fix: correct value exchange math at low amounts; correct balance mutations

bmc08gt · bmc08gt · commit e0d829354453 · 2025-10-14T11:56:19.000-04:00
Signed-off-by: Brandon McAnsh &lt;git@bmcreations.dev&gt;
diff --git a/libs/currency-math/src/main/kotlin/com/flipcash/libs/currency/math/Units.kt b/libs/currency-math/src/main/kotlin/com/flipcash/libs/currency/math/Units.kt
@@ -3,4 +3,5 @@ package com.flipcash.libs.currency.math
 import com.flipcash.libs.currency.math.internal.DefaultMintQuarksPerUnit
 import java.math.BigDecimal
 
-fun BigDecimal.units(): BigDecimal = this.divide(BigDecimal(DefaultMintQuarksPerUnit), mc)
+fun BigDecimal.units(): BigDecimal = this.divide(BigDecimal(DefaultMintQuarksPerUnit), mc)
+fun BigDecimal.divideWithHighPrecision(other: BigDecimal): BigDecimal = this.divide(other, mc)
diff --git a/services/opencode/src/main/kotlin/com/getcode/opencode/ControllerFactory.kt b/services/opencode/src/main/kotlin/com/getcode/opencode/ControllerFactory.kt
@@ -48,6 +48,7 @@ object ControllerFactory {
             accountController = createAccountController(context, config),
             currencyController = createCurrencyController(context, config),
             networkObserver = NetworkFactory.createNetworkObserver(context),
+            exchange = ExchangeFactory.createOpenCodeExchange(context, config),
         )
     }
 }
diff --git a/services/opencode/src/main/kotlin/com/getcode/opencode/controllers/TokenController.kt b/services/opencode/src/main/kotlin/com/getcode/opencode/controllers/TokenController.kt
@@ -1,5 +1,6 @@
 package com.getcode.opencode.controllers
 
+import com.getcode.opencode.exchange.Exchange
 import com.getcode.opencode.model.accounts.AccountCluster
 import com.getcode.opencode.model.accounts.AccountFilter
 import com.getcode.opencode.model.accounts.AccountType
@@ -37,6 +38,7 @@ class TokenController @Inject constructor(
     private val accountController: AccountController,
     private val currencyController: CurrencyController,
     private val networkObserver: NetworkConnectivityListener,
+    private val exchange: Exchange,
 ) {
     private val scope = CoroutineScope(Dispatchers.IO + SupervisorJob())
 
@@ -87,24 +89,25 @@ class TokenController @Inject constructor(
         return mintBalances.map { it[tokenAddress] ?: Fiat.Zero }
     }
 
-    suspend fun add(token: Mint, fiat: LocalFiat) {
-        val balance = mintBalances.value[token] ?: Fiat.Zero
+    private suspend fun modifyBalance(token: Token, operation: (Fiat) -> Fiat) {
+        val balance = mintBalances.value[token.address] ?: Fiat.Zero
         if (balance.doubleValue == 0.0) {
-            // attempt to fetch prior to append
-            fetchBalanceForToken(token)
+            // attempt to fetch prior to modifying balance
+            fetchBalanceForToken(token.address)
         } else {
-            mintBalances.update { it + (token to (balance + fiat.nativeAmount)) }
+            val updatedBalance = operation(balance)
+            mintBalances.update { it + (token.address to updatedBalance) }
         }
     }
 
-    suspend fun subtract(token: Mint, fiat: LocalFiat) {
-        val balance = mintBalances.value[token] ?: Fiat.Zero
-        if (balance.doubleValue == 0.0) {
-            // attempt to fetch prior to append
-            fetchBalanceForToken(token)
-        } else {
-            mintBalances.update { it + (token to (balance - fiat.nativeAmount)) }
-        }
+    suspend fun add(token: Token, fiat: LocalFiat) {
+        val balanceAdditionAmount = fiat.nativeAmount.convertingTo(exchange.rateToUsd(fiat.rate.currency)!!)
+        modifyBalance(token) { it + balanceAdditionAmount }
+    }
+
+    suspend fun subtract(token: Token, fiat: LocalFiat) {
+        val balanceReductionAmount = fiat.nativeAmount.convertingTo(exchange.rateToUsd(fiat.rate.currency)!!)
+        modifyBalance(token) { it - balanceReductionAmount }
     }
 
