/*
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 framework

import (
	"fmt"
	"strconv"
	"strings"
	"time"

	"k8s.io/apimachinery/pkg/util/sets"
	"k8s.io/kubernetes/pkg/api/v1"
	"k8s.io/kubernetes/pkg/client/clientset_generated/clientset"
	"k8s.io/kubernetes/pkg/cloudprovider"
	gcecloud "k8s.io/kubernetes/pkg/cloudprovider/providers/gce"

	. "github.com/onsi/gomega"
	compute "google.golang.org/api/compute/v1"
)

const (
	FirewallTimeoutDefault = 3 * time.Minute
	FirewallTestTcpTimeout = time.Duration(1 * time.Second)
	// Set ports outside of 30000-32767, 80 and 8080 to avoid being whitelisted by the e2e cluster
	FirewallTestHttpPort = int32(29999)
	FirewallTestUdpPort  = int32(29998)
)

// MakeFirewallNameForLBService return the expected firewall name for a LB service.
// This should match the formatting of makeFirewallName() in pkg/cloudprovider/providers/gce/gce.go
func MakeFirewallNameForLBService(name string) string {
	return fmt.Sprintf("k8s-fw-%s", name)
}

// ConstructFirewallForLBService returns the expected GCE firewall rule for a loadbalancer type service
func ConstructFirewallForLBService(svc *v1.Service, nodesTags []string) *compute.Firewall {
	if svc.Spec.Type != v1.ServiceTypeLoadBalancer {
		Failf("can not construct firewall rule for non-loadbalancer type service")
	}
	fw := compute.Firewall{}
	fw.Name = MakeFirewallNameForLBService(cloudprovider.GetLoadBalancerName(svc))
	fw.TargetTags = nodesTags
	if svc.Spec.LoadBalancerSourceRanges == nil {
		fw.SourceRanges = []string{"0.0.0.0/0"}
	} else {
		fw.SourceRanges = svc.Spec.LoadBalancerSourceRanges
	}
	for _, sp := range svc.Spec.Ports {
		fw.Allowed = append(fw.Allowed, &compute.FirewallAllowed{
			IPProtocol: strings.ToLower(string(sp.Protocol)),
			Ports:      []string{strconv.Itoa(int(sp.Port))},
		})
	}
	return &fw
}

// GetNodeTags gets tags from one of the Kubernetes nodes
func GetNodeTags(c clientset.Interface, cloudConfig CloudConfig) *compute.Tags {
	nodes := GetReadySchedulableNodesOrDie(c)
	Expect(len(nodes.Items) > 0).Should(BeTrue())
	nodeTags := GetInstanceTags(cloudConfig, nodes.Items[0].Name)
	return nodeTags
}

// GetInstanceTags gets tags from GCE instance with given name.
func GetInstanceTags(cloudConfig CloudConfig, instanceName string) *compute.Tags {
	gceCloud := cloudConfig.Provider.(*gcecloud.GCECloud)
	res, err := gceCloud.GetComputeService().Instances.Get(cloudConfig.ProjectID, cloudConfig.Zone,
		instanceName).Do()
	if err != nil {
		Failf("Failed to get instance tags for %v: %v", instanceName, err)
	}
	return res.Tags
}

// SetInstanceTags sets tags on GCE instance with given name.
func SetInstanceTags(cloudConfig CloudConfig, instanceName string, tags []string) []string {
	gceCloud := cloudConfig.Provider.(*gcecloud.GCECloud)
	// Re-get instance everytime because we need the latest fingerprint for updating metadata
	resTags := GetInstanceTags(cloudConfig, instanceName)
	_, err := gceCloud.GetComputeService().Instances.SetTags(
		cloudConfig.ProjectID, cloudConfig.Zone, instanceName,
		&compute.Tags{Fingerprint: resTags.Fingerprint, Items: tags}).Do()
	if err != nil {
		Failf("failed to set instance tags: %v", err)
	}
	Logf("Sent request to set tags %v on instance: %v", tags, instanceName)
	return resTags.Items
}

