# -*- coding: utf-8 -*-
# Copyright 2014-2016 OpenMarket Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from twisted.internet import defer

from synapse.api.errors import StoreError
from synapse.storage.search import SearchStore
from synapse.util.caches.descriptors import cached, cachedInlineCallbacks

import collections
import logging
import ujson as json
import re

logger = logging.getLogger(__name__)


OpsLevel = collections.namedtuple(
    "OpsLevel",
    ("ban_level", "kick_level", "redact_level",)
)

RatelimitOverride = collections.namedtuple(
    "RatelimitOverride",
    ("messages_per_second", "burst_count",)
)


class RoomStore(SearchStore):

    @defer.inlineCallbacks
    def store_room(self, room_id, room_creator_user_id, is_public):
        """Stores a room.

        Args:
            room_id (str): The desired room ID, can be None.
            room_creator_user_id (str): The user ID of the room creator.
            is_public (bool): True to indicate that this room should appear in
            public room lists.
        Raises:
            StoreError if the room could not be stored.
        """
        try:
            def store_room_txn(txn, next_id):
                self._simple_insert_txn(
                    txn,
                    "rooms",
                    {
                        "room_id": room_id,
                        "creator": room_creator_user_id,
                        "is_public": is_public,
                    },
                )
                if is_public:
                    self._simple_insert_txn(
                        txn,
                        table="public_room_list_stream",
                        values={
                            "stream_id": next_id,
                            "room_id": room_id,
                            "visibility": is_public,
                        }
                    )
            with self._public_room_id_gen.get_next() as next_id:
                yield self.runInteraction(
                    "store_room_txn",
                    store_room_txn, next_id,
                )
        except Exception as e:
            logger.error("store_room with room_id=%s failed: %s", room_id, e)
            raise StoreError(500, "Problem creating room.")

    def get_room(self, room_id):
        """Retrieve a room.

        Args:
            room_id (str): The ID of the room to retrieve.
        Returns:
            A namedtuple containing the room information, or an empty list.
        """
        return self._simple_select_one(
            table="rooms",
            keyvalues={"room_id": room_id},
            retcols=("room_id", "is_public", "creator"),
            desc="get_room",
            allow_none=True,
        )

    @defer.inlineCallbacks
    def set_room_is_public(self, room_id, is_public):
        def set_room_is_public_txn(txn, next_id):
            self._simple_update_one_txn(
                txn,
                table="rooms",
                keyvalues={"room_id": room_id},
                updatevalues={"is_public": is_public},
            )

            entries = self._simple_select_list_txn(
                txn,
                table="public_room_list_stream",
                keyvalues={
                    "room_id": room_id,
                    "appservice_id": None,
                    "network_id": None,
                },
                retcols=("stream_id", "visibility"),
            )

            entries.sort(key=lambda r: r["stream_id"])

            add_to_stream = True
            if entries:
                add_to_stream = bool(entries[-1]["visibility"]) != is_public

            if add_to_stream:
                self._simple_insert_txn(
                    txn,
                    table="public_room_list_stream",
                    values={
                        "stream_id": next_id,
                        "room_id": room_id,
                        "visibility": is_public,
                        "appservice_id": None,
                        "network_id": None,
                    }
                )

        with self._public_room_id_gen.get_next() as next_id:
            yield self.runInteraction(
                "set_room_is_public",
                set_room_is_public_txn, next_id,
            )
        self.hs.get_notifier().on_new_replication_data()

    @defer.inlineCallbacks
    def set_room_is_public_appservice(self, room_id, appservice_id, network_id,
                                      is_public):
        """Edit the appservice/network specific public room list.

        Each appservice can have a number of published room lists associated
        with them, keyed off of an appservice defined `network_id`, which
        basically represents a single instance of a bridge to a third party
        network.

