/// Host scaffold that owns the bottom navigation bar and its tabs.
library;

import 'package:flutter/material.dart';

import 'balance_screen.dart';
import 'settings_screen.dart';
import 'transactions_screen.dart';

/// Switches between Balance, Transactions, and Settings without stacking routes.
class MainShell extends StatefulWidget {
  const MainShell({super.key});

  @override
  State<MainShell> createState() => _MainShellState();
}

class _MainShellState extends State<MainShell> {
  int _index = 0;

  static const _pages = [
    BalanceScreen(),
    TransactionsScreen(),
    SettingsScreen(),
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: IndexedStack(
        index: _index,
        children: _pages,
      ),
      bottomNavigationBar: NavigationBar(
        selectedIndex: _index,
        onDestinationSelected: (index) => setState(() => _index = index),
        destinations: const [
          NavigationDestination(
            icon: Icon(Icons.account_balance_wallet_outlined),
            selectedIcon: Icon(Icons.account_balance_wallet),
            label: 'Balance',
          ),
          NavigationDestination(
            icon: Icon(Icons.receipt_long_outlined),
            selectedIcon: Icon(Icons.receipt_long),
            label: 'Transactions',
          ),
          NavigationDestination(
            icon: Icon(Icons.settings_outlined),
            selectedIcon: Icon(Icons.settings),
            label: 'Settings',
          ),
        ],
      ),
    );
  }
}