#!/usr/bin/env python2
# -*- coding: utf-8 -*-
#
# libnotifyplugin.py
#
# Copyright 2013, 2014 Patrick Ulbrich <zulu99@gmx.net>
#
# This program 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 2 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
# MA 02110-1301, USA.
#

import os
import dbus
import threading
from gi.repository import Notify, Gio, Gtk
from common.plugins import Plugin, HookTypes
from common.i18n import _
from common.subproc import start_subprocess
from common.exceptions import InvalidOperationException
from daemon.mails import sort_mails

NOTIFICATION_MODE_COUNT		= '0'
NOTIFICATION_MODE_SUMMARY	= '1'
NOTIFICATION_MODE_SINGLE	= '2'

plugin_defaults = { 'notification_mode' : NOTIFICATION_MODE_SUMMARY }


class LibNotifyPlugin(Plugin):
	def __init__(self):
		# prevent flooding of the messaging tray
		self.MAIL_LIST_LIMIT = 10
		
		# dict that tracks all notifications that need to be closed
		self._notifications = {}
		self._initialized = False
		self._lock = threading.Lock()
		self._notification_server_wait_event = threading.Event()
		self._notification_server_ready = False
		self._is_gnome = False
		self._mails_added_hook = None
		self._mails_removed_hook = None
		
	
	def enable(self):
		self._notification_server_wait_event.clear()
		self._notification_server_ready = False
		self._notifications = {}
		
		# initialize Notification
		if not self._initialized:
			Notify.init("Mailnag")
			self._is_gnome = (os.environ['GDMSESSION'] == 'gnome')
			self._initialized = True
		
		def mails_added_hook(new_mails, all_mails):
			self._notify_async(new_mails, all_mails)
		
		def mails_removed_hook(remaining_mails):
			if remaining_mails == 0:
				# no mails (e.g. email client has been launched) -> close notifications
				self._close_notifications()
		
		self._mails_added_hook = mails_added_hook
		self._mails_removed_hook = mails_removed_hook
		
		controller = self.get_mailnag_controller()
		hooks = controller.get_hooks()
		
		hooks.register_hook_func(HookTypes.MAILS_ADDED, 
			self._mails_added_hook)
		hooks.register_hook_func(HookTypes.MAILS_REMOVED, 
			self._mails_removed_hook)
		
	
	def disable(self):
		controller = self.get_mailnag_controller()
		hooks = controller.get_hooks()
		
		if self._mails_added_hook != None:
			hooks.unregister_hook_func(HookTypes.MAILS_ADDED,
				self._mails_added_hook)
			self._mails_added_hook = None
		
		if self._mails_removed_hook != None:
			hooks.unregister_hook_func(HookTypes.MAILS_REMOVED,
				self._mails_removed_hook)
			self._mails_removed_hook = None
		
		# Abort possible notification server wait
		self._notification_server_wait_event.set()
		# Close all open notifications 
		# (must be called after _notification_server_wait_event.set() 
		# to prevent a possible deadlock)
		self._close_notifications()

	
	def get_manifest(self):
		return (_("LibNotify notifications"),
				_("Shows a popup when new mails arrive."),
				"1.0",
				"Patrick Ulbrich <zulu99@gmx.net>",
				False)


	def get_default_config(self):
		return plugin_defaults
	
	
	def has_config_ui(self):
		return True
	
	
	def get_config_ui(self):
		box = Gtk.Box()
		box.set_spacing(12)
		box.set_orientation(Gtk.Orientation.VERTICAL)
		
		label = Gtk.Label()
		label.set_markup('<b>%s</b>' % _('Please select a notification mode:'))
		label.set_alignment(0.0, 0.0)
		box.pack_start(label, True, True, 0)
		
		inner_box = Gtk.Box()
		inner_box.set_spacing(6)
		inner_box.set_orientation(Gtk.Orientation.VERTICAL)
		
		cb_count = Gtk.RadioButton(label = _('Count of new mails'))
		inner_box.pack_start(cb_count, True, True, 0)
		
		cb_summary = Gtk.RadioButton(label = _('Summary of new mails'), group = cb_count)
		inner_box.pack_start(cb_summary, True, True, 0)
		
		cb_single = Gtk.RadioButton(label = _('One notification per new mail'), group = cb_count)
		inner_box.pack_start(cb_single, True, True, 0)
		
		alignment = Gtk.Alignment()
		alignment.set_padding(0, 0, 18, 0)
		alignment.add(inner_box)
		
		box.pack_start(alignment, True, True, 0)
		
		return box
	
	
	def load_ui_from_config(self, config_ui):
		config = self.get_config()
		inner_box = config_ui.get_children()[1].get_child()
		cb = inner_box.get_children()[int(config['notification_mode'])]
		cb.set_active(True)
	
	
	def save_ui_to_config(self, config_ui):
		config = self.get_config()
		inner_box = config_ui.get_children()[1].get_child()
		idx = 0
		for cb in inner_box.get_children():
			if cb.get_active():
				config['notification_mode'] = str(idx)
				break
			idx += 1


	def _notify_async(self, new_mails, all_mails):
		def thread():
			with self._lock:
				# The desktop session may have started Mailnag 
				# before the libnotify dbus daemon.
				if not self._notification_server_ready:
					if not self._wait_for_notification_server():
						return
					self._notification_server_ready = True
			
				config = self.get_config()
				if config['notification_mode'] == NOTIFICATION_MODE_COUNT:
					self._notify_count(len(all_mails))
				elif config['notification_mode'] == NOTIFICATION_MODE_SUMMARY:
					self._notify_summary(new_mails, all_mails)
				else:
					self._notify_single(new_mails)
					
		
		t = threading.Thread(target = thread)
		t.start()
	
	
	def _notify_summary(self, new_mails, all_mails):
		summary = ""		
		body = ""
		
