import 'package:flutter/material.dart';

/// 应用主题：橙白「双橙策略」，回归并与旧版「云端手机端」视觉延续。
///
/// 设计依据：docs/手机端UI优化方案-v2.md
/// - 行动色 [brandPrimary] (#C2410C) 承载白字（对比度 5.18 ✅），用于主按钮 / 导航选中 / 可点文字。
/// - 品牌亮橙 [brandOrange] (#FF914D) 仅用于大色块 / 渐变 / 图表，绝不配白字（对比度仅 2.23 ❌）。
/// - 辅金 [accentGold] (#FFBE58) 用于高亮 / 星级 / 推荐位。
class AppTheme {
  AppTheme._();

  /// 行动色（主色）。
  static const Color brandPrimary = Color(0xFFC2410C);

  /// 品牌亮橙（仅大色块 / 渐变 / 图表）。
  static const Color brandOrange = Color(0xFFFF914D);

  /// 辅金。
  static const Color accentGold = Color(0xFFFFBE58);

  static const ColorScheme _light = ColorScheme(
    brightness: Brightness.light,
    primary: Color(0xFFC2410C),
    onPrimary: Color(0xFFFFFFFF),
    primaryContainer: Color(0xFFFFD3B3),
    onPrimaryContainer: Color(0xFF4A1D00),
    secondary: Color(0xFF8A5A3A),
    onSecondary: Color(0xFFFFFFFF),
    secondaryContainer: Color(0xFFF5DFCB),
    onSecondaryContainer: Color(0xFF5A3A22),
    tertiary: Color(0xFF9A6000),
    onTertiary: Color(0xFFFFFFFF),
    tertiaryContainer: Color(0xFFFFE0A3),
    onTertiaryContainer: Color(0xFF5C3D00),
    error: Color(0xFFB02A20),
    onError: Color(0xFFFFFFFF),
    errorContainer: Color(0xFFFFDDD8),
    onErrorContainer: Color(0xFF7A2A22),
    surface: Color(0xFFFCFAF8),
    onSurface: Color(0xFF1A1614),
    onSurfaceVariant: Color(0xFF6E655C),
    surfaceContainerLowest: Color(0xFFFFFFFF),
    surfaceContainerLow: Color(0xFFF7F3EF),
    surfaceContainer: Color(0xFFF2EDE8),
    surfaceContainerHigh: Color(0xFFECE5DF),
    surfaceContainerHighest: Color(0xFFE5DED7),
    outline: Color(0xFF8A8178),
    outlineVariant: Color(0xFFDCCFC2),
    shadow: Color(0xFF5C2E12),
    scrim: Color(0xFF1A1614),
    inverseSurface: Color(0xFF2E2823),
    onInverseSurface: Color(0xFFF7EFE9),
    inversePrimary: Color(0xFFFFB487),
    surfaceTint: Color(0xFFC2410C),
  );

  static const ColorScheme _dark = ColorScheme(
    brightness: Brightness.dark,
    primary: Color(0xFFFFB487),
    onPrimary: Color(0xFF542000),
    primaryContainer: Color(0xFF63300D),
    onPrimaryContainer: Color(0xFFFFDCC2),
    secondary: Color(0xFFE8C39B),
    onSecondary: Color(0xFF542000),
    secondaryContainer: Color(0xFF5A3A22),
    onSecondaryContainer: Color(0xFFFFDCC2),
    tertiary: Color(0xFFF2BE62),
    onTertiary: Color(0xFF542000),
    tertiaryContainer: Color(0xFF5C3D00),
    onTertiaryContainer: Color(0xFFFFDCC2),
    error: Color(0xFFFF8474),
    onError: Color(0xFF5A1610),
    errorContainer: Color(0xFF7A2A22),
    onErrorContainer: Color(0xFFFFC9C2),
    surface: Color(0xFF16130F),
    onSurface: Color(0xFFF3E9E2),
    onSurfaceVariant: Color(0xFFC4B8AE),
    surfaceContainerLowest: Color(0xFF0F0D0A),
    surfaceContainerLow: Color(0xFF1E1A16),
    surfaceContainer: Color(0xFF23201B),
    surfaceContainerHigh: Color(0xFF2D2924),
    surfaceContainerHighest: Color(0xFF38332D),
    outline: Color(0xFF7A7068),
    outlineVariant: Color(0xFF453F39),
    shadow: Color(0xFF000000),
    scrim: Color(0xFF0F0D0A),
    inverseSurface: Color(0xFFF3E9E2),
    onInverseSurface: Color(0xFF2E2823),
    inversePrimary: Color(0xFFC2410C),
    surfaceTint: Color(0xFFFFB487),
  );

