# -*- 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 synapse.storage._base import SQLBaseStore
from synapse.storage.database import Database


class MediaRepositoryBackgroundUpdateStore(SQLBaseStore):
    def __init__(self, database: Database, db_conn, hs):
        super(MediaRepositoryBackgroundUpdateStore, self).__init__(
            database, db_conn, hs
        )

        self.db.updates.register_background_index_update(
            update_name="local_media_repository_url_idx",
            index_name="local_media_repository_url_idx",
            table="local_media_repository",
            columns=["created_ts"],
            where_clause="url_cache IS NOT NULL",
        )


class MediaRepositoryStore(MediaRepositoryBackgroundUpdateStore):
    """Persistence for attachments and avatars"""

    def __init__(self, database: Database, db_conn, hs):
        super(MediaRepositoryStore, self).__init__(database, db_conn, hs)

    def get_local_media(self, media_id):
        """Get the metadata for a local piece of media
        Returns:
            None if the media_id doesn't exist.
        """
        return self.db.simple_select_one(
            "local_media_repository",
            {"media_id": media_id},
            (
                "media_type",
                "media_length",
                "upload_name",
                "created_ts",
                "quarantined_by",
                "url_cache",
            ),
            allow_none=True,
            desc="get_local_media",
        )

    def store_local_media(
        self,
        media_id,
        media_type,
        time_now_ms,
        upload_name,
        media_length,
        user_id,
        url_cache=None,
    ):
        return self.db.simple_insert(
            "local_media_repository",
            {
                "media_id": media_id,
                "media_type": media_type,
                "created_ts": time_now_ms,
                "upload_name": upload_name,
                "media_length": media_length,
                "user_id": user_id.to_string(),
                "url_cache": url_cache,
            },
            desc="store_local_media",
        )

    def get_url_cache(self, url, ts):
        """Get the media_id and ts for a cached URL as of the given timestamp
        Returns:
            None if the URL isn't cached.
        """

        def get_url_cache_txn(txn):
            # get the most recently cached result (relative to the given ts)
            sql = (
                "SELECT response_code, etag, expires_ts, og, media_id, download_ts"
                " FROM local_media_repository_url_cache"
                " WHERE url = ? AND download_ts <= ?"
                " ORDER BY download_ts DESC LIMIT 1"
            )
            txn.execute(sql, (url, ts))
            row = txn.fetchone()

            if not row:
                # ...or if we've requested a timestamp older than the oldest
                # copy in the cache, return the oldest copy (if any)
                sql = (
                    "SELECT response_code, etag, expires_ts, og, media_id, download_ts"
                    " FROM local_media_repository_url_cache"
                    " WHERE url = ? AND download_ts > ?"
                    " ORDER BY download_ts ASC LIMIT 1"
                )
                txn.execute(sql, (url, ts))
                row = txn.fetchone()

            if not row:
                return None

            return dict(
                zip(
                    (
                        "response_code",
                        "etag",
                        "expires_ts",
                        "og",
                        "media_id",
                        "download_ts",
                    ),
                    row,
                )
            )

        return self.db.runInteraction("get_url_cache", get_url_cache_txn)

    def store_url_cache(
        self, url, response_code, etag, expires_ts, og, media_id, download_ts
    ):
        return self.db.simple_insert(
            "local_media_repository_url_cache",
            {
                "url": url,
                "response_code": response_code,
                "etag": etag,
                "expires_ts": expires_ts,
                "og": og,
                "media_id": media_id,
                "download_ts": download_ts,
            },
            desc="store_url_cache",
        )

    def get_local_media_thumbnails(self, media_id):
        return self.db.simple_select_list(
            "local_media_repository_thumbnails",
            {"media_id": media_id},
            (
                "thumbnail_width",
                "thumbnail_height",
                "thumbnail_method",
                "thumbnail_type",
                "thumbnail_length",
            ),
            desc="get_local_media_thumbnails",
        )

    def store_local_thumbnail(
        self,
        media_id,
        thumbnail_width,
        thumbnail_height,
        thumbnail_type,
        thumbnail_method,
        thumbnail_length,
    ):
        return self.db.simple_insert(
            "local_media_repository_thumbnails",
            {
                "media_id": media_id,
                "thumbnail_width": thumbnail_width,
                "thumbnail_height": thumbnail_height,
                "thumbnail_method": thumbnail_method,
                "thumbnail_type": thumbnail_type,
                "thumbnail_length": thumbnail_length,
            },
            desc="store_local_thumbnail",
        )

    def get_cached_remote_media(self, origin, media_id):
        return self.db.simple_select_one(
            "remote_media_cache",
            {"media_origin": origin, "media_id": media_id},
            (
                "media_type",
                "media_length",
                "upload_name",
                "created_ts",
                "filesystem_id",
                "quarantined_by",
            ),
            allow_none=True,
            desc="get_cached_remote_media",
        )

    def store_cached_remote_media(
        self,
        origin,
        media_id,
        media_type,
        media_length,
        time_now_ms,
        upload_name,
        filesystem_id,
    ):
        return self.db.simple_insert(
            "remote_media_cache",
            {
                "media_origin": origin,
                "media_id": media_id,
                "media_type": media_type,
                "media_length": media_length,
                "created_ts": time_now_ms,
                "upload_name": upload_name,
                "filesystem_id": filesystem_id,
                "last_access_ts": time_now_ms,
            },
            desc="store_cached_remote_media",
        )

    def update_cached_last_access_time(self, local_media, remote_media, time_ms):
        """Updates the last access time of the given media

