/*
Copyright 2016 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 kubefed

import (
	"bytes"
	"fmt"
	"net/http"
	"strings"
	"testing"

	"k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/api/errors"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/client-go/dynamic"
	"k8s.io/client-go/rest/fake"
	"k8s.io/client-go/tools/clientcmd"
	clientcmdapi "k8s.io/client-go/tools/clientcmd/api"
	federationapi "k8s.io/kubernetes/federation/apis/federation"
	kubefedtesting "k8s.io/kubernetes/federation/pkg/kubefed/testing"
	"k8s.io/kubernetes/federation/pkg/kubefed/util"
	"k8s.io/kubernetes/pkg/api"
	"k8s.io/kubernetes/pkg/api/testapi"
	cmdtesting "k8s.io/kubernetes/pkg/kubectl/cmd/testing"
	cmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util"
)

func TestUnjoinFederation(t *testing.T) {
	cmdErrMsg := ""
	cmdutil.BehaviorOnFatal(func(str string, code int) {
		cmdErrMsg = str
	})

	fakeKubeFiles, err := kubefedtesting.FakeKubeconfigFiles()
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	defer kubefedtesting.RemoveFakeKubeconfigFiles(fakeKubeFiles)

	testCases := []struct {
		cluster            string
		wantCluster        string
		wantSecret         string
		kubeconfigGlobal   string
		kubeconfigExplicit string
		expectedServer     string
		expectedErr        string
	}{
		// Tests that the contexts and credentials are read from the
		// global, default kubeconfig and the correct cluster resource
		// is deregisterd and configmap kube-dns is removed from that cluster.
		{
			cluster:            "syndicate",
			wantCluster:        "syndicate",
			wantSecret:         "",
			kubeconfigGlobal:   fakeKubeFiles[0],
			kubeconfigExplicit: "",
			expectedServer:     "https://10.20.30.40",
			expectedErr:        "",
		},
		// Tests that the contexts and credentials are read from the
		// explicit kubeconfig file specified and the correct cluster
		// resource is deregisterd and configmap kube-dns is removed from that cluster.
		// kubeconfig contains a single cluster and context.
		{
			cluster:            "ally",
			wantCluster:        "ally",
			wantSecret:         "",
			kubeconfigGlobal:   fakeKubeFiles[0],
			kubeconfigExplicit: fakeKubeFiles[1],
			expectedServer:     "http://ally256.example.com:80",
			expectedErr:        "",
		},
		// Tests that the contexts and credentials are read from the
		// explicit kubeconfig file specified and the correct cluster
		// resource is deregisterd and configmap kube-dns is removed from that
		// cluster. kubeconfig consists of multiple clusters and contexts.
		{
			cluster:            "confederate",
			wantCluster:        "confederate",
			wantSecret:         "",
			kubeconfigGlobal:   fakeKubeFiles[1],
			kubeconfigExplicit: fakeKubeFiles[2],
			expectedServer:     "https://10.8.8.8",
			expectedErr:        "",
		},
		// Negative test to ensure that we get the right warning
		// when the specified cluster to deregister is not found.
		{
			cluster:            "noexist",
			wantCluster:        "affiliate",
			wantSecret:         "",
			kubeconfigGlobal:   fakeKubeFiles[0],
			kubeconfigExplicit: "",
			expectedServer:     "https://10.20.30.40",
			expectedErr:        fmt.Sprintf("WARNING: cluster %q not found in federation, so its credentials' secret couldn't be deleted", "affiliate"),
		},
		// Negative test to ensure that we get the right warning
		// when the specified cluster's credentials secret is not
		// found.
		{
			cluster:            "affiliate",
			wantCluster:        "affiliate",
			wantSecret:         "noexist",
			kubeconfigGlobal:   fakeKubeFiles[0],
			kubeconfigExplicit: "",
			expectedServer:     "https://10.20.30.40",
			expectedErr:        fmt.Sprintf("WARNING: secret %q not found in the host cluster, so it couldn't be deleted. Cluster has already been removed from the federation.", "noexist"),
		},
		// TODO: Figure out a way to test the scenarios of configmap deletion
		// As of now we delete the config map after deriving the clientset using
		// the cluster object we retrieved from the federation server and the
		// secret object retrieved from the base cluster.
		// Still to find out a way to introduce some fakes and unit test this path.
	}

