Server : Campaign error management

server/src/main/kotlin/com/pixelized/server/lwa/model/campaign/CampaignService.kt

@@ -37,223 +37,95 @@ class CampaignService(
         return campaignJsonFlow.value
     }
 
+    @Throws
     fun addCharacter(
         characterSheetId: String,
-    ): Boolean {
+    ) {
-        // check if the character is already in the campaign.
+        // Check if the character is already in the campaign.
-        if (campaign.characters.contains(characterSheetId)) return false
+        if (campaign.instances.contains(characterSheetId)) {
-        // update the corresponding instance
+            val root = Exception("Character with id:$characterSheetId is already in the campaign.")
-        val characters = campaign.characters.toMutableSet().also { it.add(characterSheetId) }
+            throw CampaignStore.BusinessException(root = root)
-        // save the campaign to the disk (update the flow).
-        return try {
-            store.save(
-                campaign = campaign.copy(characters = characters)
-            )
-            true
-        } catch (exception: Exception) {
-            false
         }
-    }
+        // Update the corresponding instance
-
+        val characters = campaign.characters.toMutableSet().also {
-    suspend fun addNpc(
+            it.add(characterSheetId)
-        characterSheetId: String,
-    ): Boolean {
-        // check if the character is already in the campaign.
-        if (campaign.npcs.contains(characterSheetId)) return false
-        // update the corresponding instance
-        val characters = campaign.npcs.toMutableSet().also { it.add(characterSheetId) }
-        // save the campaign to the disk (update the flow).
-        return try {
-            store.save(
-                campaign = campaign.copy(npcs = characters)
-            )
-            true
-        } catch (exception: Exception) {
-            false
         }
+        // Save the campaign to the disk (update the flow).
+        store.save(
+            campaign = campaign.copy(characters = characters)
+        )
     }
 
-    suspend fun removeCharacter(
+    @Throws
+    fun addNpc(
         characterSheetId: String,
-    ): Boolean {
+    ) {
-        // check if the character is in the campaign.
+        // Check if the character is already in the campaign.
-        if (campaign.characters.contains(characterSheetId).not()) return false
+        if (campaign.instances.contains(characterSheetId)) {
-        // update the corresponding instance
+            val root = Exception("Character with id:$characterSheetId is already in the campaign.")
-        val characters = campaign.characters.toMutableSet().also { it.remove(characterSheetId) }
+            throw CampaignStore.BusinessException(root = root)
-        // save the campaign to the disk + update the flow.
-        return try {
-            store.save(
-                campaign = campaign.copy(characters = characters)
-            )
-            true
-        } catch (exception: Exception) {
-            false
         }
-    }
+        // Update the corresponding instance
-
+        val characters = campaign.npcs.toMutableSet().also {
-    suspend fun removeNpc(
+            it.add(characterSheetId)
-        characterSheetId: String,
-    ): Boolean {
-        // check if the character is in the campaign.
-        if (campaign.npcs.contains(characterSheetId).not()) return false
-        // update the corresponding instance
-        val characters = campaign.npcs.toMutableSet().also { it.remove(characterSheetId) }
-        // save the campaign to the disk + update the flow.
-        return try {
-            store.save(
-                campaign = campaign.copy(npcs = characters)
-            )
-            true
-        } catch (exception: Exception) {
-            false
         }
+        // Save the campaign to the disk (update the flow).
+        store.save(
+            campaign = campaign.copy(npcs = characters)
+        )
     }
 
-    suspend fun removeInstance(
+    @Throws
+    fun removeCharacter(
         characterSheetId: String,
-    ): Boolean {
+    ) {
-        return removeCharacter(characterSheetId) || removeNpc(characterSheetId)
+        // Check if the character is in the campaign.
+        if (campaign.characters.contains(characterSheetId).not()) {
+            val root = Exception("Character with id:$characterSheetId is not in the party.")
+            throw CampaignStore.BusinessException(root = root)
+        }
+        // Update the corresponding instance
+        val characters = campaign.characters.toMutableSet().also {
+            it.remove(characterSheetId)
+        }
+        // Save the campaign to the disk + update the flow.
+        store.save(
+            campaign = campaign.copy(characters = characters)
+        )
     }
 
