Sell crypto balance validation

Features/FiatConnect/Sources/Scenes/FiatScene.swift

@@ -36,7 +36,7 @@ public struct FiatScene: View {
         .safeAreaView {
             StateButton(
                 text: model.actionButtonTitle,
-                type: .primary(model.state, showProgress: false),
+                type: .primary(model.actionButtonState, showProgress: false),
                 action: model.onSelectContinue
             )
             .frame(maxWidth: .scene.button.maxWidth)

Features/FiatConnect/Sources/ViewModels/FiatSceneViewModel.swift

@@ -38,6 +38,8 @@ public final class FiatSceneViewModel {
     var focusField: FiatScene.Field?
     var isPresentingFiatProvider: Bool = false
 
+    private var fetchTasks: [FiatQuoteType: Task<Void, Never>] = [:]
+
     public init(
         fiatService: any GemAPIFiatService = GemAPIService(),
         currencyFormatter: CurrencyFormatter = CurrencyFormatter(currencyCode: Currency.usd.rawValue),
@@ -88,6 +90,9 @@ public final class FiatSceneViewModel {
     }
 
     var actionButtonTitle: String { Localized.Common.continue }
+    var actionButtonState: StateViewType<[FiatQuote]> {
+        inputValidationModel.isValid ? state : .noData
+    }
     var providerTitle: String { Localized.Common.provider }
     var rateTitle: String { Localized.Buy.rate }
     var errorTitle: String { Localized.Errors.errorOccured }
@@ -194,14 +199,15 @@ extension FiatSceneViewModel {
         isPresentingFiatProvider = false
     }
 
-    func onChangeType(_: FiatQuoteType, type: FiatQuoteType) {
+    func onChangeType(_ oldValue: FiatQuoteType, type: FiatQuoteType) {
+        fetchTasks[oldValue]?.cancel()
         inputValidationModel.text = amountFormatter.format(amount: input.amount, for: type)
         inputValidationModel.update(validators: inputValidation)
         focusField = type == .buy ? .amountBuy : .amountSell
     }
 
-    func onChangeAmountValue(_ amount: Double) async {
-        await fetch()
+    func onChangeAmountValue(_ amount: Double) {
+        fetch()
     }
 
     func onChangeAmountText(_: String, text: String) {
@@ -212,17 +218,14 @@ extension FiatSceneViewModel {
 // MARK: - Private
 
 extension FiatSceneViewModel {
-    private func fetch() async {
-        input.quote = nil
+    private func fetch() {
+        fetchTasks[input.type]?.cancel()
 
-        guard shouldProceedFetch else {
-            state = .noData
-            return
-        }
-        state = .loading
+        fetchTasks[input.type] = Task {
+            input.quote = nil
+            state = .loading
 
-        do {
-            let quotes: [FiatQuote] = try await {
+            do {
                 let request = FiatQuoteRequest(
                     assetId: asset.id.identifier,
                     type: input.type,
@@ -231,19 +234,24 @@ extension FiatSceneViewModel {
                     cryptoValue: amountFormatter.formatCryptoValue(fiatAmount: input.amount, type: input.type),
                     walletAddress: assetAddress.address
                 )
-                return try await fiatService.getQuotes(asset: asset, request: request)
-            }()
-
-            if !quotes.isEmpty {
-                input.quote = quotes.first
-                state = .data(quotes)
-            } else {
-                state = .noData
-            }
-        } catch {
-            if !error.isCancelled {
-                state = .error(error)
-                NSLog("FiatSceneViewModel get quotes error: \(error)")
+
+                let quotes = try await fiatService.getQuotes(asset: asset, request: request)
+
+                try Task.checkCancellation()
+
+                if !quotes.isEmpty {
+                    input.quote = quotes.first
+                    state = .data(quotes)
+                } else {
+                    state = .noData
+                }
+            } catch {
+                guard !Task.isCancelled else { return }
+
+                if !error.isCancelled {
+                    state = .error(error)
+                    NSLog("FiatSceneViewModel get quotes error: \(error)")
+                }
             }
         }
     }
@@ -267,14 +275,6 @@ extension FiatSceneViewModel {
         }
     }
 
-    private var shouldProceedFetch: Bool {
-        guard !input.amount.isZero else { return false }
-        switch input.type {
-        case .buy: return true
-        case .sell: return input.amount <= maxAmount
-        }
-    }
-
     private var fiatProvidersViewModelState: StateViewType<SelectableListType<FiatQuoteViewModel>> {
         switch state {
         case .error(let error): .error(error)
@@ -297,7 +297,11 @@ extension FiatSceneViewModel {
                     )]
                 )
             ]
-        case .sell: []
+        case .sell: [
+            .assetAmount(decimals: asset.decimals.asInt, validators: [
+                BalanceValueValidator(available: assetData.balance.available, asset: asset)
+            ])
+        ]
         }
     }
 

Features/FiatConnect/Tests/FiatSceneViewModelTests.swift

@@ -135,17 +135,63 @@ final class FiatSceneViewModelTests {
     @Test
     func testFiatValidation() {
         let model = FiatSceneViewModelTests.mock()
-        
+
         model.inputValidationModel.text = "4"
         #expect(model.inputValidationModel.update() == false)
-        
+
         model.inputValidationModel.text = "5"
         #expect(model.inputValidationModel.update() == true)
-        
+
         model.inputValidationModel.text = "10000"
         #expect(model.inputValidationModel.update() == true)
-        
+
         model.inputValidationModel.text = "10001"
         #expect(model.inputValidationModel.update() == false)
     }
+
+    @Test
+    func actionButtonStateInvalidInput() {
+        let model = FiatSceneViewModelTests.mock()
+        model.state = .data([])
+
+        model.inputValidationModel.text = "4"
+        model.inputValidationModel.update()
+
+        #expect(model.actionButtonState.value == nil)
+    }
+
+    @Test
+    func actionButtonStateLoading() {
+        let model = FiatSceneViewModelTests.mock()
+        model.state = .loading
+
+        model.inputValidationModel.text = "100"
+        model.inputValidationModel.update()
+
+        #expect(model.actionButtonState.value == nil)
+    }
+
+    @Test
+    func actionButtonStateValidWithQuote() {
+        let model = FiatSceneViewModelTests.mock()
+        let quote = FiatQuote.mock(fiatAmount: 100, cryptoAmount: 1, type: .buy)
+
+        model.state = .data([quote])
+        model.input.quote = quote
+        model.inputValidationModel.text = "100"
+        model.inputValidationModel.update()
+
+        #expect(model.actionButtonState.value != nil)
+    }
+
+    @Test
+    func actionButtonStateValidNoQuote() {
+        let model = FiatSceneViewModelTests.mock()
+        model.state = .noData
+
+        model.inputValidationModel.text = "100"
+        model.inputValidationModel.update()
+
+        #expect(model.actionButtonState.value == nil)
+    }
 }