/*
   Copyright 2020 Docker Compose CLI 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 ecs

import (
	"context"
	"fmt"
	"io/ioutil"
	"regexp"
	"strings"

	ecsapi "github.com/aws/aws-sdk-go/service/ecs"
	"github.com/aws/aws-sdk-go/service/elbv2"
	cloudmapapi "github.com/aws/aws-sdk-go/service/servicediscovery"
	"github.com/awslabs/goformation/v4/cloudformation"
	"github.com/awslabs/goformation/v4/cloudformation/ec2"
	"github.com/awslabs/goformation/v4/cloudformation/ecs"
	"github.com/awslabs/goformation/v4/cloudformation/elasticloadbalancingv2"
	"github.com/awslabs/goformation/v4/cloudformation/iam"
	"github.com/awslabs/goformation/v4/cloudformation/logs"
	"github.com/awslabs/goformation/v4/cloudformation/secretsmanager"
	cloudmap "github.com/awslabs/goformation/v4/cloudformation/servicediscovery"
	"github.com/compose-spec/compose-go/types"
)

func (b *ecsAPIService) Convert(ctx context.Context, project *types.Project) ([]byte, error) {
	err := b.checkCompatibility(project)
	if err != nil {
		return nil, err
	}

	err = b.resources.parse(ctx, project)
	if err != nil {
		return nil, err
	}

	template, err := b.convert(project)
	if err != nil {
		return nil, err
	}

	// Create a NFS inbound rule on each mount target for volumes
	// as "source security group" use an arbitrary network attached to service(s) who mounts target volume
	for n, vol := range project.Volumes {
		err := b.SDK.WithVolumeSecurityGroups(ctx, vol.Name, func(securityGroups []string) error {
			return b.createNFSmountIngress(securityGroups, project, n, template)
		})
		if err != nil {
			return nil, err
		}
	}

	err = b.createCapacityProvider(ctx, project, template)
	if err != nil {
		return nil, err
	}

	return marshall(template)
}

// Convert a compose project into a CloudFormation template
func (b *ecsAPIService) convert(project *types.Project) (*cloudformation.Template, error) { //nolint:gocyclo
	template := cloudformation.NewTemplate()
	b.resources.ensure(project, template)

	for name, secret := range project.Secrets {
		err := b.createSecret(project, name, secret, template)
		if err != nil {
			return nil, err
		}
	}

	b.createLogGroup(project, template)

	// Private DNS namespace will allow DNS name for the services to be <service>.<project>.local
	b.createCloudMap(project, template)

	for _, service := range project.Services {
		taskExecutionRole := b.createTaskExecutionRole(project, service, template)
		taskRole := b.createTaskRole(service, template)

		definition, err := b.createTaskExecution(project, service)
		if err != nil {
			return nil, err
		}
		definition.ExecutionRoleArn = cloudformation.Ref(taskExecutionRole)
		if taskRole != "" {
			definition.TaskRoleArn = cloudformation.Ref(taskRole)
		}

		taskDefinition := fmt.Sprintf("%sTaskDefinition", normalizeResourceName(service.Name))
		template.Resources[taskDefinition] = definition

		var healthCheck *cloudmap.Service_HealthCheckConfig
		serviceRegistry := b.createServiceRegistry(service, template, healthCheck)

		var (
			dependsOn []string
			serviceLB []ecs.Service_LoadBalancer
		)
		for _, port := range service.Ports {
			for net := range service.Networks {
				b.createIngress(service, net, port, template)
			}

			protocol := strings.ToUpper(port.Protocol)
			if b.resources.loadBalancerType == elbv2.LoadBalancerTypeEnumApplication {
				// we don't set Https as a certificate must be specified for HTTPS listeners
				protocol = elbv2.ProtocolEnumHttp
			}
			targetGroupName := b.createTargetGroup(project, service, port, template, protocol)
			listenerName := b.createListener(service, port, template, targetGroupName, b.resources.loadBalancer, protocol)
			dependsOn = append(dependsOn, listenerName)
			serviceLB = append(serviceLB, ecs.Service_LoadBalancer{
				ContainerName:  service.Name,
				ContainerPort:  int(port.Target),
				TargetGroupArn: cloudformation.Ref(targetGroupName),
			})
		}

