epoching API: add epoch msg range queries and add timestamp to validator lifecycle

proto/babylon/epoching/v1/epoching.proto

@@ -33,6 +33,11 @@ message QueuedMessage {
   }
 }
 
+message QueuedMessageList {
+  uint64 epoch_number = 1;
+  repeated QueuedMessage msgs = 2;
+}
+
 enum ValState {
   CREATED = 0;
   BONDED = 1;
@@ -43,7 +48,8 @@ enum ValState {
 
 message ValStateUpdate {
   ValState state = 1;
-  uint64 height = 2;
+  uint64 block_height = 2;
+  google.protobuf.Timestamp block_time = 3 [(gogoproto.stdtime) = true];
 }
 
 message ValidatorLifecycle {

proto/babylon/epoching/v1/query.proto

@@ -23,7 +23,12 @@ service Query {
 
   // EpochMsgs queries the messages of a given epoch
   rpc EpochMsgs(QueryEpochMsgsRequest) returns (QueryEpochMsgsResponse) {
-    option (google.api.http).get = "/babylon/epoching/v1/epoch_msgs/{epoch_num}";
+    option (google.api.http).get = "/babylon/epoching/v1/epochs/{epoch_num=*}/messages";
+  }
+
+  // LatestEpochMsgs queries the messages within a given number of most recent epochs
+  rpc LatestEpochMsgs(QueryLatestEpochMsgsRequest) returns (QueryLatestEpochMsgsResponse) {
+    option (google.api.http).get = "/babylon/epoching/v1/epochs:latest/messages";
   }
 
   // ValidatorLifecycle queries the lifecycle of a given validator
@@ -69,6 +74,26 @@ message QueryEpochMsgsResponse {
   cosmos.base.query.v1beta1.PageResponse pagination = 2;
 }
 
+// QueryLatestEpochMsgsRequest is request type for the Query/LatestEpochMsgs RPC method
+// it returns epoch msgs within epoch [min(1, end_epoch-epoch_count+1), end_epoch]
+message QueryLatestEpochMsgsRequest {
+  // end_epoch is the number of the last epoch to query
+  uint64 end_epoch = 1;
+  // epoch_count is the number of epochs to query
+  uint64 epoch_count = 2;
+
+  cosmos.base.query.v1beta1.PageRequest pagination = 3;
+}
+
+// QueryLatestEpochMsgsResponse is response type for the Query/LatestEpochMsgs RPC method
+message QueryLatestEpochMsgsResponse {
+  // epoch_msg_map is a list of QueuedMessageList
+  // each QueuedMessageList has a field identifying the epoch number
+  repeated babylon.epoching.v1.QueuedMessageList latest_epoch_msgs = 1;
+
+  cosmos.base.query.v1beta1.PageResponse pagination = 2;
+}
+
 message QueryValidatorLifecycleRequest {
   string val_addr = 1;
 }

x/epoching/keeper/epoch_msg_queue_test.go

@@ -95,7 +95,7 @@ func FuzzHandleQueuedMsg_MsgWrappedDelegate(f *testing.F) {
 		require.NotNil(t, lc)
 		require.Equal(t, 1, len(lc.ValLife))
 		require.Equal(t, types.ValState_CREATED, lc.ValLife[0].State)
-		require.Equal(t, uint64(0), lc.ValLife[0].Height)
+		require.Equal(t, uint64(0), lc.ValLife[0].BlockHeight)
 
 		// delegate a random amount of tokens to the validator
 		numNewDels := rand.Int63n(1000) + 1
@@ -161,7 +161,7 @@ func FuzzHandleQueuedMsg_MsgWrappedUndelegate(f *testing.F) {
 		require.NotNil(t, lc)
 		require.Equal(t, 1, len(lc.ValLife))
 		require.Equal(t, types.ValState_CREATED, lc.ValLife[0].State)
-		require.Equal(t, uint64(0), lc.ValLife[0].Height)
+		require.Equal(t, uint64(0), lc.ValLife[0].BlockHeight)
 
 		// unbond a random amount of tokens from the validator
 		// Note that for any pair of delegator and validator, there can be `<=DefaultMaxEntries=7` concurrent undelegations at any time slot
@@ -245,7 +245,7 @@ func FuzzHandleQueuedMsg_MsgWrappedBeginRedelegate(f *testing.F) {
 			require.NotNil(t, lc)
 			require.Equal(t, 1, len(lc.ValLife))
 			require.Equal(t, types.ValState_CREATED, lc.ValLife[0].State)
-			require.Equal(t, uint64(0), lc.ValLife[0].Height)
+			require.Equal(t, uint64(0), lc.ValLife[0].BlockHeight)
 		}
 
