import SwiftUI
import SwiftData

struct EntityAddEditView<T: EditableEntity, Content: View>: View {
    @Environment(\.dismiss) private var dismiss
    @Environment(\.modelContext) private var modelContext

    @State var model: T
    private let content: (Binding<T>) -> Content

    init(model: T, @ViewBuilder content: @escaping (Binding<T>) -> Content) {
        _model = State(initialValue: model)
        self.content = content
    }

    var body: some View {
        NavigationStack {
            Form {
                content($model)
            }
            .toolbar {
                ToolbarItem(placement: .navigationBarLeading) {
                    Button("Cancel") {
                        dismiss()
                    }
                }
                
                ToolbarItem(placement: .navigationBarTrailing) {
                    Button("Save") {
                        // If the model is not in a context, it's a new one.
                        if model.modelContext == nil {
                            modelContext.insert(model)
                        }
                        // The save is in a do-catch block to handle potential errors,
                        // such as constraint violations.
                        do {
                            try modelContext.save()
                            dismiss()
                        } catch {
                            // In a real app, you'd want to present this error to the user.
                            print("Failed to save model: \(error.localizedDescription)")
                        }
                    }
                }
            }
        }
    }
}