package ecs

import (
	"context"
	"fmt"
	"github.com/docker/api/compose"
	"strings"
	"time"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/cloudformation"
	"github.com/aws/aws-sdk-go/service/cloudformation/cloudformationiface"
	"github.com/aws/aws-sdk-go/service/cloudwatchlogs"
	"github.com/aws/aws-sdk-go/service/cloudwatchlogs/cloudwatchlogsiface"
	"github.com/aws/aws-sdk-go/service/ec2"
	"github.com/aws/aws-sdk-go/service/ec2/ec2iface"
	"github.com/aws/aws-sdk-go/service/ecs"
	"github.com/aws/aws-sdk-go/service/ecs/ecsiface"
	"github.com/aws/aws-sdk-go/service/elbv2"
	"github.com/aws/aws-sdk-go/service/elbv2/elbv2iface"
	"github.com/aws/aws-sdk-go/service/iam"
	"github.com/aws/aws-sdk-go/service/iam/iamiface"
	"github.com/aws/aws-sdk-go/service/secretsmanager"
	"github.com/aws/aws-sdk-go/service/secretsmanager/secretsmanageriface"
	cf "github.com/awslabs/goformation/v4/cloudformation"
	"github.com/sirupsen/logrus"
)

type sdk struct {
	sess *session.Session
	ECS  ecsiface.ECSAPI
	EC2  ec2iface.EC2API
	ELB  elbv2iface.ELBV2API
	CW   cloudwatchlogsiface.CloudWatchLogsAPI
	IAM  iamiface.IAMAPI
	CF   cloudformationiface.CloudFormationAPI
	SM   secretsmanageriface.SecretsManagerAPI
}

func NewSDK(sess *session.Session) sdk {
	return sdk{
		ECS: ecs.New(sess),
		EC2: ec2.New(sess),
		ELB: elbv2.New(sess),
		CW:  cloudwatchlogs.New(sess),
		IAM: iam.New(sess),
		CF:  cloudformation.New(sess),
		SM:  secretsmanager.New(sess),
	}
}

func (s sdk) CheckRequirements(ctx context.Context, region string) error {
	settings, err := s.ECS.ListAccountSettingsWithContext(ctx, &ecs.ListAccountSettingsInput{
		EffectiveSettings: aws.Bool(true),
		Name:              aws.String("serviceLongArnFormat"),
	})
	if err != nil {
		return err
	}
	serviceLongArnFormat := settings.Settings[0].Value
	if *serviceLongArnFormat != "enabled" {
		return fmt.Errorf("this tool requires the \"new ARN resource ID format\".\n"+
			"Check https://%s.console.aws.amazon.com/ecs/home#/settings\n"+
			"Learn more: https://aws.amazon.com/blogs/compute/migrating-your-amazon-ecs-deployment-to-the-new-arn-and-resource-id-format-2", region)
	}
	return nil
}

func (s sdk) ClusterExists(ctx context.Context, name string) (bool, error) {
	logrus.Debug("CheckRequirements if cluster was already created: ", name)
	clusters, err := s.ECS.DescribeClustersWithContext(ctx, &ecs.DescribeClustersInput{
		Clusters: []*string{aws.String(name)},
	})
	if err != nil {
		return false, err
	}
	return len(clusters.Clusters) > 0, nil
}

func (s sdk) CreateCluster(ctx context.Context, name string) (string, error) {
	logrus.Debug("Create cluster ", name)
	response, err := s.ECS.CreateClusterWithContext(ctx, &ecs.CreateClusterInput{ClusterName: aws.String(name)})
	if err != nil {
		return "", err
	}
	return *response.Cluster.Status, nil
}

func (s sdk) VpcExists(ctx context.Context, vpcID string) (bool, error) {
	logrus.Debug("CheckRequirements if VPC exists: ", vpcID)
	_, err := s.EC2.DescribeVpcsWithContext(ctx, &ec2.DescribeVpcsInput{VpcIds: []*string{&vpcID}})
	return err == nil, err
}

