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

/// A class that contains all theme configurations for the application.
/// Implements "Purposeful Transit Minimalism" design system with high-contrast utility colors.
class AppTheme {
  AppTheme._();

  // Core color palette - High-Contrast Utility for Panama's bright outdoor conditions
  static const Color primaryBlack = Color(0xFF101820);
  static const Color accentYellow = Color(0xFFFEE715);
  static const Color surfaceWhite = Color(0xFFFFFFFF);
  static const Color textSecondary = Color(0xFF6B7280);
  static const Color successGreen = Color(0xFF10B981);
  static const Color warningOrange = Color(0xFFF59E0B);
  static const Color errorRed = Color(0xFFEF4444);
  static const Color backgroundGray = Color(0xFFF9FAFB);
  static const Color borderLight = Color(0xFFE5E7EB);
  static const Color overlayDark = Color(0x1F2937CC);

  // Text emphasis colors for light theme
  static const Color textHighEmphasisLight = Color(0xFF101820); // Primary black
  static const Color textMediumEmphasisLight =
      Color(0xFF6B7280); // Text secondary
  static const Color textDisabledLight = Color(0xFFE5E7EB); // Border light

  // Text emphasis colors for dark theme
  static const Color textHighEmphasisDark = Color(0xFFFFFFFF);
  static const Color textMediumEmphasisDark = Color(0xFF9CA3AF);
  static const Color textDisabledDark = Color(0xFF6B7280);

  // Shadow colors for subtle elevation
  static const Color shadowLight =
      Color(0x33000000); // 20% opacity black for 2-4dp blur
  static const Color shadowDark = Color(0x33FFFFFF); // 20% opacity white

  /// Light theme - Optimized for Panama's bright outdoor conditions
  static ThemeData lightTheme = ThemeData(
    brightness: Brightness.light,
    colorScheme: ColorScheme(
      brightness: Brightness.light,
      primary: primaryBlack,
      onPrimary: surfaceWhite,
      primaryContainer: textSecondary,
      onPrimaryContainer: surfaceWhite,
      secondary: accentYellow,
      onSecondary: primaryBlack,
      secondaryContainer: warningOrange,
      onSecondaryContainer: primaryBlack,
      tertiary: successGreen,
      onTertiary: surfaceWhite,
      tertiaryContainer: successGreen,
      onTertiaryContainer: surfaceWhite,
      error: errorRed,
      onError: surfaceWhite,
      surface: surfaceWhite,
      onSurface: primaryBlack,
      onSurfaceVariant: textSecondary,
      outline: borderLight,
      outlineVariant: borderLight,
      shadow: shadowLight,
      scrim: overlayDark,
      inverseSurface: primaryBlack,
      onInverseSurface: surfaceWhite,
      inversePrimary: accentYellow,
    ),
    scaffoldBackgroundColor: backgroundGray,
    cardColor: surfaceWhite,
    dividerColor: borderLight,

    // AppBar theme - Clean, minimal header
    appBarTheme: AppBarTheme(
      backgroundColor: surfaceWhite,
      foregroundColor: primaryBlack,
      elevation: 0,
      shadowColor: shadowLight,
      surfaceTintColor: Colors.transparent,
      titleTextStyle: GoogleFonts.roboto(
        fontSize: 20,
        fontWeight: FontWeight.w500,
        color: primaryBlack,
      ),
      iconTheme: const IconThemeData(
        color: primaryBlack,
        size: 24,
      ),
    ),

    // Card theme - Clean separation without borders
    cardTheme: CardThemeData(
      color: surfaceWhite,
      elevation: 2.0,
      shadowColor: shadowLight,
      surfaceTintColor: Colors.transparent,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(12.0),
      ),
      margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
    ),

