/*
Copyright 2019 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 servicebackend

import (
	"context"
	"fmt"
	"net/http"
	"strings"

	"k8s.io/ingress-nginx/test/e2e/framework/httpexpect"

	"github.com/onsi/ginkgo/v2"
	"github.com/stretchr/testify/assert"
	corev1 "k8s.io/api/core/v1"
	networking "k8s.io/api/networking/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"

	"k8s.io/ingress-nginx/test/e2e/framework"
)

const echoHost = "echo"

var _ = framework.IngressNginxDescribe("[Service] Type ExternalName", func() {
	f := framework.NewDefaultFramework("type-externalname", framework.WithHTTPBunEnabled())

	ginkgo.It("works with external name set to incomplete fqdn", func() {
		f.NewEchoDeployment()
		host := echoHost

		svc := &corev1.Service{
			ObjectMeta: metav1.ObjectMeta{
				Name:      framework.NIPService,
				Namespace: f.Namespace,
			},
			Spec: corev1.ServiceSpec{
				ExternalName: framework.EchoService,
				Type:         corev1.ServiceTypeExternalName,
			},
		}
		f.EnsureService(svc)

		ing := framework.NewSingleIngress(host,
			"/",
			host,
			f.Namespace,
			framework.NIPService,
			80,
			nil)
		f.EnsureIngress(ing)

		f.WaitForNginxServer(host,
			func(server string) bool {
				return strings.Contains(server, "proxy_pass http://upstream_balancer;")
			})

		f.HTTPTestClient().
			GET("/get").
			WithHeader("Host", host).
			Expect().
			Status(http.StatusOK)
	})

	ginkgo.It("should return 200 for service type=ExternalName without a port defined", func() {
		host := echoHost

		svc := &corev1.Service{
			ObjectMeta: metav1.ObjectMeta{
				Name:      framework.NIPService,
				Namespace: f.Namespace,
			},
			Spec: corev1.ServiceSpec{
				ExternalName: f.GetNIPHost(),
				Type:         corev1.ServiceTypeExternalName,
			},
		}
		f.EnsureService(svc)

		annotations := map[string]string{
			"nginx.ingress.kubernetes.io/upstream-vhost": f.GetNIPHost(),
		}

		ing := framework.NewSingleIngress(host,
			"/",
			host,
			f.Namespace,
			framework.HTTPBunService,
			80,
			annotations)
		f.EnsureIngress(ing)

		f.WaitForNginxServer(host,
			func(server string) bool {
				return strings.Contains(server, "proxy_pass http://upstream_balancer;")
			})

		f.HTTPTestClient().
			GET("/get").
			WithHeader("Host", host).
			Expect().
			Status(http.StatusOK)
	})

	ginkgo.It("should return 200 for service type=ExternalName with a port defined", func() {
		host := echoHost

		svc := framework.BuildNIPExternalNameService(f, f.HTTPBunIP, host)
		f.EnsureService(svc)

		annotations := map[string]string{
			"nginx.ingress.kubernetes.io/upstream-vhost": f.GetNIPHost(),
		}
		ing := framework.NewSingleIngress(host,
			"/",
			host,
			f.Namespace,
			framework.HTTPBunService,
			80,
			annotations)
		f.EnsureIngress(ing)

		f.WaitForNginxServer(host,
			func(server string) bool {
				return strings.Contains(server, "proxy_pass http://upstream_balancer;")
			})

		f.HTTPTestClient().
			GET("/get").
			WithHeader("Host", host).
			Expect().
			Status(http.StatusOK)
	})

	ginkgo.It("should return status 502 for service type=ExternalName with an invalid host", func() {
		host := echoHost

		svc := &corev1.Service{
			ObjectMeta: metav1.ObjectMeta{
				Name:      framework.NIPService,
				Namespace: f.Namespace,
			},
			Spec: corev1.ServiceSpec{
				ExternalName: "invalid.hostname",
				Type:         corev1.ServiceTypeExternalName,
			},
		}
		f.EnsureService(svc)

		ing := framework.NewSingleIngress(host,
			"/",
			host,
			f.Namespace,
			framework.NIPService,
			80,
			nil)
		f.EnsureIngress(ing)

		f.WaitForNginxServer(host,
			func(server string) bool {
				return strings.Contains(server, "proxy_pass http://upstream_balancer;")
			})

		f.HTTPTestClient().
			GET("/get").
			WithHeader("Host", host).
			Expect().
			StatusRange(httpexpect.Status5xx)
	})

	ginkgo.It("should return 200 for service type=ExternalName using a port name", func() {
		host := echoHost

		svc := framework.BuildNIPExternalNameService(f, f.HTTPBunIP, host)
		f.EnsureService(svc)

		annotations := map[string]string{
			"nginx.ingress.kubernetes.io/upstream-vhost": f.GetNIPHost(),
		}
		ing := framework.NewSingleIngress(host,
			"/",
			host,
			f.Namespace,
			framework.HTTPBunService,
			80,
			annotations)

		namedBackend := networking.IngressBackend{
			Service: &networking.IngressServiceBackend{
				Name: framework.NIPService,
				Port: networking.ServiceBackendPort{
					Name: host,
				},
			},
		}

		ing.Spec.Rules[0].HTTP.Paths[0].Backend = namedBackend
		f.EnsureIngress(ing)

