preparing message system:

copied model from previous java implementation

core/build.gradle.kts

@@ -18,6 +18,34 @@ dependencies {
     testImplementation("org.junit.jupiter:junit-jupiter")
 }
 
-tasks.test {
-    useJUnitPlatform()
-}
+
+tasks.jar {
+    manifest.attributes["Main-Class"] = "de.srsoftware.umbrella.core.Launcher"
+    duplicatesStrategy = DuplicatesStrategy.EXCLUDE
+    val dependencies = configurations
+        .runtimeClasspath
+        .get()
+        .map(::zipTree) // OR .map { zipTree(it) }
+    from(dependencies)
+}
+
+fun download(url : String, destination : String){
+    var destFile = projectDir.toPath().resolve(destination).toFile();
+    destFile.parentFile.mkdirs()
+    if (!destFile.exists()) {
+        System.out.println("Downloading "+url)
+        ant.invokeMethod("get", mapOf("src" to url, "dest" to destFile))
+    }
+}
+
+tasks.register("downloadLib"){
+    download("https://github.com/AshurAxelR/JParsedown/raw/refs/heads/master/src/com/xrbpowered/jparsedown/JParsedown.java", "src/main/java/com/xrbpowered/jparsedown/JParsedown.java")
+}
+
+tasks.withType<org.gradle.jvm.tasks.Jar>() {
+    exclude("META-INF/*.RSA", "META-INF/*.SF", "META-INF/*.DSA")
+}
+
+tasks.named("compileJava") {
+    dependsOn("downloadLib")
+}

core/src/main/java/.gitignore

@@ -0,0 +1 @@
+com/

messages/build.gradle.kts

@@ -0,0 +1,14 @@
+description = "Umbrella : Message subsystem"
+
+dependencies{
+    implementation(project(":core"))
+    implementation(project(":user"))
+    implementation("de.srsoftware:configuration.api:1.0.2")
+    implementation("de.srsoftware:tools.jdbc:1.3.2")
+    implementation("de.srsoftware:tools.mime:1.1.2")
+    implementation("de.srsoftware:tools.optionals:1.0.0")
+    implementation("de.srsoftware:tools.util:2.0.3")
+    implementation("org.bitbucket.b_c:jose4j:0.9.6")
+    implementation("org.json:json:20240303")
+    implementation("org.xerial:sqlite-jdbc:3.49.0.0")
+}

messages/src/main/java/de/srsoftware/umbrella/message/Constants.java

@@ -0,0 +1,18 @@
+/* © SRSoftware 2025 */
+package de.srsoftware.umbrella.message;
+
+public class Constants {
+	public static final String AUTH = "mail.smtp.auth";
+	public static final String ENVELOPE_FROM = "mail.smtp.from";
+	public static final String FIELD_MESSAGES = "messages";
+	public static final String FIELD_HOST = "host";
+	public static final String FIELD_PORT = "port";
+	public static final String HOST = "mail.smtp.host";
+	public static final String JSONARRAY = "json array";
+	public static final String JSONOBJECT = "json object";
+	public static final String PORT = "mail.smtp.port";
+	public static final String RECEIVERS = "receivers";
+	public static final String SSL = "mail.smtp.ssl.enable";
+	public static final String SUBMISSION = "submission";
+
+}

messages/src/main/java/de/srsoftware/umbrella/message/MessageDb.java

@@ -0,0 +1,11 @@
+/* © SRSoftware 2025 */
+package de.srsoftware.umbrella.message;
+
+import de.srsoftware.umbrella.core.UmbrellaException;
+import de.srsoftware.umbrella.message.model.Settings;
+import de.srsoftware.umbrella.user.model.UmbrellaUser;
+
+public interface MessageDb {
+	public Settings getSettings(UmbrellaUser user) throws UmbrellaException;
+	public Settings update(UmbrellaUser user, Settings settings) throws UmbrellaException;
+}

