login: reimplement login in connector interface

Signed-off-by: Sumner Evans <sumner.evans@automattic.com>

pkg/store/session_store.go

@@ -0,0 +1,39 @@
+package store
+
+import (
+	"context"
+
+	"github.com/gotd/td/session"
+	"go.mau.fi/util/dbutil"
+)
+
+// SessionStore is a wrapper around a database that implements
+// [session.Storage] scoped to a specific Telegram user ID.
+type SessionStore struct {
+	db             *dbutil.Database
+	telegramUserID int64
+}
+
+var _ session.Storage = (*SessionStore)(nil)
+
+const (
+	loadSessionQuery  = `SELECT session_data FROM telegram_session WHERE user_id=$1`
+	storeSessionQuery = `
+		INSERT INTO telegram_session (user_id, session_data)
+		VALUES ($1, $2)
+		ON CONFLICT (user_id) DO UPDATE SET session_data=excluded.session_data
+	`
+)
+
+// LoadSession loads session data from the database.
+func (s *SessionStore) LoadSession(ctx context.Context) (sessionData []byte, err error) {
+	row := s.db.QueryRow(ctx, loadSessionQuery, s.telegramUserID)
+	err = row.Scan(&sessionData)
+	return
+}
+
+// StoreSession stores session data for a login into the database.
+func (s *SessionStore) StoreSession(ctx context.Context, data []byte) error {
+	_, err := s.db.Exec(ctx, storeSessionQuery, s.telegramUserID, data)
+	return err
+}