Refactoring of Notification system

src/main/kotlin/fr/dcproject/application/Application.kt

@@ -9,6 +9,7 @@ import com.fasterxml.jackson.datatype.joda.JodaModule
 import fr.dcproject.application.Env.PROD
 import fr.dcproject.application.Env.TEST
 import fr.dcproject.application.http.statusPagesInstallation
+import fr.dcproject.common.utils.onApplicationStopped
 import fr.dcproject.component.article.articleKoinModule
 import fr.dcproject.component.article.routes.installArticleRoutes
 import fr.dcproject.component.auth.authKoinModule
@@ -27,7 +28,8 @@ import fr.dcproject.component.follow.followKoinModule
 import fr.dcproject.component.follow.routes.article.installFollowArticleRoutes
 import fr.dcproject.component.follow.routes.citizen.installFollowCitizenRoutes
 import fr.dcproject.component.follow.routes.constitution.installFollowConstitutionRoutes
-import fr.dcproject.component.notification.NotificationConsumer
+import fr.dcproject.component.notification.email.NotificationEmailConsumer
+import fr.dcproject.component.notification.push.NotificationPushConsumer
 import fr.dcproject.component.notification.routes.installNotificationsRoutes
 import fr.dcproject.component.opinion.opinionKoinModule
 import fr.dcproject.component.opinion.routes.installOpinionRoutes
@@ -38,7 +40,6 @@ import fr.dcproject.component.workgroup.routes.installWorkgroupRoutes
 import fr.dcproject.component.workgroup.workgroupKoinModule
 import fr.postgresjson.migration.Migrations
 import io.ktor.application.Application
-import io.ktor.application.ApplicationStopped
 import io.ktor.application.install
 import io.ktor.auth.Authentication
 import io.ktor.client.HttpClient
@@ -118,11 +119,14 @@ fun Application.module(env: Env = PROD) {
         masking = false
     }
 
-    get<NotificationConsumer>().run {
+    get<NotificationEmailConsumer>().run {
         start()
-        environment.monitor.subscribe(ApplicationStopped) {
-            close()
-        }
+        onApplicationStopped { close() }
+    }
+
+    get<NotificationPushConsumer>().run {
+        start()
+        onApplicationStopped { close() }
     }
 
     install(Authentication, jwtInstallation(get(), get()))

src/main/kotlin/fr/dcproject/application/KoinModule.kt

@@ -10,10 +10,11 @@ import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
 import com.rabbitmq.client.ConnectionFactory
 import fr.dcproject.common.email.Mailer
 import fr.dcproject.component.auth.jwt.JwtConfig
-import fr.dcproject.component.notification.NotificationConsumer
-import fr.dcproject.component.notification.NotificationEmailSender
-import fr.dcproject.component.notification.NotificationsPush
-import fr.dcproject.component.notification.Publisher
+import fr.dcproject.component.notification.NotificationPublisherAsync
+import fr.dcproject.component.notification.email.NotificationEmailConsumer
+import fr.dcproject.component.notification.email.NotificationEmailSender
+import fr.dcproject.component.notification.push.NotificationPushConsumer
+import fr.dcproject.component.notification.push.NotificationPushListener
 import fr.postgresjson.connexion.Connection
 import fr.postgresjson.connexion.Requester
 import fr.postgresjson.migration.Migrations
@@ -65,11 +66,15 @@ val KoinModule = module {
         }
     }
 
-    single { NotificationsPush.Builder(get()) }
+    single { NotificationPushListener.Builder(get()) }
 
     single {
         val config: Configuration = get()
-        NotificationConsumer(get(), get(), get(), get(), get(), get(), config.exchangeNotificationName)
+        NotificationEmailConsumer(get(), get(), get(), get(), get(), config.exchangeNotificationName)
+    }
+    single {
+        val config: Configuration = get()
+        NotificationPushConsumer(get(), get(), get(), get(), get(), config.exchangeNotificationName)
     }
 
     // RabbitMQ
@@ -114,7 +119,7 @@ val KoinModule = module {
 
     single {
         val config: Configuration = get()
-        Publisher(factory = get(), exchangeName = config.exchangeNotificationName)
+        NotificationPublisherAsync(factory = get(), exchangeName = config.exchangeNotificationName)
     }
 
     single {

src/main/kotlin/fr/dcproject/common/email/Mailer.kt

@@ -9,6 +9,9 @@ import java.io.IOException
 class Mailer(
     private val key: String
 ) {
+    /**
+     * Send email via Sendgrid
+     */
     fun sendEmail(action: () -> Mail): Boolean {
         val mail = action()
 

src/main/kotlin/fr/dcproject/common/utils/Ktor.kt

@@ -0,0 +1,10 @@
+package fr.dcproject.common.utils
+
+import io.ktor.application.Application
+import io.ktor.application.ApplicationStopped
+
+fun Application.onApplicationStopped(callback: Application.() -> Unit) {
+    environment.monitor.subscribe(ApplicationStopped) {
+        callback()
+    }
+}

src/main/kotlin/fr/dcproject/common/utils/RabbitConsume.kt

@@ -0,0 +1,30 @@
+package fr.dcproject.common.utils
+
+import com.rabbitmq.client.AMQP
+import com.rabbitmq.client.Channel
+import com.rabbitmq.client.Consumer
+import com.rabbitmq.client.DefaultConsumer
+import com.rabbitmq.client.Envelope
+import kotlinx.coroutines.runBlocking
+import java.io.IOException
+
+fun Channel.consumeQueue(queueName: String, callback: DefaultConsumer.(ByteArray) -> Unit) {
+    val consumer: Consumer = object : DefaultConsumer(this) {
+        @Throws(IOException::class)
+        override fun handleDelivery(
+            consumerTag: String,
+            envelope: Envelope,
+            properties: AMQP.BasicProperties,
+            body: ByteArray
+        ) = runBlocking {
+            try {
+                callback(body)
+                basicAck(envelope.deliveryTag, false)
+            } catch (e: Throwable) {
+                basicNack(envelope.deliveryTag, false, true)
+            }
+        }
+    }
+    /* Launch Consumer */
+    basicConsume(queueName, false, consumer)
+}

