import 'package:flutter/material.dart';

@immutable
class AppSurfaces extends ThemeExtension<AppSurfaces> {
  const AppSurfaces({
    required this.cardRadius,
    required this.compactCardRadius,
    required this.dialogRadius,
    required this.cardElevation,
    required this.cardShadowColor,
    required this.compactShadowColor,
  });

  final double cardRadius;
  final double compactCardRadius;
  final double dialogRadius;
  final double cardElevation;
  final Color cardShadowColor;
  final Color compactShadowColor;

  // convenience shapes
  RoundedRectangleBorder get standardShape =>
      RoundedRectangleBorder(borderRadius: BorderRadius.circular(cardRadius));
  RoundedRectangleBorder get compactShape => RoundedRectangleBorder(
    borderRadius: BorderRadius.circular(compactCardRadius),
  );
  RoundedRectangleBorder get dialogShape =>
      RoundedRectangleBorder(borderRadius: BorderRadius.circular(dialogRadius));

  static AppSurfaces of(BuildContext context) {
    final ext = Theme.of(context).extension<AppSurfaces>();
    return ext ??
        const AppSurfaces(
          cardRadius: 16,
          compactCardRadius: 12,
          dialogRadius: 20,
          cardElevation: 3,
          cardShadowColor: Color.fromRGBO(0, 0, 0, 0.12),
          compactShadowColor: Color.fromRGBO(0, 0, 0, 0.08),
        );
  }

  @override
  AppSurfaces copyWith({
    double? cardRadius,
    double? compactCardRadius,
    double? dialogRadius,
    double? cardElevation,
    Color? cardShadowColor,
    Color? compactShadowColor,
  }) {
    return AppSurfaces(
      cardRadius: cardRadius ?? this.cardRadius,
      compactCardRadius: compactCardRadius ?? this.compactCardRadius,
      dialogRadius: dialogRadius ?? this.dialogRadius,
      cardElevation: cardElevation ?? this.cardElevation,
      cardShadowColor: cardShadowColor ?? this.cardShadowColor,
      compactShadowColor: compactShadowColor ?? this.compactShadowColor,
    );
  }

  @override
  AppSurfaces lerp(ThemeExtension<AppSurfaces>? other, double t) {
    if (other is! AppSurfaces) return this;
    return AppSurfaces(
      cardRadius: lerpDouble(cardRadius, other.cardRadius, t) ?? cardRadius,
      compactCardRadius:
          lerpDouble(compactCardRadius, other.compactCardRadius, t) ??
          compactCardRadius,
      dialogRadius:
          lerpDouble(dialogRadius, other.dialogRadius, t) ?? dialogRadius,
      cardElevation:
          lerpDouble(cardElevation, other.cardElevation, t) ?? cardElevation,
      cardShadowColor:
          Color.lerp(cardShadowColor, other.cardShadowColor, t) ??
          cardShadowColor,
      compactShadowColor:
          Color.lerp(compactShadowColor, other.compactShadowColor, t) ??
          compactShadowColor,
    );
  }
}

// Helper because dart:ui lerpDouble isn't exported here
double? lerpDouble(num? a, num? b, double t) {
  if (a == null && b == null) return null;
  a = a ?? 0;
  b = b ?? 0;
  return a + (b - a) * t;
}