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

class AppColors {
  // Brand colors (stable across light/dark)
  static const primary = Color(0xFF1A56DB);
  static const primaryLight = Color(0xFF3B82F6);
  static const primaryDark = Color(0xFF1E40AF);
  static const accent = Color(0xFF00C9A7);
  static const accentLight = Color(0xFF6EE7B7);
  static const error = Color(0xFFEF4444);
  static const warning = Color(0xFFF59E0B);
  static const success = Color(0xFF10B981);
  static const gradientStart = Color(0xFF1A56DB);
  static const gradientEnd = Color(0xFF00C9A7);
  static const chatUserBubble = Color(0xFF1A56DB);
  static const scanOverlay = Color(0x801A56DB);

  // Light palette (raw values)
  static const _lightBackground = Color(0xFFF8FAFC);
  static const _lightSurface = Color(0xFFFFFFFF);
  static const _lightTextPrimary = Color(0xFF1E293B);
  static const _lightTextSecondary = Color(0xFF64748B);
  static const _lightTextTertiary = Color(0xFF94A3B8);
  static const _lightDivider = Color(0xFFE2E8F0);
  static const _lightCardShadow = Color(0x1A000000);
  static const _lightChatAiBubble = Color(0xFFF1F5F9);

  // Dark palette (raw values)
  static const _darkBackground = Color(0xFF0F172A);
  static const _darkSurface = Color(0xFF1E293B);
  static const _darkTextPrimary = Color(0xFFE2E8F0);
  static const _darkTextSecondary = Color(0xFF94A3B8);
  static const _darkTextTertiary = Color(0xFF64748B);
  static const _darkDivider = Color(0xFF334155);
  static const _darkCardShadow = Color(0x40000000);
  static const _darkChatAiBubble = Color(0xFF1E293B);

  // Mutable references — flipped at runtime via applyMode.
  static Color background = _lightBackground;
  static Color surface = _lightSurface;
  static Color textPrimary = _lightTextPrimary;
  static Color textSecondary = _lightTextSecondary;
  static Color textTertiary = _lightTextTertiary;
  static Color divider = _lightDivider;
  static Color cardShadow = _lightCardShadow;
  static Color chatAiBubble = _lightChatAiBubble;
  static bool isDark = false;

  static void applyMode(bool dark) {
    isDark = dark;
    if (dark) {
      background = _darkBackground;
      surface = _darkSurface;
      textPrimary = _darkTextPrimary;
      textSecondary = _darkTextSecondary;
      textTertiary = _darkTextTertiary;
      divider = _darkDivider;
      cardShadow = _darkCardShadow;
      chatAiBubble = _darkChatAiBubble;
    } else {
      background = _lightBackground;
      surface = _lightSurface;
      textPrimary = _lightTextPrimary;
      textSecondary = _lightTextSecondary;
      textTertiary = _lightTextTertiary;
      divider = _lightDivider;
      cardShadow = _lightCardShadow;
      chatAiBubble = _lightChatAiBubble;
    }
  }
}

