GattServer.getUUIDbyHandle added

src/GattServer.js

@@ -54,6 +54,38 @@ class GattServer {
 
     throw new Error('Service not available')
   }
+
+  /**
+   * Find the service UUID and characteristic UUID based on a characteristic handle
+   * @param {number} charHandle
+   * @returns {<Object|null>}
+   */
+  async getUUIDbyHandle(charHandle) {
+    const handle = charHandle - 1;
+    const handleStr = 'char' + handle.toString(16).padStart(4, '0');
+
+    for (const key in this.dbus._matchRules) {
+      if (key.includes(handleStr)) {
+        const match = key.match(/service[0-9a-fA-F]+/);
+        if (match) {
+          const service = match[0];
+          const services = this._services;
+          for (const skey in services) {
+            if (services[skey].service === service) {
+              const characteristics = services[skey]._characteristics;
+              for (const ckey in characteristics) {
+                if (characteristics[ckey].characteristic === handleStr) {
+                  return { 'service': skey, 'char': ckey };
+                }
+              }
+              return null;
+            }
+          }
+        }
+      }
+    }
+    return null;
+  }  
 }
 
 module.exports = GattServer