-    suspend fun setScene(
+    @Throws
+    fun removeNpc(
+        characterSheetId: String,
+    ) {
+        // Check if the character is in the campaign.
+        if (campaign.npcs.contains(characterSheetId).not()) {
+            val root = Exception("Character with id:$characterSheetId is not in the npcs.")
+            throw CampaignStore.BusinessException(root = root)
+        }
+        // Update the corresponding instance
+        val characters = campaign.npcs.toMutableSet().also {
+            it.remove(characterSheetId)
+        }
+        // Save the campaign to the disk + update the flow.
+        store.save(
+            campaign = campaign.copy(npcs = characters)
+        )
+    }
+
+    @Throws
+    fun setScene(
         scene: Campaign.Scene,
-    ): Boolean {
+    ) {
         // save the campaign to the disk + update the flow.
-        return try {
+        store.save(
-            store.save(
+            campaign = campaign.copy(scene = scene)
-                campaign.copy(scene = scene)
+        )
-            )
-            true
-        } catch (exception: Exception) {
-            false
-        }
     }
 
     // Data manipulation through WebSocket.
 
-//    suspend fun updateCharacteristic(
+    fun updateToggleParty() {
-//        characterInstanceId: Campaign.CharacterInstance.Id,
-//        characteristic: Campaign.CharacterInstance.Characteristic,
-//        value: Int,
-//    ) {
-//        when (characterInstanceId.prefix) {
-//            Campaign.CharacterInstance.Id.PLAYER -> {
-//                // fetch all the current campaign character
-//                val characters = campaign.characters.toMutableMap()
-//                // update the corresponding character using the use case.
-//                characters[characterInstanceId] = useCase.updateCharacteristic(
-//                    instance = campaign.character(id = characterInstanceId),
-//                    characteristic = characteristic,
-//                    value = value,
-//                )
-//                // save the campaign to the disk + update the flow.
-//                store.save(
-//                    campaign = campaign.copy(characters = characters)
-//                )
-//            }
-//
-//            Campaign.CharacterInstance.Id.NPC -> {
-//                // fetch all the current campaign character
-//                val npcs = campaign.npcs.toMutableMap()
-//                // update the corresponding character using the use case.
-//                npcs[characterInstanceId] = useCase.updateCharacteristic(
-//                    instance = campaign.npc(id = characterInstanceId),
-//                    characteristic = characteristic,
-//                    value = value,
-//                )
-//                // save the campaign to the disk + update the flow.
-//                store.save(
-//                    campaign = campaign.copy(npcs = npcs)
-//                )
-//            }
-//        }
-//    }
-//
-//    suspend fun updateDiminished(
-//        characterInstanceId: Campaign.CharacterInstance.Id,
-//        diminished: Int,
-//    ) {
-//        when (characterInstanceId.prefix) {
-//            Campaign.CharacterInstance.Id.PLAYER -> {
-//                // fetch all the current campaign character
-//                val characters = campaign.characters.toMutableMap()
-//                // update the corresponding character using the use case.
-//                characters[characterInstanceId] = useCase.updateDiminished(
-//                    instance = campaign.character(id = characterInstanceId),
-//                    diminished = diminished,
-//                )
-//                // save the campaign to the disk + update the flow.
-//                store.save(
-//                    campaign = campaign.copy(characters = characters)
-//                )
-//            }
-//
-//            Campaign.CharacterInstance.Id.NPC -> {
-//                // fetch all the current campaign character
-//                val npcs = campaign.npcs.toMutableMap()
-//                // update the corresponding character using the use case.
-//                npcs[characterInstanceId] = useCase.updateDiminished(
-//                    instance = campaign.npc(id = characterInstanceId),
-//                    diminished = diminished,
-//                )
-//                // save the campaign to the disk + update the flow.
-//                store.save(
-//                    campaign = campaign.copy(npcs = npcs)
-//                )
-//            }
-//        }
-//    }
-//
-//    suspend fun toggleAlteration(
-//        characterInstanceId: Campaign.CharacterInstance.Id,
-//        alterationId: String,
-//    ) {
-//        when (characterInstanceId.prefix) {
-//            Campaign.CharacterInstance.Id.PLAYER -> {
-//                // fetch all the current campaign character
-//                val characters = campaign.characters.toMutableMap()
-//                // update the corresponding character alterations
-//                characters[characterInstanceId]?.let { character ->
-//                    characters[characterInstanceId] = character.copy(
-//                        alterations = character.alterations.toMutableList().also { alterations ->
-//                            if (alterations.contains(alterationId)) {
-//                                alterations.remove(alterationId)
-//                            } else {
-//                                alterations.add(alterationId)
-//                            }
-//                        },
-//                    )
-//                }
-//                // save the campaign to the disk + update the flow.
-//                store.save(
-//                    campaign = campaign.copy(characters = characters)
-//                )
-//            }
-//
-//            Campaign.CharacterInstance.Id.NPC -> {
-//                // fetch all the current campaign character
-//                val characters = campaign.npcs.toMutableMap()
-//                // update the corresponding character alterations
-//                characters[characterInstanceId]?.let { character ->
-//                    characters[characterInstanceId] = character.copy(
-//                        alterations = character.alterations.toMutableList().also { alterations ->
-//                            if (alterations.contains(alterationId)) {
-//                                alterations.remove(alterationId)
-//                            } else {
-//                                alterations.add(alterationId)
-//                            }
-//                        },
-//                    )
-//                }
-//                // save the campaign to the disk + update the flow.
-//                store.save(
-//                    campaign = campaign.copy(npcs = characters)
-//                )
-//            }
-//        }
-//    }
-
-    suspend fun updateToggleParty() {
         store.save(
             campaign = campaign.copy(
                 options = campaign.options.copy(
@@ -263,7 +135,7 @@ class CampaignService(
         )
     }
 