func (s sdk) GetDefaultVPC(ctx context.Context) (string, error) {
	logrus.Debug("Retrieve default VPC")
	vpcs, err := s.EC2.DescribeVpcsWithContext(ctx, &ec2.DescribeVpcsInput{
		Filters: []*ec2.Filter{
			{
				Name:   aws.String("isDefault"),
				Values: []*string{aws.String("true")},
			},
		},
	})
	if err != nil {
		return "", err
	}
	if len(vpcs.Vpcs) == 0 {
		return "", fmt.Errorf("account has not default VPC")
	}
	return *vpcs.Vpcs[0].VpcId, nil
}

func (s sdk) GetSubNets(ctx context.Context, vpcID string) ([]string, error) {
	logrus.Debug("Retrieve SubNets")
	subnets, err := s.EC2.DescribeSubnetsWithContext(ctx, &ec2.DescribeSubnetsInput{
		DryRun: nil,
		Filters: []*ec2.Filter{
			{
				Name:   aws.String("vpc-id"),
				Values: []*string{aws.String(vpcID)},
			},
		},
	})
	if err != nil {
		return nil, err
	}

	ids := []string{}
	for _, subnet := range subnets.Subnets {
		ids = append(ids, *subnet.SubnetId)
	}
	return ids, nil
}

func (s sdk) GetRoleArn(ctx context.Context, name string) (string, error) {
	role, err := s.IAM.GetRoleWithContext(ctx, &iam.GetRoleInput{
		RoleName: aws.String(name),
	})
	if err != nil {
		return "", err
	}
	return *role.Role.Arn, nil
}

func (s sdk) StackExists(ctx context.Context, name string) (bool, error) {
	stacks, err := s.CF.DescribeStacksWithContext(ctx, &cloudformation.DescribeStacksInput{
		StackName: aws.String(name),
	})
	if err != nil {
		if strings.HasPrefix(err.Error(), fmt.Sprintf("ValidationError: Stack with id %s does not exist", name)) {
			return false, nil
		}
		return false, nil
	}
	return len(stacks.Stacks) > 0, nil
}

func (s sdk) CreateStack(ctx context.Context, name string, template *cf.Template, parameters map[string]string) error {
	logrus.Debug("Create CloudFormation stack")
	json, err := Marshall(template)
	if err != nil {
		return err
	}

	param := []*cloudformation.Parameter{}
	for name, value := range parameters {
		param = append(param, &cloudformation.Parameter{
			ParameterKey:   aws.String(name),
			ParameterValue: aws.String(value),
		})
	}

	_, err = s.CF.CreateStackWithContext(ctx, &cloudformation.CreateStackInput{
		OnFailure:        aws.String("DELETE"),
		StackName:        aws.String(name),
		TemplateBody:     aws.String(string(json)),
		Parameters:       param,
		TimeoutInMinutes: nil,
		Capabilities: []*string{
			aws.String(cloudformation.CapabilityCapabilityIam),
		},
	})
	return err
}

func (s sdk) CreateChangeSet(ctx context.Context, name string, template *cf.Template, parameters map[string]string) (string, error) {
	logrus.Debug("Create CloudFormation Changeset")
	json, err := Marshall(template)
	if err != nil {
		return "", err
	}

	param := []*cloudformation.Parameter{}
	for name := range parameters {
		param = append(param, &cloudformation.Parameter{
			ParameterKey:     aws.String(name),
			UsePreviousValue: aws.Bool(true),
		})
	}

	update := fmt.Sprintf("Update%s", time.Now().Format("2006-01-02-15-04-05"))
	changeset, err := s.CF.CreateChangeSetWithContext(ctx, &cloudformation.CreateChangeSetInput{
		ChangeSetName: aws.String(update),
		ChangeSetType: aws.String(cloudformation.ChangeSetTypeUpdate),
		StackName:     aws.String(name),
		TemplateBody:  aws.String(string(json)),
		Parameters:    param,
		Capabilities: []*string{
			aws.String(cloudformation.CapabilityCapabilityIam),
		},
	})
	if err != nil {
		return "", err
	}

	err = s.CF.WaitUntilChangeSetCreateCompleteWithContext(ctx, &cloudformation.DescribeChangeSetInput{
		ChangeSetName: changeset.Id,
	})
	return *changeset.Id, err
}

func (s sdk) UpdateStack(ctx context.Context, changeset string) error {
	desc, err := s.CF.DescribeChangeSetWithContext(ctx, &cloudformation.DescribeChangeSetInput{
		ChangeSetName: aws.String(changeset),
	})
	if err != nil {
		return err
	}

	if strings.HasPrefix(aws.StringValue(desc.StatusReason), "The submitted information didn't contain changes.") {
		return nil
	}