		desiredCount := 1
		if service.Deploy != nil && service.Deploy.Replicas != nil {
			desiredCount = int(*service.Deploy.Replicas)
		}

		for dependency := range service.DependsOn {
			dependsOn = append(dependsOn, serviceResourceName(dependency))
		}

		minPercent, maxPercent, err := computeRollingUpdateLimits(service)
		if err != nil {
			return nil, err
		}

		assignPublicIP := ecsapi.AssignPublicIpEnabled
		launchType := ecsapi.LaunchTypeFargate
		platformVersion := "1.4.0" // LATEST which is set to 1.3.0 (?) which doesn’t allow efs volumes.
		if requireEC2(service) {
			assignPublicIP = ecsapi.AssignPublicIpDisabled
			launchType = ecsapi.LaunchTypeEc2
			platformVersion = "" // The platform version must be null when specifying an EC2 launch type
		}

		template.Resources[serviceResourceName(service.Name)] = &ecs.Service{
			AWSCloudFormationDependsOn: dependsOn,
			Cluster:                    b.resources.cluster,
			DesiredCount:               desiredCount,
			DeploymentController: &ecs.Service_DeploymentController{
				Type: ecsapi.DeploymentControllerTypeEcs,
			},
			DeploymentConfiguration: &ecs.Service_DeploymentConfiguration{
				MaximumPercent:        maxPercent,
				MinimumHealthyPercent: minPercent,
			},
			LaunchType: launchType,
			// TODO we miss support for https://github.com/aws/containers-roadmap/issues/631 to select a capacity provider
			LoadBalancers: serviceLB,
			NetworkConfiguration: &ecs.Service_NetworkConfiguration{
				AwsvpcConfiguration: &ecs.Service_AwsVpcConfiguration{
					AssignPublicIp: assignPublicIP,
					SecurityGroups: b.resources.serviceSecurityGroups(service),
					Subnets:        b.resources.subnets,
				},
			},
			PlatformVersion:    platformVersion,
			PropagateTags:      ecsapi.PropagateTagsService,
			SchedulingStrategy: ecsapi.SchedulingStrategyReplica,
			ServiceRegistries:  []ecs.Service_ServiceRegistry{serviceRegistry},
			Tags:               serviceTags(project, service),
			TaskDefinition:     cloudformation.Ref(normalizeResourceName(taskDefinition)),
		}
	}
	return template, nil
}

func (b *ecsAPIService) createIngress(service types.ServiceConfig, net string, port types.ServicePortConfig, template *cloudformation.Template) {
	protocol := strings.ToUpper(port.Protocol)
	if protocol == "" {
		protocol = "-1"
	}
	ingress := fmt.Sprintf("%s%dIngress", normalizeResourceName(net), port.Target)
	template.Resources[ingress] = &ec2.SecurityGroupIngress{
		CidrIp:      "0.0.0.0/0",
		Description: fmt.Sprintf("%s:%d/%s on %s nextwork", service.Name, port.Target, port.Protocol, net),
		GroupId:     b.resources.securityGroups[net],
		FromPort:    int(port.Target),
		IpProtocol:  protocol,
		ToPort:      int(port.Target),
	}
}

func (b *ecsAPIService) createSecret(project *types.Project, name string, s types.SecretConfig, template *cloudformation.Template) error {
	if s.External.External {
		return nil
	}
	sensitiveData, err := ioutil.ReadFile(s.File)
	if err != nil {
		return err
	}

	resource := fmt.Sprintf("%sSecret", normalizeResourceName(s.Name))
	template.Resources[resource] = &secretsmanager.Secret{
		Description:  fmt.Sprintf("Secret %s", s.Name),
		SecretString: string(sensitiveData),
		Tags:         projectTags(project),
	}
	s.Name = cloudformation.Ref(resource)
	project.Secrets[name] = s
	return nil
}