src/main/kotlin/fr/dcproject/component/article/routes/UpsertArticle.kt

@@ -10,8 +10,8 @@ import fr.dcproject.component.article.routes.UpsertArticle.UpsertArticleRequest.
 import fr.dcproject.component.auth.citizen
 import fr.dcproject.component.auth.citizenOrNull
 import fr.dcproject.component.auth.mustBeAuth
-import fr.dcproject.component.notification.ArticleUpdateNotification
-import fr.dcproject.component.notification.Publisher
+import fr.dcproject.component.notification.ArticleUpdateNotificationMessage
+import fr.dcproject.component.notification.NotificationPublisherAsync
 import fr.dcproject.component.workgroup.database.WorkgroupRef
 import io.konform.validation.Validation
 import io.konform.validation.jsonschema.maxItems
@@ -63,7 +63,7 @@ object UpsertArticle {
         }
     }
 
-    fun Route.upsertArticle(repo: ArticleRepository, publisher: Publisher, ac: ArticleAccessControl) {
+    fun Route.upsertArticle(repo: ArticleRepository, notificationPublisher: NotificationPublisherAsync, ac: ArticleAccessControl) {
         suspend fun ApplicationCall.convertRequestToEntity(): ArticleForUpdate = receiveOrBadRequest<Input>().run {
             validate().badRequestIfNotValid()
             ArticleForUpdate(
@@ -92,7 +92,7 @@ object UpsertArticle {
                         val versionNumber = a.versionNumber
                     }
                 )
-                publisher.publish(ArticleUpdateNotification(a))
+                notificationPublisher.publishAsync(ArticleUpdateNotificationMessage(a))
             } ?: error("Article not updated")
         }
     }

src/main/kotlin/fr/dcproject/component/notification/NotificationConsumer.kt

@@ -1,115 +0,0 @@
-package fr.dcproject.component.notification
-
-import com.rabbitmq.client.AMQP.BasicProperties
-import com.rabbitmq.client.BuiltinExchangeType.DIRECT
-import com.rabbitmq.client.ConnectionFactory
-import com.rabbitmq.client.Consumer
-import com.rabbitmq.client.DefaultConsumer
-import com.rabbitmq.client.Envelope
-import fr.dcproject.common.entity.TargetRef
-import fr.dcproject.component.follow.database.FollowArticleRepository
-import fr.dcproject.component.follow.database.FollowCitizenRepository
-import fr.dcproject.component.follow.database.FollowConstitutionRepository
-import fr.dcproject.component.follow.database.FollowForView
-import io.ktor.utils.io.errors.IOException
-import io.lettuce.core.RedisClient
-import io.lettuce.core.api.async.RedisAsyncCommands
-import kotlinx.coroutines.flow.collect
-import kotlinx.coroutines.runBlocking
-import org.slf4j.Logger
-import org.slf4j.LoggerFactory
-
-class NotificationConsumer(
-    private val rabbitFactory: ConnectionFactory,
-    private val redisClient: RedisClient,
-    private val followConstitutionRepo: FollowConstitutionRepository,
-    private val followArticleRepo: FollowArticleRepository,
-    private val followCitizenRepo: FollowCitizenRepository,
-    private val notificationEmailSender: NotificationEmailSender,
-    private val exchangeName: String,
-) {
-    private val redisConnection = redisClient.connect() ?: error("Unable to connect to redis")
-    private val redis: RedisAsyncCommands<String, String> = redisConnection.async() ?: error("Unable to connect to redis")
-    private val rabbitConnection = rabbitFactory.newConnection()
-    private val rabbitChannel = rabbitConnection.createChannel()
-    private val logger: Logger = LoggerFactory.getLogger(Publisher::class.qualifiedName)
-
-    fun close() {
-        rabbitChannel.close()
-        rabbitConnection.close()
-    }
-
-    fun start() {
-        /* Config Rabbit */
-        rabbitFactory.newConnection().use { connection ->
-            connection.createChannel().use { channel ->
-                channel.queueDeclare("push", true, false, false, null)
-                channel.queueDeclare("email", true, false, false, null)
-                channel.exchangeDeclare(exchangeName, DIRECT, true)
-                channel.queueBind("push", exchangeName, "")
-                channel.queueBind("email", exchangeName, "")
-            }
-        }
-
-        /* Define Consumer */
-        val consumerPush: Consumer = object : DefaultConsumer(rabbitChannel) {
-            @Throws(IOException::class)
-            override fun handleDelivery(
-                consumerTag: String,
-                envelope: Envelope,
-                properties: BasicProperties,
-                body: ByteArray
-            ) = runBlocking {
-                followersFromMessage(body) {
-                    redis.zadd(
-                        "notification:${it.follow.createdBy.id}",
-                        it.event.id,
-                        it.rawMessage
-                    )
-                }
-
-                rabbitChannel.basicAck(envelope.deliveryTag, false)
-            }
-        }
-
-        val consumerEmail: Consumer = object : DefaultConsumer(rabbitChannel) {
-            @Throws(IOException::class)
-            override fun handleDelivery(
-                consumerTag: String,
-                envelope: Envelope,
-                properties: BasicProperties,
-                body: ByteArray
-            ) {
-                runBlocking {
-                    followersFromMessage(body) {
-                        notificationEmailSender.sendEmail(it.follow)
-                        logger.debug("EmailSend to: ${it.follow.createdBy.id}")
-                    }
-                }
-                rabbitChannel.basicAck(envelope.deliveryTag, false)
-            }
-        }
-        /* Launch Consumer */
-        rabbitChannel.basicConsume("push", false, consumerPush) // The front consume the redis via Websocket
-        rabbitChannel.basicConsume("email", false, consumerEmail)
-    }
-
-    private suspend fun followersFromMessage(body: ByteArray, action: suspend (DecodedMessage) -> Unit) {
-        val rawMessage: String = body.toString(Charsets.UTF_8)
-        val notification: EntityNotification = Notification.fromString(rawMessage)
-        val follows = when (notification.type) {
-            "article" -> followArticleRepo.findFollowsByTarget(notification.target)
-            "constitution" -> followConstitutionRepo.findFollowsByTarget(notification.target)
-            "citizen" -> followCitizenRepo.findFollowsByTarget(notification.target)
-            else -> error("event '${notification.type}' not implemented")
-        }
-
-        follows.collect { action(DecodedMessage(notification, rawMessage, it)) }
-    }
-
-    private class DecodedMessage(
-        val event: EntityNotification,
-        val rawMessage: String,
-        val follow: FollowForView<out TargetRef>
-    )
-}

