// pangolin_theme.dart
// 穿山甲 · Pangolin — Flutter theme implementation
//
// Token 数值层（颜色/间距/圆角/动效/阴影）由 codegen 自动维护，见 pangolin_tokens.gen.dart。
// 本文件只保留 Flutter 实现层：
//   · PangolinScheme  — ThemeExtension（语义色映射 + light/dark 实例）
//   · PangolinContext — BuildContext 扩展
//   · PangolinFonts   — 字族标签常量
//   · PangolinText    — google_fonts 运行时字型
//   · PangolinTheme   — ThemeData 组装
//
// Usage:
//   MaterialApp(
//     theme: PangolinTheme.light,
//     darkTheme: PangolinTheme.dark,
//     themeMode: ThemeMode.system,
//   );
//   // tokens: context.pangolin.accent, PangolinSpacing.x4, PangolinRadius.lg ...

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

// token 数值层：import 供本文件使用，export 让调用方 import pangolin_theme.dart 时也能访问。
import 'pangolin_tokens.gen.dart';
export 'pangolin_tokens.gen.dart';

/// ── Semantic tokens, resolved per brightness ───────────────────────
@immutable
class PangolinScheme extends ThemeExtension<PangolinScheme> {
  const PangolinScheme({
    required this.bg,
    required this.bgSubtle,
    required this.surface,
    required this.surface2,
    required this.overlay,
    required this.fg1,
    required this.fg2,
    required this.fg3,
    required this.fgOnAccent,
    required this.accent,
    required this.accentHover,
    required this.accentPress,
    required this.accentSubtle,
    required this.accentBorder,
    required this.border,
    required this.borderStrong,
    required this.ring,
    required this.success,
    required this.successSubtle,
    required this.warning,
    required this.warningSubtle,
    required this.danger,
    required this.dangerSubtle,
  });

  final Color bg, bgSubtle, surface, surface2, overlay;
  final Color fg1, fg2, fg3, fgOnAccent;
  final Color accent, accentHover, accentPress, accentSubtle, accentBorder;
  final Color border, borderStrong, ring;
  final Color success, successSubtle, warning, warningSubtle, danger, dangerSubtle;

  static const light = PangolinScheme(
    bg: PangolinColors.sand50,
    bgSubtle: PangolinColors.sand100,
    surface: PangolinColors.white,
    surface2: PangolinColors.sand50,
    overlay: Color(0x731F1C18),
    fg1: PangolinColors.sand900,
    fg2: PangolinColors.sand600,
    fg3: PangolinColors.sand500,
    fgOnAccent: PangolinColors.white,
    accent: PangolinColors.clay500,
    accentHover: PangolinColors.clay600,
    accentPress: PangolinColors.clay700,
    accentSubtle: PangolinColors.clay50,
    accentBorder: PangolinColors.clay200,
    border: PangolinColors.sand200,
    borderStrong: PangolinColors.sand300,
    ring: Color(0x59B96A3D),
    success: PangolinColors.green500,
    successSubtle: Color(0xFFE9F0E6),
    warning: PangolinColors.amber500,
    warningSubtle: Color(0xFFF8EED6),
    danger: PangolinColors.red500,
    dangerSubtle: Color(0xFFF6E1DA),
  );

  static const dark = PangolinScheme(
    bg: PangolinColors.sand950,
    bgSubtle: PangolinColors.sand900,
    surface: Color(0xFF221E19),
    surface2: Color(0xFF2A251F),
    overlay: Color(0x99000000),
    fg1: Color(0xFFF4EFE8),
    fg2: Color(0xFFB6AC9C),
    fg3: Color(0xFF897F6F),
    fgOnAccent: PangolinColors.sand900,
    accent: PangolinColors.clay400,
    accentHover: PangolinColors.clay300,
    accentPress: PangolinColors.clay500,
    accentSubtle: Color(0x24CC8B5C),
    accentBorder: Color(0x4DCC8B5C),
    border: Color(0x1AF2EEE7),
    borderStrong: Color(0x2EF2EEE7),
    ring: Color(0x73CC8B5C),
    success: PangolinColors.green400,
    successSubtle: Color(0x297FB07A),
    warning: PangolinColors.amber400,
    warningSubtle: Color(0x29E2B05A),
    danger: PangolinColors.red400,
    dangerSubtle: Color(0x29D4715A),
  );

