/*
Copyright 2020 The Flux 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 router

import (
	"context"
	"encoding/json"
	"fmt"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"

	"github.com/fluxcd/flagger/pkg/apis/flagger/v1beta1"
	istiov1alpha3 "github.com/fluxcd/flagger/pkg/apis/istio/v1alpha3"
)

func TestIstioRouter_Sync(t *testing.T) {
	mocks := newFixture(nil)
	router := &IstioRouter{
		logger:        mocks.logger,
		flaggerClient: mocks.flaggerClient,
		istioClient:   mocks.meshClient,
		kubeClient:    mocks.kubeClient,
	}

	err := router.Reconcile(mocks.canary)
	require.NoError(t, err)

	// test insert
	_, err = mocks.meshClient.NetworkingV1alpha3().DestinationRules("default").Get(context.TODO(), "podinfo-canary", metav1.GetOptions{})
	require.NoError(t, err)

	_, err = mocks.meshClient.NetworkingV1alpha3().DestinationRules("default").Get(context.TODO(), "podinfo-primary", metav1.GetOptions{})
	require.NoError(t, err)

	vs, err := mocks.meshClient.NetworkingV1alpha3().VirtualServices("default").Get(context.TODO(), "podinfo", metav1.GetOptions{})
	require.NoError(t, err)
	require.Len(t, vs.Spec.Http, 1)
	require.Len(t, vs.Spec.Http[0].Route, 2)

	// test update
	cd, err := mocks.flaggerClient.FlaggerV1beta1().Canaries("default").Get(context.TODO(), "podinfo", metav1.GetOptions{})
	require.NoError(t, err)

	cdClone := cd.DeepCopy()
	hosts := cdClone.Spec.Service.Hosts
	hosts = append(hosts, "test.example.com")
	cdClone.Spec.Service.Hosts = hosts
	canary, err := mocks.flaggerClient.FlaggerV1beta1().Canaries("default").Update(context.TODO(), cdClone, metav1.UpdateOptions{})
	require.NoError(t, err)

	// apply change
	err = router.Reconcile(canary)
	require.NoError(t, err)

	// verify
	vs, err = mocks.meshClient.NetworkingV1alpha3().VirtualServices("default").Get(context.TODO(), "podinfo", metav1.GetOptions{})
	require.NoError(t, err)
	assert.Len(t, vs.Spec.Hosts, 2)

	// test drift
	vsClone := vs.DeepCopy()
	gateways := vsClone.Spec.Gateways
	gateways = append(gateways, "test-gateway.istio-system")
	vsClone.Spec.Gateways = gateways
	totalGateways := len(mocks.canary.Spec.Service.Gateways)

	vsGateways, err := mocks.meshClient.NetworkingV1alpha3().VirtualServices("default").Update(context.TODO(), vsClone, metav1.UpdateOptions{})
	require.NoError(t, err)

	totalGateways++
	assert.Len(t, vsGateways.Spec.Gateways, totalGateways)

	// undo change
	totalGateways--
	err = router.Reconcile(mocks.canary)
	require.NoError(t, err)

	// verify
	vs, err = mocks.meshClient.NetworkingV1alpha3().VirtualServices("default").Get(context.TODO(), "podinfo", metav1.GetOptions{})
	require.NoError(t, err)
	assert.Len(t, vs.Spec.Gateways, totalGateways)
}

func TestIstioRouter_SetRoutes(t *testing.T) {
	mocks := newFixture(nil)
	router := &IstioRouter{
		logger:        mocks.logger,
		flaggerClient: mocks.flaggerClient,
		istioClient:   mocks.meshClient,
		kubeClient:    mocks.kubeClient,
	}

	err := router.Reconcile(mocks.canary)
	require.NoError(t, err)

	pHost := fmt.Sprintf("%s-primary", mocks.canary.Spec.TargetRef.Name)
	cHost := fmt.Sprintf("%s-canary", mocks.canary.Spec.TargetRef.Name)

	t.Run("normal", func(t *testing.T) {
		p, c := 60, 40
		err := router.SetRoutes(mocks.canary, p, c, false)
		require.NoError(t, err)

		vs, err := mocks.meshClient.NetworkingV1alpha3().VirtualServices("default").Get(context.TODO(), "podinfo", metav1.GetOptions{})
		require.NoError(t, err)

		var pRoute, cRoute istiov1alpha3.DestinationWeight
		var mirror *istiov1alpha3.Destination
		for _, http := range vs.Spec.Http {
			for _, route := range http.Route {
				if route.Destination.Host == pHost {
					pRoute = route
				}
				if route.Destination.Host == cHost {
					cRoute = route
					mirror = http.Mirror
				}
			}
		}

		assert.Equal(t, p, pRoute.Weight)
		assert.Equal(t, c, cRoute.Weight)
		assert.Nil(t, mirror)