        Args:
            room_id (str)
            appservice_id (str)
            network_id (str)
            is_public (bool): Whether to publish or unpublish the room from the
                list.
        """
        def set_room_is_public_appservice_txn(txn, next_id):
            if is_public:
                try:
                    self._simple_insert_txn(
                        txn,
                        table="appservice_room_list",
                        values={
                            "appservice_id": appservice_id,
                            "network_id": network_id,
                            "room_id": room_id
                        },
                    )
                except self.database_engine.module.IntegrityError:
                    # We've already inserted, nothing to do.
                    return
            else:
                self._simple_delete_txn(
                    txn,
                    table="appservice_room_list",
                    keyvalues={
                        "appservice_id": appservice_id,
                        "network_id": network_id,
                        "room_id": room_id
                    },
                )

            entries = self._simple_select_list_txn(
                txn,
                table="public_room_list_stream",
                keyvalues={
                    "room_id": room_id,
                    "appservice_id": appservice_id,
                    "network_id": network_id,
                },
                retcols=("stream_id", "visibility"),
            )

            entries.sort(key=lambda r: r["stream_id"])

            add_to_stream = True
            if entries:
                add_to_stream = bool(entries[-1]["visibility"]) != is_public

            if add_to_stream:
                self._simple_insert_txn(
                    txn,
                    table="public_room_list_stream",
                    values={
                        "stream_id": next_id,
                        "room_id": room_id,
                        "visibility": is_public,
                        "appservice_id": appservice_id,
                        "network_id": network_id,
                    }
                )

        with self._public_room_id_gen.get_next() as next_id:
            yield self.runInteraction(
                "set_room_is_public_appservice",
                set_room_is_public_appservice_txn, next_id,
            )
        self.hs.get_notifier().on_new_replication_data()

    def get_public_room_ids(self):
        return self._simple_select_onecol(
            table="rooms",
            keyvalues={
                "is_public": True,
            },
            retcol="room_id",
            desc="get_public_room_ids",
        )

    def get_room_count(self):
        """Retrieve a list of all rooms
        """

        def f(txn):
            sql = "SELECT count(*)  FROM rooms"
            txn.execute(sql)
            row = txn.fetchone()
            return row[0] or 0

        return self.runInteraction(
            "get_rooms", f
        )

    def _store_room_topic_txn(self, txn, event):
        if hasattr(event, "content") and "topic" in event.content:
            self._simple_insert_txn(
                txn,
                "topics",
                {
                    "event_id": event.event_id,
                    "room_id": event.room_id,
                    "topic": event.content["topic"],
                },
            )

            self.store_event_search_txn(
                txn, event, "content.topic", event.content["topic"],
            )

    def _store_room_name_txn(self, txn, event):
        if hasattr(event, "content") and "name" in event.content:
            self._simple_insert_txn(
                txn,
                "room_names",
                {
                    "event_id": event.event_id,
                    "room_id": event.room_id,
                    "name": event.content["name"],
                }
            )

            self.store_event_search_txn(
                txn, event, "content.name", event.content["name"],
            )

    def _store_room_message_txn(self, txn, event):
        if hasattr(event, "content") and "body" in event.content:
            self.store_event_search_txn(
                txn, event, "content.body", event.content["body"],
            )

    def _store_history_visibility_txn(self, txn, event):
        self._store_content_index_txn(txn, event, "history_visibility")

    def _store_guest_access_txn(self, txn, event):
        self._store_content_index_txn(txn, event, "guest_access")

    def _store_content_index_txn(self, txn, event, key):
        if hasattr(event, "content") and key in event.content:
            sql = (
                "INSERT INTO %(key)s"
                " (event_id, room_id, %(key)s)"
                " VALUES (?, ?, ?)" % {"key": key}
            )
            txn.execute(sql, (
                event.event_id,
                event.room_id,
                event.content[key]
            ))

    def add_event_report(self, room_id, event_id, user_id, reason, content,
                         received_ts):
        next_id = self._event_reports_id_gen.get_next()
        return self._simple_insert(
            table="event_reports",
            values={
                "id": next_id,
                "received_ts": received_ts,
                "room_id": room_id,
                "event_id": event_id,
                "user_id": user_id,
                "reason": reason,
                "content": json.dumps(content),
            },
            desc="add_event_report"
        )

    def get_current_public_room_stream_id(self):
        return self._public_room_id_gen.get_current_token()

    @cached(num_args=2, max_entries=100)
    def get_public_room_ids_at_stream_id(self, stream_id, network_tuple):
        """Get pulbic rooms for a particular list, or across all lists.

