/*
Copyright 2015 The Kubernetes Authors All rights reserved.

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 testing

import (
	"fmt"
	"math/rand"
	"reflect"
	"strconv"
	"testing"

	docker "github.com/fsouza/go-dockerclient"
	"k8s.io/kubernetes/pkg/api"
	"k8s.io/kubernetes/pkg/api/resource"
	"k8s.io/kubernetes/pkg/api/testapi"
	"k8s.io/kubernetes/pkg/api/unversioned"
	"k8s.io/kubernetes/pkg/apis/extensions"
	"k8s.io/kubernetes/pkg/fields"
	"k8s.io/kubernetes/pkg/labels"
	"k8s.io/kubernetes/pkg/runtime"
	"k8s.io/kubernetes/pkg/types"
	"k8s.io/kubernetes/pkg/util/intstr"

	"github.com/google/gofuzz"
)

// FuzzerFor can randomly populate api objects that are destined for version.
func FuzzerFor(t *testing.T, version unversioned.GroupVersion, src rand.Source) *fuzz.Fuzzer {
	f := fuzz.New().NilChance(.5).NumElements(1, 1)
	if src != nil {
		f.RandSource(src)
	}
	f.Funcs(
		func(j *int, c fuzz.Continue) {
			*j = int(c.Int31())
		},
		func(j **int, c fuzz.Continue) {
			if c.RandBool() {
				i := int(c.Int31())
				*j = &i
			} else {
				*j = nil
			}
		},
		func(q *resource.Quantity, c fuzz.Continue) {
			*q = *resource.NewQuantity(c.Int63n(1000), resource.DecimalExponent)
		},
		func(j *runtime.TypeMeta, c fuzz.Continue) {
			// We have to customize the randomization of TypeMetas because their
			// APIVersion and Kind must remain blank in memory.
			j.APIVersion = ""
			j.Kind = ""
		},
		func(j *unversioned.TypeMeta, c fuzz.Continue) {
			// We have to customize the randomization of TypeMetas because their
			// APIVersion and Kind must remain blank in memory.
			j.APIVersion = ""
			j.Kind = ""
		},
		func(j *api.ObjectMeta, c fuzz.Continue) {
			j.Name = c.RandString()
			j.ResourceVersion = strconv.FormatUint(c.RandUint64(), 10)
			j.SelfLink = c.RandString()
			j.UID = types.UID(c.RandString())
			j.GenerateName = c.RandString()

			var sec, nsec int64
			c.Fuzz(&sec)
			c.Fuzz(&nsec)
			j.CreationTimestamp = unversioned.Unix(sec, nsec).Rfc3339Copy()
		},
		func(j *api.ObjectReference, c fuzz.Continue) {
			// We have to customize the randomization of TypeMetas because their
			// APIVersion and Kind must remain blank in memory.
			j.APIVersion = c.RandString()
			j.Kind = c.RandString()
			j.Namespace = c.RandString()
			j.Name = c.RandString()
			j.ResourceVersion = strconv.FormatUint(c.RandUint64(), 10)
			j.FieldPath = c.RandString()
		},
		func(j *unversioned.ListMeta, c fuzz.Continue) {
			j.ResourceVersion = strconv.FormatUint(c.RandUint64(), 10)
			j.SelfLink = c.RandString()
		},
		func(j *api.ListOptions, c fuzz.Continue) {
			label, _ := labels.Parse("a=b")
			j.LabelSelector = label
			field, _ := fields.ParseSelector("a=b")
			j.FieldSelector = field
		},
		func(j *api.PodExecOptions, c fuzz.Continue) {
			j.Stdout = true
			j.Stderr = true
		},
		func(j *api.PodAttachOptions, c fuzz.Continue) {
			j.Stdout = true
			j.Stderr = true
		},
		func(s *api.PodSpec, c fuzz.Continue) {
			c.FuzzNoCustom(s)
			// has a default value
			ttl := int64(30)
			if c.RandBool() {
				ttl = int64(c.Uint32())
			}
			s.TerminationGracePeriodSeconds = &ttl

			c.Fuzz(s.SecurityContext)

