// 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 wsdaemon

import (
	"fmt"

	"github.com/gitpod-io/gitpod/installer/pkg/cluster"
	"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 daemonset(ctx *common.RenderContext) ([]runtime.Object, error) {
	cfg := ctx.Config
	labels := common.CustomizeLabel(ctx, Component, common.TypeMetaDaemonset)

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

	initContainers := []corev1.Container{
		{
			Name:  "seccomp-profile-installer",
			Image: ctx.ImageName(cfg.Repository, "seccomp-profile-installer", ctx.VersionManifest.Components.WSDaemon.UserNamespaces.SeccompProfileInstaller.Version),
			Command: []string{
				"/bin/sh",
				"-c",
				fmt.Sprintf("cp -f /installer/workspace_default.json /mnt/dst/workspace_default_%s.json", ctx.VersionManifest.Version),
			},
			VolumeMounts: []corev1.VolumeMount{{
				Name:      "hostseccomp",
				MountPath: "/mnt/dst",
			}},
			SecurityContext: &corev1.SecurityContext{Privileged: pointer.Bool(true)},
		},
		{
			Name:  "sysctl",
			Image: ctx.ImageName(cfg.Repository, "ws-daemon", ctx.VersionManifest.Components.WSDaemon.Version),
			Command: []string{
				"sh",
				"-c",
				`(
	echo "running sysctls" &&
	sysctl -w net.core.somaxconn=4096 &&
	sysctl -w "net.ipv4.ip_local_port_range=5000 65000" &&
	sysctl -w "net.ipv4.tcp_tw_reuse=1" &&
	sysctl -w fs.inotify.max_user_watches=1000000 &&
	sysctl -w "kernel.dmesg_restrict=1" &&
	sysctl -w vm.unprivileged_userfaultfd=0
) && echo "done!" || echo "failed!"
`,
			},
			SecurityContext: &corev1.SecurityContext{Privileged: pointer.Bool(true)},
		},
	}

	volumes := []corev1.Volume{
		{
			Name: "hostfs",
			VolumeSource: corev1.VolumeSource{HostPath: &corev1.HostPathVolumeSource{
				Path: "/",
			}},
		},
		{
			Name: "working-area-mk2",
			VolumeSource: corev1.VolumeSource{HostPath: &corev1.HostPathVolumeSource{
				Path: HostWorkingAreaMk2,
				Type: func() *corev1.HostPathType { r := corev1.HostPathDirectoryOrCreate; return &r }(),
			}},
		},
		{
			Name:         "tls-certs",
			VolumeSource: corev1.VolumeSource{Secret: &corev1.SecretVolumeSource{SecretName: TLSSecretName}},
		},
		{
			Name: "config",
			VolumeSource: corev1.VolumeSource{ConfigMap: &corev1.ConfigMapVolumeSource{
				LocalObjectReference: corev1.LocalObjectReference{Name: Component},
			}},
		},
		{
			Name: "containerd-socket",
			VolumeSource: corev1.VolumeSource{HostPath: &corev1.HostPathVolumeSource{
				Path: ctx.Config.Workspace.Runtime.ContainerDSocketDir,
			}},
		},
		{
			Name: "node-fs0",
			VolumeSource: corev1.VolumeSource{HostPath: &corev1.HostPathVolumeSource{
				Path: ctx.Config.Workspace.Runtime.ContainerDRuntimeDir,
				Type: func() *corev1.HostPathType { r := corev1.HostPathDirectory; return &r }(),
			}},
		},
		{
			Name: "node-mounts",
			VolumeSource: corev1.VolumeSource{HostPath: &corev1.HostPathVolumeSource{
				Path: "/proc/mounts",
				Type: func() *corev1.HostPathType { r := corev1.HostPathFile; return &r }(),
			}},
		},
		{
			Name: "node-cgroups",
			VolumeSource: corev1.VolumeSource{HostPath: &corev1.HostPathVolumeSource{
				Path: "/sys/fs/cgroup",
				Type: func() *corev1.HostPathType { r := corev1.HostPathDirectory; return &r }(),
			}},
		},
		{
			Name: "node-hosts",
			VolumeSource: corev1.VolumeSource{HostPath: &corev1.HostPathVolumeSource{
				Path: "/etc/hosts",
				Type: func() *corev1.HostPathType { r := corev1.HostPathFile; return &r }(),
			}},
		},
		{
			Name: "node-linux-src",
			VolumeSource: corev1.VolumeSource{HostPath: &corev1.HostPathVolumeSource{
				Path: "/usr/src",
				Type: func() *corev1.HostPathType { r := corev1.HostPathDirectory; return &r }(),
			}},
		},
		{
			Name:         "hostseccomp",
			VolumeSource: corev1.VolumeSource{HostPath: &corev1.HostPathVolumeSource{Path: "/var/lib/kubelet/seccomp"}},
		},
		{
			Name: "gcloud-tmp",
			VolumeSource: corev1.VolumeSource{HostPath: &corev1.HostPathVolumeSource{
				Path: HostBackupPath,
				Type: func() *corev1.HostPathType { r := corev1.HostPathDirectoryOrCreate; return &r }(),
			}},
		},
		common.CAVolume(),
	}

