// Copyright (c) 2021 Gitpod GmbH. All rights reserved.
// Licensed under the GNU Affero General Public License (AGPL).
// See License.AGPL.txt in the project root for license information.

package proxy

import (
	"fmt"
	"strings"

	"github.com/gitpod-io/gitpod/common-go/baseserver"
	"github.com/gitpod-io/gitpod/installer/pkg/cluster"
	"github.com/gitpod-io/gitpod/installer/pkg/config/v1/experimental"

	"github.com/gitpod-io/gitpod/installer/pkg/common"

	appsv1 "k8s.io/api/apps/v1"
	corev1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/api/resource"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/util/intstr"
	"k8s.io/utils/pointer"
)

func deployment(ctx *common.RenderContext) ([]runtime.Object, error) {
	labels := common.CustomizeLabel(ctx, Component, common.TypeMetaDeployment)

	var hashObj []runtime.Object
	if objs, err := configmap(ctx); err != nil {
		return nil, err
	} else {
		hashObj = append(hashObj, objs...)
	}

	prometheusPort := corev1.ContainerPort{
		ContainerPort: baseserver.BuiltinMetricsPort,
		Name:          baseserver.BuiltinMetricsPortName,
	}

	volumes := []corev1.Volume{{
		Name: "vhosts",
		VolumeSource: corev1.VolumeSource{
			ConfigMap: &corev1.ConfigMapVolumeSource{
				LocalObjectReference: corev1.LocalObjectReference{Name: fmt.Sprintf("%s-config", Component)},
			},
		},
	}, {
		Name: "config-certificates",
		VolumeSource: corev1.VolumeSource{
			Secret: &corev1.SecretVolumeSource{
				SecretName: ctx.Config.Certificate.Name,
			},
		},
	}}

	volumeMounts := []corev1.VolumeMount{{
		Name:      "vhosts",
		MountPath: "/etc/caddy/vhosts",
	}, {
		Name:      "config-certificates",
		MountPath: "/etc/caddy/certificates",
	}}

	if pointer.BoolDeref(ctx.Config.ContainerRegistry.InCluster, false) {
		volumes = append(volumes, corev1.Volume{
			Name: RegistryAuthSecret,
			VolumeSource: corev1.VolumeSource{
				Secret: &corev1.SecretVolumeSource{
					SecretName: RegistryAuthSecret,
				},
			},
		}, corev1.Volume{
			Name: RegistryTLSCertSecret,
			VolumeSource: corev1.VolumeSource{
				Secret: &corev1.SecretVolumeSource{
					SecretName: RegistryTLSCertSecret,
				},
			},
		})
		volumeMounts = append(volumeMounts, corev1.VolumeMount{
			Name:      RegistryAuthSecret,
			MountPath: "/etc/caddy/registry-auth",
		}, corev1.VolumeMount{
			Name:      RegistryTLSCertSecret,
			MountPath: "/etc/caddy/registry-certs",
		})

		if objs, err := common.DockerRegistryHash(ctx); err != nil {
			return nil, err
		} else {
			hashObj = append(hashObj, objs...)
		}
	}

	configHash, err := common.ObjectHash(hashObj, nil)
	if err != nil {
		return nil, err
	}

	var podAntiAffinity *corev1.PodAntiAffinity
	_ = ctx.WithExperimental(func(cfg *experimental.Config) error {
		if cfg.WebApp != nil && cfg.WebApp.UsePodAntiAffinity {
			podAntiAffinity = &corev1.PodAntiAffinity{
				PreferredDuringSchedulingIgnoredDuringExecution: []corev1.WeightedPodAffinityTerm{{
					Weight: 100,
					PodAffinityTerm: corev1.PodAffinityTerm{
						LabelSelector: &metav1.LabelSelector{
							MatchExpressions: []metav1.LabelSelectorRequirement{{
								Key:      "component",
								Operator: "In",
								Values:   []string{Component},
							}},
						},
						TopologyKey: cluster.AffinityLabelMeta,
					},
				}},
			}
		}
		return nil
	})

	var frontendDevEnabled bool
	_ = ctx.WithExperimental(func(cfg *experimental.Config) error {
		if cfg.WebApp != nil && cfg.WebApp.ProxyConfig != nil {
			frontendDevEnabled = cfg.WebApp.ProxyConfig.FrontendDevEnabled
		}
		return nil
	})

	const kubeRbacProxyContainerName = "kube-rbac-proxy"
	return []runtime.Object{
		&appsv1.Deployment{
			TypeMeta: common.TypeMetaDeployment,
			ObjectMeta: metav1.ObjectMeta{
				Name:        Component,
				Namespace:   ctx.Namespace,
				Labels:      labels,
				Annotations: common.CustomizeAnnotation(ctx, Component, common.TypeMetaDeployment),
			},
			Spec: appsv1.DeploymentSpec{
				Selector: &metav1.LabelSelector{MatchLabels: common.DefaultLabels(Component)},
				Replicas: common.Replicas(ctx, Component),
				Strategy: common.DeploymentStrategy,
				Template: corev1.PodTemplateSpec{
					ObjectMeta: metav1.ObjectMeta{
						Name:      Component,
						Namespace: ctx.Namespace,
						Labels:    labels,
						Annotations: common.CustomizeAnnotation(ctx, Component, common.TypeMetaDeployment, func() map[string]string {
							return map[string]string{
								common.AnnotationConfigChecksum: configHash,
							}
						}),
					},
					Spec: corev1.PodSpec{
						Affinity: &corev1.Affinity{
							NodeAffinity:    common.NodeAffinity(cluster.AffinityLabelMeta).NodeAffinity,
							PodAntiAffinity: podAntiAffinity,
						},
						PriorityClassName:             common.SystemNodeCritical,
						ServiceAccountName:            Component,
						EnableServiceLinks:            pointer.Bool(false),
						DNSPolicy:                     "ClusterFirst",
						RestartPolicy:                 "Always",
						TerminationGracePeriodSeconds: pointer.Int64(30),
						SecurityContext: &corev1.PodSecurityContext{

