// SignSDKRequest signs an AWS request with the V4 signature. This
// request handler is bested used only with the SDK's built in service client's
// API operation requests.
//
// This function should not be used on its on its own, but in conjunction with
// an AWS service client's API operation call. To sign a standalone request
// not created by a service client's API operation method use the "Sign" or
// "Presign" functions of the "Signer" type.
//
// If the credentials of the request's config are set to
// credentials.AnonymousCredentials the request will not be signed.
func SignSDKRequest(req *request.Request) {
	// If the request does not need to be signed ignore the signing of the
	// request if the AnonymousCredentials object is used.
	if req.Config.Credentials == credentials.AnonymousCredentials {
		return
	}

	region := req.ClientInfo.SigningRegion
	if region == "" {
		region = aws.StringValue(req.Config.Region)
	}

	name := req.ClientInfo.SigningName
	if name == "" {
		name = req.ClientInfo.ServiceName
	}

	v4 := NewSigner(req.Config.Credentials, func(v4 *Signer) {
		v4.Debug = req.Config.LogLevel.Value()
		v4.Logger = req.Config.Logger
		v4.DisableHeaderHoisting = req.NotHoist
	})

	signedHeaders, err := v4.signWithBody(req.HTTPRequest, req.Body, name, region, req.ExpireTime, req.Time)
	req.SignedHeaderVals = signedHeaders
	req.Error = err
}

// UnmarshalError unmarshals a response error for the REST JSON protocol.
func UnmarshalError(r *request.Request) {
	code := r.HTTPResponse.Header.Get("X-Amzn-Errortype")
	bodyBytes, err := ioutil.ReadAll(r.HTTPResponse.Body)
	if err != nil {
		r.Error = awserr.New("SerializationError", "failed reading REST JSON error response", err)
		return
	}
	if len(bodyBytes) == 0 {
		r.Error = awserr.NewRequestFailure(
			awserr.New("SerializationError", r.HTTPResponse.Status, nil),
			r.HTTPResponse.StatusCode,
			"",
		)
		return
	}
	var jsonErr jsonErrorResponse
	if err := json.Unmarshal(bodyBytes, &jsonErr); err != nil {
		r.Error = awserr.New("SerializationError", "failed decoding REST JSON error response", err)
		return
	}

	if code == "" {
		code = jsonErr.Code
	}

	code = strings.SplitN(code, ":", 2)[0]
	r.Error = awserr.NewRequestFailure(
		awserr.New(code, jsonErr.Message, nil),
		r.HTTPResponse.StatusCode,
		r.RequestID,
	)
}

func verifyReceiveMessage(r *request.Request) {
	if r.DataFilled() && r.ParamsFilled() {
		ids := []string{}
		out := r.Data.(*ReceiveMessageOutput)
		for i, msg := range out.Messages {
			err := checksumsMatch(msg.Body, msg.MD5OfBody)
			if err != nil {
				if msg.MessageId == nil {
					if r.Config.Logger != nil {
						r.Config.Logger.Log(fmt.Sprintf(
							"WARN: SQS.ReceiveMessage failed checksum request id: %s, message %d has no message ID.",
							r.RequestID, i,
						))
					}
					continue
				}

				ids = append(ids, *msg.MessageId)
			}
		}
		if len(ids) > 0 {
			setChecksumError(r, "invalid messages: %s", strings.Join(ids, ", "))
		}
	}
}

// Build builds a JSON payload for a JSON RPC request.
func Build(req *request.Request) {
	var buf []byte
	var err error
	if req.ParamsFilled() {
		buf, err = jsonutil.BuildJSON(req.Params)
		if err != nil {
			req.Error = awserr.New("SerializationError", "failed encoding JSON RPC request", err)
			return
		}
	} else {
		buf = emptyJSON
	}

	if req.ClientInfo.TargetPrefix != "" || string(buf) != "{}" {
		req.SetBufferBody(buf)
	}

	if req.ClientInfo.TargetPrefix != "" {
		target := req.ClientInfo.TargetPrefix + "." + req.Operation.Name
		req.HTTPRequest.Header.Add("X-Amz-Target", target)
	}
	if req.ClientInfo.JSONVersion != "" {
		jsonVersion := req.ClientInfo.JSONVersion
		req.HTTPRequest.Header.Add("Content-Type", "application/x-amz-json-"+jsonVersion)
	}
}

