implemented transaction propagation via event bus

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

accounting/build.gradle.kts

@@ -1,5 +1,6 @@
 description = "Umbrella : Accounting"
 
 dependencies{
+    implementation(project(":bus"))
     implementation(project(":core"))
 }

accounting/src/main/java/de/srsoftware/umbrella/accounting/AccountingModule.java

@@ -10,6 +10,9 @@ import static de.srsoftware.umbrella.core.Util.mapValues;
 import static de.srsoftware.umbrella.core.constants.Path.*;
 import static de.srsoftware.umbrella.core.exceptions.UmbrellaException.invalidField;
 import static de.srsoftware.umbrella.core.exceptions.UmbrellaException.missingField;
+import static de.srsoftware.umbrella.messagebus.MessageBus.messageBus;
+import static de.srsoftware.umbrella.messagebus.events.Event.EventType.CREATE;
+import static de.srsoftware.umbrella.messagebus.events.Event.EventType.UPDATE;
 import static java.lang.System.Logger.Level.WARNING;
 
 import com.sun.net.httpserver.HttpExchange;
@@ -27,6 +30,9 @@ import java.io.IOException;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.util.*;
+
+import de.srsoftware.umbrella.messagebus.events.Event;
+import de.srsoftware.umbrella.messagebus.events.TransactionEvent;
 import org.json.JSONArray;
 import org.json.JSONObject;
 
@@ -177,6 +183,14 @@ public class AccountingModule extends BaseHandler implements AccountingService {
 
 	private boolean getAccount(UmbrellaUser user, long accountId, HttpExchange ex) throws IOException {
 		LOG.log(WARNING,"Missing authorization check in AccountingModule.getAccount(…)!");
+		return sendContent(ex, loadAccount(accountId));
+	}
+
+	private boolean getAccounts(UmbrellaUser user, HttpExchange ex) throws IOException {
+		return sendContent(ex,accountDb.listAccounts(user.id()).stream().map(Account::toMap));
+	}
+
+	public AccountData loadAccount(long accountId){
 		var account      = accountDb.loadAccount(accountId);
 		var transactions = accountDb.loadTransactions(account);
 		var userMap      = new HashMap<Long,UmbrellaUser>();
@@ -193,20 +207,9 @@ public class AccountingModule extends BaseHandler implements AccountingService {
 				if (!userMap.containsKey(userId)) userMap.put(destination.id(),userService().loadUser(userId));
 			}
 		}
-
+		return AccountData.of(account, transactions, userMap);
-		return sendContent(ex, Map.of(
-				Field.ACCOUNT,account.toMap(),
-				Field.TRANSACTIONS,transactions.stream().map(Transaction::toMap).toList(),
-				Field.USER_LIST,mapValues(userMap)
-		));
 	}
 
-	private boolean getAccounts(UmbrellaUser user, HttpExchange ex) throws IOException {
-		return sendContent(ex,accountDb.listAccounts(user.id()).stream().map(Account::toMap));
-	}
-
-
-
 	private static boolean noNumbers(String s){
 		try {
 			Long.parseLong(s);
@@ -226,7 +229,9 @@ public class AccountingModule extends BaseHandler implements AccountingService {
 		if (json.has(Field.PURPOSE)) transaction.purpose(json.getString(Field.PURPOSE));
 		if (json.has(Field.SOURCE)) transaction.source(IdOrString.of(json.getString(Field.SOURCE)));
 		if (json.has(Field.TAG)) transaction.tags().add(json.getString(Field.TAG));
-		return sendContent(ex,accountDb.save(transaction));
+		var patched = accountDb.save(transaction);
+		messageBus().dispatch(new TransactionEvent(user,patched,UPDATE));
+		return sendContent(ex,patched);
 	}
 
 	private boolean postEntry(UmbrellaUser user, HttpExchange ex) throws IOException {
@@ -291,7 +296,7 @@ public class AccountingModule extends BaseHandler implements AccountingService {
 