-    suspend fun updateToggleNpc() {
+    fun updateToggleNpc() {
         store.save(
             campaign = campaign.copy(
                 options = campaign.options.copy(

server/src/main/kotlin/com/pixelized/server/lwa/model/campaign/CampaignStore.kt

@@ -1,5 +1,6 @@
 package com.pixelized.server.lwa.model.campaign
 
+import com.pixelized.server.lwa.model.alteration.AlterationStore.AlterationStoreException
 import com.pixelized.shared.lwa.model.campaign.Campaign
 import com.pixelized.shared.lwa.model.campaign.CampaignJson
 import com.pixelized.shared.lwa.model.campaign.factory.CampaignJsonFactory
@@ -9,6 +10,7 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import kotlinx.serialization.json.Json
 import java.io.File
@@ -27,15 +29,15 @@ class CampaignStore(
         val scope = CoroutineScope(Dispatchers.IO + Job())
         // load the initial data
         scope.launch {
-            updateCampaignFromDisk()
+            updateCampaignFlow()
         }
     }
 
     fun campaignFlow(): StateFlow<Campaign> = campaignFlow
 
-    private fun updateCampaignFromDisk() {
+    private fun updateCampaignFlow() {
         campaignFlow.value = try {
-            loadCampaign()
+            load()
         } catch (exception: Exception) {
             println(exception) // TODO proper exception handling
             Campaign.empty()
@@ -44,60 +46,74 @@ class CampaignStore(
 
     @Throws(
         FileReadException::class,
+        JsonCodingException::class,
         JsonConversionException::class,
     )
-    fun loadCampaign(): Campaign {
+    fun load(): Campaign {
-        val file = file()
+        val file = campaignFile()
-        val json = try {
+        // Read the campaign file.
+        val data = try {
             file.readText(charset = Charsets.UTF_8)
         } catch (exception: Exception) {
             throw FileReadException(root = exception)
         }
-
         // Guard, if the file is empty we load a default campaign.
-        if (json.isBlank()) return Campaign.empty()
+        if (data.isBlank()) return Campaign.empty()
-
+        // Decode the json into a string.
+        val json = try {
+            this.json.decodeFromString<CampaignJson>(data)
+        } catch (exception: Exception) {
+            throw JsonCodingException(root = exception)
+        }
+        // Convert from the Json format
         val campaign = try {
-            val data = this.json.decodeFromString<CampaignJson>(json)
+            factory.convertFromJson(json)
-            factory.convertFromJson(data)
         } catch (exception: Exception) {
             throw JsonConversionException(root = exception)
         }
-
         return campaign
     }
 
