import 'package:flutter/material.dart';

import 'core/theme/app_theme.dart';
import 'core/user/user_state.dart';
import 'features/gallery/gallery_screen.dart';
import 'features/generate_video/generate_progress_screen.dart';
import 'features/generate_video/generate_video_screen.dart';
import 'features/gallery/models/gallery_task_item.dart';
import 'features/generate_video/generation_result_screen.dart';
import 'features/home/home_screen.dart';
import 'features/home/models/task_item.dart';
import 'features/profile/profile_screen.dart';
import 'features/recharge/recharge_screen.dart';
import 'shared/widgets/bottom_nav_bar.dart';

/// Root app widget with navigation
class App extends StatefulWidget {
  const App({super.key});

  @override
  State<App> createState() => _AppState();
}

class _AppState extends State<App> {
  NavTab _currentTab = NavTab.home;

  @override
  Widget build(BuildContext context) {
    return UserCreditsScope(
      child: MaterialApp(
        title: 'AI Video App',
        theme: AppTheme.light,
        debugShowCheckedModeBanner: false,
        initialRoute: '/',
        builder: (context, child) {
          return SafeArea(
            top: true,
            left: false,
            right: false,
            bottom: false,
            child: child ?? const SizedBox.shrink(),
          );
        },
        routes: {
          '/': (_) => _MainScaffold(
                currentTab: _currentTab,
                onTabSelected: (tab) => setState(() => _currentTab = tab),
              ),
          '/recharge': (_) => const RechargeScreen(),
          '/generate': (ctx) {
            final task = ModalRoute.of(ctx)?.settings.arguments as TaskItem?;
            return GenerateVideoScreen(task: task);
          },
          '/progress': (ctx) {
            final taskId = ModalRoute.of(ctx)?.settings.arguments;
            return GenerateProgressScreen(taskId: taskId);
          },
          '/result': (ctx) {
            final mediaItem =
                ModalRoute.of(ctx)?.settings.arguments as GalleryMediaItem?;
            return GenerationResultScreen(mediaItem: mediaItem);
          },
        },
      ),
    );
  }
}

class _MainScaffold extends StatelessWidget {
  const _MainScaffold({
    required this.currentTab,
    required this.onTabSelected,
  });

  final NavTab currentTab;
  final ValueChanged<NavTab> onTabSelected;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: IndexedStack(
        index: currentTab.index,
        children: [
          const HomeScreen(),
          GalleryScreen(isActive: currentTab == NavTab.gallery),
          const ProfileScreen(),
        ],
      ),
      bottomNavigationBar: BottomNavBar(
        currentTab: currentTab,
        onTabSelected: onTabSelected,
      ),
    );
  }
}