	_, err = s.CF.ExecuteChangeSet(&cloudformation.ExecuteChangeSetInput{
		ChangeSetName: aws.String(changeset),
	})
	return err
}

func (s sdk) WaitStackComplete(ctx context.Context, name string, operation int) error {
	input := &cloudformation.DescribeStacksInput{
		StackName: aws.String(name),
	}
	switch operation {
	case StackCreate:
		return s.CF.WaitUntilStackCreateCompleteWithContext(ctx, input)
	case StackDelete:
		return s.CF.WaitUntilStackDeleteCompleteWithContext(ctx, input)
	default:
		return fmt.Errorf("internal error: unexpected stack operation %d", operation)
	}
}

func (s sdk) GetStackID(ctx context.Context, name string) (string, error) {
	stacks, err := s.CF.DescribeStacksWithContext(ctx, &cloudformation.DescribeStacksInput{
		StackName: aws.String(name),
	})
	if err != nil {
		return "", err
	}
	return *stacks.Stacks[0].StackId, nil
}

func (s sdk) DescribeStackEvents(ctx context.Context, stackID string) ([]*cloudformation.StackEvent, error) {
	// Fixme implement Paginator on Events and return as a chan(events)
	events := []*cloudformation.StackEvent{}
	var nextToken *string
	for {
		resp, err := s.CF.DescribeStackEventsWithContext(ctx, &cloudformation.DescribeStackEventsInput{
			StackName: aws.String(stackID),
			NextToken: nextToken,
		})
		if err != nil {
			return nil, err
		}
		events = append(events, resp.StackEvents...)
		if resp.NextToken == nil {
			return events, nil
		}
		nextToken = resp.NextToken
	}
}

func (s sdk) ListStackParameters(ctx context.Context, name string) (map[string]string, error) {
	st, err := s.CF.DescribeStacksWithContext(ctx, &cloudformation.DescribeStacksInput{
		NextToken: nil,
		StackName: aws.String(name),
	})
	if err != nil {
		return nil, err
	}
	parameters := map[string]string{}
	for _, parameter := range st.Stacks[0].Parameters {
		parameters[aws.StringValue(parameter.ParameterKey)] = aws.StringValue(parameter.ParameterValue)
	}
	return parameters, nil
}

func (s sdk) ListStackResources(ctx context.Context, name string) ([]StackResource, error) {
	// FIXME handle pagination
	res, err := s.CF.ListStackResourcesWithContext(ctx, &cloudformation.ListStackResourcesInput{
		StackName: aws.String(name),
	})
	if err != nil {
		return nil, err
	}

	resources := []StackResource{}
	for _, r := range res.StackResourceSummaries {
		resources = append(resources, StackResource{
			LogicalID: aws.StringValue(r.LogicalResourceId),
			Type:      aws.StringValue(r.ResourceType),
			ARN:       aws.StringValue(r.PhysicalResourceId),
			Status:    aws.StringValue(r.ResourceStatus),
		})
	}
	return resources, nil
}

func (s sdk) DeleteStack(ctx context.Context, name string) error {
	logrus.Debug("Delete CloudFormation stack")
	_, err := s.CF.DeleteStackWithContext(ctx, &cloudformation.DeleteStackInput{
		StackName: aws.String(name),
	})
	return err
}

func (s sdk) CreateSecret(ctx context.Context, secret Secret) (string, error) {
	logrus.Debug("Create secret " + secret.Name)
	secretStr, err := secret.GetCredString()
	if err != nil {
		return "", err
	}

	response, err := s.SM.CreateSecret(&secretsmanager.CreateSecretInput{
		Name:         &secret.Name,
		SecretString: &secretStr,
		Description:  &secret.Description,
	})
	if err != nil {
		return "", err
	}
	return aws.StringValue(response.ARN), nil
}