     @Throws(
         JsonConversionException::class,
+        JsonCodingException::class,
         FileWriteException::class,
     )
     fun save(campaign: Campaign) {
-        // convert the data to json format
+        // Transform the json into the model.
         val json = try {
-            factory.convertToJson(campaign = campaign).let(json::encodeToString)
+            factory.convertToJson(campaign = campaign)
         } catch (exception: Exception) {
             throw JsonConversionException(root = exception)
         }
-        // write the file
+        // Encode the json into a string.
+        val data = try {
+            this.json.encodeToString(json)
+        } catch (exception: Exception) {
+            throw JsonCodingException(root = exception)
+        }
+        // Write the file
         try {
-            val file = file()
+            val file = campaignFile()
             file.writeText(
-                text = json,
+                text = data,
                 charset = Charsets.UTF_8,
             )
         } catch (exception: Exception) {
             throw FileWriteException(root = exception)
         }
         // Update the dataflow.
-        campaignFlow.value = campaign
+        campaignFlow.update { campaign }
+    }
+
+    private fun campaignFile(): File {
+        return File("${pathProvider.campaignPath()}campaign.json")
     }
 
     sealed class CampaignStoreException(root: Exception) : Exception(root)
     class JsonConversionException(root: Exception) : CampaignStoreException(root)
+    class JsonCodingException(root: Exception) : CampaignStoreException(root)
+    class BusinessException(root: Exception) : CampaignStoreException(root)
     class FileWriteException(root: Exception) : CampaignStoreException(root)
     class FileReadException(root: Exception) : CampaignStoreException(root)
-
-    private fun file(): File {
-        return File("${pathProvider.campaignPath()}campaign.json")
-    }
 }

server/src/main/kotlin/com/pixelized/server/lwa/server/rest/alteration/DELETE_Alteration.kt

@@ -11,11 +11,13 @@ import io.ktor.server.response.respond
 fun Engine.deleteAlteration(): suspend io.ktor.server.routing.RoutingContext.() -> Unit {
     return {
         try {
+            // get the query parameter
             val alterationId = call.parameters.alterationId
-
+            // delete the alteration.
             alterationService.delete(
                 alterationId = alterationId
             )
+            // API & WebSocket responses.
             call.respond(
                 message = ResultJson.Success(),
             )
@@ -32,13 +34,6 @@ fun Engine.deleteAlteration(): suspend io.ktor.server.routing.RoutingContext.()
                     message = exception.message ?: "?",
                 )
             )
-        } catch (exception: AlterationStore.BusinessException) {
-            call.respond(
-                message = ResultJson.Error(
-                    status = ResultJson.Error.FILE_DOES_NOT_EXIST,
-                    message = "Alteration doesn't exist."
-                )
-            )
         } catch (exception: Exception) {
             call.respond(
                 message = ResultJson.Error(

server/src/main/kotlin/com/pixelized/server/lwa/server/rest/alteration/PUT_Alateration.kt

@@ -36,13 +36,6 @@ fun Engine.putAlteration(): suspend io.ktor.server.routing.RoutingContext.() ->
                     message = exception.message ?: "?",
                 )
             )
-        } catch (exception: AlterationStore.BusinessException) {
-            call.respond(
-                message = ResultJson.Error(
-                    status = ResultJson.Error.FILE_ALREADY_EXIST,
-                    message = "Alteration file already exist."
-                )
-            )
         } catch (exception: Exception) {
             call.respond(
                 message = ResultJson.Error(

server/src/main/kotlin/com/pixelized/server/lwa/server/rest/campaign/DELETE_Campaign_Character.kt

@@ -1,10 +1,11 @@
 package com.pixelized.server.lwa.server.rest.campaign
 
 import com.pixelized.server.lwa.server.Engine
+import com.pixelized.server.lwa.utils.extentions.MissingParameterException
 import com.pixelized.server.lwa.utils.extentions.characterSheetId
+import com.pixelized.shared.lwa.protocol.rest.ResultJson
 import com.pixelized.shared.lwa.protocol.websocket.CampaignEvent
-import io.ktor.http.HttpStatusCode
+import io.ktor.server.response.respond
-import io.ktor.server.response.respondText
 