	})

	t.Run("mirror", func(t *testing.T) {
		for _, w := range []int{0, 10, 50} {
			p, c := 100, 0

			// set mirror weight
			mocks.canary.Spec.Analysis.MirrorWeight = w
			err := router.SetRoutes(mocks.canary, p, c, true)
			require.NoError(t, err)

			vs, err := mocks.meshClient.NetworkingV1alpha3().VirtualServices("default").Get(context.TODO(), "podinfo", metav1.GetOptions{})
			require.NoError(t, err)

			var pRoute, cRoute istiov1alpha3.DestinationWeight
			var mirror *istiov1alpha3.Destination
			var mirrorWeight *istiov1alpha3.Percent
			for _, http := range vs.Spec.Http {
				for _, route := range http.Route {
					if route.Destination.Host == pHost {
						pRoute = route
					}
					if route.Destination.Host == cHost {
						cRoute = route
						mirror = http.Mirror
						mirrorWeight = http.MirrorPercentage
					}
				}
			}

			assert.Equal(t, p, pRoute.Weight)
			assert.Equal(t, c, cRoute.Weight)
			if assert.NotNil(t, mirror) {
				assert.Equal(t, cHost, mirror.Host)
			}

			if w > 0 && assert.NotNil(t, mirrorWeight) {
				assert.Equal(t, w, int(mirrorWeight.Value))
			} else {
				assert.Nil(t, mirrorWeight)
			}
		}
	})
}

func TestIstioRouter_GetRoutes(t *testing.T) {
	mocks := newFixture(nil)
	router := &IstioRouter{
		logger:        mocks.logger,
		flaggerClient: mocks.flaggerClient,
		istioClient:   mocks.meshClient,
		kubeClient:    mocks.kubeClient,
	}

	err := router.Reconcile(mocks.canary)
	require.NoError(t, err)

	p, c, m, err := router.GetRoutes(mocks.canary)
	require.NoError(t, err)
	assert.Equal(t, 100, p)
	assert.Equal(t, 0, c)
	assert.False(t, m)

	mocks.canary = newTestMirror()

	err = router.Reconcile(mocks.canary)
	require.NoError(t, err)

	p, c, m, err = router.GetRoutes(mocks.canary)
	require.NoError(t, err)
	assert.Equal(t, 100, p)
	assert.Equal(t, 0, c)

	// A Canary resource with mirror on does not automatically create mirroring
	// in the virtual server (mirroring is activated as a temporary stage).
	assert.False(t, m)

	// Adjust vs to activate mirroring.
	vs, err := mocks.meshClient.NetworkingV1alpha3().VirtualServices("default").Get(context.TODO(), "podinfo", metav1.GetOptions{})
	require.NoError(t, err)

	cHost := fmt.Sprintf("%s-canary", mocks.canary.Spec.TargetRef.Name)
	for i, http := range vs.Spec.Http {
		for _, route := range http.Route {
			if route.Destination.Host == cHost {
				vs.Spec.Http[i].Mirror = &istiov1alpha3.Destination{
					Host: cHost,
				}
			}
		}
	}
	_, err = mocks.meshClient.NetworkingV1alpha3().VirtualServices(mocks.canary.Namespace).Update(context.TODO(), vs, metav1.UpdateOptions{})
	require.NoError(t, err)

	p, c, m, err = router.GetRoutes(mocks.canary)
	require.NoError(t, err)
	assert.Equal(t, 100, p)
	assert.Equal(t, 0, c)
	assert.True(t, m)
}

func TestIstioRouter_HTTPRequestHeaders(t *testing.T) {
	mocks := newFixture(nil)
	router := &IstioRouter{
		logger:        mocks.logger,
		flaggerClient: mocks.flaggerClient,
		istioClient:   mocks.meshClient,
		kubeClient:    mocks.kubeClient,
	}

	err := router.Reconcile(mocks.canary)
	require.NoError(t, err)

	vs, err := mocks.meshClient.NetworkingV1alpha3().VirtualServices("default").Get(context.TODO(), "podinfo", metav1.GetOptions{})
	require.NoError(t, err)
	require.Len(t, vs.Spec.Http, 1)
	assert.Equal(t, "15000", vs.Spec.Http[0].Headers.Request.Add["x-envoy-upstream-rq-timeout-ms"])
	assert.Equal(t, "test", vs.Spec.Http[0].Headers.Request.Remove[0])
	assert.Equal(t, "token", vs.Spec.Http[0].Headers.Response.Remove[0])
}