func (s sdk) InspectSecret(ctx context.Context, id string) (Secret, error) {
	logrus.Debug("Inspect secret " + id)
	response, err := s.SM.DescribeSecret(&secretsmanager.DescribeSecretInput{SecretId: &id})
	if err != nil {
		return Secret{}, err
	}
	labels := map[string]string{}
	for _, tag := range response.Tags {
		labels[aws.StringValue(tag.Key)] = aws.StringValue(tag.Value)
	}
	secret := Secret{
		ID:     aws.StringValue(response.ARN),
		Name:   aws.StringValue(response.Name),
		Labels: labels,
	}
	if response.Description != nil {
		secret.Description = *response.Description
	}
	return secret, nil
}

func (s sdk) ListSecrets(ctx context.Context) ([]Secret, error) {
	logrus.Debug("List secrets ...")
	response, err := s.SM.ListSecrets(&secretsmanager.ListSecretsInput{})
	if err != nil {
		return []Secret{}, err
	}
	var secrets []Secret

	for _, sec := range response.SecretList {

		labels := map[string]string{}
		for _, tag := range sec.Tags {
			labels[*tag.Key] = *tag.Value
		}
		description := ""
		if sec.Description != nil {
			description = *sec.Description
		}
		secrets = append(secrets, Secret{
			ID:          *sec.ARN,
			Name:        *sec.Name,
			Labels:      labels,
			Description: description,
		})
	}
	return secrets, nil
}

func (s sdk) DeleteSecret(ctx context.Context, id string, recover bool) error {
	logrus.Debug("List secrets ...")
	force := !recover
	_, err := s.SM.DeleteSecret(&secretsmanager.DeleteSecretInput{SecretId: &id, ForceDeleteWithoutRecovery: &force})
	return err
}

func (s sdk) GetLogs(ctx context.Context, name string, consumer LogConsumer) error {
	logGroup := fmt.Sprintf("/docker-compose/%s", name)
	var startTime int64
	for {
		var hasMore = true
		var token *string
		for hasMore {
			events, err := s.CW.FilterLogEvents(&cloudwatchlogs.FilterLogEventsInput{
				LogGroupName: aws.String(logGroup),
				NextToken:    token,
				StartTime:    aws.Int64(startTime),
			})
			if err != nil {
				return err
			}
			if events.NextToken == nil {
				hasMore = false
			} else {
				token = events.NextToken
			}

			for _, event := range events.Events {
				p := strings.Split(aws.StringValue(event.LogStreamName), "/")
				consumer.Log(p[1], p[2], aws.StringValue(event.Message))
				startTime = *event.IngestionTime
			}
		}
		time.Sleep(500 * time.Millisecond)
	}
}

func (s sdk) DescribeServices(ctx context.Context, cluster string, arns []string) ([]compose.ServiceStatus, error) {
	services, err := s.ECS.DescribeServicesWithContext(ctx, &ecs.DescribeServicesInput{
		Cluster:  aws.String(cluster),
		Services: aws.StringSlice(arns),
		Include:  aws.StringSlice([]string{"TAGS"}),
	})
	if err != nil {
		return nil, err
	}

	status := []compose.ServiceStatus{}
	for _, service := range services.Services {
		var name string
		for _, t := range service.Tags {
			if *t.Key == compose.ServiceTag {
				name = aws.StringValue(t.Value)
			}
		}
		if name == "" {
			return nil, fmt.Errorf("service %s doesn't have a %s tag", *service.ServiceArn, compose.ServiceTag)
		}
		targetGroupArns := []string{}
		for _, lb := range service.LoadBalancers {
			targetGroupArns = append(targetGroupArns, *lb.TargetGroupArn)
		}
		// getURLwithPortMapping makes 2 queries
		// one to get the target groups and another for load balancers
		loadBalancers, err := s.getURLWithPortMapping(ctx, targetGroupArns)
		if err != nil {
			return nil, err
		}
		status = append(status, compose.ServiceStatus{
			ID:            aws.StringValue(service.ServiceName),
			Name:          name,
			Replicas:      int(aws.Int64Value(service.RunningCount)),
			Desired:       int(aws.Int64Value(service.DesiredCount)),
			LoadBalancers: loadBalancers,
		})
	}
	return status, nil
}

