import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

import 'state/app_scope.dart';
import 'state/app_state.dart';
import 'ui/screens/auth/login_screen.dart';
import 'ui/screens/shell_screen.dart';
import 'ui/tokens.dart';

void main() {
  WidgetsFlutterBinding.ensureInitialized();

  // Draw behind the system bars — expected on Android 15+ and the reason the
  // screens manage their own SafeArea insets.
  SystemChrome.setEnabledSystemUIMode(SystemUiMode.edgeToEdge);
  SystemChrome.setPreferredOrientations([
    DeviceOrientation.portraitUp,
    DeviceOrientation.portraitDown,
  ]);

  runApp(const DoormileApp());
}

/// Doormile — customer app.
///
/// Book pickup → Track → Delivered.
///
/// `lib/data/doormile_api.dart` is the service surface, and it has exactly one
/// implementation: the live customer API. Nothing on screen is invented.
class DoormileApp extends StatefulWidget {
  const DoormileApp({super.key, this.initialState});

  /// Injectable for tests.
  final AppState? initialState;

  @override
  State<DoormileApp> createState() => _DoormileAppState();
}

class _DoormileAppState extends State<DoormileApp> {
  late final AppState _state = widget.initialState ?? AppState();

  @override
  void initState() {
    super.initState();
    // A returning customer's session outlives the process: the refresh token is
    // good for 60 days. Look for it before deciding which screen to open.
    unawaited(_state.restoreSession());
  }

  @override
  void dispose() {
    _state.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return AppScope(
      state: _state,
      child: MaterialApp(
        title: 'Doormile',
        debugShowCheckedModeBanner: false,
        theme: buildDoormileTheme(),
        home: const _Launch(),
        // No text-scale clamp: components adapt instead. Rows grow, important
        // text wraps, and ellipsis is reserved for secondary information.
        builder: (context, child) {
          return AnnotatedRegion<SystemUiOverlayStyle>(
            value: const SystemUiOverlayStyle(
              statusBarColor: Colors.transparent,
              statusBarIconBrightness: Brightness.dark,
              statusBarBrightness: Brightness.light,
              systemNavigationBarColor: Colors.transparent,
              systemNavigationBarIconBrightness: Brightness.dark,
            ),
            child: child ?? const SizedBox.shrink(),
          );
        },
      ),
    );
  }
}

ThemeData buildDoormileTheme() {
  const scheme = ColorScheme.light(
    primary: DmColors.brand,
    onPrimary: Colors.white,
    secondary: DmColors.brand,
    onSecondary: Colors.white,
    surface: DmColors.surface,
    onSurface: DmColors.ink,
    error: DmColors.danger,
  );

  return ThemeData(
    useMaterial3: true,
    fontFamily: 'Manrope',
    colorScheme: scheme,
    scaffoldBackgroundColor: DmColors.bg,
    splashFactory: InkSparkle.splashFactory,
    highlightColor: const Color(0x0A17110F),
    textSelectionTheme: const TextSelectionThemeData(
      cursorColor: DmColors.brand,
      selectionColor: Color(0x338F0F06),
      selectionHandleColor: DmColors.brand,
    ),
    textTheme: const TextTheme().apply(
      bodyColor: DmColors.ink,
      displayColor: DmColors.ink,
    ),
    dividerTheme: const DividerThemeData(
      color: DmColors.hairline,
      thickness: 1,
      space: 1,
    ),
    pageTransitionsTheme: const PageTransitionsTheme(
      builders: {
        TargetPlatform.android: _DmPageTransitions(),
        TargetPlatform.iOS: _DmPageTransitions(),
        TargetPlatform.macOS: _DmPageTransitions(),
        TargetPlatform.windows: _DmPageTransitions(),
        TargetPlatform.linux: _DmPageTransitions(),
      },
    ),
  );
}

/// Forward navigation slides in from the right and fades, matching the
/// prototype's screen transition.
class _DmPageTransitions extends PageTransitionsBuilder {
  const _DmPageTransitions();

  @override
  Widget buildTransitions<T>(
    PageRoute<T> route,
    BuildContext context,
    Animation<double> animation,
    Animation<double> secondaryAnimation,
    Widget child,
  ) {
    final curved = CurvedAnimation(
      parent: animation,
      curve: Curves.easeOutCubic,
      reverseCurve: Curves.easeInCubic,
    );
    return FadeTransition(
      opacity: curved,
      child: SlideTransition(
        position: Tween(
          begin: const Offset(0.06, 0),
          end: Offset.zero,
        ).animate(curved),
        child: child,
      ),
    );
  }
}

/// What the app opens on.
///
/// Three states, and the middle one is the reason this widget exists: until the
/// stored session has been looked for we do not yet know whether this customer
/// is signed in, and showing them a login form that vanishes a moment later is
/// worse than showing them nothing. The Android 12 splash is still up for most
/// of it.
class _Launch extends StatelessWidget {
  const _Launch();

  @override
  Widget build(BuildContext context) {
    final app = AppScope.of(context);
    if (app.restoringSession) {
      return const Scaffold(backgroundColor: DmColors.canvas, body: SizedBox());
    }
    return app.isSignedIn ? const ShellScreen() : const LoginScreen();
  }
}