fix: use backend-authoritative change amount for cash transactions

Instead of calculating change client-side (which doesn't account for
balance applied, fees, etc.), the app now uses the Change value returned
by the /tasks/complete.php endpoint after processing.

Changes:
- APIService.completeTask now returns CashCompletionResult with backend values
- Added CashCompletionResult struct (cashReceived, orderTotal, change, fees, routing)
- CashCollectionSheet shows confirmed backend change after completion
- Added ratingRequired error case to APIError enum
- Client-side estimate still shown as preview before confirmation

.gitignore

@@ -1,5 +1,6 @@
 # Xcode
 build/
+build-sim/
 DerivedData/
 *.xcuserstate
 *.xcworkspacedata

PayfritWorks.xcodeproj/project.pbxproj

@@ -43,6 +43,7 @@
 		B01000000047 /* AccountScreen.swift in Sources */ = {isa = PBXBuildFile; fileRef = B02000000047; };
 		B01000000048 /* AboutScreen.swift in Sources */ = {isa = PBXBuildFile; fileRef = B02000000048; };
 		B01000000049 /* ProfileScreen.swift in Sources */ = {isa = PBXBuildFile; fileRef = B02000000049; };
+		B0100000004A /* RatingDialog.swift in Sources */ = {isa = PBXBuildFile; fileRef = B0200000004A; };
 
 		/* Resources */
 		B01000000060 /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = B02000000060; };
@@ -90,6 +91,7 @@
 		B02000000047 /* AccountScreen.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AccountScreen.swift; sourceTree = "<group>"; };
 		B02000000048 /* AboutScreen.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AboutScreen.swift; sourceTree = "<group>"; };
 		B02000000049 /* ProfileScreen.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ProfileScreen.swift; sourceTree = "<group>"; };
+		B0200000004A /* RatingDialog.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RatingDialog.swift; sourceTree = "<group>"; };
 
 		/* Resources */
 		B02000000060 /* Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Assets.xcassets; sourceTree = "<group>"; };
@@ -186,6 +188,7 @@
 				B02000000047 /* AccountScreen.swift */,
 				B02000000048 /* AboutScreen.swift */,
 				B02000000049 /* ProfileScreen.swift */,
+				B0200000004A /* RatingDialog.swift */,
 			);
 			path = Views;
 			sourceTree = "<group>";
@@ -312,6 +315,7 @@
 				B01000000047 /* AccountScreen.swift in Sources */,
 				B01000000048 /* AboutScreen.swift in Sources */,
 				B01000000049 /* ProfileScreen.swift in Sources */,
+				B0100000004A /* RatingDialog.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

PayfritWorks/Services/APIService.swift

@@ -18,6 +18,7 @@ enum APIError: LocalizedError {
     case serverError(String)
     case unauthorized
     case networkError(String)
+    case ratingRequired(customerUserId: Int)
 
     var errorDescription: String? {
         switch self {
@@ -27,6 +28,7 @@ enum APIError: LocalizedError {
         case .serverError(let msg): return msg
         case .unauthorized: return "Unauthorized"
         case .networkError(let msg): return msg
+        case .ratingRequired: return "Rating required"
         }
     }
 }
@@ -54,6 +56,22 @@ struct ChatMessagesResult {
     let chatClosed: Bool
 }
 
+/// Backend-authoritative cash completion result.
+/// All monetary values are formatted strings (e.g. "12.50") from the server.
+struct CashCompletionResult {
+    let cashReceived: String
+    let orderTotal: String
+    let change: String
+    let customerFee: String?
+    let businessFee: String?
+    let cashRoutedTo: String  // "worker" or "business"
+    let balanceApplied: String?
+
+    var changeDollars: Double {
+        Double(change) ?? 0
+    }
+}
+
 // MARK: - API Service
 
 actor APIService {
@@ -472,11 +490,16 @@ actor APIService {
         return arr.map { WorkTask(json: $0) }
     }
 