        Args:
            stream_id (int)
            network_tuple (ThirdPartyInstanceID): The list to use (None, None)
                means the main list, None means all lsits.
        """
        return self.runInteraction(
            "get_public_room_ids_at_stream_id",
            self.get_public_room_ids_at_stream_id_txn,
            stream_id, network_tuple=network_tuple
        )

    def get_public_room_ids_at_stream_id_txn(self, txn, stream_id,
                                             network_tuple):
        return {
            rm
            for rm, vis in self.get_published_at_stream_id_txn(
                txn, stream_id, network_tuple=network_tuple
            ).items()
            if vis
        }

    def get_published_at_stream_id_txn(self, txn, stream_id, network_tuple):
        if network_tuple:
            # We want to get from a particular list. No aggregation required.

            sql = ("""
                SELECT room_id, visibility FROM public_room_list_stream
                INNER JOIN (
                    SELECT room_id, max(stream_id) AS stream_id
                    FROM public_room_list_stream
                    WHERE stream_id <= ? %s
                    GROUP BY room_id
                ) grouped USING (room_id, stream_id)
            """)

            if network_tuple.appservice_id is not None:
                txn.execute(
                    sql % ("AND appservice_id = ? AND network_id = ?",),
                    (stream_id, network_tuple.appservice_id, network_tuple.network_id,)
                )
            else:
                txn.execute(
                    sql % ("AND appservice_id IS NULL",),
                    (stream_id,)
                )
            return dict(txn)
        else:
            # We want to get from all lists, so we need to aggregate the results

            logger.info("Executing full list")

            sql = ("""
                SELECT room_id, visibility
                FROM public_room_list_stream
                INNER JOIN (
                    SELECT
                        room_id, max(stream_id) AS stream_id, appservice_id,
                        network_id
                    FROM public_room_list_stream
                    WHERE stream_id <= ?
                    GROUP BY room_id, appservice_id, network_id
                ) grouped USING (room_id, stream_id)
            """)

            txn.execute(
                sql,
                (stream_id,)
            )

            results = {}
            # A room is visible if its visible on any list.
            for room_id, visibility in txn:
                results[room_id] = bool(visibility) or results.get(room_id, False)

            return results

    def get_public_room_changes(self, prev_stream_id, new_stream_id,
                                network_tuple):
        def get_public_room_changes_txn(txn):
            then_rooms = self.get_public_room_ids_at_stream_id_txn(
                txn, prev_stream_id, network_tuple
            )

            now_rooms_dict = self.get_published_at_stream_id_txn(
                txn, new_stream_id, network_tuple
            )

            now_rooms_visible = set(
                rm for rm, vis in now_rooms_dict.items() if vis
            )
            now_rooms_not_visible = set(
                rm for rm, vis in now_rooms_dict.items() if not vis
            )

            newly_visible = now_rooms_visible - then_rooms
            newly_unpublished = now_rooms_not_visible & then_rooms

            return newly_visible, newly_unpublished

        return self.runInteraction(
            "get_public_room_changes", get_public_room_changes_txn
        )

    def get_all_new_public_rooms(self, prev_id, current_id, limit):
        def get_all_new_public_rooms(txn):
            sql = ("""
                SELECT stream_id, room_id, visibility, appservice_id, network_id
                FROM public_room_list_stream
                WHERE stream_id > ? AND stream_id <= ?
                ORDER BY stream_id ASC
                LIMIT ?
            """)

            txn.execute(sql, (prev_id, current_id, limit,))
            return txn.fetchall()

        if prev_id == current_id:
            return defer.succeed([])

        return self.runInteraction(
            "get_all_new_public_rooms", get_all_new_public_rooms
        )

    @cachedInlineCallbacks(max_entries=10000)
    def get_ratelimit_for_user(self, user_id):
        """Check if there are any overrides for ratelimiting for the given
        user

        Args:
            user_id (str)

        Returns:
            RatelimitOverride if there is an override, else None. If the contents
            of RatelimitOverride are None or 0 then ratelimitng has been
            disabled for that user entirely.
        """
        row = yield self._simple_select_one(
            table="ratelimit_override",
            keyvalues={"user_id": user_id},
            retcols=("messages_per_second", "burst_count"),
            allow_none=True,
            desc="get_ratelimit_for_user",
        )

        if row:
            defer.returnValue(RatelimitOverride(
                messages_per_second=row["messages_per_second"],
                burst_count=row["burst_count"],
            ))
        else:
            defer.returnValue(None)