 fun Engine.removeCampaignCharacter(): suspend io.ktor.server.routing.RoutingContext.() -> Unit {
     return {
@@ -12,17 +13,12 @@ fun Engine.removeCampaignCharacter(): suspend io.ktor.server.routing.RoutingCont
             // get the query parameter
             val characterSheetId = call.queryParameters.characterSheetId
             // remove the character form the party
-            val updated = campaignService.removeCharacter(
+            campaignService.removeCharacter(
                 characterSheetId = characterSheetId,
             )
-            // error case
-            if (updated.not()) {
-                error("Unexpected error when removing character (characterSheetId:$characterSheetId) from party.")
-            }
             // API & WebSocket responses
-            call.respondText(
+            call.respond(
-                text = "${HttpStatusCode.OK}",
+                message = ResultJson.Success(),
-                status = HttpStatusCode.OK,
             )
             webSocket.emit(
                 value = CampaignEvent.CharacterRemoved(
@@ -30,10 +26,19 @@ fun Engine.removeCampaignCharacter(): suspend io.ktor.server.routing.RoutingCont
                     characterSheetId = characterSheetId,
                 )
             )
+        } catch (exception: MissingParameterException) {
+            call.respond(
+                message = ResultJson.Error(
+                    status = exception.errorCode,
+                    message = exception.message ?: "?",
+                )
+            )
         } catch (exception: Exception) {
-            call.respondText(
+            call.respond(
-                text = exception.localizedMessage,
+                message = ResultJson.Error(
-                status = HttpStatusCode.UnprocessableEntity,
+                    status = ResultJson.Error.GENERIC,
+                    message = exception.message ?: "?",
+                )
             )
         }
     }

server/src/main/kotlin/com/pixelized/server/lwa/server/rest/campaign/DELETE_Campaign_Npc.kt

@@ -1,9 +1,12 @@
 package com.pixelized.server.lwa.server.rest.campaign
 
 import com.pixelized.server.lwa.server.Engine
+import com.pixelized.server.lwa.utils.extentions.MissingParameterException
 import com.pixelized.server.lwa.utils.extentions.characterSheetId
+import com.pixelized.shared.lwa.protocol.rest.ResultJson
 import com.pixelized.shared.lwa.protocol.websocket.CampaignEvent
 import io.ktor.http.HttpStatusCode
+import io.ktor.server.response.respond
 import io.ktor.server.response.respondText
 
 fun Engine.removeCampaignNpc(): suspend io.ktor.server.routing.RoutingContext.() -> Unit {
@@ -12,15 +15,12 @@ fun Engine.removeCampaignNpc(): suspend io.ktor.server.routing.RoutingContext.()
             // get the query parameter
             val characterSheetId = call.queryParameters.characterSheetId
             // remove the character form the party
-            val updated = campaignService.removeNpc(characterSheetId = characterSheetId)
+            campaignService.removeNpc(
-            // error case
+                characterSheetId = characterSheetId,
-            if (updated.not()) {
+            )
-                error("Unexpected error when removing character (characterSheetId:$characterSheetId) from npcs.")
-            }
             // API & WebSocket responses
-            call.respondText(
+            call.respond(
-                text = "${HttpStatusCode.OK}",
+                message = ResultJson.Success(),
-                status = HttpStatusCode.OK,
             )
             webSocket.emit(
                 value = CampaignEvent.NpcRemoved(
@@ -28,10 +28,19 @@ fun Engine.removeCampaignNpc(): suspend io.ktor.server.routing.RoutingContext.()
                     characterSheetId = characterSheetId,
                 )
             )
+        } catch (exception: MissingParameterException) {
+            call.respond(
+                message = ResultJson.Error(
+                    status = exception.errorCode,
+                    message = exception.message ?: "?",
+                )
+            )
         } catch (exception: Exception) {
-            call.respondText(
+            call.respond(
-                text = exception.localizedMessage,
+                message = ResultJson.Error(
-                status = HttpStatusCode.UnprocessableEntity,
+                    status = ResultJson.Error.GENERIC,
+                    message = exception.message ?: "?",
+                )
             )
         }
     }

server/src/main/kotlin/com/pixelized/server/lwa/server/rest/campaign/GET_Campaign.kt

@@ -1,12 +1,22 @@
 package com.pixelized.server.lwa.server.rest.campaign
 
 import com.pixelized.server.lwa.server.Engine
+import com.pixelized.shared.lwa.protocol.rest.ResultJson
 import io.ktor.server.response.respond
 
 fun Engine.getCampaign(): suspend io.ktor.server.routing.RoutingContext.() -> Unit {
     return {
-        call.respond(
+        try {
-            message = campaignService.campaignJson(),
+            call.respond(
-        )
+                message = campaignService.campaignJson(),
+            )
+        } catch (exception: Exception) {
+            call.respond(
+                message = ResultJson.Error(
+                    status = ResultJson.Error.GENERIC,
+                    message = exception.message ?: "?",
+                )
+            )
+        }
     }
 }

server/src/main/kotlin/com/pixelized/server/lwa/server/rest/campaign/PUT_Campaign_Character.kt

