package project

import (
	"errors"

	"golang.org/x/net/context"

	"github.com/docker/libcompose/config"
	"github.com/docker/libcompose/project/events"
	"github.com/docker/libcompose/project/options"
)

// Service defines what a libcompose service provides.
type Service interface {
	Build(ctx context.Context, buildOptions options.Build) error
	Create(ctx context.Context, options options.Create) error
	Delete(ctx context.Context, options options.Delete) error
	Events(ctx context.Context, messages chan events.ContainerEvent) error
	Info(ctx context.Context) (InfoSet, error)
	Log(ctx context.Context, follow bool) error
	Kill(ctx context.Context, signal string) error
	Pause(ctx context.Context) error
	Pull(ctx context.Context) error
	Restart(ctx context.Context, timeout int) error
	Run(ctx context.Context, commandParts []string, options options.Run) (int, error)
	Scale(ctx context.Context, count int, timeout int) error
	Start(ctx context.Context) error
	Stop(ctx context.Context, timeout int) error
	Unpause(ctx context.Context) error
	Up(ctx context.Context, options options.Up) error

	RemoveImage(ctx context.Context, imageType options.ImageType) error
	Containers(ctx context.Context) ([]Container, error)
	DependentServices() []ServiceRelationship
	Config() *config.ServiceConfig
	Name() string
}

// ServiceState holds the state of a service.
type ServiceState string

// State definitions
var (
	StateExecuted = ServiceState("executed")
	StateUnknown  = ServiceState("unknown")
)

// Error definitions
var (
	ErrRestart     = errors.New("Restart execution")
	ErrUnsupported = errors.New("UnsupportedOperation")
)

// ServiceFactory is an interface factory to create Service object for the specified
// project, with the specified name and service configuration.
type ServiceFactory interface {
	Create(project *Project, name string, serviceConfig *config.ServiceConfig) (Service, error)
}

// ServiceRelationshipType defines the type of service relationship.
type ServiceRelationshipType string

// RelTypeLink means the services are linked (docker links).
const RelTypeLink = ServiceRelationshipType("")

// RelTypeNetNamespace means the services share the same network namespace.
const RelTypeNetNamespace = ServiceRelationshipType("netns")

// RelTypeIpcNamespace means the service share the same ipc namespace.
const RelTypeIpcNamespace = ServiceRelationshipType("ipc")

// RelTypeVolumesFrom means the services share some volumes.
const RelTypeVolumesFrom = ServiceRelationshipType("volumesFrom")

// RelTypeDependsOn means the dependency was explicitly set using 'depends_on'.
const RelTypeDependsOn = ServiceRelationshipType("dependsOn")

// RelTypeNetworkMode means the services depends on another service on networkMode
const RelTypeNetworkMode = ServiceRelationshipType("networkMode")

// ServiceRelationship holds the relationship information between two services.
type ServiceRelationship struct {
	Target, Alias string
	Type          ServiceRelationshipType
	Optional      bool
}

// NewServiceRelationship creates a new Relationship based on the specified alias
// and relationship type.
func NewServiceRelationship(nameAlias string, relType ServiceRelationshipType) ServiceRelationship {
	name, alias := NameAlias(nameAlias)
	return ServiceRelationship{
		Target: name,
		Alias:  alias,
		Type:   relType,
	}
}