/*
Copyright 2016 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 kuberuntime

import (
	"fmt"
	"net"
	"net/url"
	"runtime"
	"sort"

	v1 "k8s.io/api/core/v1"
	kubetypes "k8s.io/apimachinery/pkg/types"
	utilfeature "k8s.io/apiserver/pkg/util/feature"
	runtimeapi "k8s.io/cri-api/pkg/apis/runtime/v1alpha2"
	"k8s.io/klog/v2"
	"k8s.io/kubernetes/pkg/features"
	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
	"k8s.io/kubernetes/pkg/kubelet/types"
	"k8s.io/kubernetes/pkg/kubelet/util"
	"k8s.io/kubernetes/pkg/kubelet/util/format"
)

// createPodSandbox creates a pod sandbox and returns (podSandBoxID, message, error).
func (m *kubeGenericRuntimeManager) createPodSandbox(pod *v1.Pod, attempt uint32) (string, string, error) {
	podSandboxConfig, err := m.generatePodSandboxConfig(pod, attempt)
	if err != nil {
		message := fmt.Sprintf("GeneratePodSandboxConfig for pod %q failed: %v", format.Pod(pod), err)
		klog.Error(message)
		return "", message, err
	}

	// Create pod logs directory
	err = m.osInterface.MkdirAll(podSandboxConfig.LogDirectory, 0755)
	if err != nil {
		message := fmt.Sprintf("Create pod log directory for pod %q failed: %v", format.Pod(pod), err)
		klog.Errorf(message)
		return "", message, err
	}

	runtimeHandler := ""
	if utilfeature.DefaultFeatureGate.Enabled(features.RuntimeClass) && m.runtimeClassManager != nil {
		runtimeHandler, err = m.runtimeClassManager.LookupRuntimeHandler(pod.Spec.RuntimeClassName)
		if err != nil {
			message := fmt.Sprintf("CreatePodSandbox for pod %q failed: %v", format.Pod(pod), err)
			return "", message, err
		}
		if runtimeHandler != "" {
			klog.V(2).Infof("Running pod %s with RuntimeHandler %q", format.Pod(pod), runtimeHandler)
		}
	}

	podSandBoxID, err := m.runtimeService.RunPodSandbox(podSandboxConfig, runtimeHandler)
	if err != nil {
		message := fmt.Sprintf("CreatePodSandbox for pod %q failed: %v", format.Pod(pod), err)
		klog.Error(message)
		return "", message, err
	}

	return podSandBoxID, "", nil
}

// generatePodSandboxConfig generates pod sandbox config from v1.Pod.
func (m *kubeGenericRuntimeManager) generatePodSandboxConfig(pod *v1.Pod, attempt uint32) (*runtimeapi.PodSandboxConfig, error) {
	// TODO: deprecating podsandbox resource requirements in favor of the pod level cgroup
	// Refer https://github.com/kubernetes/kubernetes/issues/29871
	podUID := string(pod.UID)
	podSandboxConfig := &runtimeapi.PodSandboxConfig{
		Metadata: &runtimeapi.PodSandboxMetadata{
			Name:      pod.Name,
			Namespace: pod.Namespace,
			Uid:       podUID,
			Attempt:   attempt,
		},
		Labels:      newPodLabels(pod),
		Annotations: newPodAnnotations(pod),
	}

	dnsConfig, err := m.runtimeHelper.GetPodDNS(pod)
	if err != nil {
		return nil, err
	}
	podSandboxConfig.DnsConfig = dnsConfig

	if !kubecontainer.IsHostNetworkPod(pod) {
		// TODO: Add domain support in new runtime interface
		podHostname, podDomain, err := m.runtimeHelper.GeneratePodHostNameAndDomain(pod)
		if err != nil {
			return nil, err
		}
		podHostname, err = util.GetNodenameForKernel(podHostname, podDomain, pod.Spec.SetHostnameAsFQDN)
		if err != nil {
			return nil, err
		}
		podSandboxConfig.Hostname = podHostname
	}

	logDir := BuildPodLogsDirectory(pod.Namespace, pod.Name, pod.UID)
	podSandboxConfig.LogDirectory = logDir