    // Bottom navigation - Persistent state with contextual badges
    bottomNavigationBarTheme: BottomNavigationBarThemeData(
      backgroundColor: surfaceWhite,
      selectedItemColor: primaryBlack,
      unselectedItemColor: textSecondary,
      type: BottomNavigationBarType.fixed,
      elevation: 8,
      selectedLabelStyle: GoogleFonts.openSans(
        fontSize: 12,
        fontWeight: FontWeight.w600,
      ),
      unselectedLabelStyle: GoogleFonts.openSans(
        fontSize: 12,
        fontWeight: FontWeight.w400,
      ),
    ),

    // Floating action button - High contrast accent
    floatingActionButtonTheme: const FloatingActionButtonThemeData(
      backgroundColor: accentYellow,
      foregroundColor: primaryBlack,
      elevation: 4.0,
      shape: CircleBorder(),
    ),

    // Button themes - Clear action hierarchy
    elevatedButtonTheme: ElevatedButtonThemeData(
      style: ElevatedButton.styleFrom(
        foregroundColor: primaryBlack,
        backgroundColor: accentYellow,
        elevation: 0,
        padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 16),
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(8.0),
        ),
        textStyle: GoogleFonts.openSans(
          fontSize: 16,
          fontWeight: FontWeight.w600,
        ),
      ),
    ),

    outlinedButtonTheme: OutlinedButtonThemeData(
      style: OutlinedButton.styleFrom(
        foregroundColor: primaryBlack,
        backgroundColor: Colors.transparent,
        padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 16),
        side: const BorderSide(color: primaryBlack, width: 1),
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(8.0),
        ),
        textStyle: GoogleFonts.openSans(
          fontSize: 16,
          fontWeight: FontWeight.w600,
        ),
      ),
    ),

    textButtonTheme: TextButtonThemeData(
      style: TextButton.styleFrom(
        foregroundColor: primaryBlack,
        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(8.0),
        ),
        textStyle: GoogleFonts.openSans(
          fontSize: 16,
          fontWeight: FontWeight.w600,
        ),
      ),
    ),

    // Typography - Optimized for Spanish character support and mobile readability
    textTheme: _buildTextTheme(isLight: true),

    // Input decoration - Clean form elements with clear focus states
    inputDecorationTheme: InputDecorationTheme(
      fillColor: surfaceWhite,
      filled: true,
      contentPadding: const EdgeInsets.symmetric(horizontal: 16, vertical: 16),
      border: OutlineInputBorder(
        borderRadius: BorderRadius.circular(8.0),
        borderSide: const BorderSide(color: borderLight, width: 1),
      ),
      enabledBorder: OutlineInputBorder(
        borderRadius: BorderRadius.circular(8.0),
        borderSide: const BorderSide(color: borderLight, width: 1),
      ),
      focusedBorder: OutlineInputBorder(
        borderRadius: BorderRadius.circular(8.0),
        borderSide: const BorderSide(color: primaryBlack, width: 2),
      ),
      errorBorder: OutlineInputBorder(
        borderRadius: BorderRadius.circular(8.0),
        borderSide: const BorderSide(color: errorRed, width: 1),
      ),
      focusedErrorBorder: OutlineInputBorder(
        borderRadius: BorderRadius.circular(8.0),
        borderSide: const BorderSide(color: errorRed, width: 2),
      ),
      labelStyle: GoogleFonts.openSans(
        color: textSecondary,
        fontSize: 16,
        fontWeight: FontWeight.w400,
      ),
      hintStyle: GoogleFonts.openSans(
        color: textDisabledLight,
        fontSize: 16,
        fontWeight: FontWeight.w400,
      ),
    ),