	for i, tc := range testCases {
		cmdErrMsg = ""
		f := testUnjoinFederationFactory(tc.cluster, tc.expectedServer, tc.wantSecret)
		buf := bytes.NewBuffer([]byte{})
		errBuf := bytes.NewBuffer([]byte{})

		hostFactory := fakeUnjoinHostFactory(tc.cluster)
		adminConfig, err := kubefedtesting.NewFakeAdminConfig(hostFactory, nil, "", tc.kubeconfigGlobal)
		if err != nil {
			t.Fatalf("[%d] unexpected error: %v", i, err)
		}

		cmd := NewCmdUnjoin(f, buf, errBuf, adminConfig)

		cmd.Flags().Set("kubeconfig", tc.kubeconfigExplicit)
		cmd.Flags().Set("host", "substrate")
		cmd.Run(cmd, []string{tc.wantCluster})

		if tc.expectedErr == "" {
			// uses the name from the cluster, not the response
			// Actual data passed are tested in the fake secret and cluster
			// REST clients.
			if msg := buf.String(); msg != fmt.Sprintf("Successfully removed cluster %q from federation\n", tc.cluster) {
				t.Errorf("[%d] unexpected output: %s", i, msg)
				if cmdErrMsg != "" {
					t.Errorf("[%d] unexpected error message: %s", i, cmdErrMsg)
				}
			}
			// TODO: There are warnings posted on errBuf, which we ignore as of now
			// and we should be able to test out these warnings also in future.
			// This is linked to the previous todo comment.
		} else {
			if errMsg := errBuf.String(); errMsg != tc.expectedErr {
				t.Errorf("[%d] expected warning: %s, got: %s, output: %s", i, tc.expectedErr, errMsg, buf.String())
			}

		}
	}
}

func testUnjoinFederationFactory(name, server, secret string) cmdutil.Factory {
	urlPrefix := "/clusters/"

	cluster := fakeCluster(name, name, server, true)
	if secret != "" {
		cluster.Spec.SecretRef.Name = secret
	}

	f, tf, _, _ := cmdtesting.NewAPIFactory()
	codec := testapi.Federation.Codec()
	tf.ClientConfig = kubefedtesting.DefaultClientConfig()
	ns := testapi.Federation.NegotiatedSerializer()
	tf.Client = &fake.RESTClient{
		APIRegistry:          api.Registry,
		NegotiatedSerializer: ns,
		GroupName:            "federation",
		Client: fake.CreateHTTPClient(func(req *http.Request) (*http.Response, error) {
			switch p, m := req.URL.Path, req.Method; {
			case strings.HasPrefix(p, urlPrefix):
				got := strings.TrimPrefix(p, urlPrefix)
				if got != name {
					return nil, errors.NewNotFound(federationapi.Resource("clusters"), got)
				}

				switch m {
				case http.MethodGet:
					return &http.Response{StatusCode: http.StatusOK, Header: kubefedtesting.DefaultHeader(), Body: kubefedtesting.ObjBody(codec, &cluster)}, nil
				case http.MethodDelete:
					status := metav1.Status{
						Status: "Success",
					}
					return &http.Response{StatusCode: http.StatusOK, Header: kubefedtesting.DefaultHeader(), Body: kubefedtesting.ObjBody(codec, &status)}, nil
				default:
					return nil, fmt.Errorf("unexpected method: %#v\n%#v", req.URL, req)
				}
			default:
				return nil, fmt.Errorf("unexpected request: %#v\n%#v", req.URL, req)
			}
		}),
	}
	tf.Namespace = "test"
	return f
}

func fakeUnjoinHostFactory(clusterName string) cmdutil.Factory {
	secretsPrefix := "/api/v1/namespaces/federation-system/secrets/"
	clusterRolePrefix := "/apis/rbac.authorization.k8s.io/v1beta1/clusterroles/"
	serviceAccountPrefix := "/api/v1/namespaces/federation-system/serviceaccounts/"
	clusterRoleBindingPrefix := "/apis/rbac.authorization.k8s.io/v1beta1/clusterrolebindings/"

