// Determine if a particular policy is assigned to an ELB listener
func resourceAwsELBSticknessPolicyAssigned(policyName, lbName, lbPort string, elbconn *elb.ELB) (bool, error) {
	describeElbOpts := &elb.DescribeLoadBalancersInput{
		LoadBalancerNames: []*string{aws.String(lbName)},
	}
	describeResp, err := elbconn.DescribeLoadBalancers(describeElbOpts)
	if err != nil {
		if ec2err, ok := err.(awserr.Error); ok {
			if ec2err.Code() == "LoadBalancerNotFound" {
				return false, nil
			}
		}
		return false, fmt.Errorf("Error retrieving ELB description: %s", err)
	}

	if len(describeResp.LoadBalancerDescriptions) != 1 {
		return false, fmt.Errorf("Unable to find ELB: %#v", describeResp.LoadBalancerDescriptions)
	}

	lb := describeResp.LoadBalancerDescriptions[0]
	assigned := false
	for _, listener := range lb.ListenerDescriptions {
		if lbPort != strconv.Itoa(int(*listener.Listener.LoadBalancerPort)) {
			continue
		}

		for _, name := range listener.PolicyNames {
			if policyName == *name {
				assigned = true
				break
			}
		}
	}

	return assigned, nil
}

func awsGetLoadBalancers(lb elb.ELB) ([]*elb.LoadBalancerDescription, error) {
	lbList := []*elb.LoadBalancerDescription{}
	resp, err := lb.DescribeLoadBalancers(nil)
	if err != nil {
		return nil, fmt.Errorf("unable to describe ELB Balancers")
	}
	for _, loadBalancer := range resp.LoadBalancerDescriptions {
		lbList = append(lbList, loadBalancer)
	}
	return lbList, nil
}

// setTags is a helper to set the tags for a resource. It expects the
// tags field to be named "tags"
func setTagsELB(conn *elb.ELB, d *schema.ResourceData) error {
	if d.HasChange("tags") {
		oraw, nraw := d.GetChange("tags")
		o := oraw.(map[string]interface{})
		n := nraw.(map[string]interface{})
		create, remove := diffTagsELB(tagsFromMapELB(o), tagsFromMapELB(n))

		// Set tags
		if len(remove) > 0 {
			log.Printf("[DEBUG] Removing tags: %#v", remove)
			k := make([]*elb.TagKeyOnly, 0, len(remove))
			for _, t := range remove {
				k = append(k, &elb.TagKeyOnly{Key: t.Key})
			}
			_, err := conn.RemoveTags(&elb.RemoveTagsInput{
				LoadBalancerNames: []*string{aws.String(d.Get("name").(string))},
				Tags:              k,
			})
			if err != nil {
				return err
			}
		}
		if len(create) > 0 {
			log.Printf("[DEBUG] Creating tags: %#v", create)
			_, err := conn.AddTags(&elb.AddTagsInput{
				LoadBalancerNames: []*string{aws.String(d.Get("name").(string))},
				Tags:              create,
			})
			if err != nil {
				return err
			}
		}
	}

	return nil
}

func createRoute53Upsert(r53Api *route53.Route53, elbApi *elb.ELB, domain string, hn string) (*route53.ChangeResourceRecordSetsInput, error) {
	domainParts := strings.Split(domain, ".")
	segments := len(domainParts)
	tld := strings.Join(domainParts[segments-2:], ".")
	//	subdomain := strings.Join(domainParts[:segments-2], ".")

	elbName := strings.Split(hn, "-")[0]
	lbInput := &elb.DescribeLoadBalancersInput{
		LoadBalancerNames: []*string{
			&elbName,
		},
	}
	resp, err := elbApi.DescribeLoadBalancers(lbInput)
	if err != nil {
		glog.Warningf("Could not describe load balancer: %v", err)
		return nil, err
	}
	descs := resp.LoadBalancerDescriptions
	if len(descs) < 1 {
		glog.Warningf("No lb found for %s: %v", tld, err)
		return nil, err
	}
	if len(descs) > 1 {
		glog.Warningf("Multiple lbs found for %s: %v", tld, err)
		return nil, err
	}
	hzId := descs[0].CanonicalHostedZoneNameID

	listHostedZoneInput := route53.ListHostedZonesByNameInput{
		DNSName: &tld,
	}
	hzOut, err := r53Api.ListHostedZonesByName(&listHostedZoneInput)
	if err != nil {
		glog.Warningf("No zone found for %s: %v", tld, err)
		return nil, err
	}
	zones := hzOut.HostedZones
	if len(zones) < 1 {
		glog.Warningf("No zone found for %s", tld)
		return nil, err
	}
	// The AWS API may return more than one zone, the first zone should be the relevant one
	tldWithDot := fmt.Sprint(tld, ".")
	if *zones[0].Name != tldWithDot {
		glog.Warningf("Zone found %s does not match tld given %s", *zones[0].Name, tld)
		return nil, err
	}
	zoneId := *zones[0].ID
	zoneParts := strings.Split(zoneId, "/")
	zoneId = zoneParts[len(zoneParts)-1]

