feat(api): query delegator total rewards token (piplabs#572)

Add to query the total number of rewards token of delegator. This is to
estimate the daily rewards for staking dashboard.

issue: none

Author: 0xHansLee

client/server/README.md

@@ -725,6 +725,26 @@ URL: [GET] /staking/delegators/{delegator_addr}/validators/{validator_addr}
 }
 ```
 
+## GetDelegatorTotalRewardsToken
+
+URL: [GET] /staking/delegators/{delegator_addr}/total_rewards_token
+
+### Path Params
+| Name           | Type   | Example                                      | Required |
+|----------------|--------|----------------------------------------------|----------|
+| delegator_addr | string | 0x00a842dbd3d11176b4868dd753a552b8919d5a63   | ✔        |
+
+### Response Example
+```json
+{
+    "code": 200,
+    "msg": {
+        "rewards_token": "373566680396694.500000000000000000"
+    },
+    "error": ""
+}
+```
+
 ## GetDelegatorDelegations
 
 URL: [GET] /staking/delegations/{delegator_addr}

client/server/staking.go

@@ -5,6 +5,9 @@ import (
 	"net/http"
 	"strconv"
 
+	"cosmossdk.io/math"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/query"
 	"github.com/cosmos/cosmos-sdk/x/staking/keeper"
 	stakingtypes "github.com/cosmos/cosmos-sdk/x/staking/types"
@@ -35,6 +38,7 @@ func (s *Server) initStakingRoute() {
 	s.httpMux.HandleFunc("/staking/delegators/{delegator_address}/unbonding_delegations", utils.AutoWrap(s.aminoCodec, s.GetUnbondingDelegationsByDelegatorAddress))
 	s.httpMux.HandleFunc("/staking/delegators/{delegator_address}/validators", utils.AutoWrap(s.aminoCodec, s.GetValidatorsByDelegatorAddress))
 	s.httpMux.HandleFunc("/staking/delegators/{delegator_address}/validators/{validator_address}", utils.SimpleWrap(s.aminoCodec, s.GetValidatorsByDelegatorAddressValidatorAddress))
+	s.httpMux.HandleFunc("/staking/delegators/{delegator_address}/total_rewards_token", utils.SimpleWrap(s.aminoCodec, s.GetTotalRewardsTokenByDelegatorAddress))
 }
 
 // GetStakingParams queries the staking parameters.
@@ -624,6 +628,64 @@ func (s *Server) GetValidatorsByDelegatorAddressValidatorAddress(r *http.Request
 	return queryResp, nil
 }
 
+type QueryTotalRewardsTokenByDelegatorAddressResponse struct {
+	RewardsToken math.LegacyDec `json:"rewards_token"`
+}
+
+func (s *Server) GetTotalRewardsTokenByDelegatorAddress(r *http.Request) (resp any, err error) {
+	queryContext, err := s.createQueryContextByHeader(r)
+	if err != nil {
+		return nil, err
+	}
+
+	bech32AccAddress, err := utils.EvmAddressToBech32AccAddress(mux.Vars(r)["delegator_address"])
+	if err != nil {
+		return nil, err
+	}
+
+	var nextKey []byte
+	totalRewardsToken := math.LegacyZeroDec()
+
+	for {
+		queryResp, err := keeper.NewQuerier(s.store.GetStakingKeeper()).DelegatorDelegations(queryContext, &stakingtypes.QueryDelegatorDelegationsRequest{
+			DelegatorAddr: bech32AccAddress.String(),
+			Pagination: &query.PageRequest{
+				Key:        nextKey,
+				Limit:      100,
+				CountTotal: false,
+			},
+		})
+		if err != nil {
+			return nil, err
+		}
+
+		for _, delResp := range queryResp.DelegationResponses {
+			valAddr, err := sdk.ValAddressFromBech32(delResp.Delegation.ValidatorAddress)
+			if err != nil {
+				return nil, err
+			}
+
+			val, err := keeper.NewQuerier(s.store.GetStakingKeeper()).GetValidator(queryContext, valAddr)
+			if err != nil {
+				return nil, err
+			}
+
+			rewardsToken := val.RewardsTokensFromRewardsShares(delResp.Delegation.RewardsShares)
+			totalRewardsToken = totalRewardsToken.Add(rewardsToken)
+		}
+
+		if queryResp.Pagination == nil || len(queryResp.Pagination.NextKey) == 0 {
+			break
+		}
+
+		nextKey = queryResp.Pagination.NextKey
+	}
+
+	return QueryTotalRewardsTokenByDelegatorAddressResponse{
+		RewardsToken: totalRewardsToken,
+	}, nil
+}
+
 // GetPeriodDelegations queries period delegations info for given validator delegator pair.
 func (s *Server) GetPeriodDelegations(req *getPeriodDelegationsRequest, r *http.Request) (resp any, err error) {
 	queryContext, err := s.createQueryContextByHeader(r)