 		// redelegate a random amount of tokens from val1 to val2

x/epoching/keeper/grpc_query.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/babylonchain/babylon/x/epoching/types"
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 	"github.com/cosmos/cosmos-sdk/types/query"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
@@ -74,7 +75,64 @@ func (k Keeper) EpochMsgs(c context.Context, req *types.QueryEpochMsgsRequest) (
 	return resp, nil
 }
 
+// LatestEpochMsgs handles the QueryLatestEpochMsgsRequest query
+// TODO: test this API
+func (k Keeper) LatestEpochMsgs(c context.Context, req *types.QueryLatestEpochMsgsRequest) (*types.QueryLatestEpochMsgsResponse, error) {
+	ctx := sdk.UnwrapSDKContext(c)
+
+	if req.EpochCount == 0 {
+		return nil, sdkerrors.Wrapf(
+			sdkerrors.ErrInvalidRequest, "epoch_count should be specified and be larger than zero",
+		)
+	}
+
+	// the API will return epoch msgs between [min(1, end_epoch-epoch_count+1), end_epoch].
+	// NOTE:
+	// - epoch 0 does not have any queued msg
+	// - if not specified, endEpoch will be the current epoch
+	endEpoch := req.EndEpoch
+	if endEpoch == 0 {
+		endEpoch = k.GetEpoch(ctx).EpochNumber
+	}
+	beginEpoch := endEpoch - req.EpochCount + 1
+	if beginEpoch <= 1 {
+		beginEpoch = 1
+	}
+
+	latestEpochMsgs := []*types.QueuedMessageList{}
+
+	// iterate over queueLenStore since we only need to iterate over the epoch number
+	queueLenStore := k.msgQueueLengthStore(ctx)
+	pageRes, err := query.FilteredPaginate(queueLenStore, req.Pagination, func(key []byte, _ []byte, accumulate bool) (bool, error) {
+		// unmarshal to epoch number
+		epochNumber := sdk.BigEndianToUint64(key)
+		// only return queued msgs within [beginEpoch, endEpoch]
+		if epochNumber < beginEpoch || endEpoch < epochNumber {
+			return false, nil
+		}
+
+		if accumulate {
+			msgList := &types.QueuedMessageList{
+				EpochNumber: epochNumber,
+				Msgs:        k.GetEpochMsgs(ctx, epochNumber),
+			}
+			latestEpochMsgs = append(latestEpochMsgs, msgList)
+		}
+		return true, nil
+	})
+	if err != nil {
+		return nil, status.Error(codes.Internal, err.Error())
+	}
+
+	resp := &types.QueryLatestEpochMsgsResponse{
+		LatestEpochMsgs: latestEpochMsgs,
+		Pagination:      pageRes,
+	}
+	return resp, nil
+}
+
 // ValidatorLifecycle handles the QueryValidatorLifecycleRequest query
+// TODO: test this API
 func (k Keeper) ValidatorLifecycle(c context.Context, req *types.QueryValidatorLifecycleRequest) (*types.QueryValidatorLifecycleResponse, error) {
 	ctx := sdk.UnwrapSDKContext(c)
 	valAddr, err := sdk.ValAddressFromBech32(req.ValAddr)
@@ -85,5 +143,4 @@ func (k Keeper) ValidatorLifecycle(c context.Context, req *types.QueryValidatorL
 	return &types.QueryValidatorLifecycleResponse{
 		ValLife: lc,
 	}, nil
-	// TODO: test this API
 }

x/epoching/keeper/val_lifecycle.go

@@ -20,9 +20,11 @@ func (k Keeper) RecordNewValState(ctx sdk.Context, valAddr sdk.ValAddress, state
 			ValLife: []*types.ValStateUpdate{},
 		}
 	}
+	height, time := ctx.BlockHeight(), ctx.BlockTime()
 	valStateUpdate := types.ValStateUpdate{
-		State:  state,
-		Height: uint64(ctx.BlockHeight()),
+		State:       state,
+		BlockHeight: uint64(height),
+		BlockTime:   &time,
 	}
 	lc.ValLife = append(lc.ValLife, &valStateUpdate)
 	k.SetValLifecycle(ctx, valAddr, lc)
@@ -37,6 +39,9 @@ func (k Keeper) SetValLifecycle(ctx sdk.Context, valAddr sdk.ValAddress, lc *typ
 func (k Keeper) GetValLifecycle(ctx sdk.Context, valAddr sdk.ValAddress) *types.ValidatorLifecycle {
 	store := k.valLifecycleStore(ctx)
 	lcBytes := store.Get([]byte(valAddr))
+	if len(lcBytes) == 0 {
+		return nil
+	}
 	var lc types.ValidatorLifecycle
 	k.cdc.MustUnmarshal(lcBytes, &lc)
 	return &lc