#! /usr/bin/env python3
# -*- coding: utf-8 -*-

#	Copyright 2011-2012, Marten de Vries
#	Copyright 2011, Milan Boers
#
#	This file is part of OpenTeacher.
#
#	OpenTeacher 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 3 of the License, or
#	(at your option) any later version.
#
#	OpenTeacher 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.
#
#	You should have received a copy of the GNU General Public License
#	along with OpenTeacher.  If not, see <http://www.gnu.org/licenses/>.

import weakref
import traceback

def installQtClasses():
	global RecentlyOpenedModel, RecentlyOpenedViewer

	class RecentlyOpenedModel(QtCore.QAbstractListModel):
		def __init__(self, modules, *args, **kwargs):
			super().__init__(*args, **kwargs)

			self._modules = modules

			self._items = []

		def columnCount(self, parent=None):
			return 1

		def rowCount(self, parent=None):
			return len(self._items)

		def data(self, index, role):
			if not index.isValid():
				return
			item = self._items[index.row()]
			if role == QtCore.Qt.DisplayRole:
				return item["label"]
			elif role == QtCore.Qt.DecorationRole:
				if "icon" in item:
					return QtGui.QPixmap(item["icon"])

		def update(self, items):
			self.beginResetModel()
			self._items = items
			self.endResetModel()

		def open(self, parent, row):
			item = self._items[row]

			showError = lambda: QtWidgets.QMessageBox.critical(
				parent,
				_("Can't open anymore"),
				_("It's not possible anymore to open this kind of list.")
			)

			try:
				module = self._modules.default(
					*item["moduleArgsSelectors"],
					**item["moduleKwargsSelectors"]
				)
			except IndexError:
				showError()
				return

			try:
				method = getattr(module, item["method"])
			except AttributeError:
				showError()
				return

			try:
				method(
					*item["args"],
					**item["kwargs"]
				)
			except Exception:
				#for debugging purposes
				traceback.print_exc()

				QtWidgets.QMessageBox.critical(
					parent,
					_("Can't open anymore"),
					_("It's not possible anymore to open this list.")
				)

	class RecentlyOpenedViewer(QtWidgets.QListView):
		def __init__(self, modules, *args, **kwargs):
			super().__init__(*args, **kwargs)

			self.setModel(RecentlyOpenedModel(modules))
			self.doubleClicked.connect(self._doubleClicked)

		def _doubleClicked(self, index):
			self.model().open(self, index.row())

class RecentlyOpenedViewerModule:
	def __init__(self, moduleManager, *args, **kwargs):
		super().__init__(*args, **kwargs)
		self._mm = moduleManager

		self.requires = (
			self._mm.mods(type="recentlyOpened"),
		)
		self.uses = (
			self._mm.mods(type="translator"),
		)

		self.type = "recentlyOpenedViewer"

	def enable(self):
		global QtCore, QtGui, QtWidgets
		try:
			from PyQt5 import QtCore, QtGui, QtWidgets
		except ImportError:
			return
		installQtClasses()

		self._viewers = set()

		self._modules = set(self._mm.mods(type="modules")).pop()
		try:
			translator = self._modules.default("active", type="translator")
		except IndexError:
			pass
		else:
			translator.languageChanged.handle(self._retranslate)
		self._retranslate()

		self._recentlyOpened = self._modules.default(
			"active",
			type="recentlyOpened"
		)
		self._recentlyOpened.updated.handle(self._update)
		self.active = True

	def _retranslate(self):
		#Translations
		global _
		global ngettext

		try:
			translator = self._modules.default("active", type="translator")
		except IndexError:
			_, ngettext = str, lambda a, b, n: a if n == 1 else b
		else:
			_, ngettext = translator.gettextFunctions(
				self._mm.resourcePath("translations")
			)

	def disable(self):
		self.active = False

		del self._modules
		del self._recentlyOpened
		del self._viewers

	def createViewer(self):
		"""By calling this method, you need to be able to guarantee that
		   there's already a QApplication active. E.g. by depending on
		   'ui', or by being the module that manages the QApplication...

		"""
		viewer = RecentlyOpenedViewer(self._modules)
		recentlyOpened = self._recentlyOpened.getRecentlyOpened()

		viewer.model().update(recentlyOpened)
		self._viewers.add(weakref.ref(viewer))
		return viewer

	def _update(self):
		data = self._recentlyOpened.getRecentlyOpened()
		for viewer in self._viewers:
			ref = viewer()
			if ref is not None:
				ref.model().update(data)

def init(moduleManager):
	return RecentlyOpenedViewerModule(moduleManager)
