import "package:flutter/widgets.dart";
import "package:google_fonts/google_fonts.dart";

import "package:garage_ui/theme/theme_data.dart";

export "package:garage_ui/theme/theme_data.dart";
export "package:garage_ui/theme/colour_scheme.dart";
export "package:garage_ui/theme/typography.dart";

// The apps theme. Hands the theme data down via a plain inherited scope (no
// animated wrapper, no per frame ColorScheme.lerp flattening the whole thing -
// this is the bit that used to feel second class), AND establishes a sane
// DefaultTextStyle + IconTheme so bare Text/Icon dont fall back to flutter's
// yellow-underline "unstyled" debug look (MaterialApp only styles text inside a
// Material, and our panels arent Material).
class GarageTheme extends StatelessWidget {
  const GarageTheme({super.key, required this.data, required this.child});

  final ThemeData data;
  final Widget child;

  static ThemeData of(BuildContext context) {
    final t = maybeOf(context);
    assert(
      t != null,
      "No GarageTheme found in context. Wrap the app in an GarageTheme.",
    );
    return t!;
  }

  static ThemeData? maybeOf(BuildContext context) {
    return context
        .dependOnInheritedWidgetOfExactType<_GarageThemeScope>()
        ?.data;
  }

  @override
  Widget build(BuildContext context) {
    final cs = data.colorScheme;
    return _GarageThemeScope(
      data: data,
      child: DefaultTextStyle(
        // the one app-wide UI font, declared right here at the top of the tree.
        // everything below that doesnt override fontFamily inherits Geist.
        // (canvas-painted text - station labels, watermark - sits outside the
        // widget tree so it isnt touched by this.)
        style: GoogleFonts.geist(
          color: cs.foreground,
          // off the density, not a literal times scaling. this was the third
          // independent source of text size in the package - controls read
          // density.fontSize, the .xSmall()/.small()/.large() ladder now reads
          // it too, and this floated free at 11 * scaling. Retune fontSize and
          // page copy no longer stays behind while the controls move.
          //
          // fontSize, NOT textXs. The ladder above the control font is a set
          // of MULTIPLIERS (xs 1.1x, sm 1.4x, lg 1.8x), so what textXs means
          // depends on the tier: at A&A's 10 its 11, a hair over the control
          // font and harmless, and at the product tier's 16 its 18 - body copy
          // rendering BIGGER than the text inside the buttons and fields next
          // to it. Thats backwards, and its what made the product surfaces
          // read as oversized even with their control geometry correct.
          //
          // Body copy is the control font. A sentence and the text in the box
          // under it are the same size, at every tier, by construction.
          fontSize: data.density.fontSize,
          // the important bit - kills the yellow underline.
          decoration: TextDecoration.none,
          fontWeight: FontWeight.w300,
        ),
        child: IconTheme(
          data: IconThemeData(
            color: cs.foreground,
            size: data.iconTheme.medium.size,
          ),
          child: child,
        ),
      ),
    );
  }
}

class _GarageThemeScope extends InheritedWidget {
  const _GarageThemeScope({required this.data, required super.child});

  final ThemeData data;

  @override
  bool updateShouldNotify(_GarageThemeScope oldWidget) =>
      oldWidget.data != data;
}