import 'package:flutter/material.dart';

/// Design tokens and theme construction for Bible Tracker.
///
/// Refer to `DESIGN_GUIDE.md` for the rationale behind each token.
class AppTokens {
  const AppTokens._();

  // Seed color — warm, scripture-inspired indigo.
  static const Color seed = Color(0xFF3F51B5);

  // Default palette offered when creating a new tracker.
  static const List<Color> trackerPalette = <Color>[
    Color(0xFF3F51B5), // indigo
    Color(0xFF1E88E5), // blue
    Color(0xFF00897B), // teal
    Color(0xFF43A047), // green
    Color(0xFFFDD835), // amber
    Color(0xFFFB8C00), // orange
    Color(0xFFE53935), // red
    Color(0xFFD81B60), // pink
    Color(0xFF8E24AA), // purple
    Color(0xFF6D4C41), // brown
  ];

  // Spacing scale (8pt grid).
  static const double spaceXS = 4;
  static const double spaceS = 8;
  static const double spaceM = 12;
  static const double spaceL = 16;
  static const double spaceXL = 24;
  static const double spaceXXL = 32;

  // Radius scale.
  static const double radiusS = 8;
  static const double radiusM = 12;
  static const double radiusL = 16;
}

class AppTheme {
  const AppTheme._();

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

  static ThemeData _build(Brightness brightness) {
    final ColorScheme scheme = ColorScheme.fromSeed(
      seedColor: AppTokens.seed,
      brightness: brightness,
    );
    return ThemeData(
      useMaterial3: true,
      colorScheme: scheme,
      scaffoldBackgroundColor: scheme.surface,
      appBarTheme: AppBarTheme(
        backgroundColor: scheme.surface,
        foregroundColor: scheme.onSurface,
        elevation: 0,
        centerTitle: false,
        titleTextStyle: TextStyle(
          color: scheme.onSurface,
          fontSize: 20,
          fontWeight: FontWeight.w600,
        ),
      ),
      cardTheme: CardThemeData(
        color: scheme.surfaceContainerHigh,
        elevation: 0,
        margin: EdgeInsets.zero,
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(AppTokens.radiusM),
        ),
      ),
      listTileTheme: const ListTileThemeData(
        contentPadding: EdgeInsets.symmetric(
          horizontal: AppTokens.spaceL,
          vertical: AppTokens.spaceS,
        ),
      ),
      dividerTheme: DividerThemeData(
        color: scheme.outlineVariant,
        thickness: 0.5,
        space: 0,
      ),
      filledButtonTheme: FilledButtonThemeData(
        style: FilledButton.styleFrom(
          padding: const EdgeInsets.symmetric(
            horizontal: AppTokens.spaceXL,
            vertical: AppTokens.spaceM,
          ),
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(AppTokens.radiusS),
          ),
        ),
      ),
      progressIndicatorTheme: ProgressIndicatorThemeData(
        linearTrackColor: scheme.surfaceContainerHighest,
      ),
    );
  }
}