Enhance chat key lookup with remote and cache fallback

The GET /api/chat/keys endpoint now checks a remote identity cache and, if necessary, fetches keys from remote nodes or Swarm user profiles when a local key is not found. Results from remote lookups are cached for 24 hours to improve performance and reliability.

src/app/api/chat/keys/route.ts

@@ -1,8 +1,8 @@
 import { NextRequest, NextResponse } from 'next/server';
 import { db } from '@/db';
-import { chatDeviceBundles } from '@/db/schema';
+import { chatDeviceBundles, handleRegistry, remoteIdentityCache } from '@/db/schema';
 import { requireAuth } from '@/lib/auth';
-import { eq, and } from 'drizzle-orm';
+import { eq, and, gt } from 'drizzle-orm';
 
 /**
  * GET /api/chat/keys?did=<did>
@@ -23,7 +23,7 @@ export async function GET(request: NextRequest) {
       where: eq(chatDeviceBundles.did, did),
     });
 
-    console.log('[Chat Keys GET] Found bundle:', bundle ? 'YES' : 'NO');
+    console.log('[Chat Keys GET] Found local bundle:', bundle ? 'YES' : 'NO');
     if (bundle) {
       console.log('[Chat Keys GET] Bundle data:', {
         userId: bundle.userId,
@@ -31,16 +31,123 @@ export async function GET(request: NextRequest) {
         deviceId: bundle.deviceId,
         hasIdentityKey: !!bundle.identityKey,
       });
+
+      // For libsodium, we just need the public key
+      return NextResponse.json({
+        publicKey: bundle.identityKey,
+      });
     }
 
-    if (!bundle) {
-      return NextResponse.json({ error: 'No keys found' }, { status: 404 });
-    }
-
-    // For libsodium, we just need the public key
-    return NextResponse.json({
-      publicKey: bundle.identityKey, // Reusing identityKey field for libsodium public key
+    // If not found locally, check remote identity cache
+    const cached = await db.query.remoteIdentityCache.findFirst({
+      where: and(
+        eq(remoteIdentityCache.did, did),
+        gt(remoteIdentityCache.expiresAt, new Date())
+      ),
     });
+
+    if (cached) {
+      console.log('[Chat Keys GET] Found cached remote key');
+      return NextResponse.json({
+        publicKey: cached.publicKey,
+      });
+    }
+
+    // If not in cache, try to resolve DID to a node
+    console.log('[Chat Keys GET] resolving DID to node...');
+    const handleEntry = await db.query.handleRegistry.findFirst({
+      where: eq(handleRegistry.did, did),
+    });
+
+    if (handleEntry) {
+      const { nodeDomain } = handleEntry;
+      console.log('[Chat Keys GET] Resolved to node:', nodeDomain);
+
+      // Fetch from remote node
+      const remoteUrl = `https://${nodeDomain}/api/chat/keys?did=${encodeURIComponent(did)}`;
+      console.log('[Chat Keys GET] Fetching from remote:', remoteUrl);
+
+      try {
+        const remoteRes = await fetch(remoteUrl);
+        if (remoteRes.ok) {
+          const data = await remoteRes.json();
+          if (data.publicKey) {
+            console.log('[Chat Keys GET] Successfully fetched remote key');
+
+            // Cache it
+            await db.insert(remoteIdentityCache).values({
+              did: did,
+              publicKey: data.publicKey,
+              fetchedAt: new Date(),
+              expiresAt: new Date(Date.now() + 24 * 60 * 60 * 1000), // 24 hours
+            }).onConflictDoUpdate({
+              target: remoteIdentityCache.did,
+              set: {
+                publicKey: data.publicKey,
+                fetchedAt: new Date(),
+                expiresAt: new Date(Date.now() + 24 * 60 * 60 * 1000),
+              }
+            });
+
+            return NextResponse.json({
+              publicKey: data.publicKey,
+            });
+          }
+        } else {
+          console.warn('[Chat Keys GET] Remote fetch failed:', remoteRes.status, remoteRes.statusText);
+        }
+      } catch (err) {
+        console.error('[Chat Keys GET] Remote fetch error:', err);
+      }
+
+      // FALLBACK: Try fetching from Swarm User Profile (standard endpoint)
+      if (!cached) {
+        console.log('[Chat Keys GET] Trying fallback to Swarm Profile...');
+        const swarmUrl = `https://${nodeDomain}/api/swarm/users/${handleEntry.handle}`;
+        console.log('[Chat Keys GET] Fetching Swarm Profile:', swarmUrl);
+
+        try {
+          const swarmRes = await fetch(swarmUrl);
+          if (swarmRes.ok) {
+            const data = await swarmRes.json();
+            const chatKey = data.profile?.chatPublicKey;
+
+            if (chatKey) {
+              console.log('[Chat Keys GET] Found key in Swarm Profile');
+
+              // Cache it
+              await db.insert(remoteIdentityCache).values({
+                did: did,
+                publicKey: chatKey,
+                fetchedAt: new Date(),
+                expiresAt: new Date(Date.now() + 24 * 60 * 60 * 1000), // 24 hours
+              }).onConflictDoUpdate({
+                target: remoteIdentityCache.did,
+                set: {
+                  publicKey: chatKey,
+                  fetchedAt: new Date(),
+                  expiresAt: new Date(Date.now() + 24 * 60 * 60 * 1000),
+                }
+              });
+
+              return NextResponse.json({
+                publicKey: chatKey,
+              });
+            } else {
+              console.warn('[Chat Keys GET] Swarm Profile found but no chatPublicKey');
+            }
+          } else {
+            console.warn('[Chat Keys GET] Swarm Profile fetch failed:', swarmRes.status);
+          }
+        } catch (err) {
+          console.error('[Chat Keys GET] Swarm Profile fetch error:', err);
+        }
+      }
+    } else {
+      console.log('[Chat Keys GET] DID not found in handle registry');
+    }
+
+    return NextResponse.json({ error: 'No keys found' }, { status: 404 });
   } catch (error: any) {
     console.error('[Chat Keys] Failed to fetch keys:', error);
     return NextResponse.json({ error: error.message }, { status: 500 });
@@ -58,7 +165,7 @@ export async function GET(request: NextRequest) {
 export async function POST(request: NextRequest) {
   try {
     const user = await requireAuth();
-    
+
     console.log('[Chat Keys POST] User:', user.handle, 'DID:', user.did, 'UserID:', user.id);
 
     const body = await request.json();