	// Using dummy bytes for now
	configBytes, _ := clientcmd.Write(clientcmdapi.Config{})
	secretObject := v1.Secret{
		TypeMeta: metav1.TypeMeta{
			Kind:       "Secret",
			APIVersion: "v1",
		},
		ObjectMeta: metav1.ObjectMeta{
			Name:      clusterName,
			Namespace: util.DefaultFederationSystemNamespace,
		},
		Data: map[string][]byte{
			"kubeconfig": configBytes,
		},
	}

	f, tf, codec, _ := cmdtesting.NewAPIFactory()
	ns := dynamic.ContentConfig().NegotiatedSerializer
	tf.ClientConfig = kubefedtesting.DefaultClientConfig()
	tf.Client = &fake.RESTClient{
		APIRegistry:          api.Registry,
		NegotiatedSerializer: ns,
		Client: fake.CreateHTTPClient(func(req *http.Request) (*http.Response, error) {
			switch p, m := req.URL.Path, req.Method; {
			case strings.HasPrefix(p, secretsPrefix):
				switch m {
				case http.MethodDelete:
					got := strings.TrimPrefix(p, secretsPrefix)
					if got != clusterName {
						return nil, errors.NewNotFound(api.Resource("secrets"), got)
					}
					status := metav1.Status{
						Status: "Success",
					}
					return &http.Response{StatusCode: http.StatusOK, Header: kubefedtesting.DefaultHeader(), Body: kubefedtesting.ObjBody(codec, &status)}, nil
				case http.MethodGet:
					got := strings.TrimPrefix(p, secretsPrefix)
					if got != clusterName {
						return nil, errors.NewNotFound(api.Resource("secrets"), got)
					}
					return &http.Response{StatusCode: http.StatusOK, Header: kubefedtesting.DefaultHeader(), Body: kubefedtesting.ObjBody(codec, &secretObject)}, nil
				default:
					return nil, fmt.Errorf("unexpected request method: %#v\n%#v", req.URL, req)
				}
			case strings.HasPrefix(p, serviceAccountPrefix) && m == http.MethodDelete:
				got := strings.TrimPrefix(p, serviceAccountPrefix)
				want := serviceAccountName(clusterName)
				if got != want {
					return nil, errors.NewNotFound(api.Resource("serviceaccounts"), got)
				}

				status := metav1.Status{
					Status: "Success",
				}
				return &http.Response{StatusCode: http.StatusOK, Header: kubefedtesting.DefaultHeader(), Body: kubefedtesting.ObjBody(codec, &status)}, nil
			case strings.HasPrefix(p, clusterRoleBindingPrefix) && m == http.MethodDelete:
				got := strings.TrimPrefix(p, clusterRoleBindingPrefix)
				want := util.ClusterRoleName(testFederationName, serviceAccountName(clusterName))
				if got != want {
					return nil, errors.NewNotFound(api.Resource("clusterrolebindings"), got)
				}

				status := metav1.Status{
					Status: "Success",
				}
				return &http.Response{StatusCode: http.StatusOK, Header: kubefedtesting.DefaultHeader(), Body: kubefedtesting.ObjBody(codec, &status)}, nil
			case strings.HasPrefix(p, clusterRolePrefix) && m == http.MethodDelete:
				got := strings.TrimPrefix(p, clusterRolePrefix)
				want := util.ClusterRoleName(testFederationName, serviceAccountName(clusterName))
				if got != want {
					return nil, errors.NewNotFound(api.Resource("clusterroles"), got)
				}

				status := metav1.Status{
					Status: "Success",
				}
				return &http.Response{StatusCode: http.StatusOK, Header: kubefedtesting.DefaultHeader(), Body: kubefedtesting.ObjBody(codec, &status)}, nil
			default:
				return nil, fmt.Errorf("unexpected request: %#v\n%#v", req.URL, req)
			}
		}),
	}
	return f
}