#!/usr/bin/python
#
# Copyright (C) 2014  Simo Sorce <simo@redhat.com>
#
# see file 'COPYING' for use and warranty information
#
# 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/>.

from ipsilon.util.log import Log
from ipsilon.util.plugin import PluginLoader, PluginObject
from ipsilon.util.plugin import PluginInstaller
from ipsilon.util.page import Page
import cherrypy


class ProviderException(Exception, Log):

    def __init__(self, message):
        super(ProviderException, self).__init__(message)
        self.message = message

    def __str__(self):
        return repr(self.message)


class AuthenticationError(ProviderException):

    def __init__(self, message, code):
        super(AuthenticationError, self).__init__(message)
        self.code = code
        self._debug('%s [%s]' % (message, code))


class InvalidRequest(ProviderException):

    def __init__(self, message):
        super(InvalidRequest, self).__init__(message)
        self._debug(message)


class ProviderBase(PluginObject):

    def __init__(self, name, path):
        super(ProviderBase, self).__init__()
        self.name = name
        self.path = path
        self.tree = None
        self.is_enabled = False

    def on_enable(self):
        # this one does nothing
        # derived classes can override with custom behavior
        return

    def get_tree(self, site):
        raise NotImplementedError

    def register(self, site):
        if self.tree:
            # already registered
            return

        # configure self
        plugins = site[FACILITY]
        if self.name in plugins['config']:
            self.set_config(plugins['config'][self.name])

        # init pages and admin interfaces
        self.tree = self.get_tree(site)

        self._debug('IdP Provider registered: %s' % self.name)

        if self.get_config_value('enabled') == '1':
            # and enable self
            self._enable(site)

    def _enable(self, site):
        root = site[FACILITY]['root']
        root.add_subtree(self.name, self.tree)
        self._debug('IdP Provider enabled: %s' % self.name)
        self.is_enabled = True
        self.on_enable()

    def enable(self, site):
        if self.is_enabled:
            return

        self._enable(site)
        self.set_config_value('enabled', '1')
        self.save_plugin_config(FACILITY)

    def disable(self, site):
        if not self.is_enabled:
            return

        # remove self to the root
        root = site[FACILITY]['root']
        root.del_subtree(self.name)

        self.is_enabled = False
        self.set_config_value('enabled', '0')
        self.save_plugin_config(FACILITY)
        self._debug('IdP Provider disabled: %s' % self.name)


class ProviderPageBase(Page):

    def __init__(self, site, config):
        super(ProviderPageBase, self).__init__(site)
        self.plugin_name = config.name
        self.cfg = config

    def GET(self, *args, **kwargs):
        raise cherrypy.HTTPError(501)

    def POST(self, *args, **kwargs):
        raise cherrypy.HTTPError(501)

    def root(self, *args, **kwargs):
        method = cherrypy.request.method

        preop = getattr(self, 'pre_%s' % method, None)
        if preop and callable(preop):
            preop(*args, **kwargs)

        op = getattr(self, method, self.GET)
        if callable(op):
            return op(*args, **kwargs)
        else:
            raise cherrypy.HTTPError(405)

    def _debug(self, fact):
        superfact = '%s: %s' % (self.plugin_name, fact)
        super(ProviderPageBase, self)._debug(superfact)

    def _audit(self, fact):
        cherrypy.log('%s: %s' % (self.plugin_name, fact))


FACILITY = 'provider_config'


class LoadProviders(Log):

    def __init__(self, root, site):
        loader = PluginLoader(LoadProviders, FACILITY, 'IdpProvider')
        site[FACILITY] = loader.get_plugin_data()
        providers = site[FACILITY]

        available = providers['available'].keys()
        self._debug('Available providers: %s' % str(available))

        providers['root'] = root
        for item in providers['available']:
            plugin = providers['available'][item]
            plugin.register(site)


class ProvidersInstall(object):

    def __init__(self):
        pi = PluginInstaller(ProvidersInstall)
        self.plugins = pi.get_plugins()