import 'package:dynamic_color/dynamic_color.dart';
import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';
import 'package:mileograph_flutter/components/login/login.dart';
import 'package:mileograph_flutter/components/pages/calculator.dart';
import 'package:mileograph_flutter/components/pages/calculator_details.dart';
import 'package:mileograph_flutter/components/pages/dashboard.dart';
import 'package:mileograph_flutter/components/pages/legs.dart';
import 'package:mileograph_flutter/components/pages/loco_legs.dart';
import 'package:mileograph_flutter/components/pages/loco_timeline.dart';
import 'package:mileograph_flutter/components/pages/new_entry.dart';
import 'package:mileograph_flutter/components/pages/new_traction.dart';
import 'package:mileograph_flutter/components/pages/traction.dart';
import 'package:mileograph_flutter/components/pages/trips.dart';
import 'package:mileograph_flutter/services/authservice.dart';
import 'package:mileograph_flutter/services/data_service.dart';
import 'package:mileograph_flutter/services/navigation_guard.dart';
import 'package:provider/provider.dart';

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

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  late final GoRouter _router;
  bool _routerInitialized = false;

  final ColorScheme defaultLight = ColorScheme.fromSeed(seedColor: Colors.red);
  final ColorScheme defaultDark = ColorScheme.fromSeed(
    seedColor: Colors.red,
    brightness: Brightness.dark,
  );

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    if (_routerInitialized) return;
    _routerInitialized = true;
    final auth = context.read<AuthService>();
    _router = GoRouter(
      refreshListenable: auth,
      redirect: (context, state) {
        final loggedIn = auth.isLoggedIn;
        final loggingIn = state.uri.toString() == '/login';

        if (!loggedIn && !loggingIn) return '/login';
        if (loggedIn && loggingIn) return '/';
        return null;
      },
      routes: [
        ShellRoute(
          builder: (context, state, child) => MyHomePage(child: child),
          routes: [
            GoRoute(path: '/', builder: (context, state) => const Dashboard()),
            GoRoute(
              path: '/calculator',
              builder: (context, state) => CalculatorPage(),
            ),
            GoRoute(
              path: '/calculator/details',
              builder: (context, state) =>
                  CalculatorDetailsPage(result: state.extra),
            ),
            GoRoute(path: '/legs', builder: (context, state) => LegsPage()),
            GoRoute(
              path: '/traction',
              builder: (context, state) => TractionPage(),
            ),
            GoRoute(
              path: '/traction/:id/timeline',
              builder: (_, state) {
                final idParam = state.pathParameters['id'];
                final locoId = int.tryParse(idParam ?? '') ?? 0;
                final extra = state.extra;
                String label = state.uri.queryParameters['label'] ?? '';
                if (extra is Map && extra['label'] is String) {
                  label = extra['label'] as String;
                } else if (extra is String && extra.isNotEmpty) {
                  label = extra;
                }
                if (label.trim().isEmpty) label = 'Loco $locoId';
                return LocoTimelinePage(locoId: locoId, locoLabel: label);
              },
            ),
            GoRoute(
              path: '/traction/:id/legs',
              builder: (_, state) {
                final idParam = state.pathParameters['id'];
                final locoId = int.tryParse(idParam ?? '') ?? 0;
                final extra = state.extra;
                String label = state.uri.queryParameters['label'] ?? '';
                if (extra is Map && extra['label'] is String) {
                  label = extra['label'] as String;
                } else if (extra is String && extra.isNotEmpty) {
                  label = extra;
                }
                if (label.trim().isEmpty) label = 'Loco $locoId';
                return LocoLegsPage(locoId: locoId, locoLabel: label);
              },
            ),
            GoRoute(
              path: '/traction/new',
              builder: (context, state) => const NewTractionPage(),
            ),
            GoRoute(path: '/trips', builder: (context, state) => TripsPage()),
            GoRoute(path: '/add', builder: (context, state) => NewEntryPage()),
            GoRoute(
              path: '/legs/edit/:id',
              builder: (_, state) {
                final idParam = state.pathParameters['id'];
                final legId = idParam == null ? null : int.tryParse(idParam);
                return NewEntryPage(editLegId: legId);
              },
            ),
          ],
        ),
        GoRoute(path: '/login', builder: (context, state) => const LoginScreen()),
      ],
    );
  }

