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

import 'package:sunny_mochi/core/theme/app_colors.dart';

/// 应用主题工厂 — 按 [AppColorScheme] 真实切换全部色（对齐 iOS 4 套 plist）。
///
/// 与旧版差异：
/// - 旧版只把 primary 当作 seed，nav/btn/bg 都写死，导致 4 套主题视觉差异不明显
/// - 新版从 [AppPalettes] 读完整 10 色，AppBar/ColorScheme/extensions 全部按主题切
/// - 通过 ThemeExtension 暴露 [AppPalette]，业务代码 `Theme.of(context).extension<AppPalette>()!.buttonBg` 读
abstract class AppTheme {
  static ThemeData light({AppColorScheme scheme = AppColorScheme.white}) {
    final palette = AppPalettes.of(scheme);
    return ThemeData(
      useMaterial3: true,
      // BackButton 图标：iOS 平台渲染 arrow_back_ios_new（< 样式），与登录页一致。
      // ScrollBehavior 使用 defaultTargetPlatform，不受此字段影响。
      platform: TargetPlatform.iOS,
      // 全局字体 — HarmonyOS Sans SC（GB2312 子集，pubspec 注册）
      fontFamily: 'HarmonyOS Sans SC',
      colorScheme: ColorScheme.fromSeed(
        seedColor: palette.primary,
        primary: palette.primary,
        secondary: palette.secondary,
        surface: AppColors.surface,
        error: AppColors.error,
      ),
      scaffoldBackgroundColor: palette.background,
      primaryColor: palette.primary,
      appBarTheme: AppBarTheme(
        backgroundColor: palette.navBar,
        foregroundColor: palette.navBarText,
        elevation: 0,
        // Material 3 默认会在滚动时给 AppBar 叠加 surfaceTint 染色（紫色）；
        // 设计稿要求 navBar 保持纯白，必须显式置为 transparent + 0 elevation。
        surfaceTintColor: Colors.transparent,
        scrolledUnderElevation: 0,
        centerTitle: true,
        titleTextStyle: TextStyle(
          color: palette.navBarText,
          fontSize: 18.sp,
          fontWeight: FontWeight.w600,
        ),
        iconTheme: IconThemeData(color: palette.navBarText, size: 22.sp),
      ),
      elevatedButtonTheme: ElevatedButtonThemeData(
        style: ElevatedButton.styleFrom(
          backgroundColor: palette.buttonBg,
          foregroundColor: palette.buttonText,
        ),
      ),
      filledButtonTheme: FilledButtonThemeData(
        style: FilledButton.styleFrom(
          backgroundColor: palette.buttonBg,
          foregroundColor: palette.buttonText,
        ),
      ),
      textButtonTheme: TextButtonThemeData(
        style: TextButton.styleFrom(foregroundColor: palette.primary),
      ),
      tabBarTheme: TabBarThemeData(
        labelColor: palette.tabBarSelected,
        unselectedLabelColor: palette.tabBarNormal,
        indicatorColor: palette.tabBarSelected,
      ),
      bottomNavigationBarTheme: BottomNavigationBarThemeData(
        selectedItemColor: palette.tabBarSelected,
        unselectedItemColor: palette.tabBarNormal,
      ),
      textTheme: TextTheme(
        bodyLarge: TextStyle(fontSize: 16.sp, color: palette.text),
        bodyMedium: TextStyle(fontSize: 14.sp, color: AppColors.textSecondary),
        bodySmall: TextStyle(fontSize: 12.sp, color: AppColors.textHint),
        titleLarge: TextStyle(
          fontSize: 18.sp,
          fontWeight: FontWeight.w600,
          color: palette.text,
        ),
      ),
      dividerColor: AppColors.divider,
      dividerTheme: const DividerThemeData(space: 1, thickness: 1),
      extensions: [palette],
    );
  }

  static ThemeData dark({AppColorScheme scheme = AppColorScheme.white}) {
    final palette = AppPalettes.of(scheme);
    return ThemeData(
      useMaterial3: true,
      platform: TargetPlatform.iOS,
      brightness: Brightness.dark,
      colorScheme: ColorScheme.fromSeed(
        seedColor: palette.primary,
        primary: palette.primary,
        secondary: palette.secondary,
        brightness: Brightness.dark,
      ),
      primaryColor: palette.primary,
      scaffoldBackgroundColor: const Color(0xFF121212),
      appBarTheme: AppBarTheme(
        backgroundColor: AppColors.navBarDark,
        foregroundColor: Colors.white,
        elevation: 0,
        centerTitle: true,
        titleTextStyle: TextStyle(
          color: Colors.white,
          fontSize: 17.sp,
          fontWeight: FontWeight.w600,
        ),
      ),
      bottomNavigationBarTheme: BottomNavigationBarThemeData(
        selectedItemColor: palette.tabBarSelected,
        unselectedItemColor: palette.tabBarNormal,
      ),
      extensions: [palette],
    );
  }
}