			if s.SecurityContext == nil {
				s.SecurityContext = new(api.PodSecurityContext)
			}
		},
		func(j *api.PodPhase, c fuzz.Continue) {
			statuses := []api.PodPhase{api.PodPending, api.PodRunning, api.PodFailed, api.PodUnknown}
			*j = statuses[c.Rand.Intn(len(statuses))]
		},
		func(j *api.Binding, c fuzz.Continue) {
			c.Fuzz(&j.ObjectMeta)
			j.Target.Name = c.RandString()
		},
		func(j *api.ReplicationControllerSpec, c fuzz.Continue) {
			c.FuzzNoCustom(j) // fuzz self without calling this function again
			//j.TemplateRef = nil // this is required for round trip
		},
		func(j *extensions.DeploymentStrategy, c fuzz.Continue) {
			c.FuzzNoCustom(j) // fuzz self without calling this function again
			// Ensure that strategyType is one of valid values.
			strategyTypes := []extensions.DeploymentStrategyType{extensions.RecreateDeploymentStrategyType, extensions.RollingUpdateDeploymentStrategyType}
			j.Type = strategyTypes[c.Rand.Intn(len(strategyTypes))]
			if j.Type != extensions.RollingUpdateDeploymentStrategyType {
				j.RollingUpdate = nil
			} else {
				rollingUpdate := extensions.RollingUpdateDeployment{}
				if c.RandBool() {
					rollingUpdate.MaxUnavailable = intstr.FromInt(int(c.RandUint64()))
					rollingUpdate.MaxSurge = intstr.FromInt(int(c.RandUint64()))
				} else {
					rollingUpdate.MaxSurge = intstr.FromString(fmt.Sprintf("%d%%", c.RandUint64()))
				}
				j.RollingUpdate = &rollingUpdate
			}
		},
		func(j *extensions.JobSpec, c fuzz.Continue) {
			c.FuzzNoCustom(j) // fuzz self without calling this function again
			completions := int(c.Rand.Int31())
			parallelism := int(c.Rand.Int31())
			j.Completions = &completions
			j.Parallelism = &parallelism
		},
		func(j *api.List, c fuzz.Continue) {
			c.FuzzNoCustom(j) // fuzz self without calling this function again
			// TODO: uncomment when round trip starts from a versioned object
			if false { //j.Items == nil {
				j.Items = []runtime.Object{}
			}
		},
		func(j *runtime.Object, c fuzz.Continue) {
			// TODO: uncomment when round trip starts from a versioned object
			if true { //c.RandBool() {
				*j = &runtime.Unknown{
					// We do not set TypeMeta here because it is not carried through a round trip
					RawJSON: []byte(`{"apiVersion":"unknown.group/unknown","kind":"Something","someKey":"someValue"}`),
				}
			} else {
				types := []runtime.Object{&api.Pod{}, &api.ReplicationController{}}
				t := types[c.Rand.Intn(len(types))]
				c.Fuzz(t)
				*j = t
			}
		},
		func(pb map[docker.Port][]docker.PortBinding, c fuzz.Continue) {
			// This is necessary because keys with nil values get omitted.
			// TODO: Is this a bug?
			pb[docker.Port(c.RandString())] = []docker.PortBinding{
				{c.RandString(), c.RandString()},
				{c.RandString(), c.RandString()},
			}
		},
		func(pm map[string]docker.PortMapping, c fuzz.Continue) {
			// This is necessary because keys with nil values get omitted.
			// TODO: Is this a bug?
			pm[c.RandString()] = docker.PortMapping{
				c.RandString(): c.RandString(),
			}
		},
		func(q *api.ResourceRequirements, c fuzz.Continue) {
			randomQuantity := func() resource.Quantity {
				var q resource.Quantity
				c.Fuzz(&q)
				return q
			}
			q.Limits = make(api.ResourceList)
			q.Requests = make(api.ResourceList)
			cpuLimit := randomQuantity()
			q.Limits[api.ResourceCPU] = *cpuLimit.Copy()
			q.Requests[api.ResourceCPU] = *cpuLimit.Copy()
			memoryLimit := randomQuantity()
			q.Limits[api.ResourceMemory] = *memoryLimit.Copy()
			q.Requests[api.ResourceMemory] = *memoryLimit.Copy()
			storageLimit := randomQuantity()
			q.Limits[api.ResourceStorage] = *storageLimit.Copy()
			q.Requests[api.ResourceStorage] = *storageLimit.Copy()
		},
		func(q *api.LimitRangeItem, c fuzz.Continue) {
			var cpuLimit resource.Quantity
			c.Fuzz(&cpuLimit)

			q.Type = api.LimitTypeContainer
			q.Default = make(api.ResourceList)
			q.Default[api.ResourceCPU] = *(cpuLimit.Copy())

			q.DefaultRequest = make(api.ResourceList)
			q.DefaultRequest[api.ResourceCPU] = *(cpuLimit.Copy())

			q.Max = make(api.ResourceList)
			q.Max[api.ResourceCPU] = *(cpuLimit.Copy())

			q.Min = make(api.ResourceList)
			q.Min[api.ResourceCPU] = *(cpuLimit.Copy())