    @cached(max_entries=10000)
    def is_room_blocked(self, room_id):
        return self._simple_select_one_onecol(
            table="blocked_rooms",
            keyvalues={
                "room_id": room_id,
            },
            retcol="1",
            allow_none=True,
            desc="is_room_blocked",
        )

    @defer.inlineCallbacks
    def block_room(self, room_id, user_id):
        yield self._simple_insert(
            table="blocked_rooms",
            values={
                "room_id": room_id,
                "user_id": user_id,
            },
            desc="block_room",
        )
        self.is_room_blocked.invalidate((room_id,))

    def get_media_mxcs_in_room(self, room_id):
        """Retrieves all the local and remote media MXC URIs in a given room

        Args:
            room_id (str)

        Returns:
            The local and remote media as a lists of tuples where the key is
            the hostname and the value is the media ID.
        """
        def _get_media_mxcs_in_room_txn(txn):
            local_mxcs, remote_mxcs = self._get_media_mxcs_in_room_txn(txn, room_id)
            local_media_mxcs = []
            remote_media_mxcs = []

            # Convert the IDs to MXC URIs
            for media_id in local_mxcs:
                local_media_mxcs.append("mxc://%s/%s" % (self.hostname, media_id))
            for hostname, media_id in remote_mxcs:
                remote_media_mxcs.append("mxc://%s/%s" % (hostname, media_id))

            return local_media_mxcs, remote_media_mxcs
        return self.runInteraction("get_media_ids_in_room", _get_media_mxcs_in_room_txn)

    def quarantine_media_ids_in_room(self, room_id, quarantined_by):
        """For a room loops through all events with media and quarantines
        the associated media
        """
        def _quarantine_media_in_room_txn(txn):
            local_mxcs, remote_mxcs = self._get_media_mxcs_in_room_txn(txn, room_id)
            total_media_quarantined = 0

            # Now update all the tables to set the quarantined_by flag

            txn.executemany("""
                UPDATE local_media_repository
                SET quarantined_by = ?
                WHERE media_id = ?
            """, ((quarantined_by, media_id) for media_id in local_mxcs))

            txn.executemany(
                """
                    UPDATE remote_media_cache
                    SET quarantined_by = ?
                    WHERE media_origin = ? AND media_id = ?
                """,
                (
                    (quarantined_by, origin, media_id)
                    for origin, media_id in remote_mxcs
                )
            )

            total_media_quarantined += len(local_mxcs)
            total_media_quarantined += len(remote_mxcs)

            return total_media_quarantined

        return self.runInteraction(
            "quarantine_media_in_room",
            _quarantine_media_in_room_txn,
        )

    def _get_media_mxcs_in_room_txn(self, txn, room_id):
        """Retrieves all the local and remote media MXC URIs in a given room

        Args:
            txn (cursor)
            room_id (str)

        Returns:
            The local and remote media as a lists of tuples where the key is
            the hostname and the value is the media ID.
        """
        mxc_re = re.compile("^mxc://([^/]+)/([^/#?]+)")

        next_token = self.get_current_events_token() + 1
        local_media_mxcs = []
        remote_media_mxcs = []

        while next_token:
            sql = """
                SELECT stream_ordering, content FROM events
                WHERE room_id = ?
                    AND stream_ordering < ?
                    AND contains_url = ? AND outlier = ?
                ORDER BY stream_ordering DESC
                LIMIT ?
            """
            txn.execute(sql, (room_id, next_token, True, False, 100))

            next_token = None
            for stream_ordering, content_json in txn:
                next_token = stream_ordering
                content = json.loads(content_json)

                content_url = content.get("url")
                thumbnail_url = content.get("info", {}).get("thumbnail_url")

                for url in (content_url, thumbnail_url):
                    if not url:
                        continue
                    matches = mxc_re.match(url)
                    if matches:
                        hostname = matches.group(1)
                        media_id = matches.group(2)
                        if hostname == self.hostname:
                            local_media_mxcs.append(media_id)
                        else:
                            remote_media_mxcs.append((hostname, media_id))

        return local_media_mxcs, remote_media_mxcs