src/main/kotlin/fr/dcproject/component/notification/NotificationConsumerAbstract.kt

@@ -0,0 +1,67 @@
+package fr.dcproject.component.notification
+
+import com.rabbitmq.client.BuiltinExchangeType.DIRECT
+import com.rabbitmq.client.ConnectionFactory
+import com.rabbitmq.client.DefaultConsumer
+import fr.dcproject.common.entity.Entity
+import fr.dcproject.common.entity.TargetRef
+import fr.dcproject.common.utils.consumeQueue
+import fr.dcproject.component.follow.database.FollowArticleRepository
+import fr.dcproject.component.follow.database.FollowCitizenRepository
+import fr.dcproject.component.follow.database.FollowConstitutionRepository
+import fr.dcproject.component.follow.database.FollowForView
+import kotlinx.coroutines.flow.collect
+import kotlinx.coroutines.runBlocking
+
+abstract class NotificationConsumerAbstract(
+    private val rabbitFactory: ConnectionFactory,
+    private val followConstitutionRepo: FollowConstitutionRepository,
+    private val followArticleRepo: FollowArticleRepository,
+    private val followCitizenRepo: FollowCitizenRepository,
+) {
+    private val rabbitConnection = rabbitFactory.newConnection()
+    private val rabbitChannel = rabbitConnection.createChannel()
+
+    fun close() {
+        rabbitChannel.close()
+        rabbitConnection.close()
+    }
+
+    fun declareQueue(queueName: String, exchangeName: String) {
+        rabbitFactory.newConnection().use { connection ->
+            connection.createChannel().use { channel ->
+                channel.queueDeclare(queueName, true, false, false, null)
+                channel.exchangeDeclare(exchangeName, DIRECT, true)
+                channel.queueBind(queueName, exchangeName, "")
+            }
+        }
+    }
+
+    protected fun consumeQueue(queueName: String, callback: DefaultConsumer.(DecodedMessage<*>) -> Unit) =
+        rabbitChannel.consumeQueue(queueName) { body ->
+            runBlocking {
+                followersFromMessage(body) {
+                    callback(it)
+                }
+            }
+        }
+
+    protected suspend fun followersFromMessage(body: ByteArray, action: suspend (DecodedMessage<*>) -> Unit) {
+        val rawMessage: String = body.toString(Charsets.UTF_8)
+        val notification: EntityNotificationMessage<*> = NotificationMessage.fromString(rawMessage)
+        val follows = when (notification.type) {
+            "article" -> followArticleRepo.findFollowsByTarget(notification.target)
+            "constitution" -> followConstitutionRepo.findFollowsByTarget(notification.target)
+            "citizen" -> followCitizenRepo.findFollowsByTarget(notification.target)
+            else -> error("event '${notification.type}' not implemented")
+        }
+
+        follows.collect { action(DecodedMessage(notification, rawMessage, it)) }
+    }
+
+    protected class DecodedMessage <E : Entity> (
+        val event: EntityNotificationMessage<E>,
+        val rawMessage: String,
+        val follow: FollowForView<out TargetRef>
+    )
+}

src/main/kotlin/fr/dcproject/component/notification/NotificationEmailSender.kt

@@ -1,70 +0,0 @@
-package fr.dcproject.component.notification
-
-import com.sendgrid.helpers.mail.Mail
-import com.sendgrid.helpers.mail.objects.Content
-import com.sendgrid.helpers.mail.objects.Email
-import fr.dcproject.common.email.Mailer
-import fr.dcproject.common.entity.EntityI
-import fr.dcproject.common.entity.TargetRef
-import fr.dcproject.component.article.database.ArticleRepository
-import fr.dcproject.component.article.database.ArticleWithTitleI
-import fr.dcproject.component.citizen.database.CitizenCreatorI
-import fr.dcproject.component.citizen.database.CitizenRepository
-import fr.dcproject.component.follow.database.FollowForView
-import java.util.UUID
-
-class NotificationEmailSender(
-    private val mailer: Mailer,
-    private val domain: String,
-    private val citizenRepo: CitizenRepository,
-    private val articleRepo: ArticleRepository
-) {
-    fun sendEmail(follow: FollowForView<out TargetRef>) {
-        val citizen = citizenRepo.findById(follow.createdBy.id) ?: noCitizen(follow.createdBy.id)
-        val target = when (follow.target.reference) {
-            "article" ->
-                articleRepo.findById(follow.target.id) ?: noTarget(follow.target.id)
-            else -> noTarget(follow.target.id)
-        }
-        val subject = when (follow.target.reference) {
-            "article" -> """New version for article "${target.title}""""
-            else -> "Notification"
-        }
-        mailer.sendEmail {
-            Mail(
-                Email("notification@$domain"),
-                subject,
-                Email(citizen.email),
-                Content("text/plain", generateContent(citizen, target))
-            ).apply {
-                addContent(Content("text/html", generateHtmlContent(citizen, target)))
-            }
-        }
-    }
-
-    private fun generateHtmlContent(citizen: CitizenCreatorI, target: EntityI): String? {
-        return when (target) {
-            is ArticleWithTitleI -> """
-                Hello ${citizen.name.getFullName()},<br/>
-                The article "${target.title}" was updated, check it <a href="http://$domain/articles/${target.id}">here</a>
-            """.trimIndent()
-            else -> noTarget(target.id)
-        }
-    }
-
-    private fun generateContent(citizen: CitizenCreatorI, target: EntityI): String {
-        return when (target) {
-            is ArticleWithTitleI -> """
-                Hello ${citizen.name.getFullName()},
-                The article "${target.title}" was updated, check it here: http://$domain/articles/${target.id}
-            """.trimIndent()
-            else -> noTarget(target.id)
-        }
-    }
-
-    class NoCitizen(message: String) : Exception(message)
-    class NoTarget(message: String) : Exception(message)
-
-    private fun noCitizen(id: UUID): Nothing = throw NoCitizen("No Citizen with this id : $id")
-    private fun noTarget(id: UUID): Nothing = throw NoTarget("No Target with this id : $id")
-}

