# -*- coding: utf-8 -*-
# test_imap.py
# Copyright (C) 2014 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/>.
"""
Test case for leap.email.imap.fetch

@authors: Ruben Pollan, <meskio@sindominio.net>

@license: GPLv3, see included LICENSE file
"""

import json

from email.mime.application import MIMEApplication
from email.mime.multipart import MIMEMultipart
from email.parser import Parser
from mock import Mock
from twisted.trial import unittest

from leap.keymanager.openpgp import OpenPGPKey
from leap.mail.imap.account import SoledadBackedAccount
from leap.mail.imap.fetch import LeapIncomingMail
from leap.mail.imap.fields import fields
from leap.mail.imap.memorystore import MemoryStore
from leap.mail.imap.service.imap import INCOMING_CHECK_PERIOD
from leap.mail.tests import (
    TestCaseWithKeyManager,
    ADDRESS,
)
from leap.soledad.common.document import SoledadDocument
from leap.soledad.common.crypto import (
    EncryptionSchemes,
    ENC_JSON_KEY,
    ENC_SCHEME_KEY,
)


class LeapIncomingMailTestCase(TestCaseWithKeyManager, unittest.TestCase):
    """
    Tests for the incoming mail parser
    """
    NICKSERVER = "http://domain"
    FROM_ADDRESS = "test@somedomain.com"
    BODY = """
Governments of the Industrial World, you weary giants of flesh and steel, I
come from Cyberspace, the new home of Mind. On behalf of the future, I ask
you of the past to leave us alone. You are not welcome among us. You have
no sovereignty where we gather.
    """
    EMAIL = """from: Test from SomeDomain <%(from)s>
to: %(to)s
subject: independence of cyberspace

%(body)s
    """ % {
        "from": FROM_ADDRESS,
        "to": ADDRESS,
        "body": BODY
    }

    def setUp(self):
        super(LeapIncomingMailTestCase, self).setUp()

        # Soledad sync makes trial block forever. The sync it's mocked to fix
        # this problem. _mock_soledad_get_from_index can be used from the tests
        # to provide documents.
        self._soledad.sync = Mock()

        memstore = MemoryStore()
        theAccount = SoledadBackedAccount(
            ADDRESS,
            soledad=self._soledad,
            memstore=memstore)
        self.fetcher = LeapIncomingMail(
            self._km,
            self._soledad,
            theAccount,
            INCOMING_CHECK_PERIOD,
            ADDRESS)

    def tearDown(self):
        del self.fetcher
        super(LeapIncomingMailTestCase, self).tearDown()

    def testExtractOpenPGPHeader(self):
        """
        Test the OpenPGP header key extraction
        """
        KEYURL = "https://somedomain.com/key.txt"
        OpenPGP = "id=12345678; url=\"%s\"; preference=signencrypt" % (KEYURL,)

        message = Parser().parsestr(self.EMAIL)
        message.add_header("OpenPGP", OpenPGP)
        email = self._create_incoming_email(message.as_string())
        self._mock_soledad_get_from_index(fields.JUST_MAIL_IDX, [email])
        self.fetcher._keymanager.fetch_key = Mock()

        def fetch_key_called(ret):
            self.fetcher._keymanager.fetch_key.assert_called_once_with(
                self.FROM_ADDRESS, KEYURL, OpenPGPKey)

        d = self.fetcher.fetch()
        d.addCallback(fetch_key_called)
        return d

    def testExtractOpenPGPHeaderInvalidUrl(self):
        """
        Test the OpenPGP header key extraction
        """
        KEYURL = "https://someotherdomain.com/key.txt"
        OpenPGP = "id=12345678; url=\"%s\"; preference=signencrypt" % (KEYURL,)

        message = Parser().parsestr(self.EMAIL)
        message.add_header("OpenPGP", OpenPGP)
        email = self._create_incoming_email(message.as_string())
        self._mock_soledad_get_from_index(fields.JUST_MAIL_IDX, [email])
        self.fetcher._keymanager.fetch_key = Mock()

        def fetch_key_called(ret):
            self.assertFalse(self.fetcher._keymanager.fetch_key.called)

        d = self.fetcher.fetch()
        d.addCallback(fetch_key_called)
        return d

    def testExtractAttachedKey(self):
        """
        Test the OpenPGP header key extraction
        """
        KEY = "-----BEGIN PGP PUBLIC KEY BLOCK-----\n..."

        message = MIMEMultipart()
        message.add_header("from", self.FROM_ADDRESS)
        key = MIMEApplication("", "pgp-keys")
        key.set_payload(KEY)
        message.attach(key)
        email = self._create_incoming_email(message.as_string())
        self._mock_soledad_get_from_index(fields.JUST_MAIL_IDX, [email])
        self.fetcher._keymanager.put_raw_key = Mock()

        def put_raw_key_called(ret):
            self.fetcher._keymanager.put_raw_key.assert_called_once_with(
                KEY, OpenPGPKey, address=self.FROM_ADDRESS)

        d = self.fetcher.fetch()
        d.addCallback(put_raw_key_called)
        return d

    def _create_incoming_email(self, email_str):
        email = SoledadDocument()
        pubkey = self._km.get_key(ADDRESS, OpenPGPKey)
        data = json.dumps(
            {"incoming": True, "content": email_str},
            ensure_ascii=False)
        email.content = {
            fields.INCOMING_KEY: True,
            fields.ERROR_DECRYPTING_KEY: False,
            ENC_SCHEME_KEY: EncryptionSchemes.PUBKEY,
            ENC_JSON_KEY: str(self._km.encrypt(data, pubkey))
        }
        return email

    def _mock_soledad_get_from_index(self, index_name, value):
        get_from_index = self._soledad.get_from_index

        def soledad_mock(idx_name, *key_values):
            if index_name == idx_name:
                return value
            return get_from_index(idx_name, *key_values)
        self.fetcher._soledad.get_from_index = Mock(side_effect=soledad_mock)