feat: add server liveness sweep and rule registry

plugin/core/rules.ts

@@ -0,0 +1,89 @@
+import {
+  BUILTIN_RULE,
+  CodecError,
+  parseRewrittenRuleMessage
+} from "../../../Yonexus.Protocol/src/index.js";
+
+export type ServerRuleProcessor = (message: string) => unknown;
+
+export class ServerRuleRegistryError extends Error {
+  constructor(message: string) {
+    super(message);
+    this.name = "ServerRuleRegistryError";
+  }
+}
+
+export interface ServerRuleRegistry {
+  readonly size: number;
+  registerRule(rule: string, processor: ServerRuleProcessor): void;
+  hasRule(rule: string): boolean;
+  dispatch(raw: string): boolean;
+  getRules(): readonly string[];
+}
+
+export class YonexusServerRuleRegistry implements ServerRuleRegistry {
+  private readonly rules = new Map<string, ServerRuleProcessor>();
+
+  get size(): number {
+    return this.rules.size;
+  }
+
+  registerRule(rule: string, processor: ServerRuleProcessor): void {
+    const normalizedRule = this.normalizeRule(rule);
+    if (this.rules.has(normalizedRule)) {
+      throw new ServerRuleRegistryError(
+        `Rule '${normalizedRule}' is already registered`
+      );
+    }
+
+    this.rules.set(normalizedRule, processor);
+  }
+
+  hasRule(rule: string): boolean {
+    return this.rules.has(rule.trim());
+  }
+
+  dispatch(raw: string): boolean {
+    const parsed = parseRewrittenRuleMessage(raw);
+    const processor = this.rules.get(parsed.ruleIdentifier);
+    if (!processor) {
+      return false;
+    }
+
+    processor(raw);
+    return true;
+  }
+
+  getRules(): readonly string[] {
+    return [...this.rules.keys()];
+  }
+
+  private normalizeRule(rule: string): string {
+    const normalizedRule = rule.trim();
+    if (!normalizedRule) {
+      throw new ServerRuleRegistryError("Rule identifier must be a non-empty string");
+    }
+
+    if (normalizedRule === BUILTIN_RULE) {
+      throw new ServerRuleRegistryError(
+        `Rule identifier '${BUILTIN_RULE}' is reserved`
+      );
+    }
+
+    try {
+      parseRewrittenRuleMessage(`${normalizedRule}::sender::probe`);
+    } catch (error) {
+      if (error instanceof CodecError) {
+        throw new ServerRuleRegistryError(error.message);
+      }
+
+      throw error;
+    }
+
+    return normalizedRule;
+  }
+}
+
+export function createServerRuleRegistry(): ServerRuleRegistry {
+  return new YonexusServerRuleRegistry();
+}

plugin/core/runtime.ts

@@ -8,8 +8,10 @@ import {
   YONEXUS_PROTOCOL_VERSION,
   buildAuthFailed,
   buildAuthSuccess,
+  buildDisconnectNotice,
   buildError,
   buildHeartbeatAck,
+  buildStatusUpdate,
   buildHelloAck,
   buildPairFailed,
   buildPairRequest,
@@ -47,6 +49,7 @@ export interface YonexusServerRuntimeOptions {
   store: YonexusServerStore;
   transport: ServerTransport;
   now?: () => number;
+  sweepIntervalMs?: number;
 }
 
 export interface ServerLifecycleState {
@@ -60,6 +63,8 @@ export class YonexusServerRuntime {
   private readonly registry: ServerRegistry;
   private readonly pairingService: PairingService;
   private readonly notificationService: DiscordNotificationService;
+  private readonly sweepIntervalMs: number;
+  private sweepTimer: NodeJS.Timeout | null = null;
   private started = false;
 
   constructor(options: YonexusServerRuntimeOptions) {
@@ -69,6 +74,7 @@ export class YonexusServerRuntime {
       clients: new Map(),
       sessions: new Map()
     };
+    this.sweepIntervalMs = options.sweepIntervalMs ?? 30_000;
     this.pairingService = createPairingService({ now: this.now });
     this.notificationService = createDiscordNotificationService({
       botToken: options.config.notifyBotToken,
@@ -100,6 +106,7 @@ export class YonexusServerRuntime {
     }
 
     await this.options.transport.start();
+    this.startSweepTimer();
     this.started = true;
   }
 
@@ -108,6 +115,7 @@ export class YonexusServerRuntime {
       return;
     }
 
+    this.stopSweepTimer();
     await this.persist();
     this.registry.sessions.clear();
     await this.options.transport.stop();
@@ -669,6 +677,97 @@ export class YonexusServerRuntime {
     await this.persist();
   }
 
+  private startSweepTimer(): void {
+    this.stopSweepTimer();
+    this.sweepTimer = setInterval(() => {
+      void this.runLivenessSweep();
+    }, this.sweepIntervalMs);
+  }
+
+  private stopSweepTimer(): void {
+    if (!this.sweepTimer) {
+      return;
+    }
+
+    clearInterval(this.sweepTimer);
+    this.sweepTimer = null;
+  }
+
+  private async runLivenessSweep(): Promise<void> {
+    const now = this.now();
+    let hasChanges = false;
+
+    for (const record of this.registry.clients.values()) {
+      const nextStatus = this.getLivenessStatus(record, now);
+      if (!nextStatus || nextStatus === record.status) {
+        continue;
+      }
+
+      record.status = nextStatus;
+      record.updatedAt = now;
+      hasChanges = true;
+
+      if (nextStatus === "unstable") {
+        this.options.transport.send(
+          record.identifier,
+          encodeBuiltin(
+            buildStatusUpdate(
+              {
+                identifier: record.identifier,
+                status: "unstable",
+                reason: "heartbeat_timeout_7m"
+              },
+              { timestamp: now }
+            )
+          )
+        );
+        continue;
+      }
+
+      if (nextStatus === "offline") {
+        this.options.transport.send(
+          record.identifier,
+          encodeBuiltin(
+            buildDisconnectNotice(
+              {
+                identifier: record.identifier,
+                reason: "heartbeat_timeout_11m"
+              },
+              { timestamp: now }
+            )
+          )
+        );
+        this.options.transport.closeConnection(record.identifier, 1001, "Heartbeat timeout");
+        this.registry.sessions.delete(record.identifier);
+      }
+    }
+
+    if (hasChanges) {
+      await this.persist();
+    }
+  }
+
+  private getLivenessStatus(
+    record: ClientRecord,
+    now: number
+  ): "online" | "unstable" | "offline" | null {
+    const session = this.registry.sessions.get(record.identifier);
+    if (!session || !session.isAuthenticated || !record.lastHeartbeatAt) {
+      return null;
+    }
+
+    const silenceSeconds = now - record.lastHeartbeatAt;
+    if (silenceSeconds >= 11 * 60) {
+      return "offline";
+    }
+
+    if (silenceSeconds >= 7 * 60) {
+      return "unstable";
+    }
+
+    return "online";
+  }
+
   private async triggerRePairRequired(
     connection: ClientConnection,
     record: ClientRecord,

plugin/index.ts

@@ -73,6 +73,13 @@ export {
   type YonexusServerRuntimeOptions,
   type ServerLifecycleState
 } from "./core/runtime.js";
+export {
+  createServerRuleRegistry,
+  YonexusServerRuleRegistry,
+  ServerRuleRegistryError,
+  type ServerRuleRegistry,
+  type ServerRuleProcessor
+} from "./core/rules.js";
 
 export {
   createPairingService,