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

# Blackmore's Enhanced IRC-Notification Collection (BEINC) v1.0
# Copyright (C) 2013-2014 Simeon Simeonov

# 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 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 General Public License for more details.

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


import argparse
import errno
import getpass
import json
import os
import random
import sys

import cherrypy

try:
    import pynotify
except ImportError as e:
    pynotify = None


__author__ = 'Simeon Simeonov'
__version__ = '1.0'
__license__ = 'GPL3'


BEINC_OSD_TYPE_NONE = 0
BEINC_OSD_TYPE_PYNOTIFY = 1


class BEINCInstance(object):
    """
    Represents a single server-instance
    """

    def __init__(self, instance_dict):
        """
        instance_dict: the config-dictionary node that represents this instance
        """

        self.__message_queue = list()
        self.__osd_type = BEINC_OSD_TYPE_NONE
        self.__osd_notification = None

        self.__name = instance_dict.get('name')
        self.__password = instance_dict.get('password', '')
        self.__queue_size = int(instance_dict.get('queue_size', 3))

        if instance_dict['osd_system'].lower() == 'pynotify':
            self.__queue_size = 0  # disable queueing
            if not pynotify:
                sys.stderr.write(
                    'This server does not possess pynotify capability\n')
                sys.stderr.write(
                    'Remove the instance {0}'.format(self.__name))
                sys.stderr.write("or define it with 'osd_system': 'none'\n")
                sys.exit(errno.EPERM)

            try:
                self.__osd_notification = pynotify.Notification(' ')
                self.__osd_notification.set_timeout(
                    int(instance_dict.get('osd_timeout', 5000)))
                self.__osd_notification.set_property(
                    'app_name',
                    '{0} {1}'.format(sys.argv[0], __version__))
            except Exception as e:
                sys.stderr.write(
                    'Unable to set up a notification object for {0} ({1})\n')
                sys.exit(errno.EPERM)

            self.__osd_type = BEINC_OSD_TYPE_PYNOTIFY


    @property
    def name(self):
        """
        name-property for the server instance
        """
        return self.__name

    @property
    def queueable(self):
        """
        True if this instance has a queueing capability
        """
        return bool(self.__queue_size)

    def password_match(self, password):
        """
        Returns True if 'passowrd' matches the instance-password,
        otherwise - False
        """
        return True if self.__password == password else False

    def send_message(self, title, message):
        """
        Displays or enqueues the message,
        depending on the instance's type in regard to the osd_system
        """
        if self.__osd_type == BEINC_OSD_TYPE_PYNOTIFY:
            self.__send_pynotify_messaage(title, message)
        else:
            self.__send_message_to_queue(title, message)

    def get_queue(self):
        """
        Reruens a json representation of the message queue
        """
        jstr = json.dumps(self.__message_queue)
        self.__message_queue = list()
        return jstr

    def __send_pynotify_messaage(self, title, message):
        """
        Displays pynotify message
        """

        self.__osd_notification.set_properties(summary=title, body=message)
        self.__osd_notification.show()

    def __send_message_to_queue(self, title, message):
        """
        Enqueues the message
        """

        if len(self.__message_queue) >= self.__queue_size:
            self.__message_queue.pop(0)

        self.__message_queue.append({'title': title, 'message': message})


def beinc_instance_login(method):
    """
    decorator for checking login credentials
    """

    def wrapper(self, *args, **kwargs):

        if not args:
            raise cherrypy.HTTPError(status = 404)

        try:
            instance = self.instances[args[0]]
        except Exception as e:
            raise cherrypy.HTTPError(status = 401,
                                     message = 'Wrong instance or password')

        if not instance.password_match(kwargs.get('password')):
            raise cherrypy.HTTPError(status = 401,
                                     message = 'Wrong instance or password')

        return method(self, *args, **kwargs)

    return wrapper


class WebNotifyServer(object):

    def __init__(self, config):
        """
        """
        self.__config = config
        self.__instances = dict()

