import 'package:flutter/material.dart';

/// Toss-inspired palette (unofficial — evokes clean fintech / super-app UI).
abstract final class TossColors {
  static const Color blue = Color(0xFF3182F6);
  static const Color blueDark = Color(0xFF1B64DA);
  static const Color bg = Color(0xFFF2F4F6);
  static const Color surface = Color(0xFFFFFFFF);
  static const Color textPrimary = Color(0xFF191F28);
  static const Color textSecondary = Color(0xFF8B95A1);
  static const Color line = Color(0xFFE5E8EB);
  static const Color inputFill = Color(0xFFF2F4F6);
}

/// Global theme: light, high whitespace, blue CTAs.
ThemeData buildTossTheme() {
  const primary = TossColors.blue;
  const colorScheme = ColorScheme.light(
    primary: primary,
    onPrimary: Colors.white,
    primaryContainer: Color(0xFFE8F3FF),
    onPrimaryContainer: TossColors.blueDark,
    surface: TossColors.surface,
    onSurface: TossColors.textPrimary,
    onSurfaceVariant: TossColors.textSecondary,
    outline: TossColors.line,
    error: Color(0xFFF04452),
    onError: Colors.white,
  );

  final base = ThemeData.light();
  return ThemeData(
    useMaterial3: true,
    colorScheme: colorScheme,
    scaffoldBackgroundColor: TossColors.bg,
    splashFactory: InkRipple.splashFactory,
    textTheme: base.textTheme.copyWith(
      headlineLarge: const TextStyle(
        fontSize: 28,
        fontWeight: FontWeight.w700,
        height: 1.25,
        letterSpacing: -0.5,
        color: TossColors.textPrimary,
      ),
      headlineMedium: const TextStyle(
        fontSize: 22,
        fontWeight: FontWeight.w700,
        height: 1.3,
        color: TossColors.textPrimary,
      ),
      titleLarge: const TextStyle(
        fontSize: 20,
        fontWeight: FontWeight.w700,
        color: TossColors.textPrimary,
      ),
      titleMedium: const TextStyle(
        fontSize: 17,
        fontWeight: FontWeight.w600,
        color: TossColors.textPrimary,
      ),
      titleSmall: const TextStyle(
        fontSize: 15,
        fontWeight: FontWeight.w600,
        color: TossColors.textPrimary,
      ),
      bodyLarge: const TextStyle(
        fontSize: 16,
        height: 1.45,
        color: TossColors.textPrimary,
      ),
      bodyMedium: const TextStyle(
        fontSize: 15,
        height: 1.45,
        color: TossColors.textSecondary,
      ),
      bodySmall: const TextStyle(
        fontSize: 13,
        height: 1.4,
        color: TossColors.textSecondary,
      ),
      labelLarge: const TextStyle(
        fontSize: 16,
        fontWeight: FontWeight.w600,
        color: TossColors.textPrimary,
      ),
    ),
    appBarTheme: const AppBarTheme(
      elevation: 0,
      scrolledUnderElevation: 0,
      centerTitle: false,
      backgroundColor: TossColors.surface,
      foregroundColor: TossColors.textPrimary,
      titleTextStyle: TextStyle(
        fontSize: 20,
        fontWeight: FontWeight.w700,
        color: TossColors.textPrimary,
      ),
      iconTheme: IconThemeData(color: TossColors.textPrimary, size: 22),
    ),
    cardTheme: CardThemeData(
      color: TossColors.surface,
      elevation: 0,
      shadowColor: Colors.black.withValues(alpha: 0.06),
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(16)),
      margin: EdgeInsets.zero,
    ),
    inputDecorationTheme: InputDecorationTheme(
      filled: true,
      fillColor: TossColors.inputFill,
      contentPadding: const EdgeInsets.symmetric(horizontal: 16, vertical: 16),
      hintStyle: const TextStyle(color: TossColors.textSecondary, fontSize: 16),
      labelStyle: const TextStyle(color: TossColors.textSecondary, fontSize: 14),
      border: OutlineInputBorder(
        borderRadius: BorderRadius.circular(14),
        borderSide: BorderSide.none,
      ),
      enabledBorder: OutlineInputBorder(
        borderRadius: BorderRadius.circular(14),
        borderSide: BorderSide.none,
      ),
      focusedBorder: OutlineInputBorder(
        borderRadius: BorderRadius.circular(14),
        borderSide: const BorderSide(color: TossColors.blue, width: 1.5),
      ),
      errorBorder: OutlineInputBorder(
        borderRadius: BorderRadius.circular(14),
        borderSide: BorderSide(color: colorScheme.error.withValues(alpha: 0.8)),
      ),
    ),
    filledButtonTheme: FilledButtonThemeData(
      style: FilledButton.styleFrom(
        backgroundColor: primary,
        foregroundColor: Colors.white,
        disabledBackgroundColor: TossColors.line,
        disabledForegroundColor: TossColors.textSecondary,
        padding: const EdgeInsets.symmetric(vertical: 16, horizontal: 24),
        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
        textStyle: const TextStyle(fontSize: 17, fontWeight: FontWeight.w600),
        elevation: 0,
      ),
    ),
    outlinedButtonTheme: OutlinedButtonThemeData(
      style: OutlinedButton.styleFrom(
        foregroundColor: primary,
        side: const BorderSide(color: TossColors.line),
        padding: const EdgeInsets.symmetric(vertical: 14, horizontal: 20),
        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
      ),
    ),
    textButtonTheme: TextButtonThemeData(
      style: TextButton.styleFrom(
        foregroundColor: TossColors.textSecondary,
        textStyle: const TextStyle(fontSize: 15, fontWeight: FontWeight.w500),
      ),
    ),
    floatingActionButtonTheme: const FloatingActionButtonThemeData(
      backgroundColor: TossColors.blue,
      foregroundColor: Colors.white,
      elevation: 2,
      shape: CircleBorder(),
    ),
    dividerTheme: const DividerThemeData(color: TossColors.line, thickness: 1),
  );
}