import 'package:flutter/material.dart';

import 'core/auth/auth_service.dart';
import 'core/theme/app_colors.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';
import 'shared/tab_selector_scope.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: TabSelectorScope(
        selectTab: (tab) => setState(() => _currentTab = tab),
        child: MaterialApp(
          title: 'AI Video App',
          theme: AppTheme.light,
          debugShowCheckedModeBanner: false,
          initialRoute: '/',
          builder: (context, child) {
            return Stack(
              fit: StackFit.expand,
              children: [
                SafeArea(
                  top: true,
                  left: false,
                  right: false,
                  bottom: false,
                  child: child ?? const SizedBox.shrink(),
                ),
                FutureBuilder<void>(
                  future: AuthService.loginComplete,
                  builder: (context, snapshot) {
                    if (snapshot.connectionState == ConnectionState.done) {
                      return const SizedBox.shrink();
                    }
                    return Positioned.fill(
                      child: AbsorbPointer(
                        child: Container(
                          color: Colors.black.withValues(alpha: 0.2),
                          child: const Center(
                            child: CircularProgressIndicator(
                              color: AppColors.primary,
                            ),
                          ),
                        ),
                      ),
                    );
                  },
                ),
              ],
            );
          },
          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 args = ModalRoute.of(ctx)?.settings.arguments;
            final taskId = args is Map ? args['taskId'] : args;
            final imagePath = args is Map ? args['imagePath'] as String? : null;
            return GenerateProgressScreen(
              taskId: taskId,
              imagePath: imagePath,
            );
          },
          '/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: [
          HomeScreen(isActive: currentTab == NavTab.home),
          GalleryScreen(isActive: currentTab == NavTab.gallery),
          ProfileScreen(isActive: currentTab == NavTab.profile),
        ],
      ),
      bottomNavigationBar: BottomNavBar(
        currentTab: currentTab,
        onTabSelected: onTabSelected,
      ),
    );
  }
}