/*
Copyright 2024 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package drain

import (
	"testing"

	"github.com/google/go-cmp/cmp"
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/runtime/schema"
)

type newCordonHelperFromRuntimeObjectTestCase struct {
	name        string
	nodeObject  runtime.Object
	expectError bool
	expected    *CordonHelper
}

func TestNewCordonHelperFromRuntimeObject(t *testing.T) {
	tests := []newCordonHelperFromRuntimeObjectTestCase{
		{
			name: "valid node object",
			nodeObject: &corev1.Node{
				ObjectMeta: metav1.ObjectMeta{
					Name: "test-node",
				},
			},
			expectError: false,
			expected: &CordonHelper{
				node: &corev1.Node{
					TypeMeta: metav1.TypeMeta{
						Kind:       "Node",
						APIVersion: "v1",
					},
					ObjectMeta: metav1.ObjectMeta{
						Name: "test-node",
					},
				},
			},
		},
		{
			name: "invalid object type",
			nodeObject: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "test-pod",
				},
			},
			expectError: true,
			expected:    nil,
		},
	}
	scheme := runtime.NewScheme()
	_ = corev1.AddToScheme(scheme)
	gvk := schema.GroupVersionKind{
		Group:   "",
		Version: "v1",
		Kind:    "Node",
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			helper, err := NewCordonHelperFromRuntimeObject(tt.nodeObject, scheme, gvk)
			if tt.expectError && err == nil {
				t.Error("Expected error but got none")
			}
			if !tt.expectError && err != nil {
				t.Errorf("Unexpected error: %v", err)
			}
			if !tt.expectError && helper == nil {
				t.Error("Expected non-nil helper")
			}
			if tt.expected != nil && helper != nil {
				if diff := cmp.Diff(tt.expected.node, helper.node); diff != "" {
					t.Errorf("Node mismatch (-want +got):\n%s", diff)
				}
			}
		})
	}
}

type updateIfRequiredTestCase struct {
	name          string
	currentState  bool
	desiredState  bool
	expectUpdated bool
}

func TestUpdateIfRequired(t *testing.T) {
	tests := []updateIfRequiredTestCase{
		{
			name:          "no change required",
			currentState:  true,
			desiredState:  true,
			expectUpdated: false,
		},
		{
			name:          "update required - cordon",
			currentState:  false,
			desiredState:  true,
			expectUpdated: true,
		},
		{
			name:          "update required - uncordon",
			currentState:  true,
			desiredState:  false,
			expectUpdated: true,
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			node := &corev1.Node{
				ObjectMeta: metav1.ObjectMeta{
					Name: "test-node",
				},
				Spec: corev1.NodeSpec{
					Unschedulable: tt.currentState,
				},
			}

			helper := NewCordonHelper(node)
			updated := helper.UpdateIfRequired(tt.desiredState)
			if updated != tt.expectUpdated {
				t.Errorf("Expected UpdateIfRequired to return %v, got %v", tt.expectUpdated, updated)
			}
			if helper.desired != tt.desiredState {
				t.Errorf("Expected desired state to be %v, got %v", tt.desiredState, helper.desired)
			}
		})
	}
}