Initial bot functionality

* The bot now properly joins the management room
* The management room is persisted in the database
* Welcome/help messages are sent in the management room

database/portal.go

@@ -0,0 +1,53 @@
+package database
+
+import (
+	"database/sql"
+
+	log "maunium.net/go/maulogger/v2"
+	"maunium.net/go/mautrix/id"
+)
+
+type Portal struct {
+	db  *Database
+	log log.Logger
+
+	Key  PortalKey
+	MXID id.RoomID
+
+	Name  string
+	Topic string
+
+	Avatar    string
+	AvatarURL id.ContentURI
+}
+
+func (p *Portal) Scan(row Scannable) *Portal {
+	var mxid, avatarURL sql.NullString
+
+	err := row.Scan(&p.Key.ID, &p.Key.Receiver, &mxid, &p.Name, &p.Topic, &p.Avatar, &avatarURL)
+	if err != nil {
+		if err != sql.ErrNoRows {
+			p.log.Errorln("Database scan failed:", err)
+		}
+
+		return nil
+	}
+
+	p.MXID = id.RoomID(mxid.String)
+	p.AvatarURL, _ = id.ParseContentURI(avatarURL.String)
+
+	return p
+}
+
+func (p *Portal) Insert() {
+	query := "INSERT INTO portal" +
+		" (id, receiver, mxid, name, topic, avatar, avatar_url)" +
+		" VALUES ($1, $2, $3, $4, $5, $6, $7)"
+
+	_, err := p.db.Exec(query, p.Key.ID, p.Key.Receiver, p.MXID,
+		p.Name, p.Topic, p.Avatar, p.AvatarURL.String())
+
+	if err != nil {
+		p.log.Warnfln("Failed to insert %s: %v", p.Key, err)
+	}
+}