import "package:flutter/widgets.dart";

import "package:garage_ui/scrollbar.dart";
import "package:garage_ui/theme/garage_theme.dart";

/// The application shell for Garage UI apps.
///
/// This deliberately uses [WidgetsApp] rather than [MaterialApp]. Garage UI
/// owns the visual system while Flutter still supplies routing, overlays,
/// media queries, directionality, and localization plumbing.
class GarageApp extends StatelessWidget {
  const GarageApp.router({
    super.key,
    required this.routerConfig,
    required this.theme,
    this.title = "",
    this.builder,
    this.locale,
    this.localizationsDelegates,
    this.supportedLocales = const <Locale>[Locale("en", "US")],
    this.debugShowCheckedModeBanner = false,
  });

  final RouterConfig<Object> routerConfig;
  final ThemeData theme;
  final String title;
  final TransitionBuilder? builder;
  final Locale? locale;
  final Iterable<LocalizationsDelegate<dynamic>>? localizationsDelegates;
  final Iterable<Locale> supportedLocales;
  final bool debugShowCheckedModeBanner;

  @override
  Widget build(BuildContext context) {
    return WidgetsApp.router(
      key: key,
      title: title,
      routerConfig: routerConfig,
      color: theme.colorScheme.background,
      locale: locale,
      localizationsDelegates: localizationsDelegates,
      supportedLocales: supportedLocales,
      debugShowCheckedModeBanner: debugShowCheckedModeBanner,
      // the Builder matters: without it `builder` is handed the context ABOVE
      // this GarageTheme, so GarageTheme.of() asserts inside the very callback
      // you were given for theming.
      // ScrollConfiguration, not WidgetsApp's `scrollBehavior` - that
      // parameter only exists on MaterialApp/CupertinoApp.
      builder: (context, child) => ScrollConfiguration(
        behavior: const GarageScrollBehavior(),
        child: GarageTheme(
          data: theme,
          child: Builder(
            builder: (themedContext) =>
                builder?.call(themedContext, child) ??
                child ??
                const SizedBox.shrink(),
          ),
        ),
      ),
    );
  }
}

/// Scrolling without Material's overscroll glow.
///
/// The default ScrollBehavior hangs a GlowingOverscrollIndicator off every
/// scrollable on Android and Fuchsia - the grey arc that swells out of the
/// top or bottom edge when you drag past the end. Its a Material idiom, and
/// this kit isnt a Material app: it paints a big soft shape over flat chrome
/// and reads as a rendering fault rather than as feedback.
///
/// Physics and drag devices are untouched, so a list still throws and settles
/// the way the OS expects - it just doesnt glow at the ends. iOS and desktop
/// never had the glow in the first place, so this only levels the other
/// platforms up to what they already do.
///
/// The scrollbar is ours too. The base behaviour hands desktop a stock
/// [RawScrollbar] - 8px, square ends, a hardcoded grey that knows nothing
/// about the scheme - and thats the pale bar that used to sit beside every
/// nav list. [GarageScrollbar] replaces it here, once, for every scrollable
/// in the app. Touch platforms keep no bar at all, same as the default.
class GarageScrollBehavior extends ScrollBehavior {
  const GarageScrollBehavior();

  @override
  Widget buildOverscrollIndicator(
    BuildContext context,
    Widget child,
    ScrollableDetails details,
  ) => child;

  @override
  Widget buildScrollbar(
    BuildContext context,
    Widget child,
    ScrollableDetails details,
  ) {
    switch (getPlatform(context)) {
      case TargetPlatform.linux:
      case TargetPlatform.macOS:
      case TargetPlatform.windows:
        return GarageScrollbar(controller: details.controller, child: child);

      case TargetPlatform.android:
      case TargetPlatform.fuchsia:
      case TargetPlatform.iOS:
        return child;
    }
  }
}