  @override
  Widget build(BuildContext context) {
    return DynamicColorBuilder(
      builder: (ColorScheme? lightDynamic, ColorScheme? darkDynamic) {
        return MaterialApp.router(
          title: 'Mileograph',
          routerConfig: _router,
          theme: ThemeData(
            useMaterial3: true,
            colorScheme: lightDynamic ?? defaultLight,
          ),
          darkTheme: ThemeData(
            useMaterial3: true,
            colorScheme: darkDynamic ?? defaultDark,
          ),
          themeMode: ThemeMode.system,
        );
      },
    );
  }
}

class MyHomePage extends StatefulWidget {
  final Widget child;
  const MyHomePage({super.key, required this.child});

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final List<String> contentPages = [
    "/",
    "/calculator",
    "/legs",
    "/traction",
    "/trips",
    "/add",
  ];

  int _getIndexFromLocation(String location) {
    int newIndex = contentPages.indexWhere((path) {
      if (location == path) return true;
      if (path == '/') return location == '/';
      return location.startsWith('$path/');
    });
    if (newIndex < 0) {
      return 0;
    }
    return newIndex;
  }

  Future<void> _onItemTapped(int index, int currentIndex) async {
    if (index < 0 || index >= contentPages.length || index == currentIndex) {
      return;
    }
    await NavigationGuard.attemptNavigation(() async {
      if (!mounted) return;
      context.go(contentPages[index]);
    });
  }

  bool _fetched = false;

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();

    if (_fetched) return;
    _fetched = true;
    WidgetsBinding.instance.addPostFrameCallback((_) {
      Future(() async {
        if (!mounted) return;
        final data = context.read<DataService>();
        final auth = context.read<AuthService>();
        await auth.tryRestoreSession();
        if (!auth.isLoggedIn) return;
        data.fetchEventFields();
        if (data.homepageStats == null) {
          data.fetchHomepageStats();
        }
        if (data.legs.isEmpty) {
          data.fetchLegs();
        }
        if (data.traction.isEmpty) {
          data.fetchHadTraction();
        }
        if (data.onThisDay.isEmpty) {
          data.fetchOnThisDay();
        }
        if (data.tripDetails.isEmpty) {
          data.fetchTripDetails();
        }
      });
    });
  }

  @override
  Widget build(BuildContext context) {
    final location = GoRouterState.of(context).uri.toString();
    final pageIndex = _getIndexFromLocation(location);
    final homepageReady = context.select<DataService, bool>(
      (data) => data.homepageStats != null || !data.isHomepageLoading,
    );
    final auth = context.read<AuthService>();

    final currentPage = homepageReady
        ? widget.child
        : const Center(child: CircularProgressIndicator());

    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text.rich(
          TextSpan(
            children: const [
              TextSpan(text: "Mile"),
              TextSpan(text: "O", style: TextStyle(color: Colors.red)),
              TextSpan(text: "graph"),
            ],
            style: const TextStyle(
              decoration: TextDecoration.none,
              color: Colors.white,
              fontFamily: "Tomatoes",
            ),
          ),
        ),
        actions: [
          const IconButton(onPressed: null, icon: Icon(Icons.account_circle)),
          IconButton(onPressed: auth.logout, icon: const Icon(Icons.logout)),
        ],
      ),
      bottomNavigationBar: NavigationBar(
        selectedIndex: pageIndex,
        onDestinationSelected: (int index) => _onItemTapped(index, pageIndex),
        destinations: const [
          NavigationDestination(icon: Icon(Icons.home), label: "Home"),
          NavigationDestination(icon: Icon(Icons.route), label: "Calculator"),
          NavigationDestination(icon: Icon(Icons.list), label: "Entries"),
          NavigationDestination(icon: Icon(Icons.train), label: "Traction"),
          NavigationDestination(icon: Icon(Icons.book), label: "Trips"),
          NavigationDestination(icon: Icon(Icons.add), label: "Add"),
        ],
      ),
      body: currentPage,
    );
  }
}