    // Interactive elements
    switchTheme: SwitchThemeData(
      thumbColor: WidgetStateProperty.resolveWith((states) {
        if (states.contains(WidgetState.selected)) {
          return accentYellow;
        }
        return borderLight;
      }),
      trackColor: WidgetStateProperty.resolveWith((states) {
        if (states.contains(WidgetState.selected)) {
          return primaryBlack;
        }
        return textSecondary;
      }),
    ),

    checkboxTheme: CheckboxThemeData(
      fillColor: WidgetStateProperty.resolveWith((states) {
        if (states.contains(WidgetState.selected)) {
          return primaryBlack;
        }
        return Colors.transparent;
      }),
      checkColor: WidgetStateProperty.all(accentYellow),
      side: const BorderSide(color: borderLight, width: 1),
    ),

    radioTheme: RadioThemeData(
      fillColor: WidgetStateProperty.resolveWith((states) {
        if (states.contains(WidgetState.selected)) {
          return primaryBlack;
        }
        return textSecondary;
      }),
    ),

    progressIndicatorTheme: const ProgressIndicatorThemeData(
      color: primaryBlack,
      linearTrackColor: borderLight,
    ),

    sliderTheme: SliderThemeData(
      activeTrackColor: primaryBlack,
      thumbColor: accentYellow,
      overlayColor: accentYellow.withValues(alpha: 0.2),
      inactiveTrackColor: borderLight,
    ),

    tabBarTheme: TabBarThemeData(
      labelColor: primaryBlack,
      unselectedLabelColor: textSecondary,
      indicatorColor: accentYellow,
      indicatorSize: TabBarIndicatorSize.tab,
      labelStyle: GoogleFonts.roboto(
        fontSize: 16,
        fontWeight: FontWeight.w500,
      ),
      unselectedLabelStyle: GoogleFonts.roboto(
        fontSize: 16,
        fontWeight: FontWeight.w400,
      ),
    ),

    tooltipTheme: TooltipThemeData(
      decoration: BoxDecoration(
        color: primaryBlack,
        borderRadius: BorderRadius.circular(8),
      ),
      textStyle: GoogleFonts.openSans(
        color: surfaceWhite,
        fontSize: 14,
        fontWeight: FontWeight.w400,
      ),
    ),

    snackBarTheme: SnackBarThemeData(
      backgroundColor: primaryBlack,
      contentTextStyle: GoogleFonts.openSans(
        color: surfaceWhite,
        fontSize: 16,
        fontWeight: FontWeight.w400,
      ),
      actionTextColor: accentYellow,
      behavior: SnackBarBehavior.floating,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(8.0),
      ),
      elevation: 4,
    ), dialogTheme: DialogThemeData(backgroundColor: surfaceWhite),
  );