src/main/kotlin/fr/dcproject/component/notification/NotificationMessage.kt

@@ -16,9 +16,9 @@ import java.util.concurrent.atomic.AtomicInteger
 
 @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.EXISTING_PROPERTY, property = "type", visible = true)
 @JsonSubTypes(
-    JsonSubTypes.Type(value = ArticleUpdateNotification::class, name = "article")
+    JsonSubTypes.Type(value = ArticleUpdateNotificationMessage::class, name = "article")
 )
-open class Notification(
+open class NotificationMessage(
     val type: String,
     val createdAt: DateTime = DateTime.now()
 ) {
@@ -48,16 +48,16 @@ open class Notification(
             configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
         }
 
-        inline fun <reified T : Notification> fromString(raw: String): T = mapper.readValue(raw)
+        inline fun <reified T : NotificationMessage> fromString(raw: String): T = mapper.readValue(raw)
     }
 }
 
-open class EntityNotification(
-    val target: Entity,
+open class EntityNotificationMessage <E : Entity> (
+    val target: E,
     type: String,
     val action: String
-) : Notification(type)
+) : NotificationMessage(type)
 
-class ArticleUpdateNotification(
+class ArticleUpdateNotificationMessage(
     target: ArticleForView
-) : EntityNotification(target, "article", "update")
+) : EntityNotificationMessage<ArticleForView>(target, "article", "update")

src/main/kotlin/fr/dcproject/component/notification/NotificationPublisherAsync.kt

@@ -7,12 +7,15 @@ import kotlinx.coroutines.coroutineScope
 import org.slf4j.Logger
 import org.slf4j.LoggerFactory
 
-class Publisher(
+class NotificationPublisherAsync(
     private val factory: ConnectionFactory,
-    private val logger: Logger = LoggerFactory.getLogger(Publisher::class.qualifiedName),
+    private val logger: Logger = LoggerFactory.getLogger(NotificationPublisherAsync::class.qualifiedName),
     private val exchangeName: String,
 ) {
-    suspend fun <T : EntityNotification> publish(it: T): Deferred<Unit> = coroutineScope {
+    /**
+     * Publish a new notification message to RabbitMQ
+     */
+    suspend fun <T : EntityNotificationMessage<*>> publishAsync(it: T): Deferred<Unit> = coroutineScope {
         async {
             factory.newConnection().use { connection ->
                 connection.createChannel().use { channel ->

src/main/kotlin/fr/dcproject/component/notification/email/NotificationEmailConsumer.kt

@@ -0,0 +1,33 @@
+package fr.dcproject.component.notification.email
+
+import com.rabbitmq.client.ConnectionFactory
+import fr.dcproject.component.follow.database.FollowArticleRepository
+import fr.dcproject.component.follow.database.FollowCitizenRepository
+import fr.dcproject.component.follow.database.FollowConstitutionRepository
+import fr.dcproject.component.notification.NotificationConsumerAbstract
+import org.slf4j.Logger
+import org.slf4j.LoggerFactory
+
+class NotificationEmailConsumer(
+    rabbitFactory: ConnectionFactory,
+    followConstitutionRepo: FollowConstitutionRepository,
+    followArticleRepo: FollowArticleRepository,
+    followCitizenRepo: FollowCitizenRepository,
+    private val notificationEmailSender: NotificationEmailSender,
+    private val exchangeName: String,
+) : NotificationConsumerAbstract(rabbitFactory, followConstitutionRepo, followArticleRepo, followCitizenRepo) {
+    private val logger: Logger = LoggerFactory.getLogger(NotificationEmailConsumer::class.qualifiedName)
+
+    fun start() {
+        /* Config Rabbit */
+        declareQueue(QUEUE_NAME, exchangeName)
+        consumeQueue(QUEUE_NAME) { message ->
+            notificationEmailSender.sendEmail(message.follow)
+            logger.debug("EmailSend to: ${message.follow.createdBy.id}")
+        }
+    }
+
+    companion object {
+        private const val QUEUE_NAME = "email"
+    }
+}

src/main/kotlin/fr/dcproject/component/notification/email/NotificationEmailSender.kt

