:
						treeiter = self.get_iter(treepath)
						self.emit('row-changed', treepath, treeiter)

	def get_indexpath(self, treeiter):
		'''Get an L{PageIndexRecord} for a C{Gtk.TreeIter}

		@param treeiter: a C{Gtk.TreeIter}
		@returns: an L{PageIndexRecord} object
		'''
		mytreeiter = self.get_user_data(treeiter)
		if mytreeiter.hint == IS_PAGE:
			return PageIndexRecord(mytreeiter.row)
		elif mytreeiter.hint == IS_TAG:
			return IndexTag(mytreeiter.row['name'], mytreeiter.row['id'])
		else:
			raise ValueError


class TagsPageTreeStore(TagsTreeModelMixin, DuplicatePageTreeStore):
	'''Subclass of the PageTreeStore that shows tags as the top level
	for sub-sets of the page tree.
	'''

	def __init__(self, index, tags=None, show_full_page_name=True):
		TagsTreeModelMixin.__init__(self, index, tags)
		PageTreeStoreBase.__init__(self)
		self.show_full_page_name = show_full_page_name

	def on_get_value(self, iter, column):
		'''Returns the data for a specific column'''
		if iter.hint == IS_TAG:
			if column == NAME_COL:
				return iter.row['name']
			elif column == TIP_COL:
				return encode_markup_text(iter.row['name'])
			elif column == PATH_COL:
				return IndexTag(*iter.row)
			elif column == EXISTS_COL:
				return True
			elif column == STYLE_COL:
				return Pango.Style.NORMAL
			elif column == WEIGHT_COL:
				return Pango.Weight.NORMAL
			elif column == N_CHILD_COL:
				return iter.n_children
		else:
			if self.show_full_page_name \
			and column == NAME_COL and len(iter.treepath) == 2:
				# Show top level pages with full contex
				# top level tree is tags, so top level pages len(path) is 2
				return iter.row['name']
			else:
				return PageTreeStoreBase.on_get_value(self, iter, column)


class TaggedPageTreeStore(TaggedPagesTreeModelMixin, DuplicatePageTreeStore):
	'''A TreeModel that lists all Zim pages in a flat list.
	Pages with associated sub-pages still show them as sub-nodes.
	Intended to be filtered by tags.
	'''

	def __init__(self, index, tags, show_full_page_name=True):
		TaggedPagesTreeModelMixin.__init__(self, index, tags)
		PageTreeStoreBase.__init__(self)
		self.show_full_page_name = show_full_page_name

	def on_get_value(self, iter, column):
		'''Returns the data for a specific column'''
		if self.show_full_page_name \
		and column == NAME_COL and len(iter.treepath) == 1:
			# Show top level pages with full contex
			return iter.row['name']
		else:
			return PageTreeStoreBase.on_get_value(self, iter, column)


class TagsPageTreeView(PageTreeView):

	def do_drag_data_get(self, dragcontext, selectiondata, info, time):
		assert selectiondata.get_target().name() == INTERNAL_PAGELIST_TARGET_NAME
		model, iter = self.get_selection().get_selected()
		path = model.get_indexpath(iter)
		if isinstance(path, IndexTag):
			link = '@' + path.name
		else:
			link = path.name
		logger.debug('Drag data requested, we have internal tag/path "%s"', link)
		data = pack_urilist((link,))
		selectiondata.set(selectiondata.get_target(), 8, data)
		zim.gui.clipboard._internal_selection_data = data # HACK issue #390

	def set_current_page(self, path, vivificate=False):
		'''Set the current page in the treeview

		@param path: a notebook L{Path} object for the page
		@keyword vivificate: when C{True} the path is created
		temporarily when it did not yet exist

		@returns: a gtk TreePath (tuple of intergers) or C{None}
		'''
		#~ print('!! SELECT', path)
		model = self.get_model()
		if model is None:
			return None # index not yet initialized ...

		try:
			treepath = model.find(path)
			model.set_current_page(path) # highlight in model
		except IndexNotFoundError:
			pass
		else:
			return treepath


class TagCloudItem(Gtk.ToggleButton):
	'''Button item used on the tag cloud widget'''

	def __init__(self, indextag):
		Gtk.ToggleButton.__init__(self, indextag.name, use_underline=False)
		self.set_relief(Gtk.ReliefStyle.NONE)
		self.indextag = indextag

		def update_label(self):
			# Make button text bold when active
			label = self.get_child()
			if self.get_active():
				label.set_markup('<b>' + label.get_text() + '</b>')
			else:
				label.set_text(label.get_text())
					# get_text() gives string without markup

		self.connect_after('toggled', update_label)


class TagCloudWidget(ConnectorMixin, Gtk.TextView):
	'''Text-view based list of tags, where each tag is represented by a
	button inserted as a child in the textview.

