Send to by node name or broadcast sentinel (GET-free resolution via node DB) (#9)

src/mesh/mesh.service.ts

@@ -8,6 +8,7 @@ import {
 import * as net from 'node:net';
 import type * as Proto from '@meshtastic/protobufs';
 import {
+  BROADCAST_ADDR,
   PORT_POSITION_APP,
   PORT_ROUTING_APP,
   PORT_TEXT_MESSAGE_APP,
@@ -176,6 +177,34 @@ export class MeshService implements OnModuleInit, OnModuleDestroy {
     return null;
   }
 
+  /**
+   * Resolve a send target to a node number for sendText().
+   * undefined/"" and "!b"/"broadcast" (case-insensitive, trimmed) → BROADCAST_ADDR;
+   * numbers pass through as-is (must be an integer in 1..0xffffffff); numeric strings are parsed the same way;
+   * anything else is looked up via node() — throws `no node matching '<to>'` when nothing or more than one matches.
+   */
+  async resolveDest(to?: number | string): Promise<number> {
+    if (typeof to === 'number') {
+      this.assertNodeNum(to);
+      return to;
+    }
+    const s = String(to ?? '').trim();
+    if (!s) return BROADCAST_ADDR; // omitted or empty → broadcast
+    if (s === '!b' || s.toLowerCase() === 'broadcast') return BROADCAST_ADDR;
+    if (/^\d+$/.test(s)) {
+      this.assertNodeNum(Number(s));
+      return Number(s);
+    }
+    const hit = await this.node(s);
+    if (!hit) throw new Error(`no node matching '${to}'`);
+    return hit.num;
+  }
+
+  private assertNodeNum(n: number): void {
+    if (!Number.isInteger(n) || n < 1 || n > BROADCAST_ADDR)
+      throw new Error(`invalid node number '${n}'`);
+  }
+
   /**
    * Message history, newest first: inbound TEXT_MESSAGE_APP packets (dir 'rx') and our sends (dir 'tx').
    * tx records start 'pending' and move to 'delivered'/'failed' when the routing ACK/NACK arrives;