Implement review comments

internal/environment/abstract_manager.go

@@ -1,6 +1,7 @@
 package environment
 
 import (
+	"fmt"
 	"github.com/openHPI/poseidon/internal/runner"
 	"github.com/openHPI/poseidon/pkg/dto"
 )
@@ -8,7 +9,8 @@ import (
 // AbstractManager is used to have a fallback environment manager in the chain of responsibility
 // following the null object pattern.
 type AbstractManager struct {
-	nextHandler ManagerHandler
+	nextHandler   ManagerHandler
+	runnerManager runner.Manager
 }
 
 func (n *AbstractManager) SetNextHandler(next ManagerHandler) {
@@ -35,8 +37,25 @@ func (n *AbstractManager) CreateOrUpdate(_ dto.EnvironmentID, _ dto.ExecutionEnv
 	return false, nil
 }
 
-func (n *AbstractManager) Delete(_ dto.EnvironmentID) (bool, error) {
-	return false, nil
+func (n *AbstractManager) Delete(id dto.EnvironmentID) (bool, error) {
+	e, ok := n.runnerManager.GetEnvironment(id)
+	if !ok {
+		if n.nextHandler != nil {
+			isFound, err := n.NextHandler().Delete(id)
+			if err != nil {
+				return false, fmt.Errorf("aws wrapped: %w", err)
+			}
+			return isFound, nil
+		} else {
+			return false, nil
+		}
+	}
+
+	n.runnerManager.DeleteEnvironment(id)
+	if err := e.Delete(); err != nil {
+		return true, fmt.Errorf("could not delete environment: %w", err)
+	}
+	return true, nil
 }
 
 func (n *AbstractManager) Statistics() map[dto.EnvironmentID]*dto.StatisticalExecutionEnvironmentData {