class AppTheme {
  static ThemeData get theme {
    final dark = AppColors.isDark;
    return ThemeData(
      useMaterial3: true,
      brightness: dark ? Brightness.dark : Brightness.light,
      colorScheme: dark
          ? ColorScheme.dark(
              primary: AppColors.primaryLight,
              onPrimary: Colors.white,
              secondary: AppColors.accent,
              onSecondary: Colors.white,
              surface: AppColors.surface,
              onSurface: AppColors.textPrimary,
              error: AppColors.error,
              onError: Colors.white,
              background: AppColors.background,
              onBackground: AppColors.textPrimary,
            )
          : ColorScheme.light(
              primary: AppColors.primary,
              onPrimary: Colors.white,
              secondary: AppColors.accent,
              onSecondary: Colors.white,
              surface: AppColors.surface,
              onSurface: AppColors.textPrimary,
              error: AppColors.error,
              onError: Colors.white,
              background: AppColors.background,
              onBackground: AppColors.textPrimary,
            ),
      scaffoldBackgroundColor: AppColors.background,
      textTheme: GoogleFonts.notoSansScTextTheme().copyWith(
        displayLarge: GoogleFonts.notoSansSc(
          fontSize: 32, fontWeight: FontWeight.bold, color: AppColors.textPrimary,
        ),
        displayMedium: GoogleFonts.notoSansSc(
          fontSize: 24, fontWeight: FontWeight.bold, color: AppColors.textPrimary,
        ),
        titleLarge: GoogleFonts.notoSansSc(
          fontSize: 20, fontWeight: FontWeight.w600, color: AppColors.textPrimary,
        ),
        titleMedium: GoogleFonts.notoSansSc(
          fontSize: 16, fontWeight: FontWeight.w600, color: AppColors.textPrimary,
        ),
        bodyLarge: GoogleFonts.notoSansSc(
          fontSize: 16, color: AppColors.textPrimary,
        ),
        bodyMedium: GoogleFonts.notoSansSc(
          fontSize: 14, color: AppColors.textSecondary,
        ),
        labelLarge: GoogleFonts.notoSansSc(
          fontSize: 14, fontWeight: FontWeight.w500,
        ),
      ),
      appBarTheme: AppBarTheme(
        elevation: 0,
        centerTitle: true,
        backgroundColor: AppColors.surface,
        foregroundColor: AppColors.textPrimary,
        systemOverlayStyle:
            dark ? SystemUiOverlayStyle.light : SystemUiOverlayStyle.dark,
        titleTextStyle: GoogleFonts.notoSansSc(
          fontSize: 18, fontWeight: FontWeight.w600, color: AppColors.textPrimary,
        ),
      ),
      cardTheme: CardThemeData(
        elevation: 0,
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(16),
        ),
        color: AppColors.surface,
      ),
      inputDecorationTheme: InputDecorationTheme(
        filled: true,
        fillColor: AppColors.background,
        border: OutlineInputBorder(
          borderRadius: BorderRadius.circular(12),
          borderSide: BorderSide.none,
        ),
        enabledBorder: OutlineInputBorder(
          borderRadius: BorderRadius.circular(12),
          borderSide: BorderSide.none,
        ),
        focusedBorder: OutlineInputBorder(
          borderRadius: BorderRadius.circular(12),
          borderSide: const BorderSide(color: AppColors.primary, width: 1.5),
        ),
        errorBorder: OutlineInputBorder(
          borderRadius: BorderRadius.circular(12),
          borderSide: const BorderSide(color: AppColors.error, width: 1),
        ),
        contentPadding: const EdgeInsets.symmetric(horizontal: 16, vertical: 14),
        hintStyle: GoogleFonts.notoSansSc(
          fontSize: 14, color: AppColors.textTertiary,
        ),
      ),
      elevatedButtonTheme: ElevatedButtonThemeData(
        style: ElevatedButton.styleFrom(
          elevation: 0,
          padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 14),
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(12),
          ),
          backgroundColor: AppColors.primary,
          foregroundColor: Colors.white,
          textStyle: GoogleFonts.notoSansSc(
            fontSize: 16, fontWeight: FontWeight.w600,
          ),
        ),
      ),
      outlinedButtonTheme: OutlinedButtonThemeData(
        style: OutlinedButton.styleFrom(
          padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 14),
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(12),
          ),
          side: const BorderSide(color: AppColors.primary),
          foregroundColor: AppColors.primary,
          textStyle: GoogleFonts.notoSansSc(
            fontSize: 14, fontWeight: FontWeight.w500,
          ),
        ),
      ),
      textButtonTheme: TextButtonThemeData(
        style: TextButton.styleFrom(
          foregroundColor: AppColors.primary,
          textStyle: GoogleFonts.notoSansSc(
            fontSize: 14, fontWeight: FontWeight.w500,
          ),
        ),
      ),
      floatingActionButtonTheme: const FloatingActionButtonThemeData(
        backgroundColor: AppColors.primary,
        foregroundColor: Colors.white,
        elevation: 4,
      ),
      bottomNavigationBarTheme: BottomNavigationBarThemeData(
        backgroundColor: AppColors.surface,
        selectedItemColor: AppColors.primary,
        unselectedItemColor: AppColors.textTertiary,
        type: BottomNavigationBarType.fixed,
        elevation: 8,
      ),
      chipTheme: ChipThemeData(
        backgroundColor: AppColors.background,
        selectedColor: AppColors.primary.withOpacity(0.1),
        labelStyle: GoogleFonts.notoSansSc(fontSize: 12),
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(8),
        ),
      ),
      dividerTheme: DividerThemeData(
        color: AppColors.divider,
        thickness: 1,
        space: 1,
      ),
      tabBarTheme: TabBarThemeData(
        labelColor: AppColors.primary,
        unselectedLabelColor: AppColors.textSecondary,
        labelStyle: GoogleFonts.notoSansSc(
          fontSize: 14, fontWeight: FontWeight.w600,
        ),
        unselectedLabelStyle: GoogleFonts.notoSansSc(
          fontSize: 14, fontWeight: FontWeight.w400,
        ),
        indicatorSize: TabBarIndicatorSize.tab,
      ),
    );
  }
}

class AppGradients {
  // Light: bright brand blue → teal. Dark: deeper, more subdued.
  static const _lightStart = Color(0xFF1A56DB);
  static const _lightEnd = Color(0xFF00C9A7);
  static const _darkStart = Color(0xFF1E3A8A);
  static const _darkEnd = Color(0xFF0F766E);

  static LinearGradient get primary => LinearGradient(
        colors: AppColors.isDark
            ? const [_darkStart, _darkEnd]
            : const [_lightStart, _lightEnd],
        begin: Alignment.topLeft,
        end: Alignment.bottomRight,
      );

  static const card = LinearGradient(
    colors: [Color(0xFF1A56DB), Color(0xFF2563EB)],
    begin: Alignment.topLeft,
    end: Alignment.bottomRight,
  );

  static const shimmer = LinearGradient(
    colors: [Color(0xFFE2E8F0), Color(0xFFF1F5F9), Color(0xFFE2E8F0)],
    stops: [0.0, 0.5, 1.0],
    begin: Alignment(-1.0, -0.3),
    end: Alignment(1.0, 0.3),
  );
}

class AppAnimations {
  static const defaultDuration = Duration(milliseconds: 300);
  static const slowDuration = Duration(milliseconds: 500);
  static const fastDuration = Duration(milliseconds: 150);

  static Widget fadeSlide(Widget child, {int delay = 0}) {
    return child
        .animate()
        .fadeIn(duration: defaultDuration, delay: Duration(milliseconds: delay))
        .slideY(begin: 0.2, end: 0, duration: defaultDuration, delay: Duration(milliseconds: delay));
  }

  static Widget scaleIn(Widget child, {int delay = 0}) {
    return child
        .animate()
        .scale(begin: const Offset(0.9, 0.9), duration: defaultDuration, delay: Duration(milliseconds: delay))
        .fadeIn(duration: defaultDuration, delay: Duration(milliseconds: delay));
  }
}