/*
Copyright 2017 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 controller

import (
	"encoding/json"
	"io"
	"io/ioutil"
	"net"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	apiv1 "k8s.io/api/core/v1"
	"k8s.io/ingress-nginx/internal/ingress"
)

func TestIsDynamicConfigurationEnough(t *testing.T) {
	backends := []*ingress.Backend{{
		Name: "fakenamespace-myapp-80",
		Endpoints: []ingress.Endpoint{
			{
				Address: "10.0.0.1",
				Port:    "8080",
			},
			{
				Address: "10.0.0.2",
				Port:    "8080",
			},
		},
	}}

	servers := []*ingress.Server{{
		Hostname: "myapp.fake",
		Locations: []*ingress.Location{
			{
				Path:    "/",
				Backend: "fakenamespace-myapp-80",
			},
		},
		SSLCert: ingress.SSLCert{
			PemCertKey: "fake-certificate",
		},
	}}

	commonConfig := &ingress.Configuration{
		Backends: backends,
		Servers:  servers,
	}

	n := &NGINXController{
		runningConfig: &ingress.Configuration{
			Backends: backends,
			Servers:  servers,
		},
		cfg: &Configuration{
			DynamicCertificatesEnabled: false,
		},
	}

	newConfig := commonConfig
	if !n.IsDynamicConfigurationEnough(newConfig) {
		t.Errorf("When new config is same as the running config it should be deemed as dynamically configurable")
	}

	newConfig = &ingress.Configuration{
		Backends: []*ingress.Backend{{Name: "another-backend-8081"}},
		Servers:  []*ingress.Server{{Hostname: "myapp1.fake"}},
	}
	if n.IsDynamicConfigurationEnough(newConfig) {
		t.Errorf("Expected to not be dynamically configurable when there's more than just backends change")
	}

	newConfig = &ingress.Configuration{
		Backends: []*ingress.Backend{{Name: "a-backend-8080"}},
		Servers:  servers,
	}
	if !n.IsDynamicConfigurationEnough(newConfig) {
		t.Errorf("Expected to be dynamically configurable when only backends change")
	}

	n.cfg.DynamicCertificatesEnabled = true

	newServers := []*ingress.Server{{
		Hostname: "myapp1.fake",
		Locations: []*ingress.Location{
			{
				Path:    "/",
				Backend: "fakenamespace-myapp-80",
			},
		},
		SSLCert: ingress.SSLCert{
			PemCertKey: "fake-certificate",
		},
	}}

	newConfig = &ingress.Configuration{
		Backends: backends,
		Servers:  newServers,
	}
	if n.IsDynamicConfigurationEnough(newConfig) {
		t.Errorf("Expected to not be dynamically configurable when dynamic certificates is enabled and a non-certificate field in servers is updated")
	}

	newServers[0].Hostname = "myapp.fake"
	newServers[0].SSLCert.PemCertKey = "new-fake-certificate"

	newConfig = &ingress.Configuration{
		Backends: backends,
		Servers:  newServers,
	}
	if !n.IsDynamicConfigurationEnough(newConfig) {
		t.Errorf("Expected to be dynamically configurable when only SSLCert changes")
	}

	newConfig = &ingress.Configuration{
		Backends: []*ingress.Backend{{Name: "a-backend-8080"}},
		Servers:  newServers,
	}
	if !n.IsDynamicConfigurationEnough(newConfig) {
		t.Errorf("Expected to be dynamically configurable when backend and SSLCert changes")
	}

	if !n.runningConfig.Equal(commonConfig) {
		t.Errorf("Expected running config to not change")
	}

	if !newConfig.Equal(&ingress.Configuration{Backends: []*ingress.Backend{{Name: "a-backend-8080"}}, Servers: newServers}) {
		t.Errorf("Expected new config to not change")
	}
}

func TestConfigureDynamically(t *testing.T) {
	target := &apiv1.ObjectReference{}

	backends := []*ingress.Backend{{
		Name:    "fakenamespace-myapp-80",
		Service: &apiv1.Service{},
		Endpoints: []ingress.Endpoint{
			{
				Address: "10.0.0.1",
				Port:    "8080",
				Target:  target,
			},
			{
				Address: "10.0.0.2",
				Port:    "8080",
				Target:  target,
			},
		},
	}}

	servers := []*ingress.Server{{
		Hostname: "myapp.fake",
		Locations: []*ingress.Location{
			{
				Path:    "/",
				Backend: "fakenamespace-myapp-80",
				Service: &apiv1.Service{},
			},
		},
	}}

	commonConfig := &ingress.Configuration{
		Backends: backends,
		Servers:  servers,
	}

