Improve IBC query API (#25)

* Refactor IbcQuery and IbcResponse to provide ibc_query with a better signature

* Remove associated type from IbcResponse trait

relayer/relay/src/query.rs

@@ -1,25 +1,32 @@
 use tendermint::abci;
-use tendermint::rpc::{self, endpoint::abci_query::AbciQuery};
+use tendermint::rpc::endpoint::abci_query::AbciQuery;
 
 use relayer_modules::Height;
 
 use crate::chain::Chain;
+use crate::error;
 
-mod client_consensus_state;
-pub use client_consensus_state::*;
+pub mod client_consensus_state;
 
-pub trait IbcResponse: Sized {}
+pub trait IbcResponse<Query>: Sized {
+    fn from_abci_response(query: Query, response: AbciQuery) -> Result<Self, error::Error>;
+}
 
-pub trait IbcQuery {
-    type Response: IbcResponse;
+pub trait IbcQuery: Sized {
+    type Response: IbcResponse<Self>;
 
     fn path(&self) -> abci::Path;
     fn height(&self) -> Height;
     fn prove(&self) -> bool;
     fn data(&self) -> Vec<u8>;
+
+    fn build_response(self, response: AbciQuery) -> Result<Self::Response, error::Error> {
+        Self::Response::from_abci_response(self, response)
+    }
 }
 
-pub async fn ibc_query<C, Q>(chain: &C, query: Q) -> Result<AbciQuery, rpc::Error>
+/// Perform an IBC `query` on the given `chain`, and return the corresponding IBC response.
+pub async fn ibc_query<C, Q>(chain: &C, query: Q) -> Result<Q::Response, error::Error>
 where
     C: Chain,
     Q: IbcQuery,
@@ -32,19 +39,19 @@ where
             Some(query.height().into()),
             query.prove(),
         )
-        .await?;
+        .await
+        .map_err(|e| error::Kind::Rpc.context(e))?;
 
     if !abci_response.code.is_ok() {
-        todo!() // fail with response log
+        todo!() // TODO: Fail with response log
     }
 
-    // Data from trusted node or subspace query doesn't need verification
-    if !is_query_store_with_proof(&query.path()) {
-        return Ok(abci_response);
+    // Data that is not from trusted node or subspace query needs verification
+    if is_query_store_with_proof(&query.path()) {
+        todo!() // TODO: Verify proof
     }
 
-    // TODO: Verify proof and return response
-    Ok(abci_response)
+    query.build_response(abci_response)
 }
 
 /// Whether or not this path requires proof verification.

relayer/relay/src/query/client_consensus_state.rs

@@ -1,4 +1,5 @@
 use std::marker::PhantomData;
+use tendermint::rpc::endpoint::abci_query::AbciQuery;
 
 use tendermint::abci;
 
@@ -14,6 +15,7 @@ use crate::error;
 
 pub struct QueryClientConsensusState<CS> {
     pub height: Height,
+    pub client_id: ClientId,
     pub consensus_state_path: ConsensusStatePath,
     marker: PhantomData<CS>,
 }
@@ -22,7 +24,8 @@ impl<CS> QueryClientConsensusState<CS> {
     pub fn new(height: Height, client_id: ClientId) -> Self {
         Self {
             height,
-            consensus_state_path: ConsensusStatePath { client_id, height },
+            client_id: client_id.clone(),
+            consensus_state_path: ConsensusStatePath::new(client_id, height),
             marker: PhantomData,
         }
     }
@@ -78,13 +81,28 @@ impl<CS> ConsensusStateResponse<CS> {
     }
 }
 
-impl<CS> IbcResponse for ConsensusStateResponse<CS>
+impl<CS> IbcResponse<QueryClientConsensusState<CS>> for ConsensusStateResponse<CS>
 where
     CS: ConsensusState,
 {
-    // fn from_bytes(_bytes: &[u8]) -> Result<Self, rpc::Error> {
-    //     todo!()
-    // }
+    fn from_abci_response(
+        query: QueryClientConsensusState<CS>,
+        response: AbciQuery,
+    ) -> Result<Self, error::Error> {
+        match (response.value, response.proof) {
+            (Some(value), Some(proof)) => {
+                let consensus_state = amino_unmarshal_binary_length_prefixed(&value)?;
+
+                Ok(ConsensusStateResponse::new(
+                    query.client_id,
+                    consensus_state,
+                    proof,
+                    response.height.into(),
+                ))
+            }
+            _ => todo!(),
+        }
+    }
 }
 
 pub async fn query_client_consensus_state<C>(
@@ -95,21 +113,9 @@ pub async fn query_client_consensus_state<C>(
 where
     C: Chain,
 {
-    let query = QueryClientConsensusState::<C::ConsensusState>::new(height, client_id.clone());
-
-    let response = ibc_query(chain, query)
-        .await
-        .map_err(|e| error::Kind::Rpc.context(e))?;
-
-    // FIXME: Handle case where there is no value
-    let consensus_state = amino_unmarshal_binary_length_prefixed(&response.value.unwrap())?;
+    let query = QueryClientConsensusState::new(height, client_id);
 
-    Ok(ConsensusStateResponse::new(
-        client_id,
-        consensus_state,
-        response.proof.unwrap(), // FIXME: Handle case where there is no proof
-        response.height.into(),
-    ))
+    ibc_query(chain, query).await
 }
 
 fn amino_unmarshal_binary_length_prefixed<T>(_bytes: &[u8]) -> Result<T, error::Error> {