@@ -0,0 +1,70 @@
+package fr.dcproject.component.notification.email
+
+import com.sendgrid.helpers.mail.Mail
+import com.sendgrid.helpers.mail.objects.Content
+import com.sendgrid.helpers.mail.objects.Email
+import fr.dcproject.common.email.Mailer
+import fr.dcproject.common.entity.TargetRef
+import fr.dcproject.component.article.database.ArticleForView
+import fr.dcproject.component.article.database.ArticleRepository
+import fr.dcproject.component.citizen.database.Citizen
+import fr.dcproject.component.citizen.database.CitizenRepository
+import fr.dcproject.component.follow.database.FollowForView
+import fr.dcproject.component.notification.email.content.ArticleNotificationEmailContent
+import fr.dcproject.component.notification.email.content.CitizenNotificationEmailContent
+import java.util.UUID
+
+/**
+ * Send notification email on the follower
+ */
+class NotificationEmailSender(
+    private val mailer: Mailer,
+    private val domain: String,
+    private val citizenRepo: CitizenRepository,
+    private val articleRepo: ArticleRepository
+) {
+    /**
+     * Send the Notification Email to the follower user
+     */
+    fun sendEmail(follow: FollowForView<out TargetRef>) {
+        val citizen = citizenRepo.findById(follow.createdBy.id) ?: noCitizen(follow.createdBy.id)
+
+        /**
+         * Find the complete target entity by its ID according to its reference
+         */
+        val target = when (follow.target.reference) {
+            "article" -> articleRepo.findById(follow.target.id) ?: noTarget(follow.target.id)
+            "citizen" -> citizenRepo.findById(follow.target.id) ?: noTarget(follow.target.id)
+            else -> noTarget(follow.target.id)
+        }
+
+        /**
+         * Find content of the email according to the target type
+         */
+        val content = when (target) {
+            is ArticleForView -> ArticleNotificationEmailContent(citizen, target, domain)
+            is Citizen -> CitizenNotificationEmailContent(citizen, target, domain)
+            else -> noTargetTypeImplementation(follow.target.reference)
+        }
+
+        /* Send email */
+        mailer.sendEmail {
+            Mail(
+                Email("notification@$domain"),
+                content.subject,
+                Email(citizen.email),
+                Content("text/plain", content.content)
+            ).apply {
+                addContent(Content("text/html", content.contentHtml))
+            }
+        }
+    }
+
+    class NoCitizen(message: String) : Exception(message)
+    class NoTarget(message: String) : Exception(message)
+    class NoTargetTypeImplement(message: String) : Exception(message)
+
+    private fun noCitizen(id: UUID): Nothing = throw NoCitizen("No Citizen with this id : $id")
+    private fun noTarget(id: UUID): Nothing = throw NoTarget("No Target with this id : $id")
+    private fun noTargetTypeImplementation(type: String): Nothing = throw NoTargetTypeImplement("No Target type implemented: $type")
+}

src/main/kotlin/fr/dcproject/component/notification/email/content/ArticleNotificationEmailContent.kt

@@ -0,0 +1,29 @@
+package fr.dcproject.component.notification.email.content
+
+import fr.dcproject.component.article.database.ArticleWithTitleI
+import fr.dcproject.component.citizen.database.Citizen
+
+class ArticleNotificationEmailContent(
+    private val citizen: Citizen,
+    private val target: ArticleWithTitleI,
+    private val domain: String,
+) : NotificationEmailContent {
+    override val subject: String
+        get() = """New version for article "${target.title}""""
+
+    override val contentHtml
+        get() = run {
+            """
+                Hello ${citizen.name.getFullName()},<br/>
+                The article "${target.title}" was updated, check it <a href="http://$domain/articles/${target.id}">here</a>
+            """.trimIndent()
+        }
+
+    override val content
+        get() = run {
+            """
+                Hello ${citizen.name.getFullName()},
+                The article "${target.title}" was updated, check it here: http://$domain/articles/${target.id}
+            """.trimIndent()
+        }
+}

src/main/kotlin/fr/dcproject/component/notification/email/content/CitizenNotificationEmailContent.kt

@@ -0,0 +1,28 @@
+package fr.dcproject.component.notification.email.content
+
+import fr.dcproject.component.citizen.database.Citizen
+
+class CitizenNotificationEmailContent(
+    private val citizen: Citizen,
+    private val target: Citizen,
+    private val domain: String,
+) : NotificationEmailContent {
+    override val subject: String
+        get() = """New activity for the citizen "${target.name}""""
+
+    override val contentHtml
+        get() = run {
+            """
+                Hello ${citizen.name.getFullName()},
+                The citizen "${target.name}" was new activity, check it here: <a href="http://$domain/citizens/${target.id}">here</a>
+            """.trimIndent()
+        }
+
+    override val content
+        get() = run {
+            """
+                Hello ${citizen.name.getFullName()},
+                The citizen "${target.name}" was new activity, check it here: http://$domain/citizens/${target.id}
+            """.trimIndent()
+        }
+}

src/main/kotlin/fr/dcproject/component/notification/email/content/NotificationEmailContent.kt

@@ -0,0 +1,7 @@
+package fr.dcproject.component.notification.email.content
+
+interface NotificationEmailContent {
+    val subject: String
+    val content: String
+    val contentHtml: String
+}

src/main/kotlin/fr/dcproject/component/notification/push/NotificationPushConsumer.kt

@@ -0,0 +1,41 @@
+package fr.dcproject.component.notification.push
+
+import com.rabbitmq.client.ConnectionFactory
+import fr.dcproject.component.follow.database.FollowArticleRepository
+import fr.dcproject.component.follow.database.FollowCitizenRepository
+import fr.dcproject.component.follow.database.FollowConstitutionRepository
+import fr.dcproject.component.notification.NotificationConsumerAbstract
+import io.lettuce.core.RedisClient
+import io.lettuce.core.api.async.RedisAsyncCommands
+import org.slf4j.Logger
+import org.slf4j.LoggerFactory
+
+class NotificationPushConsumer(
+    rabbitFactory: ConnectionFactory,
+    followConstitutionRepo: FollowConstitutionRepository,
+    followArticleRepo: FollowArticleRepository,
+    followCitizenRepo: FollowCitizenRepository,
+    redisClient: RedisClient,
+    private val exchangeName: String,
+) : NotificationConsumerAbstract(rabbitFactory, followConstitutionRepo, followArticleRepo, followCitizenRepo) {
+    private val redisConnection = redisClient.connect() ?: error("Unable to connect to redis")
+    private val redis: RedisAsyncCommands<String, String> = redisConnection.async() ?: error("Unable to connect to redis")
+    private val logger: Logger = LoggerFactory.getLogger(NotificationPushConsumer::class.qualifiedName)
+
+    fun start() {
+        /* Config Rabbit */
+        declareQueue(QUEUE_NAME, exchangeName)
+        consumeQueue(QUEUE_NAME) { message ->
+            redis.zadd(
+                "notification:${message.follow.createdBy.id}",
+                message.event.id,
+                message.rawMessage
+            )
+            logger.debug("Notification was transferred to the redis (follower: ${message.follow.createdBy.id})")
+        }
+    }
+
+    companion object {
+        private const val QUEUE_NAME = "push"
+    }
+}

src/main/kotlin/fr/dcproject/component/notification/push/NotificationPushListener.kt

