chore(all): return concrete types, accept interfaces

- Remove exported interfaces unused locally
- Define interfaces to accept arguments
- Return concrete types, not interfaces

internal/dns/state/settings.go

@@ -8,12 +8,6 @@ import (
 	"github.com/qdm12/gluetun/internal/constants"
 )
 
-type SettingsGetSetter interface {
-	GetSettings() (settings settings.DNS)
-	SetSettings(ctx context.Context,
-		settings settings.DNS) (outcome string)
-}
-
 func (s *State) GetSettings() (settings settings.DNS) {
 	s.settingsMu.RLock()
 	defer s.settingsMu.RUnlock()

internal/dns/state/state.go

@@ -1,19 +1,14 @@
 package state
 
 import (
+	"context"
 	"sync"
 
 	"github.com/qdm12/gluetun/internal/configuration/settings"
-	"github.com/qdm12/gluetun/internal/loopstate"
+	"github.com/qdm12/gluetun/internal/models"
 )
 
-var _ Manager = (*State)(nil)
-
-type Manager interface {
-	SettingsGetSetter
-}
-
-func New(statusApplier loopstate.Applier,
+func New(statusApplier StatusApplier,
 	settings settings.DNS,
 	updateTicker chan<- struct{}) *State {
 	return &State{
@@ -24,10 +19,15 @@ func New(statusApplier loopstate.Applier,
 }
 
 type State struct {
-	statusApplier loopstate.Applier
+	statusApplier StatusApplier
 
 	settings   settings.DNS
 	settingsMu sync.RWMutex
 
 	updateTicker chan<- struct{}
 }
+
+type StatusApplier interface {
+	ApplyStatus(ctx context.Context, status models.LoopStatus) (
+		outcome string, err error)
+}