messages/src/main/java/de/srsoftware/umbrella/message/SqliteDb.java

@@ -0,0 +1,126 @@
+/* © SRSoftware 2025 */
+package de.srsoftware.umbrella.message;
+
+import de.srsoftware.umbrella.core.UmbrellaException;
+import de.srsoftware.umbrella.user.model.UmbrellaUser;
+import de.srsoftware.umbrella.message.model.Settings;
+
+import java.sql.Connection;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.util.HashSet;
+import java.util.stream.Collectors;
+
+import static de.srsoftware.tools.jdbc.Condition.equal;
+import static de.srsoftware.tools.jdbc.Query.*;
+import static de.srsoftware.umbrella.core.Constants.*;
+import static de.srsoftware.umbrella.message.model.Settings.Times;
+import static java.lang.System.Logger.Level.ERROR;
+import static java.lang.System.Logger.Level.WARNING;
+import static java.text.MessageFormat.format;
+
+public class SqliteDb implements MessageDb{
+	private static final System.Logger LOG = System.getLogger(SqliteDb.class.getSimpleName());
+	private final Connection db;
+	private static final String DB_VERSION = "message_db_version";
+	private static final int INITIAL_DB_VERSION = 1;
+	private static final String TABLE_SUBMISSIONS = "message_submission";
+
+	public SqliteDb(Connection conn){
+		db = conn;
+		init();
+	}
+
+	private void createSubmissionTable() {
+		var createTable = """
+CREATE TABLE IF NOT EXISTS {0} ( {1} Integer PRIMARY KEY, {2} VARCHAR(255) NOT NULL);
+""";
+		try {
+			var stmt = db.prepareStatement(format(createTable,TABLE_SUBMISSIONS, USER_ID, VALUE));
+			stmt.execute();
+			stmt.close();
+		} catch (SQLException e) {
+			LOG.log(ERROR,ERROR_FAILED_CREATE_TABLE,TABLE_SUBMISSIONS,e);
+			throw new RuntimeException(e);
+		}
+	}
+
+
+	private int createSettingsTable() {
+		var createTable = """
+CREATE TABLE IF NOT EXISTS {0} ( {1} VARCHAR(255) PRIMARY KEY, {2} VARCHAR(255) NOT NULL);
+""";
+		try {
+			var stmt = db.prepareStatement(format(createTable,TABLE_SETTINGS, KEY, VALUE));
+			stmt.execute();
+			stmt.close();
+		} catch (SQLException e) {
+			LOG.log(ERROR,ERROR_FAILED_CREATE_TABLE,TABLE_SETTINGS,e);
+			throw new RuntimeException(e);
+		}
+
+		Integer version = null;
+		try {
+			var rs = select(VALUE).from(TABLE_SETTINGS).where(KEY, equal(DB_VERSION)).exec(db);
+			if (rs.next()) version = rs.getInt(VALUE);
+			rs.close();
+			if (version == null) {
+				version = INITIAL_DB_VERSION;
+				insertInto(TABLE_SETTINGS, KEY, VALUE).values(DB_VERSION,version).execute(db).close();
+			}
+
+			return version;
+		} catch (SQLException e) {
+			LOG.log(ERROR,ERROR_FAILED_CREATE_TABLE,DB_VERSION,TABLE_SETTINGS,e);
+			throw new RuntimeException(e);
+		}
+	}
+
+	private int createTables() {
+		createSubmissionTable();
+		return createSettingsTable();
+	}
+
+	@Override
+	public Settings getSettings(UmbrellaUser user) throws UmbrellaException {
+		try {
+			Settings settings = null;
+			var rs = select(VALUE).from(TABLE_SUBMISSIONS).where(USER_ID,equal(user.id())).exec(db);
+			if (rs.next()) settings = toSettings(rs);
+			rs.close();
+			if (settings != null) return settings;
+			throw new UmbrellaException(500,"No submission settings stored for {0}",user);
+		} catch (SQLException e) {
+			LOG.log(ERROR,"Failed to read settings for {0} from {1} table",user,TABLE_SUBMISSIONS,e);
+			throw new UmbrellaException(500,"Failed to read settings for {0} from {1} table",user,TABLE_SUBMISSIONS).causedBy(e);
+		}
+	}
+
+	private void init() {
+		var version = createTables();
+	}
+
+	private Settings toSettings(ResultSet rs) throws SQLException {
+		var submission = rs.getString(VALUE);
+		var parts = submission.split(",");
+		var times = new HashSet<Times>();
+		for (var part : parts) try {
+			times.add(Times.valueOf(part));
+		} catch (IllegalArgumentException e) {
+			LOG.log(WARNING,"encountered {0}, which is not a valid Times enumeration value!",part);
+		}
+		return new Settings(times);
+	}
+
+	@Override
+	public Settings update(UmbrellaUser user, Settings settings) throws UmbrellaException {
+		var times = settings.times().stream().map(Times::toString).collect(Collectors.joining(","));
+		try {
+			replaceInto(TABLE_SUBMISSIONS, USER_ID, VALUE).values(user.id(),times).execute(db).close();
+			return settings;
+		} catch (SQLException e) {
+			LOG.log(WARNING,"Failed to store submission data for {0}!",user.name(),e);
+			throw new UmbrellaException(500,"Failed to store submission data for {0}!",user.name()).causedBy(e);
+		}
+	}
+}