func (s sdk) getURLWithPortMapping(ctx context.Context, targetGroupArns []string) ([]compose.LoadBalancer, error) {
	if len(targetGroupArns) == 0 {
		return nil, nil
	}
	groups, err := s.ELB.DescribeTargetGroups(&elbv2.DescribeTargetGroupsInput{
		TargetGroupArns: aws.StringSlice(targetGroupArns),
	})
	if err != nil {
		return nil, err
	}
	lbarns := []*string{}
	for _, tg := range groups.TargetGroups {
		lbarns = append(lbarns, tg.LoadBalancerArns...)
	}

	lbs, err := s.ELB.DescribeLoadBalancersWithContext(ctx, &elbv2.DescribeLoadBalancersInput{
		LoadBalancerArns: lbarns,
	})

	if err != nil {
		return nil, err
	}
	filterLB := func(arn *string, lbs []*elbv2.LoadBalancer) *elbv2.LoadBalancer {
		if aws.StringValue(arn) == "" {
			// load balancer arn is nil/""
			return nil
		}
		for _, lb := range lbs {
			if aws.StringValue(lb.LoadBalancerArn) == aws.StringValue(arn) {
				return lb
			}
		}
		return nil
	}
	loadBalancers := []compose.LoadBalancer{}
	for _, tg := range groups.TargetGroups {
		for _, lbarn := range tg.LoadBalancerArns {
			lb := filterLB(lbarn, lbs.LoadBalancers)
			if lb == nil {
				continue
			}
			loadBalancers = append(loadBalancers, compose.LoadBalancer{
				URL:           aws.StringValue(lb.DNSName),
				TargetPort:    int(aws.Int64Value(tg.Port)),
				PublishedPort: int(aws.Int64Value(tg.Port)),
				Protocol:      aws.StringValue(tg.Protocol),
			})

		}
	}
	return loadBalancers, nil
}

func (s sdk) ListTasks(ctx context.Context, cluster string, family string) ([]string, error) {
	tasks, err := s.ECS.ListTasksWithContext(ctx, &ecs.ListTasksInput{
		Cluster: aws.String(cluster),
		Family:  aws.String(family),
	})
	if err != nil {
		return nil, err
	}
	arns := []string{}
	for _, arn := range tasks.TaskArns {
		arns = append(arns, *arn)
	}
	return arns, nil
}

func (s sdk) GetPublicIPs(ctx context.Context, interfaces ...string) (map[string]string, error) {
	desc, err := s.EC2.DescribeNetworkInterfaces(&ec2.DescribeNetworkInterfacesInput{
		NetworkInterfaceIds: aws.StringSlice(interfaces),
	})
	if err != nil {
		return nil, err
	}
	publicIPs := map[string]string{}
	for _, interf := range desc.NetworkInterfaces {
		if interf.Association != nil {
			publicIPs[aws.StringValue(interf.NetworkInterfaceId)] = aws.StringValue(interf.Association.PublicIp)
		}
	}
	return publicIPs, nil
}

func (s sdk) LoadBalancerExists(ctx context.Context, arn string) (bool, error) {
	logrus.Debug("CheckRequirements if LoadBalancer exists: ", arn)
	lbs, err := s.ELB.DescribeLoadBalancersWithContext(ctx, &elbv2.DescribeLoadBalancersInput{
		LoadBalancerArns: []*string{aws.String(arn)},
	})
	if err != nil {
		return false, err
	}
	return len(lbs.LoadBalancers) > 0, nil
}

func (s sdk) GetLoadBalancerURL(ctx context.Context, arn string) (string, error) {
	logrus.Debug("Retrieve load balancer URL: ", arn)
	lbs, err := s.ELB.DescribeLoadBalancersWithContext(ctx, &elbv2.DescribeLoadBalancersInput{
		LoadBalancerArns: []*string{aws.String(arn)},
	})
	if err != nil {
		return "", err
	}
	dnsName := aws.StringValue(lbs.LoadBalancers[0].DNSName)
	if dnsName == "" {
		return "", fmt.Errorf("Load balancer %s doesn't have a dns name", aws.StringValue(lbs.LoadBalancers[0].LoadBalancerArn))
	}
	return dnsName, nil
}