// Helpful guides:
// - https://flutter.dev/docs/cookbook/forms/validation

import 'package:flutter/material.dart';

import '/pages/expense.dart';
import '/pages/income.dart';
import '/pages/asset.dart';
import '/pages/report.dart';
import '/pages/settings.dart';

void main() {
  runApp(const MainApp());
}

class MainApp extends StatelessWidget {
  const MainApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Recurring Expense Tracker',
      theme: ThemeData(
        useMaterial3: true,
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.green),
      ),
      home: HomePage(),
    );
  }
}

class HomePage extends StatefulWidget {
  const HomePage({
    super.key,
  });

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  var pageSelected = 0;

  @override
  Widget build(BuildContext context) {
    Widget page;
    Widget? dialog;
    switch (pageSelected) {
      case 0:
        page = ExpensePage();
        dialog = ExpenseInputDialog();
      case 1:
        page = IncomePage();
      case 2:
        page = AssetPage();
      case 3:
        page = ProjectionPage();
      case 4:
        page = SettingsPage();
      default:
        throw UnimplementedError('No widget for page $pageSelected yet!');
    }

    Future<void> addNewValue(BuildContext context) {
      return showDialog(
          context: context, builder: (_) => AlertDialog(content: dialog));
    }

    Widget? floatingButton;
    if (dialog != null) {
      floatingButton = IconButton(
        onPressed: () {
          addNewValue(context);
        },
        icon: Icon(Icons.add),
        color: Theme.of(context).colorScheme.onSurface,
      );
    }

    return LayoutBuilder(builder: (context, constraints) {
      return Scaffold(
        // TODO: Add a drawer instead of nav rail.
        body: Row(
          children: [
            SafeArea(
              child: NavigationRail(
                extended: constraints.maxWidth >= 800,
                destinations: [
                  NavigationRailDestination(
                    icon: Icon(Icons.payment),
                    label: Text('Expenses'),
                  ),
                  NavigationRailDestination(
                    icon: Icon(Icons.account_balance),
                    label: Text('Income'),
                  ),
                  NavigationRailDestination(
                    icon: Icon(Icons.attach_money),
                    label: Text('Liquid Assets'),
                  ),
                  NavigationRailDestination(
                    icon: Icon(Icons.bar_chart),
                    label: Text('Projections'),
                  ),
                  NavigationRailDestination(
                    icon: Icon(Icons.settings),
                    label: Text('Settings'),
                  ),
                ],
                selectedIndex: pageSelected,
                onDestinationSelected: (value) {
                  setState(() {
                    pageSelected = value;
                  });
                },
              ),
            ),
            Expanded(
              child: Container(
                color: Theme.of(context).colorScheme.primaryContainer,
                child: page,
              ),
            ),
          ],
        ),
        floatingActionButton: floatingButton,
      );
    });
  }
}