  @override
  PangolinScheme copyWith({Color? bg, Color? fg1, Color? accent}) => PangolinScheme(
        bg: bg ?? this.bg, bgSubtle: bgSubtle, surface: surface, surface2: surface2,
        overlay: overlay, fg1: fg1 ?? this.fg1, fg2: fg2, fg3: fg3, fgOnAccent: fgOnAccent,
        accent: accent ?? this.accent, accentHover: accentHover, accentPress: accentPress,
        accentSubtle: accentSubtle, accentBorder: accentBorder, border: border,
        borderStrong: borderStrong, ring: ring, success: success, successSubtle: successSubtle,
        warning: warning, warningSubtle: warningSubtle, danger: danger, dangerSubtle: dangerSubtle,
      );

  @override
  PangolinScheme lerp(ThemeExtension<PangolinScheme>? other, double t) {
    if (other is! PangolinScheme) return this;
    Color c(Color a, Color b) => Color.lerp(a, b, t)!;
    return PangolinScheme(
      bg: c(bg, other.bg), bgSubtle: c(bgSubtle, other.bgSubtle), surface: c(surface, other.surface),
      surface2: c(surface2, other.surface2), overlay: c(overlay, other.overlay),
      fg1: c(fg1, other.fg1), fg2: c(fg2, other.fg2), fg3: c(fg3, other.fg3), fgOnAccent: c(fgOnAccent, other.fgOnAccent),
      accent: c(accent, other.accent), accentHover: c(accentHover, other.accentHover), accentPress: c(accentPress, other.accentPress),
      accentSubtle: c(accentSubtle, other.accentSubtle), accentBorder: c(accentBorder, other.accentBorder),
      border: c(border, other.border), borderStrong: c(borderStrong, other.borderStrong), ring: c(ring, other.ring),
      success: c(success, other.success), successSubtle: c(successSubtle, other.successSubtle),
      warning: c(warning, other.warning), warningSubtle: c(warningSubtle, other.warningSubtle),
      danger: c(danger, other.danger), dangerSubtle: c(dangerSubtle, other.dangerSubtle),
    );
  }
}

extension PangolinContext on BuildContext {
  PangolinScheme get pangolin => Theme.of(this).extension<PangolinScheme>()!;
}

/// ── Font families ───────────────────────────────────────────────────
/// 生产用 google_fonts 运行时加载；测试态设 [useBundled]=true，改用本地
/// FontLoader 注册的同名 family（避免 google_fonts 在无网/禁拉取时抛异常，
/// 让 golden 截图回归可跑）。封装函数是 PangolinText/_build 的唯一字体入口。
class PangolinFonts {
  PangolinFonts._();
  static const display = 'Sora';
  static const sans = 'Manrope';
  static const cjk = 'Noto Sans SC';
  static const mono = 'JetBrains Mono';

  /// 测试钩子：true 时用 bundled family（test/fonts/ 经 FontLoader 注册），不走 google_fonts。
  static bool useBundled = false;

  static TextStyle sora({double? fontSize, FontWeight? fontWeight, double? height, double? letterSpacing}) =>
      useBundled
          ? TextStyle(fontFamily: display, fontSize: fontSize, fontWeight: fontWeight, height: height, letterSpacing: letterSpacing)
          : GoogleFonts.sora(fontSize: fontSize, fontWeight: fontWeight, height: height, letterSpacing: letterSpacing);

  static TextStyle manrope(
          {double? fontSize, FontWeight? fontWeight, double? height, double? letterSpacing, List<FontFeature>? fontFeatures}) =>
      useBundled
          ? TextStyle(
              fontFamily: sans,
              fontSize: fontSize,
              fontWeight: fontWeight,
              height: height,
              letterSpacing: letterSpacing,
              fontFeatures: fontFeatures)
          : GoogleFonts.manrope(
              fontSize: fontSize, fontWeight: fontWeight, height: height, letterSpacing: letterSpacing, fontFeatures: fontFeatures);

  static TextStyle jetBrainsMono({double? fontSize, FontWeight? fontWeight, List<FontFeature>? fontFeatures}) =>
      useBundled
          ? TextStyle(fontFamily: mono, fontSize: fontSize, fontWeight: fontWeight, fontFeatures: fontFeatures)
          : GoogleFonts.jetBrainsMono(fontSize: fontSize, fontWeight: fontWeight, fontFeatures: fontFeatures);

  static TextTheme manropeTextTheme(TextTheme base) =>
      useBundled ? base.apply(fontFamily: sans) : GoogleFonts.manropeTextTheme(base);
}