	volumeMounts := []corev1.VolumeMount{
		{
			Name:             "working-area-mk2",
			MountPath:        ContainerWorkingAreaMk2,
			MountPropagation: func() *corev1.MountPropagationMode { r := corev1.MountPropagationBidirectional; return &r }(),
		},
		{
			Name:      "config",
			MountPath: "/config",
		},
		{
			Name:      "containerd-socket",
			MountPath: "/mnt/containerd",
		},
		{
			Name:      "node-fs0",
			MountPath: "/mnt/node0",
		},
		{
			Name:             "node-mounts",
			ReadOnly:         true,
			MountPath:        "/mnt/mounts",
			MountPropagation: func() *corev1.MountPropagationMode { r := corev1.MountPropagationHostToContainer; return &r }(),
		},
		{
			Name:             "node-cgroups",
			MountPath:        "/mnt/node-cgroups",
			MountPropagation: func() *corev1.MountPropagationMode { r := corev1.MountPropagationHostToContainer; return &r }(),
		},
		{
			Name:      "node-hosts",
			MountPath: "/mnt/hosts",
		},
		{
			Name:      "tls-certs",
			MountPath: "/certs",
		},
		{
			Name:      "gcloud-tmp",
			MountPath: "/mnt/sync-tmp",
		},
		common.CAVolumeMount(),
	}

	tolerations := []corev1.Toleration{
		{
			Key:      "node.kubernetes.io/disk-pressure",
			Operator: "Exists",
			Effect:   "NoExecute",
		},
		{
			Key:      "node.kubernetes.io/memory-pressure",
			Operator: "Exists",
			Effect:   "NoExecute",
		},
		{
			Key:      "node.kubernetes.io/out-of-disk",
			Operator: "Exists",
			Effect:   "NoExecute",
		},
		{
			Operator: "Exists",
		},
	}

	podSpec := corev1.PodSpec{
		Volumes:        volumes,
		InitContainers: initContainers,
		Containers: []corev1.Container{
			{
				Name:  Component,
				Image: ctx.ImageName(ctx.Config.Repository, Component, ctx.VersionManifest.Components.WSDaemon.Version),
				Args: []string{
					"run",
					"--config",
					"/config/config.json",
				},
				Ports: []corev1.ContainerPort{{
					Name:          "rpc",
					ContainerPort: ServicePort,
				}},
				Env: common.CustomizeEnvvar(ctx, Component, common.MergeEnv(
					common.DefaultEnv(&cfg),
					common.WorkspaceTracingEnv(ctx, Component),
					common.NodeNameEnv(ctx),
				)),
				Resources: common.ResourceRequirements(ctx, Component, Component, corev1.ResourceRequirements{Requests: corev1.ResourceList{
					"cpu":    resource.MustParse("500m"),
					"memory": resource.MustParse("2Gi"),
				}}),
				VolumeMounts:    volumeMounts,
				ImagePullPolicy: corev1.PullIfNotPresent,
				SecurityContext: &corev1.SecurityContext{
					Privileged: pointer.Bool(true),
				},
				ReadinessProbe: &corev1.Probe{
					ProbeHandler: corev1.ProbeHandler{
						HTTPGet: &corev1.HTTPGetAction{
							Path: "/ready",
							Port: intstr.IntOrString{IntVal: ReadinessPort},
						},
					},
					InitialDelaySeconds: 5,
					PeriodSeconds:       5,
					TimeoutSeconds:      1,
					SuccessThreshold:    2,
					FailureThreshold:    5,
				},
				LivenessProbe: &corev1.Probe{
					ProbeHandler: corev1.ProbeHandler{
						HTTPGet: &corev1.HTTPGetAction{
							Path: "/live",
							Port: intstr.IntOrString{IntVal: ReadinessPort},
						},
					},
					InitialDelaySeconds: 5,
					PeriodSeconds:       10,
					TimeoutSeconds:      1,
					SuccessThreshold:    1,
					FailureThreshold:    5,
				},
			},
			*common.KubeRBACProxyContainer(ctx),
		},
		RestartPolicy:                 corev1.RestartPolicyAlways,
		TerminationGracePeriodSeconds: pointer.Int64(30),
		DNSPolicy:                     corev1.DNSClusterFirst,
		ServiceAccountName:            Component,
		HostPID:                       true,
		Affinity:                      cluster.WithNodeAffinity(cluster.AffinityLabelWorkspacesRegular, cluster.AffinityLabelWorkspacesHeadless),
		Tolerations:                   tolerations,
		PriorityClassName:             common.SystemNodeCritical,
		EnableServiceLinks:            pointer.Bool(false),
	}

	err = common.AddStorageMounts(ctx, &podSpec, Component)
	if err != nil {
		return nil, err
	}

	return []runtime.Object{&appsv1.DaemonSet{
		TypeMeta: common.TypeMetaDaemonset,
		ObjectMeta: metav1.ObjectMeta{
			Name:        Component,
			Namespace:   ctx.Namespace,
			Labels:      labels,
			Annotations: common.CustomizeAnnotation(ctx, Component, common.TypeMetaDaemonset),
		},
		Spec: appsv1.DaemonSetSpec{
			Selector: &metav1.LabelSelector{MatchLabels: common.DefaultLabels(Component)},
			Template: corev1.PodTemplateSpec{
				ObjectMeta: metav1.ObjectMeta{
					Labels: labels,
					Annotations: common.CustomizeAnnotation(ctx, Component, common.TypeMetaDaemonset, func() map[string]string {
						return map[string]string{
							common.AnnotationConfigChecksum: configHash,
						}
					}),
				},
				Spec: podSpec,
			},
			UpdateStrategy: common.DaemonSetRolloutStrategy(),
		},
	}}, nil
}