From 23f99b06680136a53ac51283b89a1b198c573435 Mon Sep 17 00:00:00 2001
From: Christian Schaible <christian.schaible@novatec-gmbh.de>
Date: Tue, 30 Jul 2024 13:17:02 +0200
Subject: [PATCH] Add mutex api wrapper

---
 README.md                    |  1 -
 audit/api/api_legacy.go      |  2 +-
 audit/messaging/messaging.go | 28 ++++++++++++++++++++++++++++
 3 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index 304706b..9232c05 100644
--- a/README.md
+++ b/README.md
@@ -197,7 +197,6 @@ Python) will be extracted into separate repositories.
 - Finalizing messaging schema
   - Check if fields and constraints are correct and compatible with expected use cases
   - Check that routing api specific parameters are independent of AuditEventLog
-- Clarify if a mutex is needed? Should we provide a MutexMessagingApi?
 - Clarify if `client.go` file can be used for licence / legal reasons  
 - Extraction of python / java configurations and code  
 - Clean up repo (delete main.go, etc. files)
diff --git a/audit/api/api_legacy.go b/audit/api/api_legacy.go
index 026c3f7..2dc832e 100644
--- a/audit/api/api_legacy.go
+++ b/audit/api/api_legacy.go
@@ -42,7 +42,7 @@ type LegacyAuditApi struct {
 	validator         *ProtobufValidator
 }
 
-// NewLegacyAuditApi can be used to initialize the audit log api with LegacyAuditLogConnectionDetails.
+// NewLegacyAuditApi can be used to initialize the audit log api.
 //
 // Note: The NewLegacyAuditApi method will be deprecated and replaced with "newRoutableAuditApi" once the new audit log routing is implemented
 func NewLegacyAuditApi(
diff --git a/audit/messaging/messaging.go b/audit/messaging/messaging.go
index 3e16f8d..cfae248 100644
--- a/audit/messaging/messaging.go
+++ b/audit/messaging/messaging.go
@@ -2,10 +2,12 @@ package messaging
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"github.com/Azure/go-amqp"
 	"log/slog"
 	"strings"
+	"sync"
 	"time"
 )
 
@@ -28,6 +30,32 @@ type Api interface {
 	Send(ctx context.Context, topic string, data []byte, contentType string, applicationProperties map[string]any) error
 }
 
+// MutexApi is wrapper around an API implementation that controls mutual exclusive access to the api.
+type MutexApi struct {
+	mutex *sync.Mutex
+	api   *Api
+}
+
+func NewMutexApi(api *Api) (*Api, error) {
+	if api == nil {
+		return nil, errors.New("api is nil")
+	}
+	mutexApi := MutexApi{
+		mutex: &sync.Mutex{},
+		api:   api,
+	}
+
+	var genericApi Api = &mutexApi
+	return &genericApi, nil
+}
+
+// Send implements Api.Send
+func (m *MutexApi) Send(ctx context.Context, topic string, data []byte, contentType string, applicationProperties map[string]any) error {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+	return (*m.api).Send(ctx, topic, data, contentType, applicationProperties)
+}
+
 // AmqpConfig provides AMQP connection related parameters.
 type AmqpConfig struct {
 	URL      string