# -*- coding: utf-8 -*-
from __future__ import absolute_import
from __future__ import print_function

from django.conf import settings
from django.test import TestCase

import os
import shutil
import ujson

from mock import patch, MagicMock
from six.moves import range
from typing import Any, Dict, List, Set

from zerver.lib.actions import (
    do_claim_attachments,
)

from zerver.lib.export import (
    do_export_realm,
    export_usermessages_batch,
)
from zerver.lib.upload import (
    claim_attachment,
    upload_message_image,
)
from zerver.lib.utils import (
    mkdir_p,
    query_chunker,
)
from zerver.lib.test_classes import (
    ZulipTestCase,
)

from zerver.lib.test_runner import slow

from zerver.models import (
    Message,
    Realm,
    Recipient,
    UserMessage,
)

def rm_tree(path):
    # type: (str) -> None
    if os.path.exists(path):
        shutil.rmtree(path)

class QueryUtilTest(ZulipTestCase):
    def _create_messages(self):
        # type: () -> None
        for email in [self.example_email('cordelia'),
                      self.example_email('hamlet'),
                      self.example_email('iago')]:
            for _ in range(5):
                self.send_message(email, self.example_email('othello'), Recipient.PERSONAL)

    @slow('creates lots of data')
    def test_query_chunker(self):
        # type: () -> None
        self._create_messages()

        cordelia = self.example_user('cordelia')
        hamlet = self.example_user('hamlet')

        def get_queries():
            # type: () -> List[Any]
            queries = [
                Message.objects.filter(sender_id=cordelia.id),
                Message.objects.filter(sender_id=hamlet.id),
                Message.objects.exclude(sender_id__in=[cordelia.id, hamlet.id])
            ]
            return queries

        for query in get_queries():
            # For our test to be meaningful, we want non-empty queries
            # at first
            assert len(list(query)) > 0

        queries = get_queries()

        all_msg_ids = set()  # type: Set[int]
        chunker = query_chunker(
            queries=queries,
            id_collector=all_msg_ids,
            chunk_size=20,
        )

        all_row_ids = []
        for chunk in chunker:
            for row in chunk:
                all_row_ids.append(row.id)

        self.assertEqual(all_row_ids, sorted(all_row_ids))
        self.assertEqual(len(all_msg_ids), len(Message.objects.all()))

        # Now just search for cordelia/hamlet.  Note that we don't really
        # need the order_by here, but it should be harmless.
        queries = [
            Message.objects.filter(sender_id=cordelia.id).order_by('id'),
            Message.objects.filter(sender_id=hamlet.id),
        ]
        all_msg_ids = set()
        chunker = query_chunker(
            queries=queries,
            id_collector=all_msg_ids,
            chunk_size=7,  # use a different size
        )
        list(chunker)  # exhaust the iterator
        self.assertEqual(
            len(all_msg_ids),
            len(Message.objects.filter(sender_id__in=[cordelia.id, hamlet.id]))
        )

        # Try just a single query to validate chunking.
        queries = [
            Message.objects.exclude(sender_id=cordelia.id),
        ]
        all_msg_ids = set()
        chunker = query_chunker(
            queries=queries,
            id_collector=all_msg_ids,
            chunk_size=11,  # use a different size each time
        )
        list(chunker)  # exhaust the iterator
        self.assertEqual(
            len(all_msg_ids),
            len(Message.objects.exclude(sender_id=cordelia.id))
        )
        self.assertTrue(len(all_msg_ids) > 15)

        # Verify assertions about disjoint-ness.
        queries = [
            Message.objects.exclude(sender_id=cordelia.id),
            Message.objects.filter(sender_id=hamlet.id),
        ]
        all_msg_ids = set()
        chunker = query_chunker(
            queries=queries,
            id_collector=all_msg_ids,
            chunk_size=13,  # use a different size each time
        )
        with self.assertRaises(AssertionError):
            list(chunker)  # exercise the iterator

        # Try to confuse things with ids part of the query...
        queries = [
            Message.objects.filter(id__lte=10),
            Message.objects.filter(id__gt=10),
        ]
        all_msg_ids = set()
        chunker = query_chunker(
            queries=queries,
            id_collector=all_msg_ids,
            chunk_size=11,  # use a different size each time
        )
        self.assertEqual(len(all_msg_ids), 0)  # until we actually use the iterator
        list(chunker)  # exhaust the iterator
        self.assertEqual(len(all_msg_ids), len(Message.objects.all()))