func (b *ecsAPIService) createLogGroup(project *types.Project, template *cloudformation.Template) {
	retention := 0
	if v, ok := project.Extensions[extensionRetention]; ok {
		retention = v.(int)
	}
	logGroup := fmt.Sprintf("/docker-compose/%s", project.Name)
	template.Resources["LogGroup"] = &logs.LogGroup{
		LogGroupName:    logGroup,
		RetentionInDays: retention,
	}
}

func computeRollingUpdateLimits(service types.ServiceConfig) (int, int, error) {
	maxPercent := 200
	minPercent := 100
	if service.Deploy == nil || service.Deploy.UpdateConfig == nil {
		return minPercent, maxPercent, nil
	}
	updateConfig := service.Deploy.UpdateConfig
	min, okMin := updateConfig.Extensions[extensionMinPercent]
	if okMin {
		minPercent = min.(int)
	}
	max, okMax := updateConfig.Extensions[extensionMaxPercent]
	if okMax {
		maxPercent = max.(int)
	}
	if okMin && okMax {
		return minPercent, maxPercent, nil
	}

	if updateConfig.Parallelism != nil {
		parallelism := int(*updateConfig.Parallelism)
		if service.Deploy.Replicas == nil {
			return minPercent, maxPercent,
				fmt.Errorf("rolling update configuration require deploy.replicas to be set")
		}
		replicas := int(*service.Deploy.Replicas)
		if replicas < parallelism {
			return minPercent, maxPercent,
				fmt.Errorf("deploy.replicas (%d) must be greater than deploy.update_config.parallelism (%d)", replicas, parallelism)
		}
		if !okMin {
			minPercent = (replicas - parallelism) * 100 / replicas
		}
		if !okMax {
			maxPercent = (replicas + parallelism) * 100 / replicas
		}
	}
	return minPercent, maxPercent, nil
}

func (b *ecsAPIService) createListener(service types.ServiceConfig, port types.ServicePortConfig,
	template *cloudformation.Template,
	targetGroupName string, loadBalancerARN string, protocol string) string {
	listenerName := fmt.Sprintf(
		"%s%s%dListener",
		normalizeResourceName(service.Name),
		strings.ToUpper(port.Protocol),
		port.Target,
	)
	//add listener to dependsOn
	//https://stackoverflow.com/questions/53971873/the-target-group-does-not-have-an-associated-load-balancer
	template.Resources[listenerName] = &elasticloadbalancingv2.Listener{
		DefaultActions: []elasticloadbalancingv2.Listener_Action{
			{
				ForwardConfig: &elasticloadbalancingv2.Listener_ForwardConfig{
					TargetGroups: []elasticloadbalancingv2.Listener_TargetGroupTuple{
						{
							TargetGroupArn: cloudformation.Ref(targetGroupName),
						},
					},
				},
				Type: elbv2.ActionTypeEnumForward,
			},
		},
		LoadBalancerArn: loadBalancerARN,
		Protocol:        protocol,
		Port:            int(port.Target),
	}
	return listenerName
}

func (b *ecsAPIService) createTargetGroup(project *types.Project, service types.ServiceConfig, port types.ServicePortConfig, template *cloudformation.Template, protocol string) string {
	targetGroupName := fmt.Sprintf(
		"%s%s%dTargetGroup",
		normalizeResourceName(service.Name),
		strings.ToUpper(port.Protocol),
		port.Published,
	)
	template.Resources[targetGroupName] = &elasticloadbalancingv2.TargetGroup{
		HealthCheckEnabled: false,
		Port:               int(port.Target),
		Protocol:           protocol,
		Tags:               projectTags(project),
		TargetType:         elbv2.TargetTypeEnumIp,
		VpcId:              b.resources.vpc,
	}
	return targetGroupName
}

func (b *ecsAPIService) createServiceRegistry(service types.ServiceConfig, template *cloudformation.Template, healthCheck *cloudmap.Service_HealthCheckConfig) ecs.Service_ServiceRegistry {
	serviceRegistration := fmt.Sprintf("%sServiceDiscoveryEntry", normalizeResourceName(service.Name))
	serviceRegistry := ecs.Service_ServiceRegistry{
		RegistryArn: cloudformation.GetAtt(serviceRegistration, "Arn"),
	}