-    func completeTask(taskId: Int, cashReceivedCents: Int? = nil, cancelOrder: Bool = false) async throws {
+    /// Complete a task. Returns CashCompletionResult when cashReceivedCents is provided.
+    @discardableResult
+    func completeTask(taskId: Int, workerRating: [String: Bool]? = nil, cashReceivedCents: Int? = nil, cancelOrder: Bool = false) async throws -> CashCompletionResult? {
         var payload: [String: Any] = [
             "TaskID": taskId,
             "UserID": userId ?? 0
         ]
+        if let rating = workerRating {
+            payload["workerRating"] = rating
+        }
         if let cents = cashReceivedCents {
             payload["CashReceivedCents"] = cents
         }
@@ -485,8 +508,27 @@ actor APIService {
         }
         let json = try await postJSON("/tasks/complete.php", payload: payload)
         guard ok(json) else {
-            throw APIError.serverError("Failed to complete task: \(err(json))")
+            let errorMsg = err(json)
+            if errorMsg == "rating_required" {
+                let customerUserId = json["CustomerUserID"] as? Int ?? 0
+                throw APIError.ratingRequired(customerUserId: customerUserId)
+            }
+            throw APIError.serverError("Failed to complete task: \(errorMsg)")
         }
+
+        // Parse cash completion response from backend (authoritative values)
+        if let _ = cashReceivedCents, json["CashProcessed"] as? Bool == true {
+            return CashCompletionResult(
+                cashReceived: json["CashReceived"] as? String ?? "0.00",
+                orderTotal: json["OrderTotal"] as? String ?? "0.00",
+                change: json["Change"] as? String ?? "0.00",
+                customerFee: json["CustomerFee"] as? String,
+                businessFee: json["BusinessFee"] as? String,
+                cashRoutedTo: json["CashRoutedTo"] as? String ?? "worker",
+                balanceApplied: json["BalanceApplied"] as? String
+            )
+        }
+        return nil
     }
 
     func closeChat(taskId: Int) async throws {

PayfritWorks/Views/RatingDialog.swift

@@ -0,0 +1,163 @@
+import SwiftUI
+
+/// Customer rating dialog shown when completing a service point task.
+/// Matches Android RatingDialog: 4 yes/no questions about the customer.
+struct RatingDialog: View {
+    let onSubmit: ([String: Bool]) -> Void
+    let onDismiss: () -> Void
+    let isSubmitting: Bool
+
+    @State private var prepared: Bool?
+    @State private var completedScope: Bool?
+    @State private var respectful: Bool?
+    @State private var wouldAutoAssign: Bool?
+
+    private var allAnswered: Bool {
+        prepared != nil && completedScope != nil && respectful != nil && wouldAutoAssign != nil
+    }
+
+    var body: some View {
+        VStack(spacing: 20) {
+            // Star icon
+            Image(systemName: "star.fill")
+                .font(.system(size: 48))
+                .foregroundColor(Color(red: 1.0, green: 0.76, blue: 0.03)) // Golden yellow
+
+            Text("Rate this customer")
+                .font(.title2.bold())
+
+            Text("Quick feedback helps improve the experience.")
+                .font(.subheadline)
+                .foregroundColor(.secondary)
+                .multilineTextAlignment(.center)
+
+            VStack(spacing: 16) {
+                RatingQuestion(question: "Was the customer prepared?", value: $prepared)
+                RatingQuestion(question: "Was the scope clear?", value: $completedScope)
+                RatingQuestion(question: "Was the customer respectful?", value: $respectful)
+                RatingQuestion(question: "Would you serve them again?", value: $wouldAutoAssign)
+            }
+
+            HStack(spacing: 12) {
+                if !isSubmitting {
+                    Button("Cancel") {
+                        onDismiss()
+                    }
+                    .buttonStyle(.bordered)
+                    .foregroundColor(.secondary)
+                }
+
+                Button {
+                    guard let p = prepared, let c = completedScope,
+                          let r = respectful, let w = wouldAutoAssign else { return }
+                    onSubmit([
+                        "prepared": p,
+                        "completedScope": c,
+                        "respectful": r,
+                        "wouldAutoAssign": w
+                    ])
+                } label: {
+                    if isSubmitting {
+                        ProgressView()
+                            .progressViewStyle(CircularProgressViewStyle(tint: .white))
+                            .frame(maxWidth: .infinity, minHeight: 44)
+                    } else {
+                        Text("Submit & Complete")
+                            .font(.headline)
+                            .frame(maxWidth: .infinity, minHeight: 44)
+                    }
+                }
+                .buttonStyle(.borderedProminent)
+                .tint(.payfritGreen)
+                .disabled(!allAnswered || isSubmitting)
+            }
+        }
+        .padding(24)
+        .background(Color(.systemBackground))
+        .cornerRadius(20)
+        .shadow(radius: 20)
+        .padding(.horizontal, 24)
+    }
+}
+
+/// A single yes/no rating question with thumb up/down toggle chips.
+private struct RatingQuestion: View {
+    let question: String
+    @Binding var value: Bool?
+
+    var body: some View {
+        VStack(alignment: .leading, spacing: 6) {
+            Text(question)
+                .font(.subheadline.weight(.medium))
+
+            HStack(spacing: 8) {
+                ToggleChip(
+                    label: "Yes",
+                    icon: "hand.thumbsup.fill",
+                    isSelected: value == true,
+                    selectedColor: .green
+                ) {
+                    value = true
+                }
+
+                ToggleChip(
+                    label: "No",
+                    icon: "hand.thumbsdown.fill",
+                    isSelected: value == false,
+                    selectedColor: .red
+                ) {
+                    value = false
+                }
+            }
+        }
+        .frame(maxWidth: .infinity, alignment: .leading)
+    }
+}
+
+/// A selectable chip with icon, similar to Android FilterChip.
+private struct ToggleChip: View {
+    let label: String
+    let icon: String
+    let isSelected: Bool
+    let selectedColor: Color
+    let action: () -> Void
+
+    var body: some View {
+        Button(action: action) {
+            HStack(spacing: 4) {
+                if isSelected {
+                    Image(systemName: icon)
+                        .font(.caption)
+                        .foregroundColor(selectedColor)
+                }
+                Text(label)
+                    .font(.subheadline)
+                    .foregroundColor(isSelected ? selectedColor : .primary)
+            }
+            .padding(.horizontal, 14)
+            .padding(.vertical, 8)
+            .background(
+                isSelected
+                    ? selectedColor.opacity(0.15)
+                    : Color(.systemGray5)
+            )
+            .cornerRadius(20)
+            .overlay(
+                RoundedRectangle(cornerRadius: 20)
+                    .stroke(isSelected ? selectedColor.opacity(0.4) : Color.clear, lineWidth: 1)
+            )
+        }
+        .buttonStyle(.plain)
+    }
+}
+
+#Preview {
+    ZStack {
+        Color.black.opacity(0.4).ignoresSafeArea()
+        RatingDialog(
+            onSubmit: { rating in print(rating) },
+            onDismiss: { print("dismissed") },
+            isSubmitting: false
+        )
+    }
+}