        # Verify that we can just get the first chunk with a next() call.
        queries = [
            Message.objects.all(),
        ]
        all_msg_ids = set()
        chunker = query_chunker(
            queries=queries,
            id_collector=all_msg_ids,
            chunk_size=10,  # use a different size each time
        )
        first_chunk = next(chunker)  # type: ignore
        self.assertEqual(len(first_chunk), 10)
        self.assertEqual(len(all_msg_ids), 10)
        expected_msg = Message.objects.all()[0:10][5]
        actual_msg = first_chunk[5]
        self.assertEqual(actual_msg.content, expected_msg.content)
        self.assertEqual(actual_msg.sender_id, expected_msg.sender_id)


class ExportTest(ZulipTestCase):

    def setUp(self):
        # type: () -> None
        rm_tree(settings.LOCAL_UPLOADS_DIR)

    def _make_output_dir(self):
        # type: () -> str
        output_dir = 'var/test-export'
        rm_tree(output_dir)
        mkdir_p(output_dir)
        return output_dir

    def _export_realm(self, realm, exportable_user_ids=None):
        # type: (Realm, Set[int]) -> Dict[str, Any]
        output_dir = self._make_output_dir()
        with patch('logging.info'), patch('zerver.lib.export.create_soft_link'):
            do_export_realm(
                realm=realm,
                output_dir=output_dir,
                threads=0,
                exportable_user_ids=exportable_user_ids,
            )
            # TODO: Process the second partial file, which can be created
            #       for certain edge cases.
            export_usermessages_batch(
                input_path=os.path.join(output_dir, 'messages-000001.json.partial'),
                output_path=os.path.join(output_dir, 'message.json')
            )

        def read_file(fn):
            # type: (str) -> Any
            full_fn = os.path.join(output_dir, fn)
            with open(full_fn) as f:
                return ujson.load(f)

        result = {}
        result['realm'] = read_file('realm.json')
        result['attachment'] = read_file('attachment.json')
        result['message'] = read_file('message.json')
        result['uploads_dir'] = os.path.join(output_dir, 'uploads')
        return result

    def test_attachment(self):
        # type: () -> None
        message = Message.objects.all()[0]
        user_profile = message.sender
        url = upload_message_image(u'dummy.txt', len(b'zulip!'), u'text/plain', b'zulip!', user_profile)
        path_id = url.replace('/user_uploads/', '')
        claim_attachment(
            user_profile=user_profile,
            path_id=path_id,
            message=message,
            is_message_realm_public=True
        )

        realm = Realm.objects.get(string_id='zulip')
        full_data = self._export_realm(realm)

        data = full_data['attachment']
        self.assertEqual(len(data['zerver_attachment']), 1)
        record = data['zerver_attachment'][0]
        self.assertEqual(record['path_id'], path_id)

        fn = os.path.join(full_data['uploads_dir'], path_id)
        with open(fn) as f:
            self.assertEqual(f.read(), 'zulip!')

    def test_zulip_realm(self):
        # type: () -> None
        realm = Realm.objects.get(string_id='zulip')
        full_data = self._export_realm(realm)

        data = full_data['realm']
        self.assertEqual(len(data['zerver_userprofile_crossrealm']), 0)
        self.assertEqual(len(data['zerver_userprofile_mirrordummy']), 0)

        def get_set(table, field):
            # type: (str, str) -> Set[str]
            values = set(r[field] for r in data[table])
            # print('set(%s)' % sorted(values))
            return values

        def find_by_id(table, db_id):
            # type: (str, int) -> Dict[str, Any]
            return [
                r for r in data[table]
                if r['id'] == db_id][0]

        exported_user_emails = get_set('zerver_userprofile', 'email')
        self.assertIn(self.example_email('cordelia'), exported_user_emails)
        self.assertIn('default-bot@zulip.com', exported_user_emails)
        self.assertIn('emailgateway@zulip.com', exported_user_emails)

        exported_streams = get_set('zerver_stream', 'name')
        self.assertEqual(
            exported_streams,
            set([u'Denmark', u'Rome', u'Scotland', u'Venice', u'Verona'])
        )

        data = full_data['message']
        um = UserMessage.objects.all()[0]
        exported_um = find_by_id('zerver_usermessage', um.id)
        self.assertEqual(exported_um['message'], um.message_id)
        self.assertEqual(exported_um['user_profile'], um.user_profile_id)

        exported_message = find_by_id('zerver_message', um.message_id)
        self.assertEqual(exported_message['content'], um.message.content)

        # TODO, extract get_set/find_by_id, so we can split this test up

        # Now, restrict users
        cordelia = self.example_user('cordelia')
        hamlet = self.example_user('hamlet')
        user_ids = set([cordelia.id, hamlet.id])

        full_data = self._export_realm(realm, exportable_user_ids=user_ids)
        data = full_data['realm']
        exported_user_emails = get_set('zerver_userprofile', 'email')
        self.assertIn(self.example_email('cordelia'), exported_user_emails)
        self.assertIn(self.example_email('hamlet'), exported_user_emails)
        self.assertNotIn('default-bot@zulip.com', exported_user_emails)
        self.assertNotIn(self.example_email('iago'), exported_user_emails)

        dummy_user_emails = get_set('zerver_userprofile_mirrordummy', 'email')
        self.assertIn(self.example_email('iago'), dummy_user_emails)
        self.assertNotIn(self.example_email('cordelia'), dummy_user_emails)