			q.MaxLimitRequestRatio = make(api.ResourceList)
			q.MaxLimitRequestRatio[api.ResourceCPU] = resource.MustParse("10")
		},
		func(p *api.PullPolicy, c fuzz.Continue) {
			policies := []api.PullPolicy{api.PullAlways, api.PullNever, api.PullIfNotPresent}
			*p = policies[c.Rand.Intn(len(policies))]
		},
		func(rp *api.RestartPolicy, c fuzz.Continue) {
			policies := []api.RestartPolicy{api.RestartPolicyAlways, api.RestartPolicyNever, api.RestartPolicyOnFailure}
			*rp = policies[c.Rand.Intn(len(policies))]
		},
		// Only api.DownwardAPIVolumeFile needs to have a specific func since FieldRef has to be
		// defaulted to a version otherwise roundtrip will fail
		// For the remaining volume plugins the default fuzzer is enough.
		func(m *api.DownwardAPIVolumeFile, c fuzz.Continue) {
			m.Path = c.RandString()
			versions := []string{"v1"}
			m.FieldRef.APIVersion = versions[c.Rand.Intn(len(versions))]
			m.FieldRef.FieldPath = c.RandString()
		},
		func(vs *api.VolumeSource, c fuzz.Continue) {
			// Exactly one of the fields must be set.
			v := reflect.ValueOf(vs).Elem()
			i := int(c.RandUint64() % uint64(v.NumField()))
			t := v.Field(i).Addr()
			for v.Field(i).IsNil() {
				c.Fuzz(t.Interface())
			}
		},
		func(i *api.ISCSIVolumeSource, c fuzz.Continue) {
			i.ISCSIInterface = c.RandString()
			if i.ISCSIInterface == "" {
				i.ISCSIInterface = "default"
			}
		},
		func(d *api.DNSPolicy, c fuzz.Continue) {
			policies := []api.DNSPolicy{api.DNSClusterFirst, api.DNSDefault}
			*d = policies[c.Rand.Intn(len(policies))]
		},
		func(p *api.Protocol, c fuzz.Continue) {
			protocols := []api.Protocol{api.ProtocolTCP, api.ProtocolUDP}
			*p = protocols[c.Rand.Intn(len(protocols))]
		},
		func(p *api.ServiceAffinity, c fuzz.Continue) {
			types := []api.ServiceAffinity{api.ServiceAffinityClientIP, api.ServiceAffinityNone}
			*p = types[c.Rand.Intn(len(types))]
		},
		func(p *api.ServiceType, c fuzz.Continue) {
			types := []api.ServiceType{api.ServiceTypeClusterIP, api.ServiceTypeNodePort, api.ServiceTypeLoadBalancer}
			*p = types[c.Rand.Intn(len(types))]
		},
		func(ct *api.Container, c fuzz.Continue) {
			c.FuzzNoCustom(ct)                                          // fuzz self without calling this function again
			ct.TerminationMessagePath = "/" + ct.TerminationMessagePath // Must be non-empty
		},
		func(p *api.Probe, c fuzz.Continue) {
			c.FuzzNoCustom(p)
			// These fields have default values.
			intFieldsWithDefaults := [...]string{"TimeoutSeconds", "PeriodSeconds", "SuccessThreshold", "FailureThreshold"}
			v := reflect.ValueOf(p).Elem()
			for _, field := range intFieldsWithDefaults {
				f := v.FieldByName(field)
				if f.Int() == 0 {
					f.SetInt(1)
				}
			}
		},
		func(ev *api.EnvVar, c fuzz.Continue) {
			ev.Name = c.RandString()
			if c.RandBool() {
				ev.Value = c.RandString()
			} else {
				ev.ValueFrom = &api.EnvVarSource{}
				ev.ValueFrom.FieldRef = &api.ObjectFieldSelector{}

				var versions []unversioned.GroupVersion
				for _, testGroup := range testapi.Groups {
					versions = append(versions, *testGroup.GroupVersion())
				}

				ev.ValueFrom.FieldRef.APIVersion = versions[c.Rand.Intn(len(versions))].String()
				ev.ValueFrom.FieldRef.FieldPath = c.RandString()
			}
		},
		func(sc *api.SecurityContext, c fuzz.Continue) {
			c.FuzzNoCustom(sc) // fuzz self without calling this function again
			if c.RandBool() {
				priv := c.RandBool()
				sc.Privileged = &priv
			}