// UnmarshalMeta unmarshals the REST metadata of a response in a REST service
func UnmarshalMeta(r *request.Request) {
	r.RequestID = r.HTTPResponse.Header.Get("X-Amzn-Requestid")
	if r.DataFilled() {
		v := reflect.Indirect(reflect.ValueOf(r.Data))
		unmarshalLocationElements(r, v)
	}
}

// UnmarshalError unmarshals an error response for a JSON RPC service.
func UnmarshalError(req *request.Request) {
	defer req.HTTPResponse.Body.Close()
	bodyBytes, err := ioutil.ReadAll(req.HTTPResponse.Body)
	if err != nil {
		req.Error = awserr.New("SerializationError", "failed reading JSON RPC error response", err)
		return
	}
	if len(bodyBytes) == 0 {
		req.Error = awserr.NewRequestFailure(
			awserr.New("SerializationError", req.HTTPResponse.Status, nil),
			req.HTTPResponse.StatusCode,
			"",
		)
		return
	}
	var jsonErr jsonErrorResponse
	if err := json.Unmarshal(bodyBytes, &jsonErr); err != nil {
		req.Error = awserr.New("SerializationError", "failed decoding JSON RPC error response", err)
		return
	}

	codes := strings.SplitN(jsonErr.Code, "#", 2)
	req.Error = awserr.NewRequestFailure(
		awserr.New(codes[len(codes)-1], jsonErr.Message, nil),
		req.HTTPResponse.StatusCode,
		req.RequestID,
	)
}

func unmarshalChangeResourceRecordSetsError(r *request.Request) {
	defer r.HTTPResponse.Body.Close()

	responseBody, err := ioutil.ReadAll(r.HTTPResponse.Body)

	if err != nil {
		r.Error = awserr.New("SerializationError", "failed to read Route53 XML error response", err)
		return
	}

	baseError := &baseXMLErrorResponse{}

	if err := xml.Unmarshal(responseBody, baseError); err != nil {
		r.Error = awserr.New("SerializationError", "failed to decode Route53 XML error response", err)
		return
	}

	switch baseError.XMLName.Local {
	case "InvalidChangeBatch":
		unmarshalInvalidChangeBatchError(r, responseBody)
	default:
		r.HTTPResponse.Body = ioutil.NopCloser(bytes.NewReader(responseBody))
		restxml.UnmarshalError(r)
	}
}

func unmarshalError(r *request.Request) {
	defer r.HTTPResponse.Body.Close()

	if r.HTTPResponse.ContentLength == int64(0) {
		// No body, use status code to generate an awserr.Error
		r.Error = awserr.NewRequestFailure(
			awserr.New(strings.Replace(r.HTTPResponse.Status, " ", "", -1), r.HTTPResponse.Status, nil),
			r.HTTPResponse.StatusCode,
			"",
		)
		return
	}

	resp := &xmlErrorResponse{}
	err := xml.NewDecoder(r.HTTPResponse.Body).Decode(resp)
	if err != nil && err != io.EOF {
		r.Error = awserr.New("SerializationError", "failed to decode SimpleDB XML error response", nil)
	} else if len(resp.Errors) == 0 {
		r.Error = awserr.New("MissingError", "missing error code in SimpleDB XML error response", nil)
	} else {
		// If there are multiple error codes, return only the first as the aws.Error interface only supports
		// one error code.
		r.Error = awserr.NewRequestFailure(
			awserr.New(resp.Errors[0].Code, resp.Errors[0].Message, nil),
			r.HTTPResponse.StatusCode,
			resp.RequestID,
		)
	}
}

