view

type Context interface {
	SpanStarter

	// GetService returns an instance of the given type
	GetService(v interface{}) (interface{}, error)

	// ID returns the identifier of this context
	ID() string

	// RunView runs the passed view on input this context
	RunView(view View, opts ...RunViewOption) (interface{}, error)

	// Me returns the identity bound to this context
	Me() Identity

	// IsMe returns true if the passed identity is an alias
	// of the identity bound to this context, false otherwise
	IsMe(id Identity) bool

	// Initiator returns the View that initiate a call
	Initiator() View

	// GetSession returns a session to the passed remote party for the given view caller.
	// Sessions are scoped by the caller view and cached.
	// The session can be bound to other caller views by passing them as additional parameters.
	GetSession(caller View, party Identity, boundToViews ...View) (Session, error)

	// GetSessionByID returns a session to the passed remote party and id.
	// Cashing may be used.
	GetSessionByID(id string, party Identity) (Session, error)

	// Session returns the session created to respond to a
	// remote party, nil if the context was created
	// not to respond to a remote call
	Session() Session

	// Context return the associated context.Context
	Context() context.Context

	// OnError appends to passed callback function to the list of functions called when
	// the current execution return an error or panic.
	// This is useful to release resources.
	OnError(callback func())
}

type Identity = identity.Identity

type Message struct {
	SessionID    string // Session Identifier
	ContextID    string // Context Identifier
	Caller       string // View Identifier of the caller
	FromEndpoint string // Endpoint identifier of the caller
	FromPKID     []byte // PK identifier of the caller
	Status       int32  // Message Status (OK, ERROR)
	Payload      []byte // Payload
	Ctx          context.Context
}

type MutableContext interface {
	// ResetSessions disposes all sessions created in this context
	ResetSessions() error
	// PutService registers a service in this context
	PutService(v interface{}) error
}

type RunViewOption func(*RunViewOptions) error

type RunViewOptions struct {
	Session     Session
	AsInitiator bool
	Call        func(Context) (interface{}, error)
	SameContext bool
}

type Session interface {
	Info() SessionInfo

	// Send sends the payload to the endpoint
	Send(payload []byte) error

	// SendWithContext sends the payload to the endpoint with the passed context
	SendWithContext(ctx context.Context, payload []byte) error

	// SendError sends an error to the endpoint with the passed payload
	SendError(payload []byte) error

	// SendErrorWithContext sends an error to the endpoint with the passed payload and context
	SendErrorWithContext(ctx context.Context, payload []byte) error

	// Receive returns a channel of messages received from the endpoint
	Receive() <-chan *Message

	// Close releases all the resources allocated by this session
	Close()
}

type SessionInfo struct {
	ID           string
	Caller       Identity
	CallerViewID string
	Endpoint     string
	EndpointPKID []byte
	Closed       bool
}

type SpanStarter interface {
	// StartSpanFrom creates a new child span from the passed context
	StartSpanFrom(ctx context.Context, name string, opts ...trace.SpanStartOption) (context.Context, trace.Span)
}

type View interface {
	// Call invokes the View on input the passed argument.
	// It returns a result and error in case of failure.
	Call(context Context) (interface{}, error)
}