	@signal: C{selection-changed ()}: emitted when tag selection changes
	@signal: C{sorting-changed ()}: emitted when tag sorting changes
	'''

	# define signals we want to use - (closure type, return type and arg types)
	__gsignals__ = {
		'selection-changed': (GObject.SignalFlags.RUN_LAST, None, ()),
		'sorting-changed': (GObject.SignalFlags.RUN_LAST, None, (object,)),
	}

	def __init__(self, index, sorting='score'):
		GObject.GObject.__init__(self)
		self.set_name('zim-tags-tagcloud')
		self.index = None

		self.set_editable(False)
		self.set_cursor_visible(False)
		self.set_wrap_mode(Gtk.WrapMode.CHAR)

		self.set_sorting(sorting)
		self.connect_index(index)

	def set_sorting(self, sorting):
		self._alphabetically = (sorting == 'alpha')

	def connect_index(self, index):
		'''Connect to an Index object'''
		self.disconnect_index() # just to be sure
		self.index = index
		self.connectto_all(self.index.update_iter.tags, (
			('tag-row-inserted', self._update),
			('tag-row-deleted', self._update),
		))
		self._update()

	def disconnect_index(self):
		'''Stop the model from listening to the index. Used to unhook
		the model before reloading the index.
		'''
		if self.index is not None:
			self.disconnect_from(self.index.update_iter.tags)
		self._clear()

	def get_tag_filter(self):
		'''Returns a tuple with two lists of tags; the first gives all
		tags that are selected, the second gives all tags shown in the
		cloud. By definition the first list is a subset of the second.
		If no tags are selected returns None instead.
		'''
		return [
			b.indextag for b in self.get_children() if b.get_active()
		]

	def _clear(self):
		'''Clears the cloud'''
		self.foreach(lambda b: self.remove(b))
		buffer = self.get_buffer()
		buffer.delete(*buffer.get_bounds())

	def _update(self, *a):
		'''Update the cloud to show only tags that share a set of pages
		with the selected tags.'''
		tagview = TagsView.new_from_index(self.index)
		selected = []
		for button in self.get_children():
			if button.get_active():
				try:
					selected.append(tagview.lookup_by_tagname(button.indextag))
				except IndexNotFoundError:
					pass
				# Need the lookup here in case the tag went missing in the
				# mean time e.g. due to editing of the page
		self._clear()

		if selected:
			tags = tagview.list_intersecting_tags(selected)
		else:
			tags = tagview.list_all_tags_by_n_pages()

		if self._alphabetically:
			tags = sorted(tags, key=lambda t: natural_sort_key(t.name))
		# else leave sorted by score

		buffer = self.get_buffer()
		for tag in tags:
			iter = buffer.get_end_iter()
			anchor = buffer.create_child_anchor(iter)
			button = TagCloudItem(tag)
			button.set_active(tag in selected)
			button.connect("toggled", lambda b: self._update())
			self.add_child_at_anchor(button, anchor)

		self.show_all()
		self.emit('selection-changed')

	def do_populate_popup(self, menu):
		populate_popup_add_separator(menu, prepend=True)

		item = Gtk.CheckMenuItem(_('Sort alphabetically')) # T: Context menu item for tag cloud
		item.set_active(self._alphabetically)
		item.connect('toggled', self._switch_sorting)
		item.show_all()
		menu.prepend(item)

	def _switch_sorting(self, widget, *a):
		self._alphabetically = widget.get_active()
		self._update()
		if self._alphabetically:
			self.emit('sorting-changed', 'alpha')
		else:
			self.emit('sorting-changed', 'score')