PayfritWorks/Views/TaskDetailScreen.swift

@@ -30,6 +30,10 @@ struct TaskDetailScreen: View {
     @State private var taskAccepted = false  // Track if task was just accepted
     @State private var customerAvatarUrl: String?  // Fetched separately if not in task details
 
+    // Rating dialog
+    @State private var showRatingDialog = false
+    @State private var isSubmittingRating = false
+
     // Computed properties for effective button visibility after accepting
     private var effectiveShowAcceptButton: Bool { showAcceptButton && !taskAccepted }
     private var effectiveShowCompleteButton: Bool { showCompleteButton || taskAccepted }
@@ -89,6 +93,10 @@ struct TaskDetailScreen: View {
                 showAutoCompleteDialog = false
                 if result == "success" {
                     appState.popToRoot()
+                } else if result == "rating_required" {
+                    autoCompleting = false
+                    beaconDetected = false
+                    showRatingDialog = true
                 } else if result == "cancelled" || result == "error" {
                     autoCompleting = false
                     beaconDetected = false
@@ -115,6 +123,25 @@ struct TaskDetailScreen: View {
                 onComplete: { appState.popToRoot() }
             )
         }
+        .overlay {
+            if showRatingDialog {
+                ZStack {
+                    Color.black.opacity(0.4)
+                        .ignoresSafeArea()
+                        .onTapGesture {
+                            if !isSubmittingRating { showRatingDialog = false }
+                        }
+
+                    RatingDialog(
+                        onSubmit: { rating in submitRating(rating) },
+                        onDismiss: { showRatingDialog = false },
+                        isSubmitting: isSubmittingRating
+                    )
+                }
+                .transition(.opacity)
+                .animation(.easeInOut(duration: 0.2), value: showRatingDialog)
+            }
+        }
         .task { await loadDetails() }
         .onDisappear { beaconScanner?.dispose() }
         .onChange(of: appState.shouldPopToTaskList) { shouldPop in
@@ -737,12 +764,34 @@ struct TaskDetailScreen: View {
             do {
                 try await APIService.shared.completeTask(taskId: task.taskId)
                 appState.popToRoot()
+            } catch let apiError as APIError {
+                if case .ratingRequired = apiError {
+                    showRatingDialog = true
+                } else {
+                    self.error = apiError.localizedDescription
+                }
             } catch {
                 self.error = error.localizedDescription
             }
         }
     }
 