 
 		var transaction = accountDb.save(new Transaction(0,accountId,dateTime,source,destination,amount.doubleValue(),purpose,tags));
-
+		messageBus().dispatch(new TransactionEvent(user,transaction, CREATE));
 		return sendContent(ex,newAccount != null ? newAccount : transaction);
 	}
 

accounting/src/main/java/de/srsoftware/umbrella/accounting/SqliteDb.java

@@ -10,6 +10,8 @@ import static de.srsoftware.umbrella.accounting.Constants.*;
 import static de.srsoftware.umbrella.core.constants.Field.*;
 import static de.srsoftware.umbrella.core.exceptions.UmbrellaException.*;
 import static de.srsoftware.umbrella.core.model.Translatable.t;
+import static de.srsoftware.umbrella.messagebus.MessageBus.messageBus;
+import static de.srsoftware.umbrella.messagebus.events.Event.EventType.UPDATE;
 import static java.text.MessageFormat.format;
 
 import de.srsoftware.tools.jdbc.Condition;
@@ -19,6 +21,8 @@ import de.srsoftware.umbrella.core.constants.Field;
 import de.srsoftware.umbrella.core.constants.Text;
 import de.srsoftware.umbrella.core.model.Account;
 import de.srsoftware.umbrella.core.model.Transaction;
+import de.srsoftware.umbrella.messagebus.events.TransactionEvent;
+
 import java.sql.Connection;
 import java.sql.SQLException;
 import java.time.ZoneOffset;

bus/src/main/java/de/srsoftware/umbrella/messagebus/MessageApi.java

@@ -65,7 +65,7 @@ public class MessageApi extends BaseHandler{
 		}
 	}
 
-	private void sendEvent(PrintWriter out, Event event) {
+	private void sendEvent(PrintWriter out, Event<?> event) {
 		if (event == null) return;
 		out.print("event: ");
 		out.println(event.eventType());

bus/src/main/java/de/srsoftware/umbrella/messagebus/events/TransactionEvent.java

@@ -0,0 +1,44 @@
+package de.srsoftware.umbrella.messagebus.events;
+
+import de.srsoftware.umbrella.core.ModuleRegistry;
+import de.srsoftware.umbrella.core.constants.Module;
+import de.srsoftware.umbrella.core.constants.Text;
+import de.srsoftware.umbrella.core.model.Transaction;
+import de.srsoftware.umbrella.core.model.Translatable;
+import de.srsoftware.umbrella.core.model.UmbrellaUser;
+import de.srsoftware.umbrella.core.model.UnTranslatable;
+
+import java.util.Collection;
+import java.util.List;
+
+import static de.srsoftware.umbrella.core.ModuleRegistry.accountingService;
+import static de.srsoftware.umbrella.core.model.Translatable.t;
+
+public class TransactionEvent extends Event<Transaction> {
+	private Collection<UmbrellaUser> audience;
+
+	public TransactionEvent(UmbrellaUser initiator, Transaction transaction, EventType type) {
+		super(initiator, Module.ACCOUNTING, transaction, type);
+		audience = null;
+	}
+
+	@Override
+	public Collection<UmbrellaUser> audience() {
+		if (audience == null) audience = accountingService().loadAccount(payload().accountId()).userMap().values();
+		return audience;
+	}
+
+	@Override
+	public Translatable describe() {
+		return new UnTranslatable(payload().purpose());
+	}
+
+	@Override
+	public Translatable subject() {
+		return switch (eventType()){
+			case CREATE -> t("user_created_entity",initiator().name(), Text.TRANSACTION);
+			case UPDATE -> t("user_updated_entity",initiator().name(), Text.TRANSACTION);
+			case null, default -> t("TODO"); // TODO
+		};
+	}
+}

core/src/main/java/de/srsoftware/umbrella/core/ModuleRegistry.java

@@ -53,6 +53,10 @@ public class ModuleRegistry {
 		}
 	}
 
+	public static AccountingService accountingService() {
+		return singleton.accountingService;
+	}
+
 	public static BookmarkService bookmarkService(){
 		return singleton.bookmarkService;
 	}

core/src/main/java/de/srsoftware/umbrella/core/api/AccountingService.java

@@ -1,5 +1,33 @@
 /* © SRSoftware 2025 */
 package de.srsoftware.umbrella.core.api;
 
