add filtering to tags. E.g. Hue,Namrom+Gisle will return all with either of the former AND the latter. - will do the opposite.

internal/mysql/devicerepo.go

@@ -58,13 +58,33 @@ func (r *DeviceRepo) Find(ctx context.Context, id int) (*models.Device, error) {
 func (r *DeviceRepo) FetchByReference(ctx context.Context, kind models.ReferenceKind, value string) ([]models.Device, error) {
 	q := sq.Select("device.*").From("device")
 
+	var requiredTags []string
+	var unwantedTags []string
+
 	switch kind {
 	case models.RKDeviceID:
 		q = q.Where(sq.Eq{"id": strings.Split(value, ",")})
 	case models.RKBridgeID:
 		q = q.Where(sq.Eq{"bridge_id": strings.Split(value, ",")})
 	case models.RKTag:
-		q = q.Join("device_tag dt ON device.id=dt.device_id").Where(sq.Eq{"dt.tag_name": strings.Split(value, ",")})
+		allTags := strings.Split(strings.ReplaceAll(strings.ReplaceAll(value, "-", ",-"), "+", ",+"), ",")
+		optionalTags := make([]string, 0, len(allTags))
+
+		for _, tag := range allTags {
+			if tag == "" || tag == "+" || tag == "-" {
+				continue
+			}
+
+			if strings.HasPrefix(tag, "+") {
+				requiredTags = append(requiredTags, tag[1:])
+			} else if strings.HasPrefix(tag, "-") {
+				unwantedTags = append(unwantedTags, tag[1:])
+			} else {
+				optionalTags = append(optionalTags, tag)
+			}
+		}
+
+		q = q.Join("device_tag dt ON device.id=dt.device_id").Where(sq.Eq{"dt.tag_name": optionalTags})
 	case models.RKAll:
 	default:
 		log.Println("Unknown reference kind used for device fetch:", kind)
@@ -82,6 +102,10 @@ func (r *DeviceRepo) FetchByReference(ctx context.Context, kind models.Reference
 		return nil, dbErr(err)
 	}
 
+	if len(requiredTags) > 0 || len(unwantedTags) > 0 {
+		return r.populateFiltered(ctx, records, requiredTags, unwantedTags)
+	}
+
 	return r.populate(ctx, records)
 }
 
@@ -211,6 +235,27 @@ func (r *DeviceRepo) populateOne(ctx context.Context, record deviceRecord) (*mod
 	return &records[0], nil
 }
 
+func (r *DeviceRepo) populateFiltered(ctx context.Context, records []deviceRecord, requiredTags []string, unwantedTags []string) ([]models.Device, error) {
+	devices, err := r.populate(ctx, records)
+	if err != nil {
+		return nil, err
+	}
+
+	filteredDevices := make([]models.Device, 0, len(devices))
+
+	for _, device := range devices {
+		if device.HasTag(unwantedTags...) {
+			continue
+		}
+
+		if len(requiredTags) == 0 || device.HasTag(requiredTags...) {
+			filteredDevices = append(filteredDevices, device)
+		}
+	}
+
+	return filteredDevices, nil
+}
+
 func (r *DeviceRepo) populate(ctx context.Context, records []deviceRecord) ([]models.Device, error) {
 	if len(records) == 0 {
 		return []models.Device{}, nil

models/device.go

@@ -99,6 +99,18 @@ func (d *Device) Validate() error {
 	return nil
 }
 
+func (d *Device) HasTag(tags ...string) bool {
+	for _, c := range d.Tags {
+		for _, c2 := range tags {
+			if c == c2 {
+				return true
+			}
+		}
+	}
+
+	return false
+}
+
 func (d *Device) HasCapability(capabilities ...DeviceCapability) bool {
 	for _, c := range d.Capabilities {
 		for _, c2 := range capabilities {