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

# Copyright (c) 2012-2019 Jérôme Poisson
# Copyright (c) 2003-2011 Ralph Meijer


# 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/>.
# --

# This program is based on Idavoll (http://idavoll.ik.nu/),
# originaly written by Ralph Meijer (http://ralphm.net/blog/)
# It is sublicensed under AGPL v3 (or any later version) as allowed by the original
# license.

# --

# Here is a copy of the original license:

# Copyright (c) 2003-2011 Ralph Meijer

# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:

# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.


import sys
import csv
import os
from os.path import expanduser, realpath
import configparser
# patch for Python 3.8 compatibility
from sat_tmp.twisted import install as install_twisted_patches
install_twisted_patches()
from zope.interface import implementer
from twisted.application.service import IServiceMaker
from twisted.application import service
from twisted.python import usage, log
from twisted.plugin import IPlugin
from twisted.words.protocols.jabber.jid import JID
import sat_pubsub




def coerceListType(value):
    return next(csv.reader(
        [value], delimiter=",", quotechar='"', skipinitialspace=True
    ))


def coerceJidListType(value):
    values = [JID(v) for v in coerceListType(value)]
    if any((j.resource for j in values)):
        raise ValueError("you must use bare jids")
    return values



OPT_PARAMETERS_BOTH = [
    ['jid', None, None, 'JID this component will be available at'],
    ['xmpp_pwd', None, None, 'XMPP server component password'],
    ['rhost', None, '127.0.0.1', 'XMPP server host'],
    ['rport', None, '5347', 'XMPP server port'],
    ['backend', None, 'pgsql', 'Choice of storage backend'],
    ['db_user', None, None, 'Database user (pgsql backend)'],
    ['db_name', None, 'pubsub', 'Database name (pgsql backend)'],
    ['db_pass', None, None, 'Database password (pgsql backend)'],
    ['db_host', None, None, 'Database host (pgsql backend)'],
    ['db_port', None, None, 'Database port (pgsql backend)'],
    ]

OPT_PARAMETERS_CFG = [
    ["admins_jids_list", None, [], "List of administrators' bare jids",
     coerceJidListType]
    ]

# prefix used for environment variables
ENV_PREFIX = "SAT_PUBSUB_"
# mapping from option name to environment variables to use
# each parameter name links to a list of variable environment name
# if an environment variable of one of the names exists it will be used
# as default value, with priority over config file
ENV_OPT_MAP = {
    # we use the same environment variables as PostgreSQL
    'db_user': ['PGUSER'],
    'db_name': ['PGDATABASE'],
    'db_pass': ['PGPASSWORD'],
    'db_host': ['PGHOST'],
    'db_port': ['PGPORT'],
}
for opt in OPT_PARAMETERS_BOTH + OPT_PARAMETERS_CFG:
    name = opt[0]
    env_name = f"{ENV_PREFIX}{name.upper()}"
    ENV_OPT_MAP.setdefault(name, []).append(env_name)

CONFIG_FILENAME = 'sat'
# List of the configuration filenames sorted by ascending priority
CONFIG_FILES = [realpath(expanduser(path) + CONFIG_FILENAME + '.conf') for path in (
    '/etc/', '/etc/{}/'.format(CONFIG_FILENAME),
    '~/', '~/.',
    '.config/', '.config/.',
    '.config/{}/'.format(CONFIG_FILENAME),
    '', '.')]
CONFIG_SECTION = 'pubsub'


class Options(usage.Options):
    optParameters = OPT_PARAMETERS_BOTH

    optFlags = [
        ('verbose', 'v', 'Show traffic'),
        ('hide-nodes', None, 'Hide all nodes for disco')
    ]

    def __init__(self):
        """Read SàT Pubsub configuration file in order to overwrite the hard-coded default values.

        Priority for the usage of the values is (from lowest to highest):
            - hard-coded default values
            - values from SàT configuration files
            - values passed on the command line
        """
        # If we do it the reading later: after the command line options have been parsed, there's no good way to know
        # if the  options values are the hard-coded ones or if they have been passed on the command line.

        # FIXME: must be refactored + code can be factorised with backend
        config_parser = configparser.ConfigParser()
        config_parser.read(CONFIG_FILES)
        for param in self.optParameters + OPT_PARAMETERS_CFG:
            name = param[0]
            for env_name in ENV_OPT_MAP[name]:
                # we first check if value is set as an environment variable
                value = os.getenv(env_name)
                if value is not None:
                    self.setDefaultOption(param, value)
                    break
            else:
                # no environment variable set, let's try with configuration
                try:
                    value = config_parser.get(CONFIG_SECTION, name)
                    self.setDefaultOption(param, value)
                except (configparser.NoSectionError, configparser.NoOptionError):
                    pass
        usage.Options.__init__(self)
        for opt_data in OPT_PARAMETERS_CFG:
            self[opt_data[0]] = opt_data[2]

    def setDefaultOption(self, param, value):
        """Set default option value using coerce method when needed