messages/src/main/java/de/srsoftware/umbrella/message/model/Attachment.java

@@ -0,0 +1,37 @@
+/* © SRSoftware 2025 */
+package de.srsoftware.umbrella.message.model;
+
+import static de.srsoftware.umbrella.core.Constants.*;
+
+import de.srsoftware.umbrella.core.UmbrellaException;
+import java.util.Arrays;
+import java.util.Base64;
+import java.util.Objects;
+import java.util.Set;
+import org.json.JSONObject;
+
+public record Attachment(String name, String mime, byte[] content) {
+
+	private static final Base64.Decoder BASE64 = Base64.getDecoder();
+
+	public static <T> Attachment of(JSONObject json) throws UmbrellaException {
+		for (var key : Set.of(NAME, MIME, DATA)) {
+			if (!json.has(key)) throw new UmbrellaException(400,ERROR_MISSING_FIELD,key);
+		}
+		if (!(json.get(NAME) instanceof String name)) throw new UmbrellaException(400,ERROR_INVALID_FIELD, NAME,STRING);
+		if (!(json.get(MIME) instanceof String mime)) throw new UmbrellaException(400,ERROR_INVALID_FIELD, MIME,STRING);
+		if (!(json.get(DATA) instanceof String data)) throw new UmbrellaException(400,ERROR_INVALID_FIELD, DATA,STRING);
+		return new Attachment(name,mime, BASE64.decode(data));
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (!(o instanceof Attachment that)) return false;
+		return Objects.equals(name, that.name) && Objects.equals(mime, that.mime) && Objects.deepEquals(content, that.content);
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(name, mime, Arrays.hashCode(content));
+	}
+}

messages/src/main/java/de/srsoftware/umbrella/message/model/CombinedMessage.java

@@ -0,0 +1,70 @@
+/* © SRSoftware 2025 */
+package de.srsoftware.umbrella.message.model;
+
+import static java.lang.System.Logger.Level.DEBUG;
+import static java.lang.System.Logger.Level.TRACE;
+import static java.text.MessageFormat.format;
+
+import de.srsoftware.umbrella.user.model.UmbrellaUser;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.function.Function;
+
+public class CombinedMessage {
+	private static final System.Logger LOG = System.getLogger(CombinedMessage.class.getSimpleName());
+
+	private final Set<Attachment> attachments = new HashSet<>();
+	private final StringBuilder body = new StringBuilder();
+	private final List<Message> mergedMessages = new ArrayList<>();
+	private final Function<String, String> translate;
+	private UmbrellaUser sender = null;
+	private String subject = null;
+
+	public CombinedMessage(Function<String,String> translate){
+		LOG.log(DEBUG,"Creating combined message…");
+		this.translate = translate;
+	}
+
+	public void merge(Message message) {
+		LOG.log(TRACE,"Merging {0} into combined message…",message);
+		switch (mergedMessages.size()){
+			case 0:
+				body.append(message.body());
+				sender = message.sender();
+				subject = message.subject();
+				break;
+			case 1:
+				body.insert(0,format("# {0}:\n# {1}:\n\n",sender,subject)); // insert sender and subject of first message right before the body of the first message
+				subject = translate.apply("Collected messages");
+				// no break here, we need to append the subject and content
+			default:
+				body.append("\n\n# ").append(message.sender()).append(":\n");
+				body.append("# ").append(message.subject()).append(":\n\n");
+				body.append(message.body());
+		}
+		attachments.addAll(message.attachments());
+		mergedMessages.add(message);
+	}
+
+	public Set<Attachment> attachments() {
+		return attachments;
+	}
+
+	public String body() {
+		return body.toString();
+	}
+
+	public UmbrellaUser sender() {
+		return sender;
+	}
+
+	public String subject() {
+		return subject;
+	}
+
+	public List<Message> messages() {
+		return mergedMessages;
+	}
+}