+import de.srsoftware.tools.Mappable;
+import de.srsoftware.umbrella.core.constants.Field;
+import de.srsoftware.umbrella.core.model.Account;
+import de.srsoftware.umbrella.core.model.Transaction;
+import de.srsoftware.umbrella.core.model.UmbrellaUser;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import static de.srsoftware.umbrella.core.Util.mapValues;
+
 public interface AccountingService {
+	public record AccountData(Account account, List<Transaction> transactions, HashMap<Long, UmbrellaUser> userMap) implements Mappable {
+		public static AccountData of(Account account, List<Transaction> transactions, HashMap<Long, UmbrellaUser> userMap) {
+			return new AccountData(account, transactions, userMap);
+		}
+
+		@Override
+		public Map<String, Object> toMap() {
+			return Map.of(
+				Field.ACCOUNT,account.toMap(),
+				Field.TRANSACTIONS,transactions.stream().map(Transaction::toMap).toList(),
+				Field.USER_LIST,mapValues(userMap)
+			);
+		}
+	}
+
+	AccountData loadAccount(long accountId);
 }

frontend/src/routes/accounting/account.svelte

@@ -1,6 +1,6 @@
 <script>
 	import { onMount } from 'svelte';
-	import { api, get } from '../../urls.svelte';
+	import { api, eventStream, get } from '../../urls.svelte';
 	import { error, yikes } from '../../warn.svelte';
 	import { t } from '../../translations.svelte';
 
@@ -9,6 +9,7 @@
 
 	let { id }       = $props();
 	let account      = $state(null);
+	let eventSource      = null;
 	let filter       = $state([]);
 	let transactions = $state([]);
 	let filtered     = $derived(transactions.filter(t => checker(t.tags,filter)));
@@ -27,7 +28,6 @@
 			if (!transaction.destination.id) sums[0] += transaction.amount;
 			if (!transaction.source.id)      sums[0] -= transaction.amount;
 		}
-		window.setTimeout(scrollToBottom,100);
 		return sums;
 	}
 
@@ -50,6 +50,34 @@
 		filter = filter.filter(x => x != tag.toLowerCase());
 	}
 
+    function handleCreateEvent(evt){
+        const event_data = JSON.parse(evt.data);
+        const new_transaction = event_data.transaction;
+        transactions.push(new_transaction);
+		window.setTimeout(scrollToBottom,100);
+    }
+
+    function handleEvent(evt,method){
+        let event_data = JSON.parse(evt.data);
+        console.log({method, event_data});
+    }
+
+	function handleDeleteEvent(evt){
+        handleEvent(evt,'delete');
+    }
+
+    function handleUpdateEvent(evt){
+        const event_data = JSON.parse(evt.data);
+        const updated_transaction = event_data.transaction;
+        for (var idx in transactions){
+            if (transactions[idx].id == updated_transaction.id) {
+                updated_transaction.tags = transactions[idx].tags;
+                transactions[idx] = updated_transaction;
+                break;
+            }
+        }
+    }
+
 	async function load(){
 		let url = api(`accounting/${id}`);
 		let res = await get(url);
@@ -59,11 +87,15 @@
 			transactions = json.transactions;
 			users        = json.user_list;
 			account      = json.account;
+			try {
+				eventSource = eventStream(handleCreateEvent,handleUpdateEvent,handleDeleteEvent);
+			} catch (ignored) {}
+			window.setTimeout(scrollToBottom,100);
 		} else error(res);
 	}
 
 	function onSave(){
-		load();
+		// load();
 	}
 
 	function scrollToBottom(){