import SwiftUI
import SwiftData

/// A view modifier that refreshes the view when CloudKit data changes
struct CloudKitSyncObserver: ViewModifier {
    @Environment(\.modelContext) private var modelContext
    @State private var refreshID = UUID()
    
    func body(content: Content) -> some View {
        content
            .id(refreshID) // Force view refresh when this changes
            .onReceive(NotificationCenter.default.publisher(for: .cloudKitDataDidChange)) { _ in
                // When we receive a notification that CloudKit data changed:
                // 1. Create a new UUID to force view refresh
                refreshID = UUID()
                
                // 2. Optionally, you can also manually refresh the model context
                // This is sometimes needed for complex relationships
                Task { @MainActor in
                    try? modelContext.fetch(FetchDescriptor<Exercise>())
                    // Add other model types as needed
                }
            }
    }
}

// Extension to make it easier to use the modifier
extension View {
    /// Adds observation for CloudKit sync changes and refreshes the view when changes occur
    func observeCloudKitChanges() -> some View {
        self.modifier(CloudKitSyncObserver())
    }
}