		# The mail list (all_mails) is sorted by date (mails with most recent 
		# date on top). New mails with no date or older mails that come in 
		# delayed won't be listed on top. So if a mail with no or an older date 
		# arrives, it gives the impression that the top most mail (i.e. the mail 
		# with the most recent date) is re-notified.
		# To fix that, simply put new mails on top explicitly.  
		mails = new_mails + [m for m in all_mails if m not in new_mails]
		
		if len(self._notifications) == 0:
			self._notifications['0'] = self._get_notification(" ", None, None) # empty string will emit a gtk warning

		ubound = len(mails) if len(mails) <= self.MAIL_LIST_LIMIT else self.MAIL_LIST_LIMIT

		for i in range(ubound):
			if self._is_gnome:
				body += "%s:\n<i>%s</i>\n\n" % (self._get_sender(mails[i]), mails[i].subject)
			else:
				body += "%s  -  %s\n" % (ellipsize(self._get_sender(mails[i]), 20), ellipsize(mails[i].subject, 20))

		if len(mails) > self.MAIL_LIST_LIMIT:
			if self._is_gnome:
				body += "<i>%s</i>" % _("(and {0} more)").format(str(len(mails) - self.MAIL_LIST_LIMIT))
			else:
				body += _("(and {0} more)").format(str(len(mails) - self.MAIL_LIST_LIMIT))

		if len(mails) > 1: # multiple new emails
			summary = _("You have {0} new mails.").format(str(len(mails)))
		else:
			summary = _("You have a new mail.")

		self._notifications['0'].update(summary, body, "mail-unread")
		self._notifications['0'].show()
	
	
	def _notify_single(self, mails):
		# In single notification mode new mails are
		# added to the *bottom* of the notification list.
		mails = sort_mails(mails, sort_desc = False)
		
		for mail in mails:
			n = self._get_notification(self._get_sender(mail), mail.subject, "mail-unread")
			notification_id = str(id(n))
			if self._is_gnome:
				n.add_action("mark-as-read", _("Mark as read"), 
					self._notification_action_handler, (mail, notification_id))			
			n.show()
			self._notifications[notification_id] = n


	def _notify_count(self, count):
		if len(self._notifications) == 0:
			self._notifications['0'] = self._get_notification(" ", None, None) # empty string will emit a gtk warning
		
		if count > 1: # multiple new emails
			summary = _("You have {0} new mails.").format(str(count))
		else:
			summary = _("You have a new mail.")
		
		self._notifications['0'].update(summary, None, "mail-unread")
		self._notifications['0'].show()
	
	
	def _close_notifications(self):
		with self._lock:
			for n in self._notifications.itervalues():
				n.close()
			self._notifications = {}
	
	
	def _get_notification(self, summary, body, icon):
		n = Notify.Notification.new(summary, body, icon)		
		n.set_category("email")
		if self._is_gnome:
			n.add_action("default", "default", self._notification_action_handler, None)

		return n
	
	
	def _wait_for_notification_server(self):
		bus = dbus.SessionBus()
		while not bus.name_has_owner('org.freedesktop.Notifications'):
			self._notification_server_wait_event.wait(5)
			if self._notification_server_wait_event.is_set():
				return False
		return True

	
	def _notification_action_handler(self, n, action, user_data):
		with self._lock:
			if action == "default":
				mailclient = get_default_mail_reader()
				if mailclient != None:
					start_subprocess(mailclient)

				# clicking the notification bubble has closed all notifications
				# so clear the reference array as well. 
				self._notifications = {}
			elif action == "mark-as-read":
				controller = self.get_mailnag_controller()
				try:
					controller.mark_mail_as_read(user_data[0].id)
				except InvalidOperationException:
					pass
				
				# clicking the action has closed the notification
				# so remove its reference.
				del self._notifications[user_data[1]]
	

	def _get_sender(self, mail):
		name, addr = mail.sender
		if len(name) > 0: return name
		else: return addr


def get_default_mail_reader():
	mail_reader = None
	app_info = Gio.AppInfo.get_default_for_type ("x-scheme-handler/mailto", False)

	if app_info != None:
		executable = Gio.AppInfo.get_executable(app_info)

		if (executable != None) and (len(executable) > 0):
			mail_reader = executable

	return mail_reader


def ellipsize(str, max_len):
	if max_len < 3: max_len = 3
	if len(str) <= max_len:
		return str
	else:
		return str[0:max_len - 3] + '...'