/*
Copyright 2014 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 debug

import (
	"context"
	"fmt"
	"sort"
	"time"

	"github.com/onsi/ginkgo/v2"

	v1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/fields"
	clientset "k8s.io/client-go/kubernetes"
	restclient "k8s.io/client-go/rest"
	"k8s.io/kubernetes/test/e2e/framework"
	e2emetrics "k8s.io/kubernetes/test/e2e/framework/metrics"
	e2epod "k8s.io/kubernetes/test/e2e/framework/pod"
)

// EventsLister is a func that lists events.
type EventsLister func(opts metav1.ListOptions, ns string) (*v1.EventList, error)

// dumpEventsInNamespace dumps events in the given namespace.
func dumpEventsInNamespace(eventsLister EventsLister, namespace string) {
	ginkgo.By(fmt.Sprintf("Collecting events from namespace %q.", namespace))
	events, err := eventsLister(metav1.ListOptions{}, namespace)
	framework.ExpectNoError(err, "failed to list events in namespace %q", namespace)

	ginkgo.By(fmt.Sprintf("Found %d events.", len(events.Items)))
	// Sort events by their first timestamp
	sortedEvents := events.Items
	if len(sortedEvents) > 1 {
		sort.Sort(byFirstTimestamp(sortedEvents))
	}
	for _, e := range sortedEvents {
		framework.Logf("At %v - event for %v: %v %v: %v", e.FirstTimestamp, e.InvolvedObject.Name, e.Source, e.Reason, e.Message)
	}
	// Note that we don't wait for any Cleanup to propagate, which means
	// that if you delete a bunch of pods right before ending your test,
	// you may or may not see the killing/deletion/Cleanup events.
}

// DumpAllNamespaceInfo dumps events, pods and nodes information in the given namespace.
func DumpAllNamespaceInfo(ctx context.Context, c clientset.Interface, namespace string) {
	dumpEventsInNamespace(func(opts metav1.ListOptions, ns string) (*v1.EventList, error) {
		return c.CoreV1().Events(ns).List(ctx, opts)
	}, namespace)

	e2epod.DumpAllPodInfoForNamespace(ctx, c, namespace, framework.TestContext.ReportDir)

	// If cluster is large, then the following logs are basically useless, because:
	// 1. it takes tens of minutes or hours to grab all of them
	// 2. there are so many of them that working with them are mostly impossible
	// So we dump them only if the cluster is relatively small.
	maxNodesForDump := framework.TestContext.MaxNodesToGather
	nodes, err := c.CoreV1().Nodes().List(ctx, metav1.ListOptions{})
	if err != nil {
		framework.Logf("unable to fetch node list: %v", err)
		return
	}
	if len(nodes.Items) <= maxNodesForDump {
		dumpAllNodeInfo(ctx, c, nodes)
	} else {
		framework.Logf("skipping dumping cluster info - cluster too large")
	}
}

// byFirstTimestamp sorts a slice of events by first timestamp, using their involvedObject's name as a tie breaker.
type byFirstTimestamp []v1.Event

func (o byFirstTimestamp) Len() int      { return len(o) }
func (o byFirstTimestamp) Swap(i, j int) { o[i], o[j] = o[j], o[i] }

func (o byFirstTimestamp) Less(i, j int) bool {
	if o[i].FirstTimestamp.Equal(&o[j].FirstTimestamp) {
		return o[i].InvolvedObject.Name < o[j].InvolvedObject.Name
	}
	return o[i].FirstTimestamp.Before(&o[j].FirstTimestamp)
}

func dumpAllNodeInfo(ctx context.Context, c clientset.Interface, nodes *v1.NodeList) {
	names := make([]string, len(nodes.Items))
	for ix := range nodes.Items {
		names[ix] = nodes.Items[ix].Name
	}
	DumpNodeDebugInfo(ctx, c, names, framework.Logf)
}

// DumpNodeDebugInfo dumps debug information of the given nodes.
func DumpNodeDebugInfo(ctx context.Context, c clientset.Interface, nodeNames []string, logFunc func(fmt string, args ...interface{})) {
	for _, n := range nodeNames {
		logFunc("\nLogging node info for node %v", n)
		node, err := c.CoreV1().Nodes().Get(ctx, n, metav1.GetOptions{})
		if err != nil {
			logFunc("Error getting node info %v", err)
		}
		logFunc("Node Info: %v", node)

		logFunc("\nLogging kubelet events for node %v", n)
		for _, e := range getNodeEvents(ctx, c, n) {
			logFunc("source %v type %v message %v reason %v first ts %v last ts %v, involved obj %+v",
				e.Source, e.Type, e.Message, e.Reason, e.FirstTimestamp, e.LastTimestamp, e.InvolvedObject)
		}
		logFunc("\nLogging pods the kubelet thinks is on node %v", n)
		podList, err := getKubeletPods(ctx, c, n)
		if err != nil {
			logFunc("Unable to retrieve kubelet pods for node %v: %v", n, err)
			continue
		}
		for _, p := range podList.Items {
			logFunc("%v started at %v (%d+%d container statuses recorded)", p.Name, p.Status.StartTime, len(p.Status.InitContainerStatuses), len(p.Status.ContainerStatuses))
			for _, c := range p.Status.InitContainerStatuses {
				logFunc("\tInit container %v ready: %v, restart count %v",
					c.Name, c.Ready, c.RestartCount)
			}
			for _, c := range p.Status.ContainerStatuses {
				logFunc("\tContainer %v ready: %v, restart count %v",
					c.Name, c.Ready, c.RestartCount)
			}
		}
		_, err = e2emetrics.HighLatencyKubeletOperations(ctx, c, 10*time.Second, n, logFunc)
		framework.ExpectNoError(err)
		// TODO: Log node resource info
	}
}

// getKubeletPods retrieves the list of pods on the kubelet.
func getKubeletPods(ctx context.Context, c clientset.Interface, node string) (*v1.PodList, error) {
	var client restclient.Result
	finished := make(chan struct{}, 1)
	go func() {
		// call chain tends to hang in some cases when Node is not ready. Add an artificial timeout for this call. #22165
		client = c.CoreV1().RESTClient().Get().
			Resource("nodes").
			SubResource("proxy").
			Name(fmt.Sprintf("%v:%v", node, framework.KubeletPort)).
			Suffix("pods").
			Do(ctx)

		finished <- struct{}{}
	}()
	select {
	case <-finished:
		result := &v1.PodList{}
		if err := client.Into(result); err != nil {
			return &v1.PodList{}, err
		}
		return result, nil
	case <-time.After(framework.PodGetTimeout):
		return &v1.PodList{}, fmt.Errorf("Waiting up to %v for getting the list of pods", framework.PodGetTimeout)
	}
}

// logNodeEvents logs kubelet events from the given node. This includes kubelet
// restart and node unhealthy events. Note that listing events like this will mess
// with latency metrics, beware of calling it during a test.
func getNodeEvents(ctx context.Context, c clientset.Interface, nodeName string) []v1.Event {
	selector := fields.Set{
		"involvedObject.kind":      "Node",
		"involvedObject.name":      nodeName,
		"involvedObject.namespace": metav1.NamespaceAll,
		"source":                   "kubelet",
	}.AsSelector().String()
	options := metav1.ListOptions{FieldSelector: selector}
	events, err := c.CoreV1().Events(metav1.NamespaceSystem).List(ctx, options)
	if err != nil {
		framework.Logf("Unexpected error retrieving node events %v", err)
		return []v1.Event{}
	}
	return events.Items
}