			if c.RandBool() {
				sc.Capabilities = &api.Capabilities{
					Add:  make([]api.Capability, 0),
					Drop: make([]api.Capability, 0),
				}
				c.Fuzz(&sc.Capabilities.Add)
				c.Fuzz(&sc.Capabilities.Drop)
			}
		},
		func(s *api.Secret, c fuzz.Continue) {
			c.FuzzNoCustom(s) // fuzz self without calling this function again
			s.Type = api.SecretTypeOpaque
		},
		func(pv *api.PersistentVolume, c fuzz.Continue) {
			c.FuzzNoCustom(pv) // fuzz self without calling this function again
			types := []api.PersistentVolumePhase{api.VolumeAvailable, api.VolumePending, api.VolumeBound, api.VolumeReleased, api.VolumeFailed}
			pv.Status.Phase = types[c.Rand.Intn(len(types))]
			pv.Status.Message = c.RandString()
			reclamationPolicies := []api.PersistentVolumeReclaimPolicy{api.PersistentVolumeReclaimRecycle, api.PersistentVolumeReclaimRetain}
			pv.Spec.PersistentVolumeReclaimPolicy = reclamationPolicies[c.Rand.Intn(len(reclamationPolicies))]
		},
		func(pvc *api.PersistentVolumeClaim, c fuzz.Continue) {
			c.FuzzNoCustom(pvc) // fuzz self without calling this function again
			types := []api.PersistentVolumeClaimPhase{api.ClaimBound, api.ClaimPending}
			pvc.Status.Phase = types[c.Rand.Intn(len(types))]
		},
		func(s *api.NamespaceSpec, c fuzz.Continue) {
			s.Finalizers = []api.FinalizerName{api.FinalizerKubernetes}
		},
		func(s *api.NamespaceStatus, c fuzz.Continue) {
			s.Phase = api.NamespaceActive
		},
		func(http *api.HTTPGetAction, c fuzz.Continue) {
			c.FuzzNoCustom(http)            // fuzz self without calling this function again
			http.Path = "/" + http.Path     // can't be blank
			http.Scheme = "x" + http.Scheme // can't be blank
		},
		func(ss *api.ServiceSpec, c fuzz.Continue) {
			c.FuzzNoCustom(ss) // fuzz self without calling this function again
			if len(ss.Ports) == 0 {
				// There must be at least 1 port.
				ss.Ports = append(ss.Ports, api.ServicePort{})
				c.Fuzz(&ss.Ports[0])
			}
			for i := range ss.Ports {
				switch ss.Ports[i].TargetPort.Type {
				case intstr.Int:
					ss.Ports[i].TargetPort.IntVal = 1 + ss.Ports[i].TargetPort.IntVal%65535 // non-zero
				case intstr.String:
					ss.Ports[i].TargetPort.StrVal = "x" + ss.Ports[i].TargetPort.StrVal // non-empty
				}
			}
		},
		func(n *api.Node, c fuzz.Continue) {
			c.FuzzNoCustom(n)
			n.Spec.ExternalID = "external"
		},
		func(s *api.NodeStatus, c fuzz.Continue) {
			c.FuzzNoCustom(s)
			s.Allocatable = s.Capacity
		},
		func(s *extensions.APIVersion, c fuzz.Continue) {
			// We can't use c.RandString() here because it may generate empty
			// string, which will cause tests failure.
			s.APIGroup = "something"
		},
		func(s *extensions.HorizontalPodAutoscalerSpec, c fuzz.Continue) {
			c.FuzzNoCustom(s) // fuzz self without calling this function again
			minReplicas := int(c.Rand.Int31())
			s.MinReplicas = &minReplicas
			s.CPUUtilization = &extensions.CPUTargetUtilization{TargetPercentage: int(int32(c.RandUint64()))}
		},
		func(s *extensions.SubresourceReference, c fuzz.Continue) {
			c.FuzzNoCustom(s) // fuzz self without calling this function again
			s.Subresource = "scale"
		},
		func(psp *extensions.PodSecurityPolicySpec, c fuzz.Continue) {
			c.FuzzNoCustom(psp) // fuzz self without calling this function again
			userTypes := []extensions.RunAsUserStrategy{extensions.RunAsUserStrategyMustRunAsNonRoot, extensions.RunAsUserStrategyMustRunAs, extensions.RunAsUserStrategyRunAsAny}
			psp.RunAsUser.Type = userTypes[c.Rand.Intn(len(userTypes))]
			seLinuxTypes := []extensions.SELinuxContextStrategy{extensions.SELinuxStrategyRunAsAny, extensions.SELinuxStrategyMustRunAs}
			psp.SELinuxContext.Type = seLinuxTypes[c.Rand.Intn(len(seLinuxTypes))]
		},
	)
	return f
}
