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/portalquery.go

@@ -0,0 +1,58 @@
+package database
+
+import (
+	log "maunium.net/go/maulogger/v2"
+	"maunium.net/go/mautrix/id"
+)
+
+type PortalQuery struct {
+	db  *Database
+	log log.Logger
+}
+
+func (pq *PortalQuery) New() *Portal {
+	return &Portal{
+		db:  pq.db,
+		log: pq.log,
+	}
+}
+
+func (pq *PortalQuery) GetAll() []*Portal {
+	return pq.getAll("SELECT * FROM portal")
+}
+
+func (pq *PortalQuery) GetByDID(key PortalKey) *Portal {
+	return pq.get("SELECT * FROM portal WHERE did=$1 AND receiver=$2", key.ID, key.Receiver)
+}
+
+func (pq *PortalQuery) GetByMXID(mxid id.RoomID) *Portal {
+	return pq.get("SELECT * FROM portal WHERE mxid=$1", mxid)
+}
+
+func (pq *PortalQuery) GetAllByDID(did string) []*Portal {
+	return pq.getAll("SELECT * FROM portal WHERE did=$1", did)
+}
+
+func (pq *PortalQuery) getAll(query string, args ...interface{}) []*Portal {
+	rows, err := pq.db.Query(query, args...)
+	if err != nil || rows == nil {
+		return nil
+	}
+	defer rows.Close()
+
+	portals := []*Portal{}
+	for rows.Next() {
+		portals = append(portals, pq.New().Scan(rows))
+	}
+
+	return portals
+}
+
+func (pq *PortalQuery) get(query string, args ...interface{}) *Portal {
+	row := pq.db.QueryRow(query, args...)
+	if row == nil {
+		return nil
+	}
+
+	return pq.New().Scan(row)
+}