/// ── Type scale ──────────────────────────────────────────────────────
/// Uses google_fonts for runtime font loading (no local ttf required).
/// All PangolinText members are static getters (not const) so they can
/// reference google_fonts, which registers fonts dynamically.
class PangolinText {
  PangolinText._();

  static TextStyle get displayXl => PangolinFonts.sora(
      fontSize: 48, fontWeight: FontWeight.w700, height: 1.15, letterSpacing: -0.96);
  static TextStyle get display => PangolinFonts.sora(
      fontSize: 36, fontWeight: FontWeight.w700, height: 1.15, letterSpacing: -0.72);
  static TextStyle get h1 => PangolinFonts.sora(
      fontSize: 30, fontWeight: FontWeight.w600, height: 1.3, letterSpacing: -0.3);
  static TextStyle get h2 => PangolinFonts.sora(
      fontSize: 24, fontWeight: FontWeight.w600, height: 1.3, letterSpacing: -0.24);
  static TextStyle get h3 => PangolinFonts.manrope(
      fontSize: 20, fontWeight: FontWeight.w600, height: 1.3);
  static TextStyle get bodyLg => PangolinFonts.manrope(
      fontSize: 18, fontWeight: FontWeight.w400, height: 1.65);
  static TextStyle get body => PangolinFonts.manrope(
      fontSize: 16, fontWeight: FontWeight.w400, height: 1.5);
  static TextStyle get sm => PangolinFonts.manrope(
      fontSize: 14, fontWeight: FontWeight.w400, height: 1.5);
  static TextStyle get caption => PangolinFonts.manrope(
      fontSize: 12, fontWeight: FontWeight.w500, height: 1.5);
  static TextStyle get overline => PangolinFonts.manrope(
      fontSize: 12, fontWeight: FontWeight.w600, letterSpacing: 0.96);
  static TextStyle get mono => PangolinFonts.jetBrainsMono(
      fontSize: 14, fontWeight: FontWeight.w400,
      fontFeatures: const [FontFeature.tabularFigures()]);
}

/// ── Ready-to-use ThemeData ──────────────────────────────────────────
class PangolinTheme {
  PangolinTheme._();

  static ThemeData get light => _build(PangolinScheme.light, Brightness.light);
  static ThemeData get dark => _build(PangolinScheme.dark, Brightness.dark);

  static ThemeData _build(PangolinScheme s, Brightness b) {
    final scheme = ColorScheme(
      brightness: b,
      primary: s.accent,
      onPrimary: s.fgOnAccent,
      secondary: s.accent,
      onSecondary: s.fgOnAccent,
      error: s.danger,
      onError: PangolinColors.white,
      surface: s.surface,
      onSurface: s.fg1,
    );
    return ThemeData(
      useMaterial3: true,
      brightness: b,
      colorScheme: scheme,
      scaffoldBackgroundColor: s.bg,
      // Manrope app-wide base font（生产 google_fonts / 测试 bundled）
      textTheme: PangolinFonts.manropeTextTheme(
        ThemeData(brightness: b).textTheme,
      ),
      extensions: [s],
      filledButtonTheme: FilledButtonThemeData(
        style: FilledButton.styleFrom(
          backgroundColor: s.accent,
          foregroundColor: s.fgOnAccent,
          textStyle: PangolinFonts.manrope(fontWeight: FontWeight.w600, fontSize: 15),
          shape: const StadiumBorder(),
          padding: const EdgeInsets.symmetric(horizontal: 22, vertical: 14),
        ),
      ),
      cardTheme: CardThemeData(
        color: s.surface,
        elevation: 0,
        shape: RoundedRectangleBorder(
          side: BorderSide(color: s.border),
          borderRadius: BorderRadius.circular(PangolinRadius.lg),
        ),
      ),
      inputDecorationTheme: InputDecorationTheme(
        filled: true,
        fillColor: s.bg,
        border: OutlineInputBorder(
          borderRadius: BorderRadius.circular(PangolinRadius.md),
          borderSide: BorderSide(color: s.borderStrong, width: 1.5),
        ),
        focusedBorder: OutlineInputBorder(
          borderRadius: BorderRadius.circular(PangolinRadius.md),
          borderSide: BorderSide(color: s.accent, width: 1.5),
        ),
      ),
    );
  }
}