  /// Dark theme - Maintains high contrast for nighttime use
  static ThemeData darkTheme = ThemeData(
    brightness: Brightness.dark,
    colorScheme: ColorScheme(
      brightness: Brightness.dark,
      primary: accentYellow,
      onPrimary: primaryBlack,
      primaryContainer: warningOrange,
      onPrimaryContainer: primaryBlack,
      secondary: primaryBlack,
      onSecondary: surfaceWhite,
      secondaryContainer: textSecondary,
      onSecondaryContainer: surfaceWhite,
      tertiary: successGreen,
      onTertiary: primaryBlack,
      tertiaryContainer: successGreen,
      onTertiaryContainer: primaryBlack,
      error: errorRed,
      onError: surfaceWhite,
      surface: primaryBlack,
      onSurface: surfaceWhite,
      onSurfaceVariant: textMediumEmphasisDark,
      outline: textSecondary,
      outlineVariant: textSecondary,
      shadow: shadowDark,
      scrim: overlayDark,
      inverseSurface: surfaceWhite,
      onInverseSurface: primaryBlack,
      inversePrimary: primaryBlack,
    ),
    scaffoldBackgroundColor: primaryBlack,
    cardColor: Color(0xFF1F2937),
    dividerColor: textSecondary,
    appBarTheme: AppBarTheme(
      backgroundColor: primaryBlack,
      foregroundColor: surfaceWhite,
      elevation: 0,
      shadowColor: shadowDark,
      surfaceTintColor: Colors.transparent,
      titleTextStyle: GoogleFonts.roboto(
        fontSize: 20,
        fontWeight: FontWeight.w500,
        color: surfaceWhite,
      ),
      iconTheme: const IconThemeData(
        color: surfaceWhite,
        size: 24,
      ),
    ),
    cardTheme: CardThemeData(
      color: Color(0xFF1F2937),
      elevation: 2.0,
      shadowColor: shadowDark,
      surfaceTintColor: Colors.transparent,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(12.0),
      ),
      margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
    ),
    bottomNavigationBarTheme: BottomNavigationBarThemeData(
      backgroundColor: primaryBlack,
      selectedItemColor: accentYellow,
      unselectedItemColor: textMediumEmphasisDark,
      type: BottomNavigationBarType.fixed,
      elevation: 8,
      selectedLabelStyle: GoogleFonts.openSans(
        fontSize: 12,
        fontWeight: FontWeight.w600,
      ),
      unselectedLabelStyle: GoogleFonts.openSans(
        fontSize: 12,
        fontWeight: FontWeight.w400,
      ),
    ),
    floatingActionButtonTheme: const FloatingActionButtonThemeData(
      backgroundColor: accentYellow,
      foregroundColor: primaryBlack,
      elevation: 4.0,
      shape: CircleBorder(),
    ),
    elevatedButtonTheme: ElevatedButtonThemeData(
      style: ElevatedButton.styleFrom(
        foregroundColor: primaryBlack,
        backgroundColor: accentYellow,
        elevation: 0,
        padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 16),
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(8.0),
        ),
        textStyle: GoogleFonts.openSans(
          fontSize: 16,
          fontWeight: FontWeight.w600,
        ),
      ),
    ),
    outlinedButtonTheme: OutlinedButtonThemeData(
      style: OutlinedButton.styleFrom(
        foregroundColor: accentYellow,
        backgroundColor: Colors.transparent,
        padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 16),
        side: const BorderSide(color: accentYellow, width: 1),
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(8.0),
        ),
        textStyle: GoogleFonts.openSans(
          fontSize: 16,
          fontWeight: FontWeight.w600,
        ),
      ),
    ),
    textButtonTheme: TextButtonThemeData(
      style: TextButton.styleFrom(
        foregroundColor: accentYellow,
        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(8.0),
        ),
        textStyle: GoogleFonts.openSans(
          fontSize: 16,
          fontWeight: FontWeight.w600,
        ),
      ),
    ),
    textTheme: _buildTextTheme(isLight: false),
    inputDecorationTheme: InputDecorationTheme(
      fillColor: Color(0xFF1F2937),
      filled: true,
      contentPadding: const EdgeInsets.symmetric(horizontal: 16, vertical: 16),
      border: OutlineInputBorder(
        borderRadius: BorderRadius.circular(8.0),
        borderSide: const BorderSide(color: textSecondary, width: 1),
      ),
      enabledBorder: OutlineInputBorder(
        borderRadius: BorderRadius.circular(8.0),
        borderSide: const BorderSide(color: textSecondary, width: 1),
      ),
      focusedBorder: OutlineInputBorder(
        borderRadius: BorderRadius.circular(8.0),
        borderSide: const BorderSide(color: accentYellow, width: 2),
      ),
      errorBorder: OutlineInputBorder(
        borderRadius: BorderRadius.circular(8.0),
        borderSide: const BorderSide(color: errorRed, width: 1),
      ),
      focusedErrorBorder: OutlineInputBorder(
        borderRadius: BorderRadius.circular(8.0),
        borderSide: const BorderSide(color: errorRed, width: 2),
      ),
      labelStyle: GoogleFonts.openSans(
        color: textMediumEmphasisDark,
        fontSize: 16,
        fontWeight: FontWeight.w400,
      ),
      hintStyle: GoogleFonts.openSans(
        color: textDisabledDark,
        fontSize: 16,
        fontWeight: FontWeight.w400,
      ),
    ),
    switchTheme: SwitchThemeData(