	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusCreated)

		if r.Method != "POST" {
			t.Errorf("expected a 'POST' request, got '%s'", r.Method)
		}

		b, err := ioutil.ReadAll(r.Body)
		if err != nil && err != io.EOF {
			t.Fatal(err)
		}
		body := string(b)
		if strings.Contains(body, "target") {
			t.Errorf("unexpected target reference in JSON content: %v", body)
		}

		if !strings.Contains(body, "service") {
			t.Errorf("service reference should be present in JSON content: %v", body)
		}

	}))

	port := ts.Listener.Addr().(*net.TCPAddr).Port
	defer ts.Close()

	err := configureDynamically(commonConfig, port, false)
	if err != nil {
		t.Errorf("unexpected error posting dynamic configuration: %v", err)
	}

	if commonConfig.Backends[0].Endpoints[0].Target != target {
		t.Errorf("unexpected change in the configuration object after configureDynamically invocation")
	}
}

func TestConfigureCertificates(t *testing.T) {

	servers := []*ingress.Server{{
		Hostname: "myapp.fake",
		SSLCert: ingress.SSLCert{
			PemCertKey: "fake-cert",
		},
	}}

	commonConfig := &ingress.Configuration{
		Servers: servers,
	}

	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusCreated)

		if r.Method != "POST" {
			t.Errorf("expected a 'POST' request, got '%s'", r.Method)
		}

		b, err := ioutil.ReadAll(r.Body)
		if err != nil && err != io.EOF {
			t.Fatal(err)
		}
		var postedServers []ingress.Server
		err = json.Unmarshal(b, &postedServers)
		if err != nil {
			t.Fatal(err)
		}

		if len(servers) != len(postedServers) {
			t.Errorf("Expected servers to be the same length as the posted servers")
		}

		for i, server := range servers {
			if !server.Equal(&postedServers[i]) {
				t.Errorf("Expected servers and posted servers to be equal")
			}
		}
	}))

	port := ts.Listener.Addr().(*net.TCPAddr).Port
	defer ts.Close()

	err := configureCertificates(commonConfig, port)
	if err != nil {
		t.Errorf("unexpected error posting dynamic certificate configuration: %v", err)
	}
}

func TestNginxHashBucketSize(t *testing.T) {
	tests := []struct {
		n        int
		expected int
	}{
		{0, 32},
		{1, 32},
		{2, 32},
		{3, 32},
		// ...
		{13, 32},
		{14, 32},
		{15, 64},
		{16, 64},
		// ...
		{45, 64},
		{46, 64},
		{47, 128},
		{48, 128},
		// ...
		// ...
		{109, 128},
		{110, 128},
		{111, 256},
		{112, 256},
		// ...
		{237, 256},
		{238, 256},
		{239, 512},
		{240, 512},
	}

	for _, test := range tests {
		actual := nginxHashBucketSize(test.n)
		if actual != test.expected {
			t.Errorf("Test nginxHashBucketSize(%d): expected %d but returned %d", test.n, test.expected, actual)
		}
	}
}

func TestNextPowerOf2(t *testing.T) {
	// Powers of 2
	actual := nextPowerOf2(2)
	if actual != 2 {
		t.Errorf("TestNextPowerOf2: expected %d but returned %d.", 2, actual)
	}
	actual = nextPowerOf2(4)
	if actual != 4 {
		t.Errorf("TestNextPowerOf2: expected %d but returned %d.", 4, actual)
	}
	actual = nextPowerOf2(32)
	if actual != 32 {
		t.Errorf("TestNextPowerOf2: expected %d but returned %d.", 32, actual)
	}
	actual = nextPowerOf2(256)
	if actual != 256 {
		t.Errorf("TestNextPowerOf2: expected %d but returned %d.", 256, actual)
	}

	// Not Powers of 2
	actual = nextPowerOf2(7)
	if actual != 8 {
		t.Errorf("TestNextPowerOf2: expected %d but returned %d.", 8, actual)
	}
	actual = nextPowerOf2(9)
	if actual != 16 {
		t.Errorf("TestNextPowerOf2: expected %d but returned %d.", 16, actual)
	}
	actual = nextPowerOf2(15)
	if actual != 16 {
		t.Errorf("TestNextPowerOf2: expected %d but returned %d.", 16, actual)
	}
	actual = nextPowerOf2(17)
	if actual != 32 {
		t.Errorf("TestNextPowerOf2: expected %d but returned %d.", 32, actual)
	}
	actual = nextPowerOf2(250)
	if actual != 256 {
		t.Errorf("TestNextPowerOf2: expected %d but returned %d.", 256, actual)
	}

	// Other
	actual = nextPowerOf2(0)
	if actual != 0 {
		t.Errorf("TestNextPowerOf2: expected %d but returned %d.", 0, actual)
	}
	actual = nextPowerOf2(-1)
	if actual != 0 {
		t.Errorf("TestNextPowerOf2: expected %d but returned %d.", 0, actual)
	}
	actual = nextPowerOf2(-2)
	if actual != 0 {
		t.Errorf("TestNextPowerOf2: expected %d but returned %d.", 0, actual)
	}
}