From b8f17a6e3ef525d9816630f8db71ca1050e8f85e Mon Sep 17 00:00:00 2001
From: Lukasz Zimnoch <lukasz.zimnoch@keep.network>
Date: Tue, 7 Nov 2023 13:50:04 +0100
Subject: [PATCH] Use satoshi amount while searching wallet for redemption

The `RedemptionsService.requestRedemption` function takes an amount in the
TBTC token precision (1e18). However, the `findWalletForRedemption`
method called to find a wallet for redemption expects an amount in the
sathoshi precision (1e8). There is a missing conversion which we are
adding in this changeset.
---
 .../api-reference/classes/RedemptionsService.md      |  6 +++---
 .../src/services/redemptions/redemptions-service.ts  | 12 +++++++++++-
 typescript/test/services/redemptions.test.ts         |  5 +++--
 typescript/test/utils/mock-tbtc-token.ts             |  2 +-
 4 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/typescript/api-reference/classes/RedemptionsService.md b/typescript/api-reference/classes/RedemptionsService.md
index 5a65618a0..be69d387b 100644
--- a/typescript/api-reference/classes/RedemptionsService.md
+++ b/typescript/api-reference/classes/RedemptionsService.md
@@ -90,7 +90,7 @@ Promise holding the wallet main UTXO or undefined value.
 
 #### Defined in
 
-[services/redemptions/redemptions-service.ts:215](https://github.com/keep-network/tbtc-v2/blob/main/typescript/src/services/redemptions/redemptions-service.ts#L215)
+[services/redemptions/redemptions-service.ts:225](https://github.com/keep-network/tbtc-v2/blob/main/typescript/src/services/redemptions/redemptions-service.ts#L225)
 
 ___
 
@@ -116,7 +116,7 @@ Promise with the wallet details needed to request a redemption.
 
 #### Defined in
 
-[services/redemptions/redemptions-service.ts:96](https://github.com/keep-network/tbtc-v2/blob/main/typescript/src/services/redemptions/redemptions-service.ts#L96)
+[services/redemptions/redemptions-service.ts:106](https://github.com/keep-network/tbtc-v2/blob/main/typescript/src/services/redemptions/redemptions-service.ts#L106)
 
 ___
 
@@ -147,7 +147,7 @@ Throws an error if no redemption request exists for the given
 
 #### Defined in
 
-[services/redemptions/redemptions-service.ts:327](https://github.com/keep-network/tbtc-v2/blob/main/typescript/src/services/redemptions/redemptions-service.ts#L327)
+[services/redemptions/redemptions-service.ts:337](https://github.com/keep-network/tbtc-v2/blob/main/typescript/src/services/redemptions/redemptions-service.ts#L337)
 
 ___
 
diff --git a/typescript/src/services/redemptions/redemptions-service.ts b/typescript/src/services/redemptions/redemptions-service.ts
index 3e8e6f5c8..a7fa57e40 100644
--- a/typescript/src/services/redemptions/redemptions-service.ts
+++ b/typescript/src/services/redemptions/redemptions-service.ts
@@ -67,9 +67,19 @@ export class RedemptionsService {
       throw new Error("Redeemer output script must be of standard type")
     }
 
+    const amountToSatoshi = (value: BigNumber): BigNumber => {
+      const satoshiMultiplier = BigNumber.from(1e10)
+      const remainder = value.mod(satoshiMultiplier)
+      const convertibleAmount = amount.sub(remainder)
+      return convertibleAmount.div(satoshiMultiplier)
+    }
+
+    // The findWalletForRedemption operates on satoshi amount precision (1e8)
+    // while the amount parameter is TBTC token precision (1e18). We need to
+    // convert the amount to get proper results.
     const { walletPublicKey, mainUtxo } = await this.findWalletForRedemption(
       redeemerOutputScript,
-      amount
+      amountToSatoshi(amount)
     )
 
     const txHash = await this.tbtcContracts.tbtcToken.requestRedemption(
diff --git a/typescript/test/services/redemptions.test.ts b/typescript/test/services/redemptions.test.ts
index 3b36489ed..adbee2cda 100644
--- a/typescript/test/services/redemptions.test.ts
+++ b/typescript/test/services/redemptions.test.ts
@@ -43,8 +43,9 @@ describe("Redemptions", () => {
       }
       const redeemerOutputScript =
         data.pendingRedemptions[0].pendingRedemption.redeemerOutputScript
+      // Use amount in TBTC token precision (1e18)
       const amount =
-        data.pendingRedemptions[0].pendingRedemption.requestedAmount
+        data.pendingRedemptions[0].pendingRedemption.requestedAmount.mul(1e10)
 
       let tbtcContracts: MockTBTCContracts
       let bitcoinClient: MockBitcoinClient
@@ -129,7 +130,7 @@ describe("Redemptions", () => {
           walletPublicKey,
           mainUtxo,
           redeemerOutputScript,
-          amount,
+          amount: amount.div(1e10),
         })
       })
     })
diff --git a/typescript/test/utils/mock-tbtc-token.ts b/typescript/test/utils/mock-tbtc-token.ts
index ba7fdc08d..e68a7451c 100644
--- a/typescript/test/utils/mock-tbtc-token.ts
+++ b/typescript/test/utils/mock-tbtc-token.ts
@@ -32,7 +32,7 @@ export class MockTBTCToken implements TBTCToken {
       walletPublicKey,
       mainUtxo,
       redeemerOutputScript,
-      amount,
+      amount: amount.div(1e10), // Store amount in satoshi.
     })
 
     return Hex.from(