func TestIstioRouter_CORS(t *testing.T) {
	mocks := newFixture(nil)
	router := &IstioRouter{
		logger:        mocks.logger,
		flaggerClient: mocks.flaggerClient,
		istioClient:   mocks.meshClient,
		kubeClient:    mocks.kubeClient,
	}

	err := router.Reconcile(mocks.canary)
	require.NoError(t, err)

	vs, err := mocks.meshClient.NetworkingV1alpha3().VirtualServices("default").Get(context.TODO(), "podinfo", metav1.GetOptions{})
	require.NoError(t, err)
	require.NoError(t, err)
	require.Len(t, vs.Spec.Http, 1)
	assert.NotNil(t, vs.Spec.Http[0].CorsPolicy)
	assert.Len(t, vs.Spec.Http[0].CorsPolicy.AllowMethods, 2)
}

func TestIstioRouter_ABTest(t *testing.T) {
	mocks := newFixture(nil)
	router := &IstioRouter{
		logger:        mocks.logger,
		flaggerClient: mocks.flaggerClient,
		istioClient:   mocks.meshClient,
		kubeClient:    mocks.kubeClient,
	}

	err := router.Reconcile(mocks.abtest)
	require.NoError(t, err)

	// test insert
	vs, err := mocks.meshClient.NetworkingV1alpha3().VirtualServices("default").Get(context.TODO(), "abtest", metav1.GetOptions{})
	require.NoError(t, err)
	assert.Len(t, vs.Spec.Http, 2)

	p := 0
	c := 100
	m := false

	err = router.SetRoutes(mocks.abtest, p, c, m)
	require.NoError(t, err)

	vs, err = mocks.meshClient.NetworkingV1alpha3().VirtualServices("default").Get(context.TODO(), "abtest", metav1.GetOptions{})
	require.NoError(t, err)

	pHost := fmt.Sprintf("%s-primary", mocks.abtest.Spec.TargetRef.Name)
	cHost := fmt.Sprintf("%s-canary", mocks.abtest.Spec.TargetRef.Name)
	pRoute := istiov1alpha3.DestinationWeight{}
	cRoute := istiov1alpha3.DestinationWeight{}
	var mirror *istiov1alpha3.Destination

	for _, http := range vs.Spec.Http {
		for _, route := range http.Route {
			if route.Destination.Host == pHost {
				pRoute = route
			}
			if route.Destination.Host == cHost {
				cRoute = route
				mirror = http.Mirror
			}
		}
	}

	assert.Equal(t, p, pRoute.Weight)
	assert.Equal(t, c, cRoute.Weight)
	assert.Nil(t, mirror)
}

func TestIstioRouter_GatewayPort(t *testing.T) {
	mocks := newFixture(nil)
	router := &IstioRouter{
		logger:        mocks.logger,
		flaggerClient: mocks.flaggerClient,
		istioClient:   mocks.meshClient,
		kubeClient:    mocks.kubeClient,
	}

	err := router.Reconcile(mocks.canary)
	require.NoError(t, err)

	vs, err := mocks.meshClient.NetworkingV1alpha3().VirtualServices("default").Get(context.TODO(), "podinfo", metav1.GetOptions{})
	require.NoError(t, err)

	port := vs.Spec.Http[0].Route[0].Destination.Port.Number
	assert.Equal(t, uint32(mocks.canary.Spec.Service.Port), port)
}

func TestIstioRouter_Delegate(t *testing.T) {
	t.Run("ok", func(t *testing.T) {
		mocks := newFixture(nil)
		mocks.canary.Spec.Service.Hosts = []string{}
		mocks.canary.Spec.Service.Gateways = []string{}
		mocks.canary.Spec.Service.Delegation = true

		router := &IstioRouter{
			logger:        mocks.logger,
			flaggerClient: mocks.flaggerClient,
			istioClient:   mocks.meshClient,
			kubeClient:    mocks.kubeClient,
		}

		err := router.Reconcile(mocks.canary)
		require.NoError(t, err)

		vs, err := mocks.meshClient.NetworkingV1alpha3().VirtualServices("default").Get(context.TODO(), "podinfo", metav1.GetOptions{})
		require.NoError(t, err)

		assert.Equal(t, 0, len(vs.Spec.Hosts))
		assert.Equal(t, 0, len(vs.Spec.Gateways))
	})