     suspend fun update() {
diff --git a/services/opencode/src/main/kotlin/com/getcode/opencode/internal/exchange/OpenCodeExchange.kt b/services/opencode/src/main/kotlin/com/getcode/opencode/internal/exchange/OpenCodeExchange.kt
@@ -190,7 +190,7 @@ internal class OpenCodeExchange @Inject constructor(
                 trace(
                     tag = "Background",
                     message = "Updated the local currency: $balanceCurrency, " +
-                            "Staleness ${System.currentTimeMillis() - rates.dateMillis} ms, " +
+                            "Staleness ${(System.currentTimeMillis() - rates.dateMillis).minutes} mins, " +
                             "Date: ${Date(rates.dateMillis)}",
                     type = TraceType.Process
                 )
diff --git a/services/opencode/src/main/kotlin/com/getcode/opencode/managers/BillTransactionManager.kt b/services/opencode/src/main/kotlin/com/getcode/opencode/managers/BillTransactionManager.kt
@@ -81,7 +81,7 @@ class BillTransactionManager @Inject constructor(
                 .onSuccess {
                     childScope.cancel()
                     onGrabbed()
-                    tokenController.subtract(token.address, LocalFiat(it.exchangeData))
+                    tokenController.subtract(token, LocalFiat(it.exchangeData))
                     transactionController.updateLimits(owner, force = true)
                 }.onFailure {
                     onError(it)
@@ -135,7 +135,7 @@ class BillTransactionManager @Inject constructor(
                         message = "Grabbed ${amount.nativeAmount.formatted()} of ${token.symbol} from sender"
                     )
                     onGrabbed(token, amount)
-                    tokenController.add(mint, amount)
+                    tokenController.add(token, amount)
                     transactionController.updateLimits(owner, force = true)
                 }.onFailure {
                     onError(it)
@@ -163,7 +163,7 @@ class BillTransactionManager @Inject constructor(
             transactor.start()
                 .onSuccess {
                     onFunded(amount)
-                    tokenController.subtract(token.address, amount)
+                    tokenController.subtract(token, amount)
                     transactionController.updateLimits(owner, force = true)
                 }.onFailure {
                     ErrorUtils.handleError(it)
@@ -198,7 +198,7 @@ class BillTransactionManager @Inject constructor(
             receiveTransactor?.start(claimIfOwned)
                 ?.onSuccess { (token, amount) ->
                     onReceived(token, amount)
-                    tokenController.add(token.address, amount)
+                    tokenController.add(token, amount)
                 }?.onFailure {
                     onError(it)
                     transactor.dispose()
diff --git a/services/opencode/src/main/kotlin/com/getcode/opencode/model/financial/LocalFiat.kt b/services/opencode/src/main/kotlin/com/getcode/opencode/model/financial/LocalFiat.kt
@@ -1,10 +1,14 @@
 package com.getcode.opencode.model.financial
 
 import com.flipcash.libs.currency.math.Estimator
+import com.flipcash.libs.currency.math.divideWithHighPrecision
 import com.flipcash.libs.currency.math.units
 import com.getcode.opencode.model.transactions.ExchangeData
 import com.getcode.solana.keys.Mint
+import com.getcode.utils.TraceType
+import com.getcode.utils.trace
 import kotlinx.serialization.Serializable
+import java.math.BigDecimal
 import javax.annotation.concurrent.Immutable
 
 typealias Usd = Fiat
@@ -80,11 +84,11 @@ data class LocalFiat(
             // determine the "full units" of the token being exchanged
             val units = estimatedTokens.units()
             // determine the exchange rate (native amount / units of token) (USD based)
-            val usdFx = usdValue.decimalValue / units.toDouble()
+            val usdFx = BigDecimal(usdValue.decimalValue).divideWithHighPrecision(units)
 
             // determine the relative exchange rate of the token in the currency selected
             // USD is a 1:1 fx so we can be blind here
-            val fx = rate.fx * usdFx
+            val fx = rate.fx * usdFx.toDouble()
 
             return LocalFiat(
                 underlyingTokenAmount = Fiat(estimatedTokens.toLong(), CurrencyCode.USD),
@@ -98,9 +102,21 @@ data class LocalFiat(
 
 fun Iterable<LocalFiat>.sum(): LocalFiat {
     return this.fold(LocalFiat.Zero) { acc, localFiat ->
-        acc.copy(
-            underlyingTokenAmount = acc.underlyingTokenAmount + localFiat.underlyingTokenAmount,
-            nativeAmount = acc.nativeAmount + localFiat.nativeAmount,
+        val base = if (acc == LocalFiat.Zero) {
+            // update to the currency of the incoming localFiat
+            LocalFiat(
+                Fiat.Zero,
+                Fiat.Zero.copy(currencyCode = localFiat.rate.currency),
+                localFiat.rate,
+                localFiat.mint
+            )
+        } else {
+            acc
+        }
+
+        base.copy(
+            underlyingTokenAmount = base.underlyingTokenAmount + localFiat.underlyingTokenAmount,
+            nativeAmount = base.nativeAmount + localFiat.nativeAmount,
         )
     }
 }

Original file line number	Diff line number	Diff line change
`@@ -48,6 +48,7 @@ object ControllerFactory {`
`48`	`48`	`accountController = createAccountController(context, config),`
`49`	`49`	`currencyController = createCurrencyController(context, config),`
`50`	`50`	`networkObserver = NetworkFactory.createNetworkObserver(context),`
	`51`	`+ exchange = ExchangeFactory.createOpenCodeExchange(context, config),`
`51`	`52`	`)`
`52`	`53`	`}`
`53`	`54`	`}`
Original file line number	Diff line number	Diff line change
`@@ -190,7 +190,7 @@ internal class OpenCodeExchange @Inject constructor(`
`190`	`190`	`trace(`
`191`	`191`	`tag = "Background",`
`192`	`192`	`message = "Updated the local currency: $balanceCurrency, " +`
`193`		`- "Staleness ${System.currentTimeMillis() - rates.dateMillis} ms, " +`
	`193`	`+ "Staleness ${(System.currentTimeMillis() - rates.dateMillis).minutes} mins, " +`
`194`	`194`	`"Date: ${Date(rates.dateMillis)}",`
`195`	`195`	`type = TraceType.Process`
`196`	`196`	`)`