							RunAsNonRoot: pointer.Bool(false),
						},
						Volumes: volumes,
						InitContainers: []corev1.Container{{
							Name:            "sysctl",
							Image:           ctx.ImageName(common.ThirdPartyContainerRepo(ctx.Config.Repository, common.DockerRegistryURL), InitContainerImage, InitContainerTag),
							ImagePullPolicy: corev1.PullIfNotPresent,
							SecurityContext: &corev1.SecurityContext{
								Privileged: pointer.Bool(true),
							},
							Command: []string{
								"sh",
								"-c",
								"sysctl -w net.core.somaxconn=32768; sysctl -w net.ipv4.ip_local_port_range='1024 65000'",
							},
						}},
						Containers: []corev1.Container{{
							Name:            kubeRbacProxyContainerName,
							Image:           ctx.ImageName(common.ThirdPartyContainerRepo(ctx.Config.Repository, KubeRBACProxyRepo), KubeRBACProxyImage, KubeRBACProxyTag),
							ImagePullPolicy: corev1.PullIfNotPresent,
							Args: []string{
								"--logtostderr",
								fmt.Sprintf("--insecure-listen-address=[$(IP)]:%d", baseserver.BuiltinMetricsPort),
								"--upstream=http://127.0.0.1:9545/",
							},
							Env: []corev1.EnvVar{{
								Name: "IP",
								ValueFrom: &corev1.EnvVarSource{
									FieldRef: &corev1.ObjectFieldSelector{
										APIVersion: "v1",
										FieldPath:  "status.podIP",
									},
								},
							}},
							Ports: []corev1.ContainerPort{{
								ContainerPort: baseserver.BuiltinMetricsPort,
								Name:          baseserver.BuiltinMetricsPortName,
								Protocol:      *common.TCPProtocol,
							}},
							Resources: common.ResourceRequirements(ctx, Component, kubeRbacProxyContainerName, corev1.ResourceRequirements{
								Requests: corev1.ResourceList{
									"cpu":    resource.MustParse("1m"),
									"memory": resource.MustParse("30Mi"),
								},
							}),
							SecurityContext: &corev1.SecurityContext{
								RunAsGroup:   pointer.Int64(65532),
								RunAsNonRoot: pointer.Bool(true),
								RunAsUser:    pointer.Int64(65532),
							},
						}, {
							Name:            Component,
							Image:           ctx.ImageName(ctx.Config.Repository, Component, ctx.VersionManifest.Components.Proxy.Version),
							ImagePullPolicy: corev1.PullIfNotPresent,
							Resources: common.ResourceRequirements(ctx, Component, Component, corev1.ResourceRequirements{
								Requests: corev1.ResourceList{
									"cpu":    resource.MustParse("100m"),
									"memory": resource.MustParse("200Mi"),
								},
							}),
							Ports: []corev1.ContainerPort{{
								ContainerPort: ContainerHTTPPort,
								Name:          "http",
							}, {
								ContainerPort: ContainerHTTPSPort,
								Name:          "https",
							}, {
								ContainerPort: ContainerSSHPort,
								Name:          ContainerSSHName,
								Protocol:      *common.TCPProtocol,
							}, prometheusPort},
							SecurityContext: &corev1.SecurityContext{
								Privileged:               pointer.Bool(false),
								AllowPrivilegeEscalation: pointer.Bool(false),
							},
							ReadinessProbe: &corev1.Probe{
								ProbeHandler: corev1.ProbeHandler{
									HTTPGet: &corev1.HTTPGetAction{
										Path: "/ready",
										Port: intstr.IntOrString{IntVal: ReadinessPort},
									},
								},
								InitialDelaySeconds: 5,
								PeriodSeconds:       5,
								TimeoutSeconds:      1,
								SuccessThreshold:    1,
								FailureThreshold:    3,
							},
							VolumeMounts: volumeMounts,
							Env: common.CustomizeEnvvar(ctx, Component, common.MergeEnv(
								common.DefaultEnv(&ctx.Config),
								common.ConfigcatProxyEnv(ctx),
								[]corev1.EnvVar{{
									Name:  "PROXY_DOMAIN",
									Value: ctx.Config.Domain,
								}, {
									Name:  "FRONTEND_DEV_ENABLED",
									Value: fmt.Sprintf("%t", frontendDevEnabled),
								}, {
									Name:  "WORKSPACE_HANDLER_FILE",
									Value: strings.ToLower(string(ctx.Config.Kind)),
								}},
							)),
						}},
					},
				},
			},
		},
	}, nil
}