added map functionality

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

de.srsoftware.cal.db/src/main/java/de/srsoftware/cal/db/Database.java

@@ -47,4 +47,6 @@ public interface Database {
 	public List<Appointment> listByTags(Set<String> tags, Integer count, Integer offset);
 
 	Result<Appointment> loadEvent(long id);
+
+	Result<List<String>> findTags(String infix);
 }

de.srsoftware.cal.db/src/main/java/de/srsoftware/cal/db/MariaDB.java

@@ -39,6 +39,7 @@ public class MariaDB implements Database {
 	private static final String	   TID	           = "tid";
 	private static final String	   MIME	           = "mime";
 	private static final String	   APPOINTMENT_ATTACHMENTS = "appointment_attachments";
+	private static final String	   TAGS	           = "tags";
 	private static Connection	   connection;
 
 	private MariaDB(Connection conn) throws SQLException {
@@ -113,6 +114,19 @@ public class MariaDB implements Database {
 		return new MariaDB(DriverManager.getConnection(jdbc, user, pass));
 	}
 
+	@Override
+	public Result<List<String>> findTags(String infix) {
+		try {
+			List<String> results = new ArrayList<>();
+			var          rs	     = Query.select(KEYWORD).from(TAGS).where(KEYWORD, like("%%%s%%".formatted(infix))).sort(KEYWORD).exec(connection);
+			while (rs.next()) results.add(rs.getString(KEYWORD));
+			rs.close();
+			return Payload.of(results);
+		} catch (SQLException e) {
+			return Error.format("failed to gather tags from DB.", e);
+		}
+	}
+
 	@Override
 	public List<Appointment> list(Integer count, Integer offset) throws SQLException {
 		var list    = new ArrayList<Appointment>();
@@ -219,16 +233,16 @@ public class MariaDB implements Database {
 
 	@Override
 	public List<Appointment> list(LocalDateTime from, LocalDateTime till) throws SQLException {
-		var list    = new ArrayList<Appointment>();
+		var list  = new ArrayList<Appointment>();
 		var query = Query  //
-				.select("appointments.*", "GROUP_CONCAT(keyword) AS tags")
-				.from(APPOINTMENTS)
-				.leftJoin(AID, "appointment_tags", AID)
-				.leftJoin("tid", "tags", "tid")
-				.groupBy(AID)
-				.sort("start DESC");
+			.select("appointments.*", "GROUP_CONCAT(keyword) AS tags")
+			.from(APPOINTMENTS)
+			.leftJoin(AID, "appointment_tags", AID)
+			.leftJoin("tid", "tags", "tid")
+			.groupBy(AID)
+			.sort("start DESC");
 		nullable(from).ifPresent(start -> query.where("start", moreThan(start)));
-		nullable(till).ifPresent(end -> query.where("end",lessThan(end)));
+		nullable(till).ifPresent(end -> query.where("end", lessThan(end)));
 
 		var results = query.exec(connection);
 		while (results.next()) createAppointmentOf(results).optional().ifPresent(list::add);