@@ -1,10 +1,11 @@
 package com.pixelized.server.lwa.server.rest.campaign
 
 import com.pixelized.server.lwa.server.Engine
+import com.pixelized.server.lwa.utils.extentions.MissingParameterException
 import com.pixelized.server.lwa.utils.extentions.characterSheetId
+import com.pixelized.shared.lwa.protocol.rest.ResultJson
 import com.pixelized.shared.lwa.protocol.websocket.CampaignEvent
-import io.ktor.http.HttpStatusCode
+import io.ktor.server.response.respond
-import io.ktor.server.response.respondText
 
 fun Engine.putCampaignCharacter(): suspend io.ktor.server.routing.RoutingContext.() -> Unit {
     return {
@@ -12,15 +13,12 @@ fun Engine.putCampaignCharacter(): suspend io.ktor.server.routing.RoutingContext
             // get the query parameter
             val characterSheetId = call.queryParameters.characterSheetId
             // add the character to the party.
-            val update = campaignService.addCharacter(characterSheetId = characterSheetId)
+            campaignService.addCharacter(
-            // error case
+                characterSheetId = characterSheetId,
-            if (update.not()) {
+            )
-                error("Unexpected error occurred when the character instance was added to the party")
-            }
             // API & WebSocket responses.
-            call.respondText(
+            call.respond(
-                text = "Character $characterSheetId successfully added to the party",
+                message = ResultJson.Success(),
-                status = HttpStatusCode.OK,
             )
             webSocket.emit(
                 value = CampaignEvent.CharacterAdded(
@@ -28,10 +26,19 @@ fun Engine.putCampaignCharacter(): suspend io.ktor.server.routing.RoutingContext
                     characterSheetId = characterSheetId,
                 )
             )
+        } catch (exception: MissingParameterException) {
+            call.respond(
+                message = ResultJson.Error(
+                    status = exception.errorCode,
+                    message = exception.message ?: "?",
+                )
+            )
         } catch (exception: Exception) {
-            call.respondText(
+            call.respond(
-                text = "${exception.message}",
+                message = ResultJson.Error(
-                status = HttpStatusCode.UnprocessableEntity,
+                    status = ResultJson.Error.GENERIC,
+                    message = exception.message ?: "?",
+                )
             )
         }
     }

server/src/main/kotlin/com/pixelized/server/lwa/server/rest/campaign/PUT_Campaign_Npc.kt

@@ -1,10 +1,11 @@
 package com.pixelized.server.lwa.server.rest.campaign
 
 import com.pixelized.server.lwa.server.Engine
+import com.pixelized.server.lwa.utils.extentions.MissingParameterException
 import com.pixelized.server.lwa.utils.extentions.characterSheetId
+import com.pixelized.shared.lwa.protocol.rest.ResultJson
 import com.pixelized.shared.lwa.protocol.websocket.CampaignEvent
-import io.ktor.http.HttpStatusCode
+import io.ktor.server.response.respond
-import io.ktor.server.response.respondText
 
 fun Engine.putCampaignNpc(): suspend io.ktor.server.routing.RoutingContext.() -> Unit {
     return {
@@ -12,15 +13,12 @@ fun Engine.putCampaignNpc(): suspend io.ktor.server.routing.RoutingContext.() ->
             // get the query parameter
             val characterSheetId = call.queryParameters.characterSheetId
             // add the character to the npcs.
-            val update = campaignService.addNpc(characterSheetId = characterSheetId)
+            campaignService.addNpc(
-            // error case
+                characterSheetId = characterSheetId,
-            if (update.not()) {
+            )
-                error("Unexpected error occurred when the character instance was added to the npcs")
-            }
             // API & WebSocket responses.
-            call.respondText(
+            call.respond(
-                text = "Character $characterSheetId successfully added to the npcs",
+                message = ResultJson.Success(),
-                status = HttpStatusCode.OK,
             )
             webSocket.emit(
                 value = CampaignEvent.NpcAdded(
@@ -28,10 +26,19 @@ fun Engine.putCampaignNpc(): suspend io.ktor.server.routing.RoutingContext.() ->
                     characterSheetId = characterSheetId,
                 )
             )
+        } catch (exception: MissingParameterException) {
+            call.respond(
+                message = ResultJson.Error(
+                    status = exception.errorCode,
+                    message = exception.message ?: "?",
+                )
+            )
         } catch (exception: Exception) {
-            call.respondText(
+            call.respond(
-                text = "${exception.message}",
+                message = ResultJson.Error(
-                status = HttpStatusCode.UnprocessableEntity,
+                    status = ResultJson.Error.GENERIC,
+                    message = exception.message ?: "?",
+                )
             )
         }
     }