	portMappings := []*runtimeapi.PortMapping{}
	for _, c := range pod.Spec.Containers {
		containerPortMappings := kubecontainer.MakePortMappings(&c)

		for idx := range containerPortMappings {
			port := containerPortMappings[idx]
			hostPort := int32(port.HostPort)
			containerPort := int32(port.ContainerPort)
			protocol := toRuntimeProtocol(port.Protocol)
			portMappings = append(portMappings, &runtimeapi.PortMapping{
				HostIp:        port.HostIP,
				HostPort:      hostPort,
				ContainerPort: containerPort,
				Protocol:      protocol,
			})
		}

	}
	if len(portMappings) > 0 {
		podSandboxConfig.PortMappings = portMappings
	}

	lc, err := m.generatePodSandboxLinuxConfig(pod)
	if err != nil {
		return nil, err
	}
	podSandboxConfig.Linux = lc

	return podSandboxConfig, nil
}

// generatePodSandboxLinuxConfig generates LinuxPodSandboxConfig from v1.Pod.
// We've to call PodSandboxLinuxConfig always irrespective of the underlying OS as securityContext is not part of
// podSandboxConfig. It is currently part of LinuxPodSandboxConfig. In future, if we have securityContext pulled out
// in podSandboxConfig we should be able to use it.
func (m *kubeGenericRuntimeManager) generatePodSandboxLinuxConfig(pod *v1.Pod) (*runtimeapi.LinuxPodSandboxConfig, error) {
	cgroupParent := m.runtimeHelper.GetPodCgroupParent(pod)
	lc := &runtimeapi.LinuxPodSandboxConfig{
		CgroupParent: cgroupParent,
		SecurityContext: &runtimeapi.LinuxSandboxSecurityContext{
			Privileged: kubecontainer.HasPrivilegedContainer(pod),

			// Forcing sandbox to run as `runtime/default` allow users to
			// use least privileged seccomp profiles at pod level. Issue #84623
			SeccompProfilePath: v1.SeccompProfileRuntimeDefault,
		},
	}

	sysctls := make(map[string]string)
	if utilfeature.DefaultFeatureGate.Enabled(features.Sysctls) {
		if pod.Spec.SecurityContext != nil {
			for _, c := range pod.Spec.SecurityContext.Sysctls {
				sysctls[c.Name] = c.Value
			}
		}
	}

	lc.Sysctls = sysctls

	if pod.Spec.SecurityContext != nil {
		sc := pod.Spec.SecurityContext
		if sc.RunAsUser != nil && runtime.GOOS != "windows" {
			lc.SecurityContext.RunAsUser = &runtimeapi.Int64Value{Value: int64(*sc.RunAsUser)}
		}
		if sc.RunAsGroup != nil && runtime.GOOS != "windows" {
			lc.SecurityContext.RunAsGroup = &runtimeapi.Int64Value{Value: int64(*sc.RunAsGroup)}
		}
		lc.SecurityContext.NamespaceOptions = namespacesForPod(pod)

		if sc.FSGroup != nil && runtime.GOOS != "windows" {
			lc.SecurityContext.SupplementalGroups = append(lc.SecurityContext.SupplementalGroups, int64(*sc.FSGroup))
		}
		if groups := m.runtimeHelper.GetExtraSupplementalGroupsForPod(pod); len(groups) > 0 {
			lc.SecurityContext.SupplementalGroups = append(lc.SecurityContext.SupplementalGroups, groups...)
		}
		if sc.SupplementalGroups != nil {
			for _, sg := range sc.SupplementalGroups {
				lc.SecurityContext.SupplementalGroups = append(lc.SecurityContext.SupplementalGroups, int64(sg))
			}
		}
		if sc.SELinuxOptions != nil && runtime.GOOS != "windows" {
			lc.SecurityContext.SelinuxOptions = &runtimeapi.SELinuxOption{
				User:  sc.SELinuxOptions.User,
				Role:  sc.SELinuxOptions.Role,
				Type:  sc.SELinuxOptions.Type,
				Level: sc.SELinuxOptions.Level,
			}
		}
	}