messages/src/main/java/de/srsoftware/umbrella/message/model/Envelope.java

@@ -0,0 +1,57 @@
+/* © SRSoftware 2025 */
+package de.srsoftware.umbrella.message.model;
+
+import static de.srsoftware.umbrella.core.Constants.ERROR_INVALID_FIELD;
+import static de.srsoftware.umbrella.core.Constants.ERROR_MISSING_FIELD;
+import static de.srsoftware.umbrella.message.Constants.*;
+import static java.text.MessageFormat.format;
+
+import de.srsoftware.umbrella.core.UmbrellaException;
+import de.srsoftware.umbrella.user.model.User;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+import org.json.JSONArray;
+import org.json.JSONObject;
+
+public class Envelope {
+	private Message message;
+	private Set<User> receivers;
+
+	public Envelope(Message message, HashSet<User> receivers) {
+		this.message = message;
+		this.receivers = receivers;
+	}
+
+	public static Envelope from(JSONObject json) throws UmbrellaException {
+		if (!json.has(RECEIVERS)) throw new UmbrellaException(400,ERROR_MISSING_FIELD,RECEIVERS);
+		var message = Message.from(json);
+		var obj = json.get(RECEIVERS);
+		if (obj instanceof JSONObject) obj = new JSONArray(List.of(obj));
+		if (!(obj instanceof JSONArray receiverList)) throw new UmbrellaException(400,ERROR_INVALID_FIELD,RECEIVERS,JSONARRAY);
+		var receivers = new HashSet<User>();
+		for (var o : receiverList){
+			if (!(o instanceof JSONObject receiverData)) throw new UmbrellaException(400,ERROR_INVALID_FIELD,"entries of "+RECEIVERS,JSONOBJECT);
+			receivers.add(User.of(receiverData));
+		}
+		return new Envelope(message,receivers);
+	}
+
+	public boolean isFor(User receiver) {
+		return receivers.contains(receiver);
+	}
+
+	public Message message(){
+		return message;
+	}
+
+	public Set<User> receivers(){
+		return receivers;
+	}
+
+	@Override
+	public String toString() {
+		return format("{0} (to: {1}), subject: {2}",getClass().getSimpleName(),receivers.stream().map(User::email).collect(Collectors.joining(", ")),message.subject());
+	}
+}

messages/src/main/java/de/srsoftware/umbrella/message/model/MailQueue.java

@@ -0,0 +1,53 @@
+/* © SRSoftware 2025 */
+package de.srsoftware.umbrella.message.model;
+
+
+import de.srsoftware.umbrella.user.model.User;
+import java.util.*;
+
+/**
+ * This maps recipient email addresses to the pending messages of that recipient
+ */
+public class MailQueue extends ArrayList<Envelope>{
+
+	private record Receiver(User user, Message message){}
+
+	private final HashMap<Receiver,List<Exception>> exceptions = new HashMap<>();
+
+	public interface Listener{
+		public void messagesAdded();
+		public void setQueue(MailQueue queue);
+	}
+
+	private final Set<Listener> listeners = new HashSet<>();
+
+	public void addListener(Listener listener) {
+		listeners.add(listener);
+		listener.setQueue(this);
+	}
+
+	public void commit() {
+		listeners.forEach(Listener::messagesAdded);
+	}
+
+	public List<Envelope> envelopesFor(User recv) {
+		return stream().filter(env -> env.isFor(recv)).toList();
+	}
+
+	public void failedAt(User receiver, CombinedMessage combined, Exception ex) {
+		for (var message : combined.messages()) exceptions.computeIfAbsent(new Receiver(receiver,message), k -> new ArrayList<>()).add(ex);
+	}
+
+	/**
+	 * return the email addresses of the recipients of all messages in the queue
+	 *
+	 * @return a list of email addresses
+	 */
+	public List<User> receivers() {
+		return stream().map(Envelope::receivers)
+				.flatMap(Set::stream)
+				.filter(Objects::nonNull)
+				.distinct()
+				.toList();
+	}
+}

