Initial commit

rss/db.py

@@ -0,0 +1,123 @@
+# rss - A maubot plugin to subscribe to RSS/Atom feeds.
+# Copyright (C) 2018 Tulir Asokan
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero 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 Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+from typing import Iterable, NamedTuple, List, Optional, Dict
+from datetime import datetime
+
+from sqlalchemy import (Column, String, Integer, DateTime, Text, ForeignKey,
+                        Table, MetaData,
+                        select, and_, or_)
+from sqlalchemy.engine.base import Engine
+
+from mautrix.types import UserID, RoomID
+
+Feed = NamedTuple("Feed", id=int, url=str, title=str, subtitle=str, link=str,
+                  subscriptions=List[RoomID])
+Entry = NamedTuple("Entry", feed_id=int, id=str, date=datetime, title=str, summary=str, link=str)
+
+
+class Database:
+    db: Engine
+    feed: Table
+    subscription: Table
+    entry: Table
+    version: Table
+
+    def __init__(self, db: Engine) -> None:
+        self.db = db
+        metadata = MetaData()
+        self.feed = Table("feed", metadata,
+                          Column("id", Integer, primary_key=True, autoincrement=True),
+                          Column("url", Text, nullable=False, unique=True),
+                          Column("title", Text, nullable=False),
+                          Column("subtitle", Text, nullable=False),
+                          Column("link", Text, nullable=False))
+        self.subscription = Table("subscription", metadata,
+                                  Column("feed_id", Integer, ForeignKey("feed.id"),
+                                         primary_key=True),
+                                  Column("room_id", String(255), primary_key=True),
+                                  Column("user_id", String(255), nullable=False))
+        self.entry = Table("entry", metadata,
+                           Column("feed_id", Integer, ForeignKey("feed.id"), primary_key=True),
+                           Column("id", String(255), primary_key=True),
+                           Column("date", DateTime, nullable=False),
+                           Column("title", Text, nullable=False),
+                           Column("summary", Text, nullable=False),
+                           Column("link", Text, nullable=False))
+        self.version = Table("version", metadata,
+                             Column("version", Integer, primary_key=True))
+        metadata.create_all(db)
+
+    def get_feeds(self) -> Iterable[Feed]:
+        rows = self.db.execute(select([self.feed, self.subscription.c.room_id])
+                               .where(self.subscription.c.feed_id == self.feed.c.id))
+        map: Dict[int, Feed] = {}
+        for row in rows:
+            feed_id, url, title, subtitle, link, room_id = row
+            map.setdefault(feed_id, Feed(feed_id, url, title, subtitle, link, subscriptions=[]))
+            map[feed_id].subscriptions.append(room_id)
+        return map.values()
+
+    def get_feeds_by_room(self, room_id: RoomID) -> Iterable[Feed]:
+        return (Feed(*row, subscriptions=[]) for row in
+                self.db.execute(select([self.feed])
+                                .where(and_(self.subscription.c.room_id == room_id,
+                                            self.subscription.c.feed_id == self.feed.c.id))))
+
+    def get_rooms_by_feed(self, feed_id: int) -> Iterable[RoomID]:
+        return (row[0] for row in
+                self.db.execute(select([self.subscription.c.room_id])
+                                .where(self.subscription.c.feed_id == feed_id)))
+
+    def get_entries(self, feed_id: int) -> Iterable[Entry]:
+        return (Entry(*row) for row in
+                self.db.execute(select([self.entry]).where(self.entry.c.feed_id == feed_id)))
+
+    def add_entries(self, entries: Iterable[Entry]) -> None:
+        if not entries:
+            return
+        self.db.execute(self.entry.insert(), [entry._asdict() for entry in entries])
+
+    def get_feed_by_url(self, url: str) -> Optional[Feed]:
+        rows = self.db.execute(select([self.feed]).where(self.feed.c.url == url))
+        try:
+            row = next(rows)
+            return Feed(*row, subscriptions=[])
+        except (StopIteration, IndexError):
+            return None
+
+    def get_feed_by_id_or_url(self, identifier: str) -> Optional[Feed]:
+        rows = self.db.execute(select([self.feed]).where(
+            or_(self.feed.c.url == identifier, self.feed.c.id == identifier)))
+        try:
+            row = next(rows)
+            return Feed(*row, subscriptions=[])
+        except (StopIteration, IndexError):
+            return None
+
+    def create_feed(self, url: str, title: str, subtitle: str, link: str) -> Feed:
+        res = self.db.execute(self.feed.insert().values(url=url, title=title, subtitle=subtitle,
+                                                        link=link))
+        return Feed(id=res.inserted_primary_key[0], url=url, title=title, subtitle=subtitle,
+                    link=link, subscriptions=[])
+
+    def subscribe(self, feed_id: int, room_id: RoomID, user_id: UserID) -> None:
+        self.db.execute(self.subscription.insert().values(feed_id=feed_id, room_id=room_id,
+                                                          user_id=user_id))
+
+    def unsubscribe(self, feed_id: int, room_id: RoomID) -> None:
+        tbl = self.subscription
+        self.db.execute(tbl.delete().where(and_(tbl.c.feed_id == feed_id,
+                                                tbl.c.room_id == room_id)))