sqs.go

package handler_utils

import (
	"encoding/json"
	"github.com/aws/aws-lambda-go/events"
	"gitlab.com/uafrica/go-utils/errors"
	"gitlab.com/uafrica/go-utils/s3"
	"gitlab.com/uafrica/go-utils/sqs"
	"reflect"
)

// ValidateSQSEndpoints checks that all SQS endpoints are correctly defined using one of the supported handler types
// return updated endpoints with additional information
func ValidateSQSEndpoints(endpoints map[string]interface{}) (map[string]interface{}, error) {
	for messageType, handlerFunc := range endpoints {
		if messageType == "" {
			return nil, errors.Errorf("blank messageType")
		}
		if handlerFunc == nil {
			return nil, errors.Errorf("nil handler on %s", messageType)
		}

		handler, err := NewSQSHandler(handlerFunc)
		if err != nil {
			return nil, errors.Wrapf(err, "%v has invalid handler %T", messageType, handlerFunc)
		}
		// replace the endpoint value so we can quickly call this handler
		endpoints[messageType] = handler
	}
	return endpoints, nil
}

func GetRecord(s3Session *s3.SessionWithHelpers, bucket string, message events.SQSMessage, recordType reflect.Type) (interface{}, error) {

	recordValuePtr := reflect.New(recordType)

	// Check if message body should be retrieved from S3
	if messageAttribute, ok := message.MessageAttributes[sqs.SQSMessageOnS3Key]; ok && messageAttribute.StringValue != nil && *messageAttribute.StringValue == "true" {
		messageBytes, err := sqs.RetrieveMessageFromS3(s3Session, bucket, message.Body)
		if err != nil {
			return nil, errors.Wrapf(err, "failed to get sqs message body from s3")
		}

		err = json.Unmarshal(messageBytes, recordValuePtr.Interface())
		if err != nil {
			return nil, errors.Wrapf(err, "failed to JSON decode message body")
		}
	} else {
		// Message was small enough, it is contained in the message body
		err := json.Unmarshal([]byte(message.Body), recordValuePtr.Interface())
		if err != nil {
			return nil, errors.Wrapf(err, "failed to JSON decode message body")
		}
	}

	if validator, ok := recordValuePtr.Interface().(IValidator); ok {
		if err := validator.Validate(); err != nil {
			return nil, errors.Wrapf(err, "invalid message body")
		}
	}

	return recordValuePtr.Elem().Interface(), nil
}

type IValidator interface {
	Validate() error
}