	return lc, nil
}

// getKubeletSandboxes lists all (or just the running) sandboxes managed by kubelet.
func (m *kubeGenericRuntimeManager) getKubeletSandboxes(all bool) ([]*runtimeapi.PodSandbox, error) {
	var filter *runtimeapi.PodSandboxFilter
	if !all {
		readyState := runtimeapi.PodSandboxState_SANDBOX_READY
		filter = &runtimeapi.PodSandboxFilter{
			State: &runtimeapi.PodSandboxStateValue{
				State: readyState,
			},
		}
	}

	resp, err := m.runtimeService.ListPodSandbox(filter)
	if err != nil {
		klog.Errorf("ListPodSandbox failed: %v", err)
		return nil, err
	}

	return resp, nil
}

// determinePodSandboxIP determines the IP addresses of the given pod sandbox.
func (m *kubeGenericRuntimeManager) determinePodSandboxIPs(podNamespace, podName string, podSandbox *runtimeapi.PodSandboxStatus) []string {
	podIPs := make([]string, 0)
	if podSandbox.Network == nil {
		klog.Warningf("Pod Sandbox status doesn't have network information, cannot report IPs")
		return podIPs
	}

	// ip could be an empty string if runtime is not responsible for the
	// IP (e.g., host networking).

	// pick primary IP
	if len(podSandbox.Network.Ip) != 0 {
		if net.ParseIP(podSandbox.Network.Ip) == nil {
			klog.Warningf("Pod Sandbox reported an unparseable IP (Primary) %v", podSandbox.Network.Ip)
			return nil
		}
		podIPs = append(podIPs, podSandbox.Network.Ip)
	}

	// pick additional ips, if cri reported them
	for _, podIP := range podSandbox.Network.AdditionalIps {
		if nil == net.ParseIP(podIP.Ip) {
			klog.Warningf("Pod Sandbox reported an unparseable IP (additional) %v", podIP.Ip)
			return nil
		}
		podIPs = append(podIPs, podIP.Ip)
	}

	return podIPs
}

// getPodSandboxID gets the sandbox id by podUID and returns ([]sandboxID, error).
// Param state could be nil in order to get all sandboxes belonging to same pod.
func (m *kubeGenericRuntimeManager) getSandboxIDByPodUID(podUID kubetypes.UID, state *runtimeapi.PodSandboxState) ([]string, error) {
	filter := &runtimeapi.PodSandboxFilter{
		LabelSelector: map[string]string{types.KubernetesPodUIDLabel: string(podUID)},
	}
	if state != nil {
		filter.State = &runtimeapi.PodSandboxStateValue{
			State: *state,
		}
	}
	sandboxes, err := m.runtimeService.ListPodSandbox(filter)
	if err != nil {
		klog.Errorf("ListPodSandbox with pod UID %q failed: %v", podUID, err)
		return nil, err
	}

	if len(sandboxes) == 0 {
		return nil, nil
	}

	// Sort with newest first.
	sandboxIDs := make([]string, len(sandboxes))
	sort.Sort(podSandboxByCreated(sandboxes))
	for i, s := range sandboxes {
		sandboxIDs[i] = s.Id
	}

	return sandboxIDs, nil
}

// GetPortForward gets the endpoint the runtime will serve the port-forward request from.
func (m *kubeGenericRuntimeManager) GetPortForward(podName, podNamespace string, podUID kubetypes.UID, ports []int32) (*url.URL, error) {
	sandboxIDs, err := m.getSandboxIDByPodUID(podUID, nil)
	if err != nil {
		return nil, fmt.Errorf("failed to find sandboxID for pod %s: %v", format.PodDesc(podName, podNamespace, podUID), err)
	}
	if len(sandboxIDs) == 0 {
		return nil, fmt.Errorf("failed to find sandboxID for pod %s", format.PodDesc(podName, podNamespace, podUID))
	}
	req := &runtimeapi.PortForwardRequest{
		PodSandboxId: sandboxIDs[0],
		Port:         ports,
	}
	resp, err := m.runtimeService.PortForward(req)
	if err != nil {
		return nil, err
	}
	return url.Parse(resp.Url)
}