	t.Run("invalid", func(t *testing.T) {
		mocks := newFixture(nil)
		if len(mocks.canary.Spec.Service.Gateways) == 0 {
			// in this case, the gateways or hosts should not be not empty because it requires to cause an error.
			mocks.canary.Spec.Service.Gateways = []string{
				"public-gateway.istio",
				"mesh",
			}
		}
		mocks.canary.Spec.Service.Delegation = true

		router := &IstioRouter{
			logger:        mocks.logger,
			flaggerClient: mocks.flaggerClient,
			istioClient:   mocks.meshClient,
			kubeClient:    mocks.kubeClient,
		}

		err := router.Reconcile(mocks.canary)
		require.Error(t, err)
	})
}

func TestIstioRouter_Finalize(t *testing.T) {
	mocks := newFixture(nil)
	router := &IstioRouter{
		logger:        mocks.logger,
		flaggerClient: mocks.flaggerClient,
		istioClient:   mocks.meshClient,
		kubeClient:    mocks.kubeClient,
	}

	flaggerSpec := &istiov1alpha3.VirtualServiceSpec{
		Http: []istiov1alpha3.HTTPRoute{
			{
				Match:      mocks.canary.Spec.Service.Match,
				Rewrite:    mocks.canary.Spec.Service.Rewrite,
				Timeout:    mocks.canary.Spec.Service.Timeout,
				Retries:    mocks.canary.Spec.Service.Retries,
				CorsPolicy: mocks.canary.Spec.Service.CorsPolicy,
			},
		},
	}

	kubectlSpec := &istiov1alpha3.VirtualServiceSpec{
		Hosts:    []string{"podinfo"},
		Gateways: []string{"ingressgateway.istio-system.svc.cluster.local"},
		Http: []istiov1alpha3.HTTPRoute{
			{
				Match: nil,
				Route: []istiov1alpha3.DestinationWeight{
					{
						Destination: istiov1alpha3.Destination{Host: "podinfo"},
					},
				},
			},
		},
	}

	tables := []struct {
		router        *IstioRouter
		spec          *istiov1alpha3.VirtualServiceSpec
		shouldError   bool
		createVS      bool
		canary        *v1beta1.Canary
		callReconcile bool
		annotation    string
	}{
		// VS not found
		{router: router, spec: nil, shouldError: true, createVS: false, canary: mocks.canary, callReconcile: false, annotation: ""},
		// No annotation found but still finalizes
		{router: router, spec: nil, shouldError: false, createVS: false, canary: mocks.canary, callReconcile: true, annotation: ""},
		// Spec should match annotation after finalize
		{router: router, spec: flaggerSpec, shouldError: false, createVS: true, canary: mocks.canary, callReconcile: true, annotation: "flagger"},
		// Need to test kubectl annotation
		{router: router, spec: kubectlSpec, shouldError: false, createVS: true, canary: mocks.canary, callReconcile: true, annotation: "kubectl"},
	}

	for _, table := range tables {
		var err error
		if table.createVS {
			vs, err := router.istioClient.NetworkingV1alpha3().VirtualServices(table.canary.Namespace).Get(context.TODO(), table.canary.Name, metav1.GetOptions{})
			require.NoError(t, err)

			if vs.Annotations == nil {
				vs.Annotations = make(map[string]string)
			}

			switch table.annotation {
			case "flagger":
				b, err := json.Marshal(table.spec)
				require.NoError(t, err)
				vs.Annotations[configAnnotation] = string(b)
			case "kubectl":
				vs.Annotations[kubectlAnnotation] = `{"apiVersion": "networking.istio.io/v1alpha3","kind": "VirtualService","metadata": {"annotations": {},"name": "podinfo","namespace": "test"},  "spec": {"gateways": ["ingressgateway.istio-system.svc.cluster.local"],"hosts": ["podinfo"],"http": [{"route": [{"destination": {"host": "podinfo"}}]}]}}`
			}
			_, err = router.istioClient.NetworkingV1alpha3().VirtualServices(table.canary.Namespace).Update(context.TODO(), vs, metav1.UpdateOptions{})
			require.NoError(t, err)
		}

		if table.callReconcile {
			err = router.Reconcile(table.canary)
			require.NoError(t, err)
		}

		err = router.Finalize(table.canary)
		if table.shouldError {
			require.Error(t, err)
		} else {
			require.NoError(t, err)
		}

		if table.spec != nil {
			vs, err := router.istioClient.NetworkingV1alpha3().VirtualServices(table.canary.Namespace).Get(context.TODO(), table.canary.Name, metav1.GetOptions{})
			require.NoError(t, err)
			require.Equal(t, *table.spec, vs.Spec)
		}
	}
}