+    private func submitRating(_ rating: [String: Bool]) {
+        isSubmittingRating = true
+        Task {
+            do {
+                try await APIService.shared.completeTask(taskId: task.taskId, workerRating: rating)
+                showRatingDialog = false
+                isSubmittingRating = false
+                appState.popToRoot()
+            } catch {
+                isSubmittingRating = false
+                showRatingDialog = false
+                self.error = error.localizedDescription
+            }
+        }
+    }
+
     private func cancelOrder() {
         isCancelingOrder = true
         Task {
@@ -785,6 +834,7 @@ struct CashCollectionSheet: View {
     @State private var cashReceivedText = ""
     @State private var isProcessing = false
     @State private var errorMessage: String?
+    @State private var completionResult: CashCompletionResult?
 
     private var isAdmin: Bool { roleId >= 2 }
 
@@ -795,7 +845,8 @@ struct CashCollectionSheet: View {
         return Int(round(dollars * 100))
     }
 
-    private var changeDue: Double? {
+    /// Client-side estimate shown before confirmation (preview only)
+    private var estimatedChangeDue: Double? {
         guard let receivedCents = cashReceivedCents else { return nil }
         let change = Double(receivedCents - orderTotalCents) / 100
         return change >= 0 ? change : nil
@@ -839,8 +890,35 @@ struct CashCollectionSheet: View {
                     .cornerRadius(12)
                 }
 
-                // Change display
-                if let change = changeDue {
+                // Change display — backend-authoritative after completion, estimate before
+                if let result = completionResult {
+                    // Show confirmed change from backend
+                    VStack(spacing: 8) {
+                        HStack {
+                            Image(systemName: "checkmark.circle.fill")
+                                .foregroundColor(.payfritGreen)
+                            Text("Change Due:")
+                                .font(.body.weight(.medium))
+                            Spacer()
+                            Text("$\(result.change)")
+                                .font(.title3.bold())
+                                .foregroundColor(.payfritGreen)
+                        }
+                        if let balanceApplied = result.balanceApplied {
+                            HStack {
+                                Text("Balance applied:")
+                                    .font(.caption)
+                                    .foregroundColor(.secondary)
+                                Spacer()
+                                Text("$\(balanceApplied)")
+                                    .font(.caption.weight(.medium))
+                            }
+                        }
+                    }
+                    .padding(16)
+                    .background(Color.payfritGreen.opacity(0.15))
+                    .cornerRadius(12)
+                } else if let change = estimatedChangeDue {
                     HStack {
                         Image(systemName: "arrow.uturn.left.circle.fill")
                             .foregroundColor(.payfritGreen)
@@ -905,7 +983,7 @@ struct CashCollectionSheet: View {
                 }
                 .buttonStyle(.borderedProminent)
                 .tint(Color(red: 0.13, green: 0.55, blue: 0.13))
-                .disabled(!isValid || isProcessing)
+                .disabled(!isValid || isProcessing || completionResult != nil)
                 .padding(.bottom, 16)
             }
             .padding(.horizontal, 24)
@@ -927,7 +1005,14 @@ struct CashCollectionSheet: View {
 
         Task {
             do {
-                try await APIService.shared.completeTask(taskId: taskId, cashReceivedCents: cents)
+                let result = try await APIService.shared.completeTask(taskId: taskId, cashReceivedCents: cents)
+                if let result = result {
+                    // Show backend-authoritative change before dismissing
+                    completionResult = result
+                    isProcessing = false
+                    // Brief pause so worker can see the confirmed change amount
+                    try? await Task.sleep(nanoseconds: 2_000_000_000)
+                }
                 dismiss()
                 onComplete()
             } catch {
@@ -985,6 +1070,12 @@ struct AutoCompleteCountdownView: View {
             message = "Closing this window now"
             try? await Task.sleep(nanoseconds: 1_000_000_000)
             onResult("success")
+        } catch let apiError as APIError {
+            if case .ratingRequired = apiError {
+                onResult("rating_required")
+            } else {
+                onResult("error")
+            }
         } catch {
             onResult("error")
         }