@@ -1,8 +1,9 @@
-package fr.dcproject.component.notification
+package fr.dcproject.component.notification.push
 
 import com.fasterxml.jackson.core.JsonProcessingException
 import fr.dcproject.component.auth.citizen
 import fr.dcproject.component.citizen.database.CitizenI
+import fr.dcproject.component.notification.NotificationMessage
 import io.ktor.http.cio.websocket.Frame
 import io.ktor.http.cio.websocket.Frame.Text
 import io.ktor.http.cio.websocket.readText
@@ -28,31 +29,42 @@ import kotlinx.coroutines.launch
 import kotlinx.coroutines.runBlocking
 import org.slf4j.LoggerFactory
 
-class NotificationsPush(
+/**
+ * Listen a custom flow to mark as read a message.
+ *
+ * And listen the redis subscription flow and call a callback when a new message arrives
+ */
+class NotificationPushListener(
     private val redis: RedisAsyncCommands<String, String>,
     private val redisConnectionPubSub: StatefulRedisPubSubConnection<String, String>,
     citizen: CitizenI,
-    incoming: Flow<Notification>,
-    onReceive: suspend (Notification) -> Unit,
+    incoming: Flow<NotificationMessage>,
+    onReceive: suspend (NotificationMessage) -> Unit,
 ) {
-    class Builder(val redisClient: RedisClient) {
+    class Builder(redisClient: RedisClient) {
         private val redisConnection = redisClient.connect() ?: error("Unable to connect to redis")
         private val redisConnectionPubSub = redisClient.connectPubSub() ?: error("Unable to connect to redis PubSub")
         private val redis: RedisAsyncCommands<String, String> = redisConnection.async() ?: error("Unable to connect to redis Async")
 
+        /**
+         * Build Listener with citizen, incoming flow and set an outgoing callback
+         */
         fun build(
             citizen: CitizenI,
-            incoming: Flow<Notification>,
-            onReceive: suspend (Notification) -> Unit,
-        ): NotificationsPush = NotificationsPush(redis, redisConnectionPubSub, citizen, incoming, onReceive)
+            incoming: Flow<NotificationMessage>,
+            onReceive: suspend (NotificationMessage) -> Unit,
+        ): NotificationPushListener = NotificationPushListener(redis, redisConnectionPubSub, citizen, incoming, onReceive)
 
+        /**
+         * Build NotificationPush with only a WebSocket session
+         */
         @ExperimentalCoroutinesApi
-        fun build(ws: DefaultWebSocketServerSession): NotificationsPush {
+        fun build(ws: DefaultWebSocketServerSession): NotificationPushListener {
             /* Convert channel of string from websocket, to a flow of Notification object */
-            val incomingFlow: Flow<Notification> = ws.incoming.consumeAsFlow()
+            val incomingFlow: Flow<NotificationMessage> = ws.incoming.consumeAsFlow()
                 .mapNotNull<Frame, Text> { it as? Frame.Text }
                 .map { it.readText() }
-                .map { Notification.fromString(it) }
+                .map { NotificationMessage.fromString(it) }
 
             return build(ws.call.citizen, incomingFlow) {
                 ws.outgoing.send(Text(it.toString()))
@@ -62,30 +74,42 @@ class NotificationsPush(
         }
     }
 
+    /**
+     * The key of the SortedSet in Redis which contains all the messages of a user
+     */
     private val key = "notification:${citizen.id}"
-    private var score: Double = 0.0
+    /**
+     * The last score (a kind of sorted ids) of message
+     */
+    private var lastScore: Double = 0.0
+    /**
+     * Configure the listener to listen all new notifications
+     */
     private val listener = object : RedisPubSubAdapter<String, String>() {
         /* On new key publish */
         override fun message(pattern: String?, channel: String?, message: String?) {
             runBlocking {
-                getNotifications().collect {
+                getNewUnreadNotifications().collect {
                     onReceive(it)
                 }
             }
         }
     }
 
+    /**
+     * Init the listener and the callback
+     */
     init {
         /* Mark as read all incoming notifications */
         GlobalScope.launch {
             incoming.collect {
-                markAsRead(it)
+                it.markAsRead()
             }
         }
 
         /* Get old notification and sent it to websocket */
         runBlocking {
-            getNotifications().collect {
+            getNewUnreadNotifications().collect {
                 onReceive(it)
             }
         }
@@ -99,34 +123,51 @@ class NotificationsPush(
         }
     }
 
+    /**
+     * Close the redis subscription
+     */
     fun close() {
         redisConnectionPubSub.removeListener(listener)
     }
 
-    /* Return flow with all new notifications */
-    private fun getNotifications() = flow<Notification> {
+    /**
+     * Get All new notification from redis and
+     * Return flow with notifications
+     *
+     * On start, on the first call, this method return all unread notification of the user
+     *
+     * Internally this method return all messages that greater of the lastScore,
+     * then define the lastScore with the score of the last message.
+     */
+    private fun getNewUnreadNotifications() = flow<NotificationMessage> {
         redis
             .zrangebyscoreWithScores(
                 key,
                 Range.from(
-                    Boundary.excluding(score),
+                    Boundary.excluding(lastScore),
                     Boundary.including(Double.POSITIVE_INFINITY)
                 ),
                 Limit.from(100)
             )
             .get().forEach {
-                emit(Notification.fromString(it.value))
-                if (it.score > score) score = it.score
+                /* Build message object from raw string and return it */
+                emit(NotificationMessage.fromString(it.value))
+                if (it.score > lastScore) lastScore = it.score
             }
     }
 