server/src/main/kotlin/com/pixelized/server/lwa/server/rest/campaign/PUT_Campaign_Scene_Name.kt

@@ -1,10 +1,13 @@
 package com.pixelized.server.lwa.server.rest.campaign
 
 import com.pixelized.server.lwa.server.Engine
+import com.pixelized.server.lwa.utils.extentions.MissingParameterException
 import com.pixelized.shared.lwa.model.campaign.CampaignJsonV2
+import com.pixelized.shared.lwa.protocol.rest.ResultJson
 import com.pixelized.shared.lwa.protocol.websocket.CampaignEvent
 import io.ktor.http.HttpStatusCode
 import io.ktor.server.request.receive
+import io.ktor.server.response.respond
 import io.ktor.server.response.respondText
 
 fun Engine.putCampaignScene(): suspend io.ktor.server.routing.RoutingContext.() -> Unit {
@@ -15,15 +18,10 @@ fun Engine.putCampaignScene(): suspend io.ktor.server.routing.RoutingContext.()
             // convert the scene into the a usable data model.
             val scene = campaignJsonFactory.convertFromJson(json = form)
             // update the campaign.
-            val updated = campaignService.setScene(scene = scene)
+            campaignService.setScene(scene = scene)
-            // error case
-            if (updated.not()) {
-                error("Unexpected error when updating the scene.")
-            }
             // API & WebSocket responses
-            call.respondText(
+            call.respond(
-                text = "${HttpStatusCode.OK}",
+                message = ResultJson.Success(),
-                status = HttpStatusCode.OK,
             )
             webSocket.emit(
                 value = CampaignEvent.UpdateScene(
@@ -31,10 +29,19 @@ fun Engine.putCampaignScene(): suspend io.ktor.server.routing.RoutingContext.()
                     name = scene.name,
                 )
             )
+        } catch (exception: MissingParameterException) {
+            call.respond(
+                message = ResultJson.Error(
+                    status = exception.errorCode,
+                    message = exception.message ?: "?",
+                )
+            )
         } catch (exception: Exception) {
-            call.respondText(
+            call.respond(
-                text = exception.localizedMessage,
+                message = ResultJson.Error(
-                status = HttpStatusCode.UnprocessableEntity,
+                    status = ResultJson.Error.GENERIC,
+                    message = exception.message ?: "?",
+                )
             )
         }
     }

server/src/main/kotlin/com/pixelized/server/lwa/server/rest/character/DELETE_Character.kt

@@ -13,11 +13,6 @@ fun Engine.deleteCharacter(): suspend io.ktor.server.routing.RoutingContext.() -
         val deleted = characterService.deleteCharacterSheet(
             characterSheetId = characterSheetId
         )
-        // Remove the character fom the campaign if needed.
-        // TODO probably useless because all data will not be cleaned up (all campaign / screnes)
-        campaignService.removeInstance(
-            characterSheetId = characterSheetId,
-        )
 
         if (deleted) {
             call.respondText(

shared/src/commonMain/kotlin/com/pixelized/shared/lwa/protocol/rest/ResultJson.kt

@@ -13,12 +13,9 @@ sealed interface ResultJson {
         val message: String,
     ) : ResultJson {
         companion object {
-            const val GENERIC = 500
+            const val GENERIC = 600
 
-            const val FILE_ALREADY_EXIST = GENERIC + 1
+            const val MISSING_PARAMETER = 700
-            const val FILE_DOES_NOT_EXIST = GENERIC + 2
-
-            const val MISSING_PARAMETER = 1000
             const val MISSING_CHARACTER_SHEET_ID = MISSING_PARAMETER + 1
             const val MISSING_ALTERATION_ID = MISSING_PARAMETER + 2
             const val MISSING_CREATE = MISSING_PARAMETER + 3