// GetInstancePrefix returns the INSTANCE_PREFIX env we set for e2e cluster.
// From cluster/gce/config-test.sh, master name is set up using below format:
// MASTER_NAME="${INSTANCE_PREFIX}-master"
func GetInstancePrefix(masterName string) (string, error) {
	if !strings.HasSuffix(masterName, "-master") {
		return "", fmt.Errorf("unexpected master name format: %v", masterName)
	}
	return masterName[:len(masterName)-7], nil
}

// GetClusterName returns the CLUSTER_NAME env we set for e2e cluster.
// From cluster/gce/config-test.sh, cluster name is set up using below format:
// CLUSTER_NAME="${CLUSTER_NAME:-${INSTANCE_PREFIX}}"
func GetClusterName(instancePrefix string) string {
	return instancePrefix
}

// GetClusterIpRange returns the CLUSTER_IP_RANGE env we set for e2e cluster.
//
// Warning: this MUST be consistent with the CLUSTER_IP_RANGE set in
// gce/config-test.sh.
func GetClusterIpRange() string {
	return "10.100.0.0/14"
}

// GetE2eFirewalls returns all firewall rules we create for an e2e cluster.
// From cluster/gce/util.sh, all firewall rules should be consistent with the ones created by startup scripts.
func GetE2eFirewalls(masterName, masterTag, nodeTag, network string) []*compute.Firewall {
	instancePrefix, err := GetInstancePrefix(masterName)
	Expect(err).NotTo(HaveOccurred())
	clusterName := GetClusterName(instancePrefix)
	clusterIpRange := GetClusterIpRange()

	fws := []*compute.Firewall{}
	fws = append(fws, &compute.Firewall{
		Name:         clusterName + "-default-internal-master",
		SourceRanges: []string{"10.0.0.0/8"},
		TargetTags:   []string{masterTag},
		Allowed: []*compute.FirewallAllowed{
			{
				IPProtocol: "tcp",
				Ports:      []string{"1-2379"},
			},
			{
				IPProtocol: "tcp",
				Ports:      []string{"2382-65535"},
			},
			{
				IPProtocol: "udp",
				Ports:      []string{"1-65535"},
			},
			{
				IPProtocol: "icmp",
			},
		},
	})
	fws = append(fws, &compute.Firewall{
		Name:         clusterName + "-default-internal-node",
		SourceRanges: []string{"10.0.0.0/8"},
		TargetTags:   []string{nodeTag},
		Allowed: []*compute.FirewallAllowed{
			{
				IPProtocol: "tcp",
				Ports:      []string{"1-65535"},
			},
			{
				IPProtocol: "udp",
				Ports:      []string{"1-65535"},
			},
			{
				IPProtocol: "icmp",
			},
		},
	})
	fws = append(fws, &compute.Firewall{
		Name:         network + "-default-ssh",
		SourceRanges: []string{"0.0.0.0/0"},
		Allowed: []*compute.FirewallAllowed{
			{
				IPProtocol: "tcp",
				Ports:      []string{"22"},
			},
		},
	})
	fws = append(fws, &compute.Firewall{
		Name:       masterName + "-etcd",
		SourceTags: []string{masterTag},
		TargetTags: []string{masterTag},
		Allowed: []*compute.FirewallAllowed{
			{
				IPProtocol: "tcp",
				Ports:      []string{"2380"},
			},
			{
				IPProtocol: "tcp",
				Ports:      []string{"2381"},
			},
		},
	})
	fws = append(fws, &compute.Firewall{
		Name:         masterName + "-https",
		SourceRanges: []string{"0.0.0.0/0"},
		TargetTags:   []string{masterTag},
		Allowed: []*compute.FirewallAllowed{
			{
				IPProtocol: "tcp",
				Ports:      []string{"443"},
			},
		},
	})
	fws = append(fws, &compute.Firewall{
		Name:         nodeTag + "-all",
		SourceRanges: []string{clusterIpRange},
		TargetTags:   []string{nodeTag},
		Allowed: []*compute.FirewallAllowed{
			{
				IPProtocol: "tcp",
			},
			{
				IPProtocol: "udp",
			},
			{
				IPProtocol: "icmp",
			},
			{
				IPProtocol: "esp",
			},
			{
				IPProtocol: "ah",
			},
			{
				IPProtocol: "sctp",
			},
		},
	})
	fws = append(fws, &compute.Firewall{
		Name:         nodeTag + "-" + instancePrefix + "-http-alt",
		SourceRanges: []string{"0.0.0.0/0"},
		TargetTags:   []string{nodeTag},
		Allowed: []*compute.FirewallAllowed{
			{
				IPProtocol: "tcp",
				Ports:      []string{"80"},
			},
			{
				IPProtocol: "tcp",
				Ports:      []string{"8080"},
			},
		},
	})
	fws = append(fws, &compute.Firewall{
		Name:         nodeTag + "-" + instancePrefix + "-nodeports",
		SourceRanges: []string{"0.0.0.0/0"},
		TargetTags:   []string{nodeTag},
		Allowed: []*compute.FirewallAllowed{
			{
				IPProtocol: "tcp",
				Ports:      []string{"30000-32767"},
			},
			{
				IPProtocol: "udp",
				Ports:      []string{"30000-32767"},
			},
		},
	})
	return fws
}