	template.Resources[serviceRegistration] = &cloudmap.Service{
		Description:       fmt.Sprintf("%q service discovery entry in Cloud Map", service.Name),
		HealthCheckConfig: healthCheck,
		HealthCheckCustomConfig: &cloudmap.Service_HealthCheckCustomConfig{
			FailureThreshold: 1,
		},
		Name:        service.Name,
		NamespaceId: cloudformation.Ref("CloudMap"),
		DnsConfig: &cloudmap.Service_DnsConfig{
			DnsRecords: []cloudmap.Service_DnsRecord{
				{
					TTL:  60,
					Type: cloudmapapi.RecordTypeA,
				},
			},
			RoutingPolicy: cloudmapapi.RoutingPolicyMultivalue,
		},
	}
	return serviceRegistry
}

func (b *ecsAPIService) createTaskExecutionRole(project *types.Project, service types.ServiceConfig, template *cloudformation.Template) string {
	taskExecutionRole := fmt.Sprintf("%sTaskExecutionRole", normalizeResourceName(service.Name))
	policies := b.createPolicies(project, service)
	template.Resources[taskExecutionRole] = &iam.Role{
		AssumeRolePolicyDocument: ecsTaskAssumeRolePolicyDocument,
		Policies:                 policies,
		ManagedPolicyArns: []string{
			ecsTaskExecutionPolicy,
			ecrReadOnlyPolicy,
		},
	}
	return taskExecutionRole
}

func (b *ecsAPIService) createTaskRole(service types.ServiceConfig, template *cloudformation.Template) string {
	taskRole := fmt.Sprintf("%sTaskRole", normalizeResourceName(service.Name))
	rolePolicies := []iam.Role_Policy{}
	if roles, ok := service.Extensions[extensionRole]; ok {
		rolePolicies = append(rolePolicies, iam.Role_Policy{
			PolicyDocument: roles,
		})
	}
	managedPolicies := []string{}
	if v, ok := service.Extensions[extensionManagedPolicies]; ok {
		for _, s := range v.([]interface{}) {
			managedPolicies = append(managedPolicies, s.(string))
		}
	}
	if len(rolePolicies) == 0 && len(managedPolicies) == 0 {
		return ""
	}
	template.Resources[taskRole] = &iam.Role{
		AssumeRolePolicyDocument: ecsTaskAssumeRolePolicyDocument,
		Policies:                 rolePolicies,
		ManagedPolicyArns:        managedPolicies,
	}
	return taskRole
}

func (b *ecsAPIService) createCloudMap(project *types.Project, template *cloudformation.Template) {
	template.Resources["CloudMap"] = &cloudmap.PrivateDnsNamespace{
		Description: fmt.Sprintf("Service Map for Docker Compose project %s", project.Name),
		Name:        fmt.Sprintf("%s.local", project.Name),
		Vpc:         b.resources.vpc,
	}
}

func (b *ecsAPIService) createPolicies(project *types.Project, service types.ServiceConfig) []iam.Role_Policy {
	var arns []string
	if value, ok := service.Extensions[extensionPullCredentials]; ok {
		arns = append(arns, value.(string))
	}
	for _, secret := range service.Secrets {
		arns = append(arns, project.Secrets[secret.Source].Name)
	}
	if len(arns) > 0 {
		return []iam.Role_Policy{
			{
				PolicyDocument: &PolicyDocument{
					Statement: []PolicyStatement{
						{
							Effect:   "Allow",
							Action:   []string{actionGetSecretValue, actionGetParameters, actionDecrypt},
							Resource: arns,
						},
					},
				},
				PolicyName: fmt.Sprintf("%sGrantAccessToSecrets", service.Name),
			},
		}
	}
	return nil
}

func networkResourceName(network string) string {
	return fmt.Sprintf("%sNetwork", normalizeResourceName(network))
}

func serviceResourceName(service string) string {
	return fmt.Sprintf("%sService", normalizeResourceName(service))
}

func normalizeResourceName(s string) string {
	return strings.Title(regexp.MustCompile("[^a-zA-Z0-9]+").ReplaceAllString(s, ""))
}