// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.

// SPDX-License-Identifier: Apache-2.0

package interop

import (

"encoding/json"

"fmt"

"io"

"net/http"

"time"

"go.amzn.com/lambda/core/statejson"

"go.amzn.com/lambda/fatalerror"

)

// MaxPayloadSize max event body size declared as LAMBDA_EVENT_BODY_SIZE

const MaxPayloadSize = 6*1024*1024 + 100 // 6 MiB + 100 bytes

const functionResponseSizeTooLargeType = "Function.ResponseSizeTooLarge"

// Message is a generic interop message.

type Message interface{}

// Invoke is an invocation request received from the slicer.

type Invoke struct {

// Tracing header.

// https://docs.aws.amazon.com/xray/latest/devguide/xray-concepts.html#xray-concepts-tracingheader

TraceID string

LambdaSegmentID string

ID string

InvokedFunctionArn string

CognitoIdentityID string

CognitoIdentityPoolID string

DeadlineNs string

ClientContext string

ContentType string

Payload io.Reader

NeedDebugLogs bool

CorrelationID string // internal use only

ReservationToken string

VersionID string

InvokeReceivedTime int64

ResyncState Resync

}

type Token struct {

ReservationToken string

InvokeID string

VersionID string

FunctionTimeout time.Duration

InvackDeadlineNs int64

TraceID string

LambdaSegmentID string

InvokeMetadata string

NeedDebugLogs bool

ResyncState Resync

}

type Resync struct {

IsResyncReceived bool

AwsKey string

AwsSecret string

AwsSession string

ReceivedTime time.Time

}

type ErrorResponse struct {

// Payload sent via shared memory.

Payload []byte `json:"Payload,omitempty"`

ContentType string `json:"-"`

// When error response body (Payload) is not provided, e.g.

// not retrievable, error type and error message will be

// used by the Slicer to construct a response json, e.g:

//

// default error response produced by the Slicer:

// '{"errorMessage":"Unknown application error occurred"}',

//

// when error type is provided, error response becomes:

// '{"errorMessage":"Unknown application error occurred","errorType":"ErrorType"}'

ErrorType string `json:"errorType,omitempty"`

ErrorMessage string `json:"errorMessage,omitempty"`

// Attached to invoke segment

ErrorCause json.RawMessage `json:"ErrorCause,omitempty"`

}

// SandboxType identifies sandbox type (PreWarmed vs Classic)

type SandboxType string

const SandboxPreWarmed SandboxType = "PreWarmed"

const SandboxClassic SandboxType = "Classic"

// Start message received from the slicer, part of the protocol.

type Start struct {

InvokeID string

Handler string

AwsKey string

AwsSecret string

AwsSession string

SuppressInit bool

XRayDaemonAddress string // only in standalone

FunctionName string // only in standalone

FunctionVersion string // only in standalone

CorrelationID string // internal use only

// TODO: define new Init type that has the Start fields as well as env vars below.

// In standalone mode, these env vars come from test/init but from environment otherwise.

CustomerEnvironmentVariables map[string]string

SandboxType SandboxType

}

// Running message is sent to the slicer, part of the protocol.

type Running struct {

WaitStartTimeNs int64

WaitEndTimeNs int64

PreLoadTimeNs int64

PostLoadTimeNs int64

ExtensionsEnabled bool

}

// Reset message is sent to rapid to initiate reset sequence

type Reset struct {

Reason string

DeadlineNs int64

CorrelationID string // internal use only

}

// Shutdown message is sent to rapid to initiate graceful shutdown

type Shutdown struct {

DeadlineNs int64

CorrelationID string // internal use only

}

// Metrics for response status of LogsAPI `/subscribe` calls

type LogsAPIMetrics map[string]int

type DoneMetadata struct {

NumActiveExtensions int

ExtensionsResetMs int64

ExtensionNames string

RuntimeRelease string

// Metrics for response status of LogsAPI `/subscribe` calls

LogsAPIMetrics LogsAPIMetrics

InvokeRequestReadTimeNs int64

InvokeRequestSizeBytes int64

InvokeCompletionTimeNs int64

InvokeReceivedTime int64

RuntimeReadyTime int64

}

type Done struct {

WaitForExit bool

ErrorType fatalerror.ErrorType

CorrelationID string // internal use only

Meta DoneMetadata

}

type DoneFail struct {

ErrorType fatalerror.ErrorType

CorrelationID string // internal use only

Meta DoneMetadata

}

// ErrInvalidInvokeID is returned when invokeID provided in Invoke2 does not match one provided in Token

var ErrInvalidInvokeID = fmt.Errorf("ErrInvalidInvokeID")