messages/src/main/java/de/srsoftware/umbrella/message/model/Message.java

@@ -0,0 +1,60 @@
+/* © SRSoftware 2025 */
+package de.srsoftware.umbrella.message.model;
+
+import static de.srsoftware.tools.Optionals.isSet;
+import static de.srsoftware.umbrella.core.Constants.*;
+import static de.srsoftware.umbrella.message.Constants.*;
+import static java.text.MessageFormat.format;
+
+import de.srsoftware.umbrella.core.UmbrellaException;
+import de.srsoftware.umbrella.user.model.UmbrellaUser;
+import de.srsoftware.umbrella.user.model.User;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+import java.util.Set;
+import org.json.JSONArray;
+import org.json.JSONObject;
+
+public record Message(UmbrellaUser sender, String subject, String body, List<Attachment> attachments) {
+	public static Message from(JSONObject json) throws UmbrellaException {
+		for (var key : Set.of(SENDER, SUBJECT, BODY)) {
+			if (!json.has(key)) throw new UmbrellaException(400,ERROR_MISSING_FIELD,key);
+		}
+		if (!(json.get(SENDER) instanceof JSONObject senderObject)) throw new UmbrellaException(400,ERROR_INVALID_FIELD, SENDER,JSONOBJECT);
+		if (!(json.get(SUBJECT) instanceof String subject && isSet(subject))) throw new UmbrellaException(400,ERROR_INVALID_FIELD, SUBJECT,STRING);
+		if (!(json.get(BODY) instanceof String body && isSet(body))) throw new UmbrellaException(400,ERROR_INVALID_FIELD, BODY,STRING);
+
+		var user = User.of(senderObject);
+		if (!(user instanceof UmbrellaUser sender)) throw new UmbrellaException(400,"Sender is not an umbrella user!");
+		var attachments = new ArrayList<Attachment>();
+		if (json.has(ATTACHMENTS)){
+			var jsonAttachments = json.get(ATTACHMENTS);
+			if (jsonAttachments instanceof JSONObject obj) jsonAttachments = new JSONArray(List.of(obj));
+			if (jsonAttachments instanceof JSONArray arr){
+				for (var att : arr){
+					if (!(att instanceof JSONObject o)) throw new UmbrellaException(400,"Attachments contains entry that is not an object: {}",att);
+					var attachment = Attachment.of(o);
+					attachments.add(attachment);
+				}
+			}
+		}
+		return new Message(sender,subject,body,attachments);
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (!(o instanceof Message message)) return false;
+		return Objects.equals(sender, message.sender) && Objects.equals(subject, message.subject) && Objects.equals(body, message.body) && Objects.equals(attachments, message.attachments);
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(subject, body, attachments);
+	}
+
+	@Override
+	public String toString() {
+		return format("{0}(from: {1}), subject: {2}",getClass().getSimpleName(),sender,subject);
+	}
+}

messages/src/main/java/de/srsoftware/umbrella/message/model/Settings.java

@@ -0,0 +1,38 @@
+/* © SRSoftware 2025 */
+package de.srsoftware.umbrella.message.model;
+
+import static de.srsoftware.umbrella.message.Constants.SUBMISSION;
+
+import de.srsoftware.tools.Mappable;
+import java.util.Map;
+import java.util.Set;
+
+public record Settings(Set<Times> times) implements Mappable {
+
+	public enum Times{
+		INSTANTLY,
+		AT8,
+		AT10,
+		AT12,
+		AT14,
+		AT16,
+		AT18,
+		AT20;
+
+		public boolean matches(int hour){
+			if (this == INSTANTLY) return false;
+			return Integer.parseInt(toString().substring(2)) == hour;
+		}
+	}
+
+	public boolean sendAt(Integer scheduledHour) {
+		return times.contains(Times.INSTANTLY) || (scheduledHour != null && times.stream().anyMatch(time -> time.matches(scheduledHour)));
+	}
+
+
+	@Override
+	public Map<String, Object> toMap() {
+		return Map.of(SUBMISSION,times);
+	}
+
+}

settings.gradle.kts

@@ -1,9 +1,9 @@
 rootProject.name = "Umbrella25"
 
 include("backend")
+include("core")
+include("legacy")
+include("messages")
 include("translations")
 include("user")
 include("web")
-
-include("core")
-include("legacy")

user/src/main/java/de/srsoftware/umbrella/user/model/User.java

@@ -2,9 +2,12 @@
 package de.srsoftware.umbrella.user.model;
 
 import static de.srsoftware.tools.Optionals.nullable;
+import static de.srsoftware.umbrella.core.Constants.*;
+import static de.srsoftware.umbrella.core.Constants.LANGUAGE;
 import static java.text.MessageFormat.format;
 
 import java.util.Objects;
+import org.json.JSONObject;
 
 public class User {
 
@@ -37,4 +40,20 @@ public class User {
 	public String toString() {
 		return format("{1}({0})", nullable(name()).orElse(email()),getClass().getSimpleName());
 	}
+
+	public static User of(JSONObject json){
+		if (json.has(USER)) json = json.getJSONObject(USER);
+		var name = json.has(NAME) ? json.getString(NAME) : null;
+		var email = json.has(EMAIL) ? json.getString(EMAIL) : null;
+		if (json.has(ID) && json.has(THEME)) {
+			return new UmbrellaUser(
+					json.getLong(ID),
+					name,
+					email,
+					json.getString(THEME),
+					json.has(LANGUAGE) ? json.getString(LANGUAGE) : null
+			);
+		}
+		return new User(name,email);
+	}
 }