القوائم والتنقّل والنماذج

import SwiftUI

struct ExpensesScreen: View {
    let store: BudgetStore
    @State private var isAdding = false

    var body: some View {
        NavigationStack {
            List {
                ForEach(store.expenses) { expense in
                    NavigationLink(value: expense) {
                        ExpenseRow(expense: expense)
                    }
                }
                .onDelete { offsets in
                    store.delete(at: offsets)
                }
            }
            .overlay {
                if store.expenses.isEmpty {
                    ContentUnavailableView("No expenses yet", systemImage: "tray",
                                           description: Text("Tap + to add your first one."))
                }
            }
            .navigationTitle("Expenses")
            .navigationDestination(for: Expense.self) { expense in
                ExpenseDetail(expense: expense)
            }
            .toolbar {
                Button("Add expense", systemImage: "plus") {
                    isAdding = true
                }
            }
            .sheet(isPresented: $isAdding) {
                AddExpenseView(store: store)
            }
        }
    }
}

@State private var path: [Expense] = []

// In body:
NavigationStack(path: $path) {
    // …the same List and modifiers as above
}

// Anywhere in this view, for example after saving:
path.append(newExpense)    // pushes ExpenseDetail
path.removeAll()           // pops back to the list

struct ExpenseDetail: View {
    let expense: Expense

    var body: some View {
        Form {
            LabeledContent("Amount", value: expense.amount, format: .currency(code: "USD"))
            LabeledContent("Category", value: expense.category.title)
            LabeledContent("Date", value: expense.date, format: .dateTime.day().month().year())
        }
        .navigationTitle(expense.title)
    }
}

struct AddExpenseView: View {
    let store: BudgetStore
    @Environment(\.dismiss) private var dismiss

    @State private var title = ""
    @State private var amount: Decimal?
    @State private var category: Category = .food
    @State private var date = Date.now

    private var canSave: Bool {
        !title.trimmingCharacters(in: .whitespaces).isEmpty && (amount ?? 0) > 0
    }

    var body: some View {
        NavigationStack {
            Form {
                Section("Details") {
                    TextField("Title", text: $title)
                    TextField("Amount", value: $amount, format: .currency(code: "USD"))
                        .keyboardType(.decimalPad)
                }
                Section {
                    Picker("Category", selection: $category) {
                        ForEach(Category.allCases, id: \.self) { category in
                            Label(category.title, systemImage: category.symbolName)
                                .tag(category)
                        }
                    }
                    DatePicker("Date", selection: $date, in: ...Date.now, displayedComponents: .date)
                }
            }
            .navigationTitle("New Expense")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .cancellationAction) {
                    Button("Cancel") { dismiss() }
                }
                ToolbarItem(placement: .confirmationAction) {
                    Button("Save") {
                        guard let amount else { return }
                        store.add(Expense(title: title, amount: amount, category: category, date: date))
                        dismiss()
                    }
                    .disabled(!canSave)
                }
            }
        }
    }
}