        Args:
            local_media (iterable[str]): Set of media_ids
            remote_media (iterable[(str, str)]): Set of (server_name, media_id)
            time_ms: Current time in milliseconds
        """

        def update_cache_txn(txn):
            sql = (
                "UPDATE remote_media_cache SET last_access_ts = ?"
                " WHERE media_origin = ? AND media_id = ?"
            )

            txn.executemany(
                sql,
                (
                    (time_ms, media_origin, media_id)
                    for media_origin, media_id in remote_media
                ),
            )

            sql = (
                "UPDATE local_media_repository SET last_access_ts = ?"
                " WHERE media_id = ?"
            )

            txn.executemany(sql, ((time_ms, media_id) for media_id in local_media))

        return self.db.runInteraction(
            "update_cached_last_access_time", update_cache_txn
        )

    def get_remote_media_thumbnails(self, origin, media_id):
        return self.db.simple_select_list(
            "remote_media_cache_thumbnails",
            {"media_origin": origin, "media_id": media_id},
            (
                "thumbnail_width",
                "thumbnail_height",
                "thumbnail_method",
                "thumbnail_type",
                "thumbnail_length",
                "filesystem_id",
            ),
            desc="get_remote_media_thumbnails",
        )

    def store_remote_media_thumbnail(
        self,
        origin,
        media_id,
        filesystem_id,
        thumbnail_width,
        thumbnail_height,
        thumbnail_type,
        thumbnail_method,
        thumbnail_length,
    ):
        return self.db.simple_insert(
            "remote_media_cache_thumbnails",
            {
                "media_origin": origin,
                "media_id": media_id,
                "thumbnail_width": thumbnail_width,
                "thumbnail_height": thumbnail_height,
                "thumbnail_method": thumbnail_method,
                "thumbnail_type": thumbnail_type,
                "thumbnail_length": thumbnail_length,
                "filesystem_id": filesystem_id,
            },
            desc="store_remote_media_thumbnail",
        )

    def get_remote_media_before(self, before_ts):
        sql = (
            "SELECT media_origin, media_id, filesystem_id"
            " FROM remote_media_cache"
            " WHERE last_access_ts < ?"
        )

        return self.db.execute(
            "get_remote_media_before", self.db.cursor_to_dict, sql, before_ts
        )

    def delete_remote_media(self, media_origin, media_id):
        def delete_remote_media_txn(txn):
            self.db.simple_delete_txn(
                txn,
                "remote_media_cache",
                keyvalues={"media_origin": media_origin, "media_id": media_id},
            )
            self.db.simple_delete_txn(
                txn,
                "remote_media_cache_thumbnails",
                keyvalues={"media_origin": media_origin, "media_id": media_id},
            )

        return self.db.runInteraction("delete_remote_media", delete_remote_media_txn)

    def get_expired_url_cache(self, now_ts):
        sql = (
            "SELECT media_id FROM local_media_repository_url_cache"
            " WHERE expires_ts < ?"
            " ORDER BY expires_ts ASC"
            " LIMIT 500"
        )

        def _get_expired_url_cache_txn(txn):
            txn.execute(sql, (now_ts,))
            return [row[0] for row in txn]

        return self.db.runInteraction(
            "get_expired_url_cache", _get_expired_url_cache_txn
        )

    def delete_url_cache(self, media_ids):
        if len(media_ids) == 0:
            return

        sql = "DELETE FROM local_media_repository_url_cache WHERE media_id = ?"

        def _delete_url_cache_txn(txn):
            txn.executemany(sql, [(media_id,) for media_id in media_ids])

        return self.db.runInteraction("delete_url_cache", _delete_url_cache_txn)

    def get_url_cache_media_before(self, before_ts):
        sql = (
            "SELECT media_id FROM local_media_repository"
            " WHERE created_ts < ? AND url_cache IS NOT NULL"
            " ORDER BY created_ts ASC"
            " LIMIT 500"
        )

        def _get_url_cache_media_before_txn(txn):
            txn.execute(sql, (before_ts,))
            return [row[0] for row in txn]

        return self.db.runInteraction(
            "get_url_cache_media_before", _get_url_cache_media_before_txn
        )

    def delete_url_cache_media(self, media_ids):
        if len(media_ids) == 0:
            return

        def _delete_url_cache_media_txn(txn):
            sql = "DELETE FROM local_media_repository WHERE media_id = ?"

            txn.executemany(sql, [(media_id,) for media_id in media_ids])

            sql = "DELETE FROM local_media_repository_thumbnails WHERE media_id = ?"

            txn.executemany(sql, [(media_id,) for media_id in media_ids])

        return self.db.runInteraction(
            "delete_url_cache_media", _delete_url_cache_media_txn
        )