// Build builds the REST component of a service request.
func Build(r *request.Request) {
	if r.ParamsFilled() {
		v := reflect.ValueOf(r.Params).Elem()
		buildLocationElements(r, v)
		buildBody(r, v)
	}
}

// presignURL will presign the request by using SoureRegion to sign with. SourceRegion is not
// sent to the service, and is only used to not have the SDKs parsing ARNs.
func presignURL(r *request.Request, sourceRegion *string, newParams interface{}) *string {
	cfg := r.Config.Copy(aws.NewConfig().
		WithEndpoint("").
		WithRegion(aws.StringValue(sourceRegion)))

	clientInfo := r.ClientInfo
	resolved, err := r.Config.EndpointResolver.EndpointFor(
		clientInfo.ServiceName, aws.StringValue(cfg.Region),
		func(opt *endpoints.Options) {
			opt.DisableSSL = aws.BoolValue(cfg.DisableSSL)
			opt.UseDualStack = aws.BoolValue(cfg.UseDualStack)
		},
	)
	if err != nil {
		r.Error = err
		return nil
	}

	clientInfo.Endpoint = resolved.URL
	clientInfo.SigningRegion = resolved.SigningRegion

	// Presign a request with modified params
	req := request.New(*cfg, clientInfo, r.Handlers, r.Retryer, r.Operation, newParams, r.Data)
	req.Operation.HTTPMethod = "GET"
	uri, err := req.Presign(5 * time.Minute) // 5 minutes should be enough.
	if err != nil {                          // bubble error back up to original request
		r.Error = err
		return nil
	}

	// We have our URL, set it on params
	return &uri
}

func unmarshalError(req *request.Request) {
	bodyBytes, err := ioutil.ReadAll(req.HTTPResponse.Body)
	if err != nil {
		req.Error = awserr.New("UnmarshaleError", req.HTTPResponse.Status, err)
		return
	}
	if len(bodyBytes) == 0 {
		req.Error = awserr.NewRequestFailure(
			awserr.New("UnmarshaleError", req.HTTPResponse.Status, fmt.Errorf("empty body")),
			req.HTTPResponse.StatusCode,
			"",
		)
		return
	}
	var jsonErr jsonErrorResponse
	if err := json.Unmarshal(bodyBytes, &jsonErr); err != nil {
		req.Error = awserr.New("UnmarshaleError", "JSON unmarshal", err)
		return
	}
	req.Error = awserr.NewRequestFailure(
		awserr.New(jsonErr.Code, jsonErr.Message, nil),
		req.HTTPResponse.StatusCode,
		"",
	)
}

func unmarshalError(r *request.Request) {
	defer r.HTTPResponse.Body.Close()

	if r.HTTPResponse.StatusCode == http.StatusMovedPermanently {
		r.Error = awserr.New("BucketRegionError",
			fmt.Sprintf("incorrect region, the bucket is not in '%s' region", aws.StringValue(r.Service.Config.Region)), nil)
		return
	}

	if r.HTTPResponse.ContentLength == int64(0) {
		// No body, use status code to generate an awserr.Error
		r.Error = awserr.NewRequestFailure(
			awserr.New(strings.Replace(r.HTTPResponse.Status, " ", "", -1), r.HTTPResponse.Status, nil),
			r.HTTPResponse.StatusCode,
			"",
		)
		return
	}

	resp := &xmlErrorResponse{}
	err := xml.NewDecoder(r.HTTPResponse.Body).Decode(resp)
	if err != nil && err != io.EOF {
		r.Error = awserr.New("SerializationError", "failed to decode S3 XML error response", nil)
	} else {
		r.Error = awserr.NewRequestFailure(
			awserr.New(resp.Code, resp.Message, nil),
			r.HTTPResponse.StatusCode,
			"",
		)
	}
}

