# -*- coding: utf-8 -*-
# smtpbootstrapper.py
# Copyright (C) 2013 LEAP
#
# 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/>.

"""
SMTP bootstrapping
"""

import logging
import os

import requests

from PySide import QtCore

from leap.common.check import leap_assert, leap_assert_type
from leap.common.files import get_mtime
from leap.config.providerconfig import ProviderConfig
from leap.crypto.srpauth import SRPAuth
from leap.util.request_helpers import get_content

logger = logging.getLogger(__name__)


class SMTPBootstrapper(QtCore.QObject):
    """
    SMTP init procedure
    """

    PASSED_KEY = "passed"
    ERROR_KEY = "error"

    IDLE_SLEEP_INTERVAL = 100

    # All dicts returned are of the form
    # {"passed": bool, "error": str}
    download_config = QtCore.Signal(dict)

    def __init__(self):
        QtCore.QObject.__init__(self)

        # **************************************************** #
        # Dependency injection helpers, override this for more
        # granular testing
        self._fetcher = requests
        # **************************************************** #

        self._session = self._fetcher.session()
        self._provider_config = None
        self._smtp_config = None
        self._download_if_needed = False

    def _download_config(self):
        """
        Downloads the SMTP config for the given provider

        :return: True if everything went as expected, False otherwise
        :rtype: bool
        """

        leap_assert(self._provider_config,
                    "We need a provider configuration!")

        logger.debug("Downloading SMTP config for %s" %
                     (self._provider_config.get_domain(),))

        download_config_data = {
            self.PASSED_KEY: False,
            self.ERROR_KEY: ""
        }

        try:
            headers = {}
            mtime = get_mtime(os.path.join(self._smtp_config
                                           .get_path_prefix(),
                                           "leap",
                                           "providers",
                                           self._provider_config.get_domain(),
                                           "smtp-service.json"))

            if self._download_if_needed and mtime:
                headers['if-modified-since'] = mtime

            # there is some confusion with this uri,
            config_uri = "%s/%s/config/smtp-service.json" % (
                self._provider_config.get_api_uri(),
                self._provider_config.get_api_version())
            logger.debug('Downloading SMTP config from: %s' % config_uri)

            srp_auth = SRPAuth(self._provider_config)
            session_id = srp_auth.get_session_id()
            cookies = None
            if session_id:
                cookies = {"_session_id": session_id}

            res = self._session.get(config_uri,
                                    verify=self._provider_config
                                    .get_ca_cert_path(),
                                    headers=headers,
                                    cookies=cookies)
            res.raise_for_status()

            # Not modified
            if res.status_code == 304:
                logger.debug("SMTP definition has not been modified")
                self._smtp_config.load(os.path.join("leap",
                                                    "providers",
                                                    self._provider_config.get_domain(),
                                                    "smtp-service.json"))
            else:
                smtp_definition, mtime = get_content(res)

                self._smtp_config.load(data=smtp_definition, mtime=mtime)
                self._smtp_config.save(["leap",
                                        "providers",
                                        self._provider_config.get_domain(),
                                        "smtp-service.json"])

            download_config_data[self.PASSED_KEY] = True
        except Exception as e:
            download_config_data[self.PASSED_KEY] = False
            download_config_data[self.ERROR_KEY] = "%s" % (e,)

        logger.debug("Emitting download_config %s" % (download_config_data,))
        self.download_config.emit(download_config_data)

        return download_config_data[self.PASSED_KEY]

    def run_smtp_setup_checks(self,
                              checker,
                              provider_config,
                              smtp_config,
                              download_if_needed=False):
        """
        Starts the checks needed for a new smtp setup

        :param checker: Object that executes actions in a different
                        thread
        :type checker: leap.util.checkerthread.CheckerThread
        :param provider_config: Provider configuration
        :type provider_config: ProviderConfig
        :param smtp_config: SMTP configuration to populate
        :type smtp_config: SMTPConfig
        :param download_if_needed: True if it should check for mtime
                                   for the file
        :type download_if_needed: bool
        """
        leap_assert_type(provider_config, ProviderConfig)

        self._provider_config = provider_config
        self._smtp_config = smtp_config
        self._download_if_needed = download_if_needed

        checker.add_checks([
            self._download_config
        ])