# Copyright 2015, 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.

import logging

from synapse.storage.prepare_database import get_statements
from synapse.storage.engines import PostgresEngine, Sqlite3Engine

import ujson

logger = logging.getLogger(__name__)


POSTGRES_TABLE = """
CREATE TABLE IF NOT EXISTS event_search (
    event_id TEXT,
    room_id TEXT,
    sender TEXT,
    key TEXT,
    vector tsvector
);

CREATE INDEX event_search_fts_idx ON event_search USING gin(vector);
CREATE INDEX event_search_ev_idx ON event_search(event_id);
CREATE INDEX event_search_ev_ridx ON event_search(room_id);
"""


SQLITE_TABLE = (
    "CREATE VIRTUAL TABLE event_search"
    " USING fts4 ( event_id, room_id, sender, key, value )"
)


def run_create(cur, database_engine, *args, **kwargs):
    if isinstance(database_engine, PostgresEngine):
        for statement in get_statements(POSTGRES_TABLE.splitlines()):
            cur.execute(statement)
    elif isinstance(database_engine, Sqlite3Engine):
        cur.execute(SQLITE_TABLE)
    else:
        raise Exception("Unrecognized database engine")

    cur.execute("SELECT MIN(stream_ordering) FROM events")
    rows = cur.fetchall()
    min_stream_id = rows[0][0]

    cur.execute("SELECT MAX(stream_ordering) FROM events")
    rows = cur.fetchall()
    max_stream_id = rows[0][0]

    if min_stream_id is not None and max_stream_id is not None:
        progress = {
            "target_min_stream_id_inclusive": min_stream_id,
            "max_stream_id_exclusive": max_stream_id + 1,
            "rows_inserted": 0,
        }
        progress_json = ujson.dumps(progress)

        sql = (
            "INSERT into background_updates (update_name, progress_json)"
            " VALUES (?, ?)"
        )

        sql = database_engine.convert_param_style(sql)

        cur.execute(sql, ("event_search", progress_json))


def run_upgrade(*args, **kwargs):
    pass