		f.WaitForNginxServer(host,
			func(server string) bool {
				return strings.Contains(server, "proxy_pass http://upstream_balancer;")
			})

		f.HTTPTestClient().
			GET("/get").
			WithHeader("Host", host).
			Expect().
			Status(http.StatusOK)
	})

	ginkgo.It("should return 200 for service type=ExternalName using FQDN with trailing dot", func() {
		host := echoHost

		svc := &corev1.Service{
			ObjectMeta: metav1.ObjectMeta{
				Name:      framework.NIPService,
				Namespace: f.Namespace,
			},
			Spec: corev1.ServiceSpec{
				ExternalName: f.GetNIPHost(),
				Type:         corev1.ServiceTypeExternalName,
			},
		}
		f.EnsureService(svc)

		ing := framework.NewSingleIngress(host,
			"/",
			host,
			f.Namespace,
			framework.HTTPBunService,
			80,
			nil)
		f.EnsureIngress(ing)

		f.WaitForNginxServer(host,
			func(server string) bool {
				return strings.Contains(server, "proxy_pass http://upstream_balancer;")
			})

		f.HTTPTestClient().
			GET("/get").
			WithHeader("Host", host).
			Expect().
			Status(http.StatusOK)
	})

	ginkgo.It("should update the external name after a service update", func() {
		host := echoHost

		svc := framework.BuildNIPExternalNameService(f, f.HTTPBunIP, host)
		f.EnsureService(svc)

		annotations := map[string]string{
			"nginx.ingress.kubernetes.io/upstream-vhost": f.GetNIPHost(),
		}

		ing := framework.NewSingleIngress(host,
			"/",
			host,
			f.Namespace,
			framework.HTTPBunService,
			80,
			annotations)

		namedBackend := networking.IngressBackend{
			Service: &networking.IngressServiceBackend{
				Name: framework.NIPService,
				Port: networking.ServiceBackendPort{
					Name: host,
				},
			},
		}
		ing.Spec.Rules[0].HTTP.Paths[0].Backend = namedBackend
		f.EnsureIngress(ing)

		f.WaitForNginxServer(host,
			func(server string) bool {
				return strings.Contains(server, "proxy_pass http://upstream_balancer;")
			})

		body := f.HTTPTestClient().
			GET("/get").
			WithHeader("Host", host).
			Expect().
			Status(http.StatusOK).
			Body().
			Raw()

		assert.Contains(ginkgo.GinkgoT(), body, `"X-Forwarded-Host": "echo"`)

		svc, err := f.KubeClientSet.
			CoreV1().
			Services(f.Namespace).
			Get(context.TODO(), framework.NIPService, metav1.GetOptions{})
		assert.Nil(ginkgo.GinkgoT(), err, "unexpected error obtaining external service")

		// Deploy a new instance to switch routing to
		ip := f.NewHttpbunDeployment(framework.WithDeploymentName("eu-server"))
		svc.Spec.ExternalName = framework.BuildNIPHost(ip)

		_, err = f.KubeClientSet.
			CoreV1().
			Services(f.Namespace).
			Update(context.Background(), svc, metav1.UpdateOptions{})
		assert.Nil(ginkgo.GinkgoT(), err, "unexpected error updating external service")

		framework.Sleep()

		body = f.HTTPTestClient().
			GET("/get").
			WithHeader("Host", host).
			Expect().
			Status(http.StatusOK).
			Body().
			Raw()

		assert.Contains(ginkgo.GinkgoT(), body, `"X-Forwarded-Host": "echo"`)

		ginkgo.By("checking the service is updated to use new host")
		dbgCmd := "/dbg backends all"
		output, err := f.ExecIngressPod(dbgCmd)
		assert.Nil(ginkgo.GinkgoT(), err)
		assert.Contains(
			ginkgo.GinkgoT(),
			output,
			fmt.Sprintf(`"address": %q`, framework.BuildNIPHost(ip)),
		)
	})

	ginkgo.It("should sync ingress on external name service addition/deletion", func() {
		host := echoHost

		// Create the Ingress first
		ing := framework.NewSingleIngress(host,
			"/",
			host,
			f.Namespace,
			framework.NIPService,
			80,
			nil)
		f.EnsureIngress(ing)

		f.WaitForNginxServer(host,
			func(server string) bool {
				return strings.Contains(server, "proxy_pass http://upstream_balancer;")
			})

		// Nginx should return 503 without the underlying service being available
		f.HTTPTestClient().
			GET("/get").
			WithHeader("Host", host).
			Expect().
			Status(http.StatusServiceUnavailable)

		// Now create the service
		svc := framework.BuildNIPExternalNameService(f, f.HTTPBunIP, host)
		f.EnsureService(svc)

		framework.Sleep()

		// 503 should change to 200 OK
		f.HTTPTestClient().
			GET("/get").
			WithHeader("Host", host).
			Expect().
			Status(http.StatusOK)

		// And back to 503 after deleting the service
		err := f.KubeClientSet.
			CoreV1().
			Services(f.Namespace).
			Delete(context.TODO(), framework.NIPService, metav1.DeleteOptions{})
		assert.Nil(ginkgo.GinkgoT(), err, "unexpected error deleting external service")

		framework.Sleep()

		f.HTTPTestClient().
			GET("/get").
			WithHeader("Host", host).
			Expect().
			Status(http.StatusServiceUnavailable)
	})
})