Merge pull request #180 from privacy-scaling-explorations/feat/fetch-…

…poll-subgraph

feat: fetch poll data from subgraph

src/contexts/Maci.tsx

@@ -44,6 +44,8 @@ export const MaciProvider: React.FC<MaciProviderProps> = ({ children }: MaciProv
     { enabled: Boolean(maciPubKey && config.maciSubgraphUrl) },
   );
 
+  const poll = api.maci.poll.useQuery(undefined, { enabled: Boolean(config.maciSubgraphUrl) });
+
   const attestations = api.voters.approvedAttestations.useQuery({
     address,
   });
@@ -70,6 +72,15 @@ export const MaciProvider: React.FC<MaciProviderProps> = ({ children }: MaciProv
     }
   }, [setMaciPrivKey, setMaciPubKey]);
 
+  // on load we fetch the data from the poll
+  useEffect(() => {
+    if (poll.data) {
+      return;
+    }
+
+    poll.refetch().catch(console.error);
+  }, [poll]);
+
   const generateKeypair = useCallback(async () => {
     // if we are not connected then do not generate the key pair
     if (!address) {
@@ -98,15 +109,13 @@ export const MaciProvider: React.FC<MaciProviderProps> = ({ children }: MaciProv
       setIsLoading(true);
 
       try {
-        const { stateIndex: index, hash } = await signup({
+        const { stateIndex: index } = await signup({
           maciPubKey,
           maciAddress: config.maciAddress!,
           sgDataArg: attestationId,
           signer,
         });
 
-        console.log(`Signup transaction hash: ${hash}`);
-
         if (index) {
           setIsRegistered(true);
           setStateIndex(index);
@@ -234,7 +243,28 @@ export const MaciProvider: React.FC<MaciProviderProps> = ({ children }: MaciProv
 
     setIsLoading(true);
 
-    Promise.all([
+    // if we have the subgraph url then it means we can get the poll data through there
+    if (config.maciSubgraphUrl) {
+      if (!poll.data) {
+        setIsLoading(false);
+        return;
+      }
+
+      const { isStateAqMerged, id } = poll.data;
+
+      setPollData(poll.data);
+
+      if (isStateAqMerged) {
+        fetch(`${config.tallyUrl}/tally-${id}.json`)
+          .then((res) => res.json() as Promise<TallyData>)
+          .then((res) => {
+            setTallyData(res);
+          })
+          .catch(() => undefined);
+      }
+
+      setIsLoading(false);
+    } else {
       getPoll({
         maciAddress: config.maciAddress!,
         signer,
@@ -255,13 +285,13 @@ export const MaciProvider: React.FC<MaciProviderProps> = ({ children }: MaciProv
               setTallyData(res);
             })
             .catch(() => undefined);
-        }),
-    ])
-      .catch(console.error)
-      .finally(() => {
-        setIsLoading(false);
-      });
-  }, [signer, votingEndsAt, setIsLoading, setTallyData, setPollData]);
+        })
+        .catch(console.error)
+        .finally(() => {
+          setIsLoading(false);
+        });
+    }
+  }, [signer, votingEndsAt, setIsLoading, setTallyData, setPollData, poll.data]);
 
   const value = useMemo(
     () => ({

src/server/api/routers/maci.ts

@@ -2,10 +2,12 @@ import { PubKey } from "maci-domainobjs";
 import { z } from "zod";
 
 import { createTRPCRouter, publicProcedure } from "~/server/api/trpc";
+import { fetchPoll } from "~/utils/fetchPoll";
 import { fetchUser } from "~/utils/fetchUser";
 
 export const maciRouter = createTRPCRouter({
   user: publicProcedure
     .input(z.object({ publicKey: z.string() }))
     .query(async ({ input }) => fetchUser(PubKey.deserialize(input.publicKey).rawPubKey)),
+  poll: publicProcedure.query(async () => fetchPoll()),
 });

src/utils/fetchPoll.ts

@@ -0,0 +1,58 @@
+import { IGetPollData } from "maci-cli/sdk";
+
+import { config } from "~/config";
+
+import { createCachedFetch } from "./fetch";
+
+const cachedFetch = createCachedFetch({ ttl: 1000 * 60 * 10 });
+
+interface Poll {
+  pollId: string;
+  createdAt: string;
+  duration: string;
+  stateRoot: string;
+  messageRoot: string;
+  numSignups: string;
+  id: string;
+}
+
+export interface GraphQLResponse {
+  data?: {
+    polls: Poll[];
+  };
+}
+
+const PollQuery = `
+  query Poll {
+    polls(orderBy: createdAt, orderDirection: desc, first: 1) {
+      pollId
+      duration
+      createdAt
+      stateRoot
+      messageRoot
+      numSignups
+      id
+    }
+  }
+`;
+
+export async function fetchPoll(): Promise<IGetPollData> {
+  const poll = (
+    await cachedFetch<{ polls: Poll[] }>(config.maciSubgraphUrl, {
+      method: "POST",
+      body: JSON.stringify({
+        query: PollQuery,
+      }),
+    }).then((response: GraphQLResponse) => response.data?.polls)
+  )?.at(0);
+
+  // cast this to a IGetPollData object so that we can deal with one object only in MACIContext
+  return {
+    isStateAqMerged: !!poll?.messageRoot,
+    id: poll?.pollId ?? 0,
+    duration: poll?.duration ?? 0,
+    deployTime: poll?.createdAt ?? 0,
+    numSignups: poll?.numSignups ?? 0,
+    address: poll?.id ?? "",
+  };
+}