-    private suspend fun markAsRead(notificationMessage: Notification) = coroutineScope {
+    /**
+     * Mark one notification as read.
+     *
+     * Internally, this method remove the message of the SortedSet in redis
+     */
+    private suspend fun NotificationMessage.markAsRead() = coroutineScope {
         try {
             redis.zremrangebyscore(
                 key,
                 Range.from(
-                    Boundary.including(notificationMessage.id),
-                    Boundary.including(notificationMessage.id)
+                    Boundary.including(id),
+                    Boundary.including(id)
                 )
             )
         } catch (e: JsonProcessingException) {

src/main/kotlin/fr/dcproject/component/notification/routes/Notification.kt

@@ -1,6 +1,6 @@
 package fr.dcproject.component.notification.routes
 
-import fr.dcproject.component.notification.NotificationsPush
+import fr.dcproject.component.notification.push.NotificationPushListener
 import io.ktor.locations.KtorExperimentalLocationsAPI
 import io.ktor.routing.Route
 import io.ktor.websocket.webSocket
@@ -13,8 +13,8 @@ import kotlinx.coroutines.ExperimentalCoroutinesApi
  */
 @ExperimentalCoroutinesApi
 @KtorExperimentalLocationsAPI
-fun Route.notificationArticle(pushBuilder: NotificationsPush.Builder) {
+fun Route.notificationArticle(pushListenerBuilder: NotificationPushListener.Builder) {
     webSocket("/notifications") {
-        pushBuilder.build(this)
+        pushListenerBuilder.build(this)
     }
 }

src/test/kotlin/functional/NotificationConsumerTest.kt

@@ -10,10 +10,11 @@ import fr.dcproject.component.citizen.database.CitizenCreator
 import fr.dcproject.component.citizen.database.CitizenI
 import fr.dcproject.component.follow.database.FollowArticleRepository
 import fr.dcproject.component.follow.database.FollowForView
-import fr.dcproject.component.notification.ArticleUpdateNotification
-import fr.dcproject.component.notification.NotificationConsumer
-import fr.dcproject.component.notification.NotificationEmailSender
-import fr.dcproject.component.notification.Publisher
+import fr.dcproject.component.notification.ArticleUpdateNotificationMessage
+import fr.dcproject.component.notification.NotificationPublisherAsync
+import fr.dcproject.component.notification.email.NotificationEmailConsumer
+import fr.dcproject.component.notification.email.NotificationEmailSender
+import fr.dcproject.component.notification.push.NotificationPushConsumer
 import io.ktor.locations.KtorExperimentalLocationsAPI
 import io.ktor.util.KtorExperimentalAPI
 import io.lettuce.core.RedisClient
@@ -88,9 +89,8 @@ class NotificationConsumerTest {
         }
 
         /* Config consumer */
-        val consumer = NotificationConsumer(
+        val emailConsumer = NotificationEmailConsumer(
             rabbitFactory = rabbitFactory,
-            redisClient = redisClient,
             followArticleRepo = followArticleRepo,
             followConstitutionRepo = mockk(), // TODO test followConstitution
             followCitizenRepo = mockk(), // TODO test followCitizen
@@ -98,12 +98,21 @@ class NotificationConsumerTest {
             exchangeName = "notification",
         ).apply { start() }
 
+        val pushConsumer = NotificationPushConsumer(
+            rabbitFactory = rabbitFactory,
+            followArticleRepo = followArticleRepo,
+            followConstitutionRepo = mockk(), // TODO test followConstitution
+            followCitizenRepo = mockk(), // TODO test followCitizen
+            redisClient = redisClient,
+            exchangeName = "notification",
+        ).apply { start() }
+
         /* Push message */
-        Publisher(
+        NotificationPublisherAsync(
             factory = rabbitFactory,
             exchangeName = "notification",
-        ).publish(
-            ArticleUpdateNotification(
+        ).publishAsync(
+            ArticleUpdateNotificationMessage(
                 ArticleForView(
                     title = "MyTitle",
                     content = "myContent",
@@ -122,6 +131,7 @@ class NotificationConsumerTest {
         verify(timeout = 2000) { emailSender.sendEmail(any()) }
         verify(timeout = 2000) { asyncCommand.zadd(any<String>(), any<Double>(), any<String>()) }
 
-        consumer.close()
+        emailConsumer.close()
+        pushConsumer.close()
     }
 }

src/test/kotlin/functional/NotificationsPushTest.kt

@@ -6,9 +6,9 @@ import fr.dcproject.component.article.database.ArticleForView
 import fr.dcproject.component.auth.database.UserCreator
 import fr.dcproject.component.citizen.database.CitizenCreator
 import fr.dcproject.component.citizen.database.CitizenI
-import fr.dcproject.component.notification.ArticleUpdateNotification
-import fr.dcproject.component.notification.Notification
-import fr.dcproject.component.notification.NotificationsPush
+import fr.dcproject.component.notification.ArticleUpdateNotificationMessage
+import fr.dcproject.component.notification.NotificationMessage
+import fr.dcproject.component.notification.push.NotificationPushListener
 import io.lettuce.core.RedisClient
 import io.mockk.every
 import io.mockk.spyk
@@ -68,14 +68,14 @@ internal class NotificationsPushTest {
             title = "Super Title",
         )
         /* Init two notification, one called before subscription, and the other after */
-        val notifBeforeSubscribe = ArticleUpdateNotification(article)
+        val notifBeforeSubscribe = ArticleUpdateNotificationMessage(article)
         runBlocking {
             delay(100)
         }
-        val notifAfterSubscribe = ArticleUpdateNotification(article)
+        val notifAfterSubscribe = ArticleUpdateNotificationMessage(article)
 