	at := route53.AliasTarget{
		DNSName:              &hn,
		EvaluateTargetHealth: aws.Boolean(false),
		HostedZoneID:         hzId,
	}
	rrs := route53.ResourceRecordSet{
		AliasTarget: &at,
		Name:        &domain,
		Type:        aws.String("A"),
	}
	change := route53.Change{
		Action:            aws.String("UPSERT"),
		ResourceRecordSet: &rrs,
	}
	batch := route53.ChangeBatch{
		Changes: []*route53.Change{&change},
		Comment: aws.String("Kubernetes Update to Service"),
	}
	crrsInput := route53.ChangeResourceRecordSetsInput{
		ChangeBatch:  &batch,
		HostedZoneID: &zoneId,
	}
	//glog.Infof("Created dns record set: tld=%s, subdomain=%s, zoneId=%s", tld, subdomain, zoneId)

	return &crrsInput, nil
}

func resourceAwsLoadBalancerPolicyUnassign(policyName, loadBalancerName string, elbconn *elb.ELB) (Reassignment, error) {
	reassignments := Reassignment{}

	describeElbOpts := &elb.DescribeLoadBalancersInput{
		LoadBalancerNames: []*string{aws.String(loadBalancerName)},
	}

	describeResp, err := elbconn.DescribeLoadBalancers(describeElbOpts)

	if err != nil {
		if ec2err, ok := err.(awserr.Error); ok {
			if ec2err.Code() == "LoadBalancerNotFound" {
				return reassignments, nil
			}
		}
		return reassignments, fmt.Errorf("Error retrieving ELB description: %s", err)
	}

	if len(describeResp.LoadBalancerDescriptions) != 1 {
		return reassignments, fmt.Errorf("Unable to find ELB: %#v", describeResp.LoadBalancerDescriptions)
	}

	lb := describeResp.LoadBalancerDescriptions[0]

	for _, backendServer := range lb.BackendServerDescriptions {
		policies := []*string{}

		for _, name := range backendServer.PolicyNames {
			if policyName != *name {
				policies = append(policies, name)
			}
		}

		if len(backendServer.PolicyNames) != len(policies) {
			setOpts := &elb.SetLoadBalancerPoliciesForBackendServerInput{
				LoadBalancerName: aws.String(loadBalancerName),
				InstancePort:     aws.Int64(*backendServer.InstancePort),
				PolicyNames:      policies,
			}

			reassignOpts := &elb.SetLoadBalancerPoliciesForBackendServerInput{
				LoadBalancerName: aws.String(loadBalancerName),
				InstancePort:     aws.Int64(*backendServer.InstancePort),
				PolicyNames:      backendServer.PolicyNames,
			}

			reassignments.backendServerPolicies = append(reassignments.backendServerPolicies, reassignOpts)

			_, err = elbconn.SetLoadBalancerPoliciesForBackendServer(setOpts)
			if err != nil {
				return reassignments, fmt.Errorf("Error Setting Load Balancer Policies for Backend Server: %s", err)
			}
		}
	}

	for _, listener := range lb.ListenerDescriptions {
		policies := []*string{}

		for _, name := range listener.PolicyNames {
			if policyName != *name {
				policies = append(policies, name)
			}
		}

		if len(listener.PolicyNames) != len(policies) {
			setOpts := &elb.SetLoadBalancerPoliciesOfListenerInput{
				LoadBalancerName: aws.String(loadBalancerName),
				LoadBalancerPort: aws.Int64(*listener.Listener.LoadBalancerPort),
				PolicyNames:      policies,
			}

			reassignOpts := &elb.SetLoadBalancerPoliciesOfListenerInput{
				LoadBalancerName: aws.String(loadBalancerName),
				LoadBalancerPort: aws.Int64(*listener.Listener.LoadBalancerPort),
				PolicyNames:      listener.PolicyNames,
			}

			reassignments.listenerPolicies = append(reassignments.listenerPolicies, reassignOpts)

			_, err = elbconn.SetLoadBalancerPoliciesOfListener(setOpts)
			if err != nil {
				return reassignments, fmt.Errorf("Error Setting Load Balancer Policies of Listener: %s", err)
			}
		}
	}

	return reassignments, nil
}