        If the value is invalid, we quit the program with exit code 1
        """
        try:
            param[2] = param[4](value)
        except IndexError: # the coerce method is optional
            param[2] = value
        except Exception as e:
            log.err('Invalid value for setting "{name}": {msg}'.format(
                name=name, msg=e))
            sys.exit(1)

    def postOptions(self):
        if self['backend'] not in ['pgsql', 'memory']:
            raise usage.UsageError("Unknown backend!")
        if self['backend'] == 'memory':
            raise NotImplementedError('memory backend is not available at the moment')

        self['jid'] = JID(self['jid']) if self['jid'] else None


@implementer(IServiceMaker, IPlugin)
class SatPubsubMaker(object):
    tapname = "sat-pubsub"
    description = "Salut à Toi Publish-Subscribe Service Component"
    options = Options

    def makeService(self, config):
        from wokkel.component import Component
        from wokkel.disco import DiscoHandler
        from wokkel.generic import FallbackHandler, VersionHandler
        from wokkel.iwokkel import IPubSubResource
        from wokkel import data_form
        from wokkel import pubsub
        from wokkel import rsm
        from wokkel import mam
        from sat_pubsub import const
        from sat_pubsub import mam as pubsub_mam
        from sat_pubsub import pubsub_admin
        from sat_pubsub.backend import BackendService, ExtraDiscoHandler
        from sat_pubsub.privilege import PrivilegesHandler
        from sat_pubsub.delegation import DelegationsHandler

        if not config['jid'] or not config['xmpp_pwd']:
            raise usage.UsageError("You must specify jid and xmpp_pwd")
        s = service.MultiService()

        # Create backend service with storage

        if config['backend'] == 'pgsql':
            from twisted.enterprise import adbapi
            from sat_pubsub.pgsql_storage import Storage
            from psycopg2.extras import NamedTupleConnection
            keys_map = {
                'db_user': 'user',
                'db_pass': 'password',
                'db_name': 'database',
                'db_host': 'host',
                'db_port': 'port',
            }
            kwargs = {}
            for config_k, k in keys_map.items():
                v = config.get(config_k)
                if v is None:
                    continue
                kwargs[k] = v
            dbpool = adbapi.ConnectionPool('psycopg2',
                                           cp_reconnect=True,
                                           client_encoding='utf-8',
                                           connection_factory=NamedTupleConnection,
                                           **kwargs
                                           )
            st = Storage(dbpool)
        elif config['backend'] == 'memory':
            raise NotImplementedError('memory backend is not available at the moment')

        bs = BackendService(st, config)
        bs.setName('backend')
        bs.setServiceParent(s)

        # Set up XMPP server-side component with publish-subscribe capabilities

        cs = Component(config["rhost"], int(config["rport"]),
                       config["jid"].full(), config["xmpp_pwd"])
        cs.setName('component')
        cs.setServiceParent(s)

        cs.factory.maxDelay = 900

        if config["verbose"]:
            cs.logTraffic = True

        FallbackHandler().setHandlerParent(cs)
        VersionHandler('SàT Pubsub', sat_pubsub.__version__).setHandlerParent(cs)
        DiscoHandler().setHandlerParent(cs)

        ph = PrivilegesHandler(config['jid'])
        ph.setHandlerParent(cs)
        bs.privilege = ph

        resource = IPubSubResource(bs)
        resource.hideNodes = config["hide-nodes"]
        resource.serviceJID = config["jid"]

        ps = (rsm if const.FLAG_ENABLE_RSM else pubsub).PubSubService(resource)
        ps.setHandlerParent(cs)
        resource.pubsubService = ps

        if const.FLAG_ENABLE_MAM:
            mam_resource = pubsub_mam.MAMResource(bs)
            mam_s = mam.MAMService(mam_resource)
            mam_s.addFilter(data_form.Field(var=const.MAM_FILTER_CATEGORY))
            mam_s.addFilter(data_form.Field(var=const.MAM_FILTER_FTS))
            mam_s.setHandlerParent(cs)

        pa = pubsub_admin.PubsubAdminHandler(bs)
        pa.setHandlerParent(cs)

        # wokkel.pubsub doesn't handle non pubsub# disco
        # and we need to announce other feature, so this is a workaround
        # to add them
        # FIXME: propose a patch upstream to fix this situation
        ed = ExtraDiscoHandler()
        ed.setHandlerParent(cs)

        # XXX: delegation must be instancied at the end,
        #      because it does some MonkeyPatching on handlers
        dh = DelegationsHandler()
        dh.setHandlerParent(cs)
        bs.delegation = dh

        return s

serviceMaker = SatPubsubMaker()