From d2ff8f7253c78642d812e97ab0811203d316bf5b Mon Sep 17 00:00:00 2001
From: ghost <paddymchale@hotmail.com>
Date: Wed, 2 Oct 2024 17:18:40 +0100
Subject: [PATCH] fix: add old supply offset functions

---
 x/bank/keeper/supply_offset_old.go | 69 ++++++++++++++++++++++++++++++
 x/bank/types/keys.go               |  5 +++
 2 files changed, 74 insertions(+)
 create mode 100644 x/bank/keeper/supply_offset_old.go

diff --git a/x/bank/keeper/supply_offset_old.go b/x/bank/keeper/supply_offset_old.go
new file mode 100644
index 000000000000..e5fc90439ebd
--- /dev/null
+++ b/x/bank/keeper/supply_offset_old.go
@@ -0,0 +1,69 @@
+package keeper
+
+import (
+	"context"
+	"fmt"
+
+	"cosmossdk.io/math"
+	"cosmossdk.io/store/prefix"
+
+	"github.com/cosmos/cosmos-sdk/runtime"
+	"github.com/cosmos/cosmos-sdk/x/bank/types"
+)
+
+// NOTE: All these functions should only be used in the v27 migration
+// this file should be removed completely after the migration
+
+// GetSupplyOffset retrieves the SupplyOffset from store for a specific denom using the pre v26 (old) key
+// TODO: Remove after v27 migration
+func (k BaseViewKeeper) GetSupplyOffsetOld(ctx context.Context, denom string) math.Int {
+	store := runtime.KVStoreAdapter(k.storeService.OpenKVStore(ctx))
+	supplyOffsetStore := prefix.NewStore(store, types.SupplyOffsetKeyOld)
+
+	bz := supplyOffsetStore.Get([]byte(denom))
+	if bz == nil {
+		return math.NewInt(0)
+	}
+
+	var amount math.Int
+	err := amount.Unmarshal(bz)
+	if err != nil {
+		panic(fmt.Errorf("unable to unmarshal supply offset value %v", err))
+	}
+
+	return amount
+}
+
+// RemoveOldSupplyOffset removes the old supply offset key
+// TODO: Remove after v27 migration
+func (k BaseViewKeeper) RemoveOldSupplyOffset(ctx context.Context, denom string) {
+	store := runtime.KVStoreAdapter(k.storeService.OpenKVStore(ctx))
+	supplyOffsetStore := prefix.NewStore(store, types.SupplyOffsetKeyOld)
+
+	supplyOffsetStore.Delete([]byte(denom))
+}
+
+// setSupplyOffsetOld sets the supply offset for the given denom using the pre v26 (old) key
+// TODO: Remove after v27 migration
+func (k BaseKeeper) setSupplyOffsetOld(ctx context.Context, denom string, offsetAmount math.Int) {
+	intBytes, err := offsetAmount.Marshal()
+	if err != nil {
+		panic(fmt.Errorf("unable to marshal amount value %v", err))
+	}
+
+	store := runtime.KVStoreAdapter(k.storeService.OpenKVStore(ctx))
+	supplyOffsetStore := prefix.NewStore(store, types.SupplyOffsetKeyOld)
+
+	// Bank invariants and IBC requires to remove zero coins.
+	if offsetAmount.IsZero() {
+		supplyOffsetStore.Delete([]byte(denom))
+	} else {
+		supplyOffsetStore.Set([]byte(denom), intBytes)
+	}
+}
+
+// AddSupplyOffset adjusts the current supply offset of a denom by the inputted offsetAmount using the pre v26 (old) key
+// TODO: Remove after v27 migration
+func (k BaseKeeper) AddSupplyOffsetOld(ctx context.Context, denom string, offsetAmount math.Int) {
+	k.setSupplyOffsetOld(ctx, denom, k.GetSupplyOffsetOld(ctx, denom).Add(offsetAmount))
+}
diff --git a/x/bank/types/keys.go b/x/bank/types/keys.go
index 68eb56a0538e..5134a0c581ce 100644
--- a/x/bank/types/keys.go
+++ b/x/bank/types/keys.go
@@ -33,7 +33,12 @@ var (
 	// ParamsKey is the prefix for x/bank parameters
 	ParamsKey = collections.NewPrefix(5)
 
+	// SupplyOffKey is a Osmosis specific key that handles supply offsets
 	SupplyOffsetKey = collections.NewPrefix(88)
+
+	// SupplyOffKeyOld is a Osmosis specific key that handles supply offsets pre v0.50
+	// TODO: Remove in the v28 upgrade
+	SupplyOffsetKeyOld = []byte{0x88}
 )
 
 // BalanceValueCodec is a codec for encoding bank balances in a backwards compatible way.