feat(fls): write the installed applications of a .fls, loaded by Java as the original

topologyWriter.ts puts each installed application of a PC or notebook under
its key and gives it the system software, as installApp does, with its
settings: a server's switch and port, a client's target, DNS recursion,
virtual hosts, the peer count, the personal firewall. The applications
follow the files, as in Java's own files: the web server, the peer-to-peer
application and the e-mail server make their directories only where the
files lack them, and the DNS server reads /dns/hosts when it is installed.
E-mail accounts, messages and address books are the next step.

The Java oracle now reports a personal firewall's rules in full, not their
number (the corpus has none; its result is byte-equal).

Checked by Java against Java: every corpus file, read and written again,
loads with the same applications as the original. The synthetic topology
adds every FILIUS application with settings away from its defaults, a
personal firewall with a rule, an own index.html (Java makes no second) and
a missing /peer2peer directory, which Java makes at the end. 12 mutation
probes, among them files and applications in reverse order, each loaded by
Java, were all caught.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/fls/src/topologyWriter.ts

@@ -14,7 +14,13 @@
 // which holds the same object (its key among the installed applications
 // differs: Firewall on a router, NatGateway on a home router). Files are
 // added to the constructor's root, as XMLEncoder adds them — on a router
-// after the files its constructor makes. Applications are a later layer.
+// after the files its constructor makes. The installed applications of a PC
+// or notebook follow the files, as in Java's own files: the constructors of
+// the web server, the peer-to-peer application and the e-mail server make
+// their directories only where the files lack them, and the DNS server reads
+// /dns/hosts when it is installed. Each is put under its key and given the
+// system software, as installApp does. E-mail accounts, messages and address
+// books are a later layer.
 //
 // Checked by Java: every corpus file, read and written again, loads in Java
 // FILIUS to the same topology and system software (topologyWriter.test.ts,
@@ -32,14 +38,19 @@ import {
   type BeanValue,
   short,
 } from './javaBeansWriter.js';
-import type { FlsFileTree, FlsFirewall, FlsSystemSoftware } from './systemSoftware.js';
+import type { FlsApplication, FlsFileTree, FlsFirewall, FlsSystemSoftware } from './systemSoftware.js';
 import type { FlsDocumentationItem, FlsInterface, FlsLink, FlsNode, FlsNodeClass } from './topology.js';
 
 /** The version line of the files this writer makes: the format of FILIUS 2.14. */
 export const WRITTEN_VERSION_LINE = 'Filius version: 2.14.0 (mdg-filius)';
 
-/** The system software's settings and files; its applications are a later layer. */
-export type SystemToWrite = Omit<FlsSystemSoftware, 'applications'>;
+/** An installed application; e-mail accounts, messages and address books are a later layer. */
+export type ApplicationToWrite = Omit<FlsApplication, 'source'>;
+
+/** The system software's settings, files and applications. */
+export type SystemToWrite = Omit<FlsSystemSoftware, 'applications'> & {
+  readonly applications?: readonly ApplicationToWrite[];
+};
 
 export type NodeToWrite = Pick<
   FlsNode,
@@ -140,7 +151,14 @@ function device(node: NodeToWrite, ports: BeanValue[]): BeanObject {
       ),
     );
   }
-  statements.push({ get: 'systemSoftware', statements: systemStatements(node.system, node.javaClass) });
+  // Named for the applications, which are given it.
+  const system = (node.system.applications?.length ?? 0) > 0 ? reference('SystemSoftware') : undefined;
+  const systemStatementList = systemStatements(node.system, node.javaClass, system);
+  statements.push(
+    system === undefined
+      ? { get: 'systemSoftware', statements: systemStatementList }
+      : { get: 'systemSoftware', statements: systemStatementList, as: system },
+  );
   return object(`filius.hardware.knoten.${node.javaClass}`, statements);
 }
 
@@ -150,7 +168,7 @@ const WEB_SERVER_CLASS = 'filius.software.www.WebServer';
  * The settings the file has, each set on the constructor's system software.
  * A switch's SSID the file lacked stays unwritten, so Java rolls one as it did.
  */
-function systemStatements(system: SystemToWrite, javaClass: FlsNodeClass): BeanStatement[] {
+function systemStatements(system: SystemToWrite, javaClass: FlsNodeClass, self: BeanReference | undefined): BeanStatement[] {
   const statements: BeanStatement[] = [];
   if (system.firewall !== undefined) {
     statements.push({
@@ -167,6 +185,15 @@ function systemStatements(system: SystemToWrite, javaClass: FlsNodeClass): BeanS
     });
   }
   if (system.fileSystem !== undefined) statements.push(fileSystemStatement(system.fileSystem, system.templateFiles !== false));
+  if (self !== undefined && system.applications !== undefined) {
+    statements.push({
+      get: 'installierteAnwendungen',
+      statements: system.applications.map((application) => ({
+        call: 'put',
+        args: [application.key, object(application.javaClass, applicationStatements(application, self))],
+      })),
+    });
+  }
   if (system.dhcpServer !== undefined) {
     const server = system.dhcpServer;
     statements.push({
@@ -236,6 +263,28 @@ function userObject(tree: FlsFileTree): BeanValue {
   return tree.kind === 'directory' ? tree.name : null;
 }
 
+/**
+ * An application's settings, after the system software it runs on. A
+ * peer-to-peer application's peer count the file lacked stays unwritten, so
+ * Java rolls one as it did.
+ */
+function applicationStatements(application: ApplicationToWrite, system: BeanReference): BeanStatement[] {
+  const statements: BeanStatement[] = [{ set: 'systemSoftware', value: system }];
+  if (application.isActive !== undefined) statements.push({ set: 'aktiv', value: application.isActive });
+  if (application.port !== undefined) statements.push({ set: 'port', value: int(application.port) });
+  if (application.targetAddress !== undefined) statements.push({ set: 'zielIPAdresse', value: application.targetAddress });
+  if (application.targetPort !== undefined) statements.push({ set: 'zielPort', value: int(application.targetPort) });
+  if (application.recursiveResolutionEnabled !== undefined) {
+    statements.push({ set: 'recursiveResolutionEnabled', value: application.recursiveResolutionEnabled });
+  }
+  if (application.useVirtualHosts !== undefined) statements.push({ set: 'useVHost', value: application.useVirtualHosts });
+  if (application.maxPeers !== undefined && application.maxPeers !== null) {
+    statements.push({ set: 'maxTeilnehmerZahl', value: int(application.maxPeers) });
+  }
+  if (application.firewall !== undefined) statements.push(...firewallStatements(application.firewall));
+  return statements;
+}
+
 /** A LinkedList of String arrays: routes, static NAT. */
 function rows(table: readonly (readonly (string | null)[])[]): BeanObject {
   return listOf(table.map((row) => ({ kind: 'array', componentClass: 'java.lang.String', items: [...row] })));