         /* init event for emulate incoming message from websocket */
-        val event = MutableSharedFlow<Notification>()
+        val event = MutableSharedFlow<NotificationMessage>()
         val incomingFlow = event.asSharedFlow()
 
         spyk(object { var counter = 0 }).run { /* Counter for count the callback of notification */
@@ -90,7 +90,7 @@ internal class NotificationsPushTest {
             }
 
             /* Init NotificationPush system, and set assertion in callback */
-            val notificationPush = NotificationsPush.Builder(redisClient).build(citizen, incomingFlow) {
+            val notificationPush = NotificationPushListener.Builder(redisClient).build(citizen, incomingFlow) {
                 counter++
                 if (counter == 1) it.id `should be equal to` notifBeforeSubscribe.id
                 else it.id `should be equal to` notifAfterSubscribe.id

src/test/kotlin/integration/Notification routes.kt

@@ -1,25 +1,19 @@
 package integration
 
-import fr.dcproject.common.utils.toUUID
-import fr.dcproject.component.article.database.ArticleForView
-import fr.dcproject.component.auth.database.UserCreator
-import fr.dcproject.component.citizen.database.CitizenCreator
 import fr.dcproject.component.citizen.database.CitizenI.Name
-import fr.dcproject.component.notification.ArticleUpdateNotification
-import fr.dcproject.component.notification.Notification
-import fr.dcproject.component.notification.Publisher
+import fr.dcproject.component.notification.ArticleUpdateNotificationMessage
+import fr.dcproject.component.notification.NotificationMessage
+import integration.steps.given.`Given I have article update notification`
 import integration.steps.given.`Given I have article`
 import integration.steps.given.`Given I have citizen`
 import integration.steps.given.`Given I have follow on article`
 import integration.steps.given.`authenticated in url as`
 import io.ktor.http.cio.websocket.Frame
 import io.ktor.http.cio.websocket.readText
-import kotlinx.coroutines.launch
 import org.junit.jupiter.api.Tag
 import org.junit.jupiter.api.Tags
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.TestInstance
-import org.koin.test.get
 import kotlin.test.assertEquals
 
 @TestInstance(TestInstance.Lifecycle.PER_CLASS)
@@ -31,26 +25,7 @@ class `Notification routes` : BaseTest() {
             `Given I have citizen`("John", "Doe", id = "1a34191a-9cde-45ba-8ac1-230138a102d3")
             `Given I have article`(id = "a06cbfb7-3094-4d64-aaa1-7486c0c292f4", createdBy = Name(firstName = "John", lastName = "Doe"))
             `Given I have follow on article`("John", "Doe", article = "a06cbfb7-3094-4d64-aaa1-7486c0c292f4")
-            val notification = ArticleUpdateNotification(
-                ArticleForView(
-                    id = "a06cbfb7-3094-4d64-aaa1-7486c0c292f4".toUUID(),
-                    title = "MyTitle",
-                    content = "myContent",
-                    description = "myDescription",
-                    createdBy = CitizenCreator(
-                        id = "1a34191a-9cde-45ba-8ac1-230138a102d3".toUUID(),
-                        name = Name(firstName = "John", lastName = "Doe"),
-                        email = "john-doe@plop.com",
-                        user = UserCreator(username = "john-doe"),
-                    )
-                )
-            )
-            val publisher = get<Publisher>()
-            launch {
-                publisher
-                    .publish(notification)
-                    .await()
-            }
+            `Given I have article update notification`("a06cbfb7-3094-4d64-aaa1-7486c0c292f4")
 
             Thread.sleep(1000)
 
@@ -62,7 +37,7 @@ class `Notification routes` : BaseTest() {
             ) { incoming, outgoing ->
                 incoming.receive().let {
                     when (it) {
-                        is Frame.Text -> Notification.fromString<ArticleUpdateNotification>(it.readText()).let { notif ->
+                        is Frame.Text -> NotificationMessage.fromString<ArticleUpdateNotificationMessage>(it.readText()).let { notif ->
                             assertEquals(
                                 "a06cbfb7-3094-4d64-aaa1-7486c0c292f4",
                                 notif.target.id.toString()

src/test/kotlin/integration/steps/given/Notification.kt

@@ -0,0 +1,40 @@
+package integration.steps.given
+
+import fr.dcproject.common.utils.toUUID
+import fr.dcproject.component.article.database.ArticleForView
+import fr.dcproject.component.auth.database.UserCreator
+import fr.dcproject.component.citizen.database.CitizenCreator
+import fr.dcproject.component.citizen.database.CitizenI
+import fr.dcproject.component.notification.ArticleUpdateNotificationMessage
+import fr.dcproject.component.notification.NotificationPublisherAsync
+import io.ktor.server.testing.TestApplicationEngine
+import kotlinx.coroutines.launch
+import org.koin.mp.KoinPlatformTools
+import java.util.UUID
+
+fun TestApplicationEngine.`Given I have article update notification`(
+    id: String = UUID.randomUUID().toString()
+) {
+    val notification = ArticleUpdateNotificationMessage(
+        ArticleForView(
+            id = id.toUUID(),
+            title = "MyTitle",
+            content = "myContent",
+            description = "myDescription",
+            createdBy = CitizenCreator(
+                id = "1a34191a-9cde-45ba-8ac1-230138a102d3".toUUID(),
+                name = CitizenI.Name(firstName = "John", lastName = "Doe"),
+                email = "john-doe@plop.com",
+                user = UserCreator(username = "john-doe"),
+            )
+        )
+    )
+    launch {
+        KoinPlatformTools
+            .defaultContext()
+            .get()
+            .get<NotificationPublisherAsync>()
+            .publishAsync(notification)
+            .await()
+    }
+}