fix: redeem PT&YT YT amount

proto/ununifi/irs/query.proto

@@ -51,6 +51,10 @@ service Query {
   rpc EstimateMintPtYtPair(QueryEstimateMintPtYtPairRequest) returns (QueryEstimateMintPtYtPairResponse) {
     option (google.api.http).get = "/ununifi/irs/estimate-mint-pt-yt-pair";
   }
+  // Estimate redeem amount of PT&YT pair 
+  rpc EstimateRedeemPtYtPair(QueryEstimateRedeemPtYtPairRequest) returns (QueryEstimateRedeemPtYtPairResponse) {
+    option (google.api.http).get = "/ununifi/irs/estimate-redeem-pt-yt-pair";
+  }
   // Estimate redeem amount of YT after maturity
   rpc EstimateRedeemYt(QueryEstimateRedeemYtRequest) returns (QueryEstimateRedeemYtResponse) {
     option (google.api.http).get = "/ununifi/irs/estimate-redeem-yt";
@@ -150,6 +154,15 @@ message QueryEstimateMintPtYtPairResponse {
   cosmos.base.v1beta1.Coin yt_amount = 2 [(gogoproto.nullable) = false];
 }
 
+message QueryEstimateRedeemPtYtPairRequest {
+  uint64 pool_id = 1;
+  string yt_amount = 2;
+}
+
+message QueryEstimateRedeemPtYtPairResponse {
+  cosmos.base.v1beta1.Coin pt_amount = 1 [(gogoproto.nullable) = false];
+}
+
 message QueryEstimateRedeemYtRequest {
   uint64 pool_id = 1;
   string denom = 2;

x/irs/keeper/grpc_query_estimate_redeem_pt_yt_pair.go

@@ -0,0 +1,36 @@
+package keeper
+
+import (
+	"context"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+
+	"github.com/UnUniFi/chain/x/irs/types"
+)
+
+func (k Keeper) EstimateRedeemPtYtPair(c context.Context, req *types.QueryEstimateRedeemPtYtPairRequest) (*types.QueryEstimateRedeemPtYtPairResponse, error) {
+	if req == nil {
+		return nil, status.Error(codes.InvalidArgument, "invalid request")
+	}
+
+	ctx := sdk.UnwrapSDKContext(c)
+	tranche, found := k.GetTranchePool(ctx, req.PoolId)
+	if !found {
+		return nil, types.ErrTrancheNotFound
+	}
+	redeemAmount, ok := sdk.NewIntFromString(req.YtAmount)
+	if !ok {
+		return nil, types.ErrInvalidAmount
+	}
+	ptAmount, err := k.CalculateRedeemRequiredPtAmount(ctx, tranche, redeemAmount)
+	if err != nil {
+		return nil, err
+	}
+
+	ptDenom := types.PtDenom(tranche)
+	return &types.QueryEstimateRedeemPtYtPairResponse{
+		PtAmount: sdk.NewCoin(ptDenom, ptAmount),
+	}, nil
+}

x/irs/keeper/stripping.go

@@ -112,11 +112,12 @@ func (k Keeper) RedeemPtYtPair(ctx sdk.Context, sender sdk.AccAddress, pool type
 
 	ptDenom := types.PtDenom(pool)
 	ytDenom := types.YtDenom(pool)
-	ptSupply := k.bankKeeper.GetSupply(ctx, ptDenom)
-	ytSupply := k.bankKeeper.GetSupply(ctx, ytDenom)
 
-	requiredPtAmount := ptSupply.Amount.Mul(redeemUt).Quo(amountFromStrategy)
-	requiredYtAmount := ytSupply.Amount.Mul(redeemUt).Quo(amountFromStrategy)
+	requiredPtAmount, err := k.CalculateRedeemRequiredPtAmount(ctx, pool, redeemUt)
+	if err != nil {
+		return err
+	}
+	requiredYtAmount := redeemUt
 
 	coins := sdk.Coins{}
 	requiredPtYt := coins.Add(sdk.NewCoin(ptDenom, requiredPtAmount)).Add(sdk.NewCoin(ytDenom, requiredYtAmount))
@@ -137,6 +138,22 @@ func (k Keeper) RedeemPtYtPair(ctx sdk.Context, sender sdk.AccAddress, pool type
 	return k.UnstakeFromStrategy(ctx, moduleAddr, sender.String(), pool.StrategyContract, redeemUt)
 }
 
+func (k Keeper) CalculateRedeemRequiredPtAmount(ctx sdk.Context, pool types.TranchePool, redeemUt sdk.Int) (sdk.Int, error) {
+	moduleAddr := types.GetVaultModuleAddress(pool)
+
+	amountFromStrategy, err := k.GetAmountFromStrategy(ctx, moduleAddr, pool.StrategyContract)
+	if err != nil {
+		return sdk.ZeroInt(), err
+	}
+	if amountFromStrategy.IsZero() {
+		return sdk.ZeroInt(), types.ErrZeroAmount
+	}
+	ptDenom := types.PtDenom(pool)
+	ptSupply := k.bankKeeper.GetSupply(ctx, ptDenom)
+	requiredPtAmount := ptSupply.Amount.Mul(redeemUt).Quo(amountFromStrategy)
+	return requiredPtAmount, nil
+}
+
 func (k Keeper) RedeemPtAtMaturity(ctx sdk.Context, sender sdk.AccAddress, pool types.TranchePool, ptAmount sdk.Coin) error {
 	if uint64(ctx.BlockTime().Unix()) < pool.StartTime+pool.Maturity {
 		return types.ErrTrancheNotMatured