chore(all): return concrete types, accept interfaces

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

internal/loopstate/apply.go

@@ -9,11 +9,6 @@ import (
 	"github.com/qdm12/gluetun/internal/models"
 )
 
-type Applier interface {
-	ApplyStatus(ctx context.Context, status models.LoopStatus) (
-		outcome string, err error)
-}
-
 var ErrInvalidStatus = errors.New("invalid status")
 
 // ApplyStatus sends signals to the running loop depending on the

internal/loopstate/get.go

@@ -2,10 +2,6 @@ package loopstate
 
 import "github.com/qdm12/gluetun/internal/models"
 
-type Getter interface {
-	GetStatus() (status models.LoopStatus)
-}
-
 // GetStatus gets the status thread safely.
 func (s *State) GetStatus() (status models.LoopStatus) {
 	s.statusMu.RLock()

internal/loopstate/lock.go

@@ -1,9 +1,4 @@
 package loopstate
 
-type Locker interface {
-	Lock()
-	Unlock()
-}
-
 func (s *State) Lock()   { s.loopMu.Lock() }
 func (s *State) Unlock() { s.loopMu.Unlock() }

internal/loopstate/set.go

@@ -2,10 +2,6 @@ package loopstate
 
 import "github.com/qdm12/gluetun/internal/models"
 
-type Setter interface {
-	SetStatus(status models.LoopStatus)
-}
-
 // SetStatus sets the status thread safely.
 // It should only be called by the loop internal code since
 // it does not interact with the loop code directly.

internal/loopstate/state.go

@@ -6,15 +6,6 @@ import (
 	"github.com/qdm12/gluetun/internal/models"
 )
 
-var _ Manager = (*State)(nil)
-
-type Manager interface {
-	Locker
-	Getter
-	Setter
-	Applier
-}
-
 func New(status models.LoopStatus,
 	start chan<- struct{}, running <-chan models.LoopStatus,
 	stop chan<- struct{}, stopped <-chan struct{}) *State {