// PackProtocolsPortsFromFirewall packs protocols and ports in an unified way for verification.
func PackProtocolsPortsFromFirewall(alloweds []*compute.FirewallAllowed) []string {
	protocolPorts := []string{}
	for _, allowed := range alloweds {
		for _, port := range allowed.Ports {
			protocolPorts = append(protocolPorts, strings.ToLower(allowed.IPProtocol+"/"+port))
		}
	}
	return protocolPorts
}

// SameStringArray verifies whether two string arrays have the same strings, return error if not.
// Order does not matter.
// When `include` is set to true, verifies whether result includes all elements from expected.
func SameStringArray(result, expected []string, include bool) error {
	res := sets.NewString(result...)
	exp := sets.NewString(expected...)
	if !include {
		diff := res.Difference(exp)
		if len(diff) != 0 {
			return fmt.Errorf("found differences: %v", diff)
		}
	} else {
		if !res.IsSuperset(exp) {
			return fmt.Errorf("some elements are missing: expected %v, got %v", expected, result)
		}
	}
	return nil
}

// VerifyFirewallRule verifies whether the result firewall is consistent with the expected firewall.
// When `portsSubset` is false, match given ports exactly. Otherwise, only check ports are included.
func VerifyFirewallRule(res, exp *compute.Firewall, network string, portsSubset bool) error {
	if res.Name != exp.Name {
		return fmt.Errorf("incorrect name: %v, expected %v", res.Name, exp.Name)
	}
	// Sample Network value: https://www.googleapis.com/compute/v1/projects/{project-id}/global/networks/e2e
	if !strings.HasSuffix(res.Network, "/"+network) {
		return fmt.Errorf("incorrect network: %v, expected ends with: %v", res.Network, "/"+network)
	}
	if err := SameStringArray(PackProtocolsPortsFromFirewall(res.Allowed),
		PackProtocolsPortsFromFirewall(exp.Allowed), portsSubset); err != nil {
		return fmt.Errorf("incorrect allowed protocols ports: %v", err)
	}
	if err := SameStringArray(res.SourceRanges, exp.SourceRanges, false); err != nil {
		return fmt.Errorf("incorrect source ranges %v, expected %v: %v", res.SourceRanges, exp.SourceRanges, err)
	}
	if err := SameStringArray(res.SourceTags, exp.SourceTags, false); err != nil {
		return fmt.Errorf("incorrect source tags %v, expected %v: %v", res.SourceTags, exp.SourceTags, err)
	}
	if err := SameStringArray(res.TargetTags, exp.TargetTags, false); err != nil {
		return fmt.Errorf("incorrect target tags %v, expected %v: %v", res.TargetTags, exp.TargetTags, err)
	}
	return nil
}