pick a server from a list

src/did/did-loader.js

@@ -10,7 +10,50 @@ if (fs.existsSync(config.did.storagePath)) {
   didState = JSON.parse(didStateJson);
 } else {
   if (config.did.method === 'ion') {
-    didState = await DIDIon.generate({ serviceEndpoint: 'https://dwn-aggregator.faktj7f1fndve.ap-southeast-2.cs.amazonlightsail.com/' });
+
+
+
+    const endpoints = [
+                    'https://dwn-usa-1.ue8cktdq71va0.us-east-2.cs.amazonlightsail.com/', 
+                    'https://dwn-aggregator.faktj7f1fndve.ap-southeast-2.cs.amazonlightsail.com/',
+                    'https://dwn-india.vtv94qck5sjvq.ap-south-1.cs.amazonlightsail.com/'
+                  ];
+
+    const selectedEndpoints = async () => {
+      let responseTimes = [];
+
+      // Pick 3 random endpoints
+      let randomEndpoints = [];
+      while (randomEndpoints.length < 3) {
+        let randomIndex = Math.floor(Math.random() * endpoints.length);
+        if (!randomEndpoints.includes(endpoints[randomIndex])) {
+          randomEndpoints.push(endpoints[randomIndex]);
+        }
+      }
+
+      // Check the response time of each endpoint and make sure it returns 200 OK
+      for (let endpoint of randomEndpoints) {
+        let start = performance.now();
+        let response = await fetch(endpoint + "health");
+        let end = performance.now();
+        if (response.status === 200) {
+          responseTimes.push({
+            endpoint,
+            responseTime: end - start
+          });
+        }
+      }
+
+      // Sort the endpoints based on response time, fastest first
+      responseTimes.sort((a, b) => a.responseTime - b.responseTime);
+
+      return responseTimes.map(rt => rt.endpoint);
+    }
+
+    const serviceEndpoints = await selectedEndpoints();
+    const serviceEndpoint = serviceEndpoints[0];
+
+    didState = await DIDIon.generate({ serviceEndpoint: serviceEndpoint });
     fs.writeFileSync(config.did.storagePath, JSON.stringify(didState, null, 2));
   } else {
     throw new Error(`DID Method ${config.did.method} not supported`);