// Sign requests with signature version 4.
//
// Will sign the requests with the service config's Credentials object
// Signing is skipped if the credentials is the credentials.AnonymousCredentials
// object.
func Sign(req *request.Request) {
	// If the request does not need to be signed ignore the signing of the
	// request if the AnonymousCredentials object is used.
	if req.Config.Credentials == credentials.AnonymousCredentials {
		return
	}

	region := req.ClientInfo.SigningRegion
	if region == "" {
		region = aws.StringValue(req.Config.Region)
	}

	name := req.ClientInfo.SigningName
	if name == "" {
		name = req.ClientInfo.ServiceName
	}

	s := signer{
		Request:     req.HTTPRequest,
		Time:        req.Time,
		ExpireTime:  req.ExpireTime,
		Query:       req.HTTPRequest.URL.Query(),
		Body:        req.Body,
		ServiceName: name,
		Region:      region,
		Credentials: req.Config.Credentials,
		Debug:       req.Config.LogLevel.Value(),
		Logger:      req.Config.Logger,
		notHoist:    req.NotHoist,
	}

	req.Error = s.sign()
	req.SignedHeaderVals = s.signedHeaderVals
}

// Unmarshal unmarshals the REST component of a response in a REST service.
func Unmarshal(r *request.Request) {
	if r.DataFilled() {
		v := reflect.Indirect(reflect.ValueOf(r.Data))
		unmarshalBody(r, v)
		unmarshalLocationElements(r, v)
	}
}

// ShouldThrottle returns true if the request should be throttled.
func (d DefaultRetryer) shouldThrottle(r *request.Request) bool {
	if r.HTTPResponse.StatusCode == 502 ||
		r.HTTPResponse.StatusCode == 503 ||
		r.HTTPResponse.StatusCode == 504 {
		return true
	}
	return r.IsErrorThrottle()
}

func assertMD5(t *testing.T, req *request.Request) {
	err := req.Build()
	assert.NoError(t, err)

	b, _ := ioutil.ReadAll(req.HTTPRequest.Body)
	out := md5.Sum(b)
	assert.NotEmpty(t, b)
	assert.Equal(t, base64.StdEncoding.EncodeToString(out[:]), req.HTTPRequest.Header.Get("Content-MD5"))
}

func verifySendMessage(r *request.Request) {
	if r.DataFilled() && r.ParamsFilled() {
		in := r.Params.(*SendMessageInput)
		out := r.Data.(*SendMessageOutput)
		err := checksumsMatch(in.MessageBody, out.MD5OfMessageBody)
		if err != nil {
			setChecksumError(r, err.Error())
		}
	}
}

func addAccountID(r *request.Request) {
	if !r.ParamsFilled() {
		return
	}

	v := reflect.Indirect(reflect.ValueOf(r.Params))
	if f := v.FieldByName("AccountId"); f.IsNil() {
		f.Set(reflect.ValueOf(&defaultAccountID))
	}
}

// Unmarshal unmarshals a response for a JSON RPC service.
func Unmarshal(req *request.Request) {
	defer req.HTTPResponse.Body.Close()
	if req.DataFilled() {
		err := jsonutil.UnmarshalJSON(req.Data, req.HTTPResponse.Body)
		if err != nil {
			req.Error = awserr.New("SerializationError", "failed decoding JSON RPC response", err)
		}
	}
	return
}

// UnmarshalMeta unmarshals the REST metadata of a response in a REST service
func UnmarshalMeta(r *request.Request) {
	r.RequestID = r.HTTPResponse.Header.Get("X-Amzn-Requestid")
	if r.RequestID == "" {
		// Alternative version of request id in the header
		r.RequestID = r.HTTPResponse.Header.Get("X-Amz-Request-Id")
	}
	if r.DataFilled() {
		v := reflect.Indirect(reflect.ValueOf(r.Data))
		unmarshalLocationElements(r, v)
	}
}