import 'package:flutter/material.dart';
import 'package:dynamic_color/dynamic_color.dart';
import 'package:mileograph_flutter/components/pages/calculator.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:provider/provider.dart';

import 'package:mileograph_flutter/components/pages/legs.dart';
import 'package:mileograph_flutter/services/apiService.dart';
import 'package:mileograph_flutter/services/authservice.dart';
import 'package:mileograph_flutter/services/dataService.dart';

import 'components/login/login.dart';
import 'components/pages/dashboard.dart';

import 'package:go_router/go_router.dart';

late ApiService api;

void main() {
  runApp(
    MultiProvider(
      providers: [
        Provider<ApiService>(
          create: (_) {
            api = ApiService(baseUrl: 'https://mileograph.co.uk/api/v1');
            return api;
          },
        ),
        ChangeNotifierProxyProvider<ApiService, AuthService>(
          create: (context) => AuthService(api: context.read<ApiService>()),
          update: (_, api, previous) {
            return previous ?? AuthService(api: api);
          },
        ),
        ProxyProvider<AuthService, void>(
          update: (_, auth, __) {
            api.setTokenProvider(() => auth.token);
            api.setUnauthorizedHandler(() => auth.handleTokenExpired());
          },
        ),
        ChangeNotifierProxyProvider<ApiService, DataService>(
          create: (context) => DataService(api: context.read<ApiService>()),
          update: (_, api, previous) => previous ?? DataService(api: api),
        ),
      ],
      child: MyApp(),
    ),
  );
}

class MyApp extends StatelessWidget {
  MyApp({super.key});

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

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    final GoRouter router = GoRouter(
      refreshListenable: context
          .read<AuthService>(), // `AuthService` extends `ChangeNotifier`
      redirect: (context, state) {
        final auth = Provider.of<AuthService>(context, listen: false);
        final loggedIn = auth.isLoggedIn;
        final loggingIn = state.uri.toString() == '/login';

        // Redirect to login if not logged in and trying to access protected pages
        if (!loggedIn && !loggingIn) return '/login';

        // Redirect to home if already logged in and trying to go to login
        if (loggedIn && loggingIn) return '/';

        // No redirection
        return null;
      },
      routes: [
        ShellRoute(
          builder: (context, state, child) {
            return MyHomePage(child: child);
          },
          routes: [
            GoRoute(path: '/', builder: (_, __) => const Dashboard()),
            GoRoute(path: '/calculator', builder: (_, __) => CalculatorPage()),
            GoRoute(
              path: '/calculator/details',
              builder: (_, __) => CalculatorPage(),
            ),
            GoRoute(path: '/legs', builder: (_, __) => LegsPage()),
            GoRoute(path: '/traction', builder: (_, __) => TractionPage()),
            GoRoute(
              path: '/traction/new',
              builder: (_, __) => const NewTractionPage(),
            ),
            GoRoute(path: '/trips', builder: (_, __) => TripsPage()),
            GoRoute(path: '/add', builder: (_, __) => NewEntryPage()),
          ],
        ),
        GoRoute(path: '/login', builder: (_, __) => const LoginScreen()),
      ],
    );

    return DynamicColorBuilder(
      builder: (ColorScheme? lightDynamic, ColorScheme? darkDynamic) {
        return MaterialApp.router(
          title: 'Flutter Demo',
          routerConfig: router,
          theme: ThemeData(
            useMaterial3: true,
            // This is the theme of your application.
            //
            // TRY THIS: Try running your application with "flutter run". You'll see
            // the application has a purple toolbar. Then, without quitting the app,
            // try changing the seedColor in the colorScheme below to Colors.green
            // and then invoke "hot reload" (save your changes or press the "hot
            // reload" button in a Flutter-supported IDE, or press "r" if you used
            // the command line to start the app).
            //fullPage
            // Notice that the counter didn't reset back to zero; the application
            // state is not lost during the reload. To reset the state, use hot
            // restart instead.
            //
            // This works for code too, not just values: Most code changes can be
            // tested with just a hot reload.
            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});

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  @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;
  }

  void _onItemTapped(int index, int currentIndex) {
    if (index < 0 || index >= contentPages.length || index == currentIndex) {
      return;
    }
    context.push(contentPages[index]);
    _getIndexFromLocation(contentPages[index]);
  }

  bool loggedIn = false;
  bool _fetched = false;

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

    if (!_fetched) {
      _fetched = true;
      WidgetsBinding.instance.addPostFrameCallback((_) {
        Future(() async {
          final data = context.read<DataService>();
          final auth = context.read<AuthService>();
          api.setTokenProvider(() => auth.token);
          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) {
    Widget currentPage;
    final location = GoRouterState.of(context).uri.toString();
    final pageIndex = _getIndexFromLocation(location);
    final data = context.watch<DataService>();
    final auth = context.read<AuthService>();

    if (data.homepageStats != null || !data.isHomepageLoading) {
      currentPage = widget.child;
    } else {
      currentPage = Center(child: CircularProgressIndicator());
    }
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // TRY THIS: Try changing the color here to a specific color (to
        // Colors.amber, perhaps?) and trigger a hot reload to see the AppBar
        // change color while the other colors stay the same.
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text.rich(
          TextSpan(
            children: [
              TextSpan(text: "Mile"),
              TextSpan(
                text: "O",
                style: TextStyle(color: Colors.red),
              ),
              TextSpan(text: "graph"),
            ],
            style: TextStyle(
              decoration: TextDecoration.none,
              color: Colors.white,
              fontFamily: "Tomatoes",
            ),
          ),
        ),
        actions: [
          IconButton(onPressed: null, icon: Icon(Icons.account_circle)),
          IconButton(onPressed: auth.logout, icon: Icon(Icons.logout)),
        ],
      ),
      bottomNavigationBar: NavigationBar(
        selectedIndex: pageIndex,
        onDestinationSelected: (int index) {
          _onItemTapped(index, pageIndex);
        },
        destinations: [
          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,
    );
  }
}