Prevented deletion of frequency if it's the only one in the network

2 files changed, 18 insertions, 1 deletions

diff --git a/internal/client/ui/core/frequencylist/frequencylist.go b/internal/client/ui/core/frequencylist/frequencylist.go
index bc4ef05..d2e7dc5 100644
--- a/internal/client/ui/core/frequencylist/frequencylist.go
+++ b/internal/client/ui/core/frequencylist/frequencylist.go
@@ -116,6 +116,11 @@ func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
 			m.index = min(m.FrequenciesLength()-1, m.index+1)
 
 		case "ctrl+d":
+			if len(m.Network().Frequencies) == 1 {
+				// Don't delete the last frequency!
+				return m, nil
+			}
+			// TODO: consider adding a confirmation popup
 			frequencyId := m.Network().Frequencies[m.index].ID
 			return m, gateway.Send(&packet.DeleteFrequency{
 				Frequency: frequencyId,
diff --git a/internal/server/api/api.go b/internal/server/api/api.go
index 479da95..75d7d02 100644
--- a/internal/server/api/api.go
+++ b/internal/server/api/api.go
@@ -331,6 +331,7 @@ func SwapFrequencies(ctx context.Context, sess *session.Session, request *packet
 func DeleteFrequency(ctx context.Context, sess *session.Session, request *packet.DeleteFrequency) packet.Payload {
 	queries := data.New(db)
 
+	// Existence
 	frequency, err := queries.GetFrequencyById(ctx, request.Frequency)
 	if err == sql.ErrNoRows {
 		return &packet.Error{Error: "frequency doesn't exist"}
@@ -340,6 +341,7 @@ func DeleteFrequency(ctx context.Context, sess *session.Session, request *packet
 		return &ErrInternalError
 	}
 
+	// Authentication
 	isAdmin, err := IsNetworkAdmin(ctx, queries, sess.ID(), frequency.NetworkID)
 	if err == sql.ErrNoRows {
 		return &packet.Error{Error: "either user or network don't exist"}
@@ -352,11 +354,21 @@ func DeleteFrequency(ctx context.Context, sess *session.Session, request *packet
 		return &ErrPermissionDenied
 	}
 
-	err = queries.DeleteFrequency(ctx, frequency.ID)
+	// At least one frequency exists
+	frequencies, err := queries.GetNetworkFrequencies(frequency.NetworkID)
 	if err != nil {
 		log.Println("database error 3:", err)
 		return &ErrInternalError
 	}
+	if len(frequencies) == 1 {
+		return &packet.Error{Error: "at least 1 frequency must exist at all times"}
+	}
+
+	err = queries.DeleteFrequency(ctx, frequency.ID)
+	if err != nil {
+		log.Println("database error 4:", err)
+		return &ErrInternalError
+	}
 
 	return &packet.FrequenciesInfo{
 		RemoveFrequencies: []snowflake.ID{frequency.ID},