        # initialize pynotify if the module exists and if needed
        if pynotify:
            for instance in self.__config['server']['instances']:
                # check if we have at least one instance that uses pynotify
                # before initializing it
                if instance.get('osd_system', '').lower() == 'pynotify':
                    if not pynotify.init('BEINC Notify'):
                        sys.stderr.write('pynotify.init failed! Exiting...\n')
                        sys.exit(1)
                    break
        try:
            for instance in self.__config['server']['instances']:
                self.__instances[instance['name']] = BEINCInstance(instance)
                print('Instance "{0}" added'.format(instance['name']))

        except Exception as e:
            sys.stderr.write('Unable to create instance "{0}": {1}\n'.format(
                instance['name'],
                e))
            sys.exit(1)


    @property
    def instances(self):
        return self.__instances

    @cherrypy.expose
    def index(self):
        """
        default dispatcher
        """
        return 'index'

    @cherrypy.expose
    def default(self, *args):
        """
        default dispatcher
        """
        return 'default'


    @cherrypy.expose
    @beinc_instance_login
    def push(self, *args, **kwargs):

        instance = self.__instances[args[0]]

        print('**kwargs: {0}'.format(str(kwargs)))
        title = kwargs.get('title', '')
        message = kwargs.get('message', '')
        try:
            instance.send_message(title, message)
            return 'OK'
        except Exception as e:
            sys.stderr.write(
                'Unable to handle message in {0}: ({1})\n'.format(
                    instance.name,
                    e))
            raise cherrypy.HTTPError(500, 'Unable to send message')


    @cherrypy.expose
    @beinc_instance_login
    def pull(self, *args, **kwargs):

        instance = self.__instances[args[0]]
        if not instance.queueable:
            raise cherrypy.HTTPError(
                status = 405,
                message = 'BEINC instance "{0}" does not support queuing'.format(
                    instance.name))

        return instance.get_queue()


def main():

    parser = argparse.ArgumentParser(
        description='The following options are available')

    parser.add_argument('-d',
                        action='store_true',
                        dest='daemonize',
                        default=False,
                        help='daemonize the server process')

    parser.add_argument('-H', '--hostname',
                        metavar='HOSTNAME',
                        type=str,
                        dest='hostname',
                        default='127.0.0.1',
                        help="Server IP / hostname")

    parser.add_argument('-p', '--port',
                        metavar='PORT',
                        type=int,
                        dest='port',
                        default=9998,
                        help="Server port")

    parser.add_argument('-c', '--config-file',
                        metavar='FILE',
                        type=str,
                        default=os.path.expanduser('~/.beinc_server.json'),
                        dest='config_file',
                        help="config file")

    parser.add_argument('-v', '--version',
                        action='version',
                        version='%(prog)s {0}'.format(__version__),
                        help='display program-version and exit')

    args = parser.parse_args()

    try:
        with open(args.config_file, 'r') as fp:
            config_dict = json.load(fp)

    except Exception as e:
        sys.stderr.write('Unable to parse {0}: {1}'.format(args.config_file,
                                                           e))
        sys.exit(errno.EIO)

    cherrypy.config.update({
        'server.socket_host': args.hostname,
        'server.socket_port': args.port,
        'server.ssl_module': config_dict['server']['general']['ssl_module'].encode('utf-8'),
        'server.ssl_certificate': config_dict['server']['general']['ssl_certificate'],
        'server.ssl_private_key': config_dict['server']['general']['ssl_private_key'],
        'tools.encode.on': True,
        'tools.encode.encoding': 'utf-8',
        'tools.log_tracebacks.on': False,
        'request.show_tracebacks': False
    })

    try:
        cherrypy.quickstart(WebNotifyServer(config_dict))

    except Exception as e:
        sys.stderr.write("WebServer error: {0}".format(e))
        sys.exit(1)

    sys.exit(0)


if __name__ == "__main__":
    main()