// ErrInvalidReservationToken is returned when reservationToken provided in Invoke2 does not match one provided in Token

var ErrInvalidReservationToken = fmt.Errorf("ErrInvalidReservationToken")

// ErrInvalidFunctionVersion is returned when functionVersion provided in Invoke2 does not match one provided in Token

var ErrInvalidFunctionVersion = fmt.Errorf("ErrInvalidFunctionVersion")

// ErrMalformedCustomerHeaders is returned when customer headers format is invalid

var ErrMalformedCustomerHeaders = fmt.Errorf("ErrMalformedCustomerHeaders")

// ErrResponseSent is returned when response with given invokeID was already sent.

var ErrResponseSent = fmt.Errorf("ErrResponseSent")

// ErrReservationExpired is returned when invoke arrived after InvackDeadline

var ErrReservationExpired = fmt.Errorf("ErrReservationExpired")

// ErrorResponseTooLarge is returned when response Payload exceeds shared memory buffer size

type ErrorResponseTooLarge struct {

MaxResponseSize int

ResponseSize int

}

// ErrorResponseTooLargeDI is used to reproduce ErrorResponseTooLarge behavior for Direct Invoke mode

type ErrorResponseTooLargeDI struct {

ErrorResponseTooLarge

}

// ErrorResponseTooLarge is returned when response provided by Runtime does not fit into shared memory buffer

func (s *ErrorResponseTooLarge) Error() string {

return fmt.Sprintf("Response payload size (%d bytes) exceeded maximum allowed payload size (%d bytes).", s.ResponseSize, s.MaxResponseSize)

}

// AsErrorResponse generates ErrorResponse from ErrorResponseTooLarge

func (s *ErrorResponseTooLarge) AsInteropError() *ErrorResponse {

resp := ErrorResponse{

ErrorType: functionResponseSizeTooLargeType,

ErrorMessage: s.Error(),

}

respJSON, err := json.Marshal(resp)

if err != nil {

panic("Failed to marshal interop.ErrorResponse")

}

resp.Payload = respJSON

resp.ContentType = "application/json"

return &resp

}

// Server implements Slicer communication protocol.

type Server interface {

// StartAcceptingDirectInvokes starts accepting on direct invoke socket (if one is available)

StartAcceptingDirectInvokes() error

// SendErrorResponse sends response.

// Errors returned:

// ErrInvalidInvokeID - validation error indicating that provided invokeID doesn't match current invokeID

// ErrResponseSent - validation error indicating that response with given invokeID was already sent

// Non-nil error - non-nil error indicating transport failure

SendResponse(invokeID string, contentType string, response io.Reader) error

// SendErrorResponse sends error response.

// Errors returned:

// ErrInvalidInvokeID - validation error indicating that provided invokeID doesn't match current invokeID

// ErrResponseSent - validation error indicating that response with given invokeID was already sent

// Non-nil error - non-nil error indicating transport failure

SendErrorResponse(invokeID string, response *ErrorResponse) error

// GetCurrentInvokeID returns current invokeID.

// NOTE, in case of INIT, when invokeID is not known in advance (e.g. provisioned concurrency),

// returned invokeID will contain empty value.

GetCurrentInvokeID() string

// CommitMessage confirms that the message written through SendResponse and SendErrorResponse is complete.

CommitResponse() error

// SendRunning sends GIRD RUNNING.

// Returns error on transport failure.

SendRunning(*Running) error

// SendRuntimeReady sends GIRD RTREADY

SendRuntimeReady() error

// SendDone sends GIRD DONE.

// Returns error on transport failure.

SendDone(*Done) error

// SendDone sends GIRD DONEFAIL.

// Returns error on transport failure.

SendDoneFail(*DoneFail) error

// StartChan returns Start emitter

StartChan() <-chan *Start

// InvokeChan returns Invoke emitter

InvokeChan() <-chan *Invoke

// ResetChan returns Reset emitter

ResetChan() <-chan *Reset

// ShutdownChan returns Shutdown emitter

ShutdownChan() <-chan *Shutdown

// TransportErrorChan emits errors if there was parsing/connection issue

TransportErrorChan() <-chan error

// Clear is called on rapid reset. It should leave server prepared for new invocations

Clear()

// IsResponseSent exposes is response sent flag

IsResponseSent() bool

// The following are used by standalone rapid only

// TODO refactor to decouple the interfaces

SetInternalStateGetter(cb InternalStateGetter)

Init(i *Start, invokeTimeoutMs int64)

Invoke(responseWriter http.ResponseWriter, invoke *Invoke) error

Shutdown(shutdown *Shutdown) *statejson.InternalStateDescription

}

type InternalStateGetter func() statejson.InternalStateDescription