  /// 浅色主题（橙白品牌主场）。
  static ThemeData light() => _base(_light).copyWith(
        extensions: const <ThemeExtension<dynamic>>[AppSemanticColors.light],
      );

  /// 深色主题（暖化 surface，主色提亮为 #FFB487）。
  static ThemeData dark() => _base(_dark).copyWith(
        extensions: const <ThemeExtension<dynamic>>[AppSemanticColors.dark],
      );

  static ThemeData _base(ColorScheme scheme) {
    return ThemeData(
      useMaterial3: true,
      brightness: scheme.brightness,
      colorScheme: scheme,
      scaffoldBackgroundColor: scheme.surface,
      // 暖棕低透明阴影，替代默认偏硬的黑色阴影（云感）。
      shadowColor: const Color(0x245C2E12),
      materialTapTargetSize: MaterialTapTargetSize.padded,
      visualDensity: VisualDensity.standard,
      extensions: const <ThemeExtension<dynamic>>[],
      iconTheme: IconThemeData(
        size: AppIconSize.regular,
        color: scheme.onSurfaceVariant,
      ),
      appBarTheme: AppBarTheme(
        centerTitle: true,
        backgroundColor: scheme.surface,
        foregroundColor: scheme.onSurface,
        elevation: 0,
        // 滚动后轻微浮起，呼应云影。
        scrolledUnderElevation: 3,
        shadowColor: const Color(0x245C2E12),
      ),
      cardTheme: CardTheme(
        elevation: 0,
        clipBehavior: Clip.antiAlias,
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(AppRadius.lg),
        ),
      ),
      chipTheme: ChipThemeData(
        backgroundColor: scheme.surfaceContainerHighest,
        labelStyle: TextStyle(color: scheme.onSurface),
        selectedColor: scheme.primaryContainer,
        checkmarkColor: scheme.onPrimaryContainer,
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(AppRadius.full),
        ),
      ),
      inputDecorationTheme: InputDecorationTheme(
        border: OutlineInputBorder(
          borderRadius: BorderRadius.circular(AppRadius.md),
        ),
        filled: true,
        fillColor: scheme.surfaceContainerHighest,
        labelStyle: TextStyle(color: scheme.onSurfaceVariant),
        hintStyle: TextStyle(color: scheme.onSurfaceVariant),
        errorStyle: TextStyle(color: scheme.error),
        contentPadding:
            const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
      ),
      snackBarTheme: const SnackBarThemeData(
        behavior: SnackBarBehavior.floating,
      ),
      // 全局兜底：30 处 showModalBottomSheet 一次性拿到把手 / 安全区 / 顶部圆角 / 限宽。
      bottomSheetTheme: BottomSheetThemeData(
        showDragHandle: true,
        backgroundColor: scheme.surface,
        surfaceTintColor: scheme.surfaceTint,
        modalBackgroundColor: scheme.surface,
        elevation: 0,
        clipBehavior: Clip.antiAlias,
        shape: RoundedRectangleBorder(borderRadius: AppRadius.sheetTop),
        constraints: const BoxConstraints(maxWidth: 640),
      ),
      navigationBarTheme: NavigationBarThemeData(
        height: 72,
        elevation: 0,
        backgroundColor: scheme.surfaceContainer,
        surfaceTintColor: scheme.surfaceTint,
        indicatorColor: scheme.secondaryContainer,
        indicatorShape: const StadiumBorder(),
        labelBehavior: NavigationDestinationLabelBehavior.alwaysShow,
        iconTheme: WidgetStateProperty.resolveWith((states) => IconThemeData(
          size: 24,
          color: states.contains(WidgetState.selected)
              ? scheme.onSecondaryContainer
              : scheme.onSurfaceVariant,
        )),
        labelTextStyle: WidgetStateProperty.resolveWith((states) => TextStyle(
          fontSize: 12,
          fontWeight: states.contains(WidgetState.selected)
              ? FontWeight.w600
              : FontWeight.w500,
          color: states.contains(WidgetState.selected)
              ? scheme.onSurface
              : scheme.onSurfaceVariant,
        )),
      ),
      navigationRailTheme: NavigationRailThemeData(
        backgroundColor: scheme.surfaceContainer,
        elevation: 0,
        indicatorColor: scheme.secondaryContainer,
        indicatorShape: const StadiumBorder(),
        minWidth: 72,
        groupAlignment: -0.2,
        labelType: NavigationRailLabelType.all,
        selectedIconTheme:
            IconThemeData(size: 24, color: scheme.onSecondaryContainer),
        unselectedIconTheme:
            IconThemeData(size: 24, color: scheme.onSurfaceVariant),
        selectedLabelTextStyle: TextStyle(
          fontSize: 12,
          fontWeight: FontWeight.w600,
          color: scheme.onSurface,
        ),
        unselectedLabelTextStyle: TextStyle(
          fontSize: 12,
          color: scheme.onSurfaceVariant,
        ),
      ),
      dialogTheme: DialogThemeData(
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(AppRadius.xxl),
        ),
        backgroundColor: scheme.surfaceContainerLow,
        surfaceTintColor: scheme.surfaceTint,
      ),
      iconButtonTheme: IconButtonThemeData(
        style: IconButton.styleFrom(
          minimumSize: const Size(48, 48),
          tapTargetSize: MaterialTapTargetSize.padded,
          padding: EdgeInsets.zero,
        ),
      ),
      filledButtonTheme: FilledButtonThemeData(
        style: FilledButton.styleFrom(
          minimumSize: const Size(64, 52),
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(AppRadius.lg),
          ),
        ),
      ),
      elevatedButtonTheme: ElevatedButtonThemeData(
        style: ElevatedButton.styleFrom(
          minimumSize: const Size(64, 52),
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(AppRadius.lg),
          ),
        ),
      ),
      outlinedButtonTheme: OutlinedButtonThemeData(
        style: OutlinedButton.styleFrom(
          minimumSize: const Size(64, 52),
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(AppRadius.lg),
          ),
        ),
      ),
      textButtonTheme: TextButtonThemeData(
        style: TextButton.styleFrom(
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(AppRadius.lg),
          ),
        ),
      ),
    );
  }
}

/// 圆角梯度：非胶囊、四角一致、克制感（呼应 logo ≈3% 圆角）。
class AppRadius {
  static const double xs = 4; // 进度条、缩略图角
  static const double sm = 8; // Chip、SnackBar、小标签
  static const double md = 12; // 输入框（沿用现值，保持手感连续）
  static const double lg = 16; // ★ 标准卡片、按钮（主力值）
  static const double xl = 20; // 分组容器、大 Banner 卡
  static const double xxl = 28; // ★ 底部弹窗顶部两角（云朵弧线核心表达）
  static const double full = 999; // 仅状态 Chip / 头像 / pill

  /// 底部弹窗顶部两角大圆角、底部直角（云朵上缘多弧、下缘平缓）。
  static const BorderRadius sheetTop =
      BorderRadius.vertical(top: Radius.circular(xxl));

  AppRadius._();
}

/// 云感暖阴影：模糊:偏移 ≈4:1，暖棕而非纯黑。
class AppShadows {
  static const List<BoxShadow> xs = [
    BoxShadow(
      color: Color(0x0F5C2E12),
      blurRadius: 8,
      offset: Offset(0, 2),
      spreadRadius: -1,
    ),
  ];
  static const List<BoxShadow> sm = [
    BoxShadow(
      color: Color(0x145C2E12),
      blurRadius: 12,
      offset: Offset(0, 4),
      spreadRadius: -2,
    ),
  ];
  static const List<BoxShadow> md = [
    BoxShadow(
      color: Color(0x1A5C2E12),
      blurRadius: 20,
      offset: Offset(0, 8),
      spreadRadius: -4,
    ),
  ];
  static const List<BoxShadow> lg = [
    BoxShadow(
      color: Color(0x245C2E12),
      blurRadius: 32,
      offset: Offset(0, 12),
      spreadRadius: -6,
    ),
  ];
  static const List<BoxShadow> xl = [
    BoxShadow(
      color: Color(0x245C2E12),
      blurRadius: 48,
      offset: Offset(0, 20),
      spreadRadius: -8,
    ),
  ];

  /// 深色：暖色阴影在暗底不可见，改用纯黑 + 描边。
  static const List<BoxShadow> dark = [
    BoxShadow(
      color: Color(0x66000000),
      blurRadius: 24,
      offset: Offset(0, 8),
      spreadRadius: -4,
    ),
  ];

  AppShadows._();
}

/// 图标尺寸栅格（24dp 为默认）。
class AppIconSize {
  static const double inline = 16; // 正文行内
  static const double dense = 20; // 密集信息行
  static const double regular = 24; // ★ 默认：列表 leading、按钮内、AppBar actions
  static const double medium = 28; // 卡片强调图标
  static const double large = 32; // 列表主 leading
  static const double display = 48; // 空状态 / 结果页
  static const double hero = 64; // 关于页 logo、引导页

  AppIconSize._();
}

/// 品牌视觉常量：logo 云朵橙→金渐变。
class AppBrand {
  static const Color cloud = Color(0xFFFF914D); // logo 主色
  static const Color cloudGold = Color(0xFFFFBE58); // logo 金黄
  static const Color onCloud = Color(0xFF3D1A00); // 亮橙底上的深棕文字（6.99 ✅）

  /// logo 橙→金渐变（云朵受光）。
  static const LinearGradient cloudGradient = LinearGradient(
    begin: Alignment.topLeft,
    end: Alignment.bottomRight,
    colors: [Color(0xFFFF914D), Color(0xFFFFBE58)],
  );

  AppBrand._();
}

/// 语义色（成功 / 警告 / 错误 / 信息），通过 ThemeExtension 暴露。
///
/// 警告用琥珀黄而非橙，避免与品牌橙语义打架。
class AppSemanticColors extends ThemeExtension<AppSemanticColors> {
  const AppSemanticColors({
    required this.success,
    required this.successContainer,
    required this.onSuccessContainer,
    required this.warning,
    required this.warningContainer,
    required this.onWarningContainer,
    required this.info,
    required this.infoContainer,
    required this.onInfoContainer,
  });

  final Color success;
  final Color successContainer;
  final Color onSuccessContainer;
  final Color warning;
  final Color warningContainer;
  final Color onWarningContainer;
  final Color info;
  final Color infoContainer;
  final Color onInfoContainer;

  static const light = AppSemanticColors(
    success: Color(0xFF1E7A4E),
    successContainer: Color(0xFFD3EDDD),
    onSuccessContainer: Color(0xFF1E5138),
    warning: Color(0xFF8A5C00),
    warningContainer: Color(0xFFFFE9B8),
    onWarningContainer: Color(0xFF5C4100),
    info: Color(0xFF0B6397),
    infoContainer: Color(0xFFD7E9FA),
    onInfoContainer: Color(0xFF1A4763),
  );

  static const dark = AppSemanticColors(
    success: Color(0xFF5FD398),
    successContainer: Color(0xFF1E5138),
    onSuccessContainer: Color(0xFFA8E6C4),
    warning: Color(0xFFF0BE4E),
    warningContainer: Color(0xFF5C4100),
    onWarningContainer: Color(0xFFFFDCA8),
    info: Color(0xFF7FC4F0),
    infoContainer: Color(0xFF1A4763),
    onInfoContainer: Color(0xFFB8DCF5),
  );

  @override
  ThemeExtension<AppSemanticColors> copyWith() => this;

  @override
  ThemeExtension<AppSemanticColors> lerp(
          covariant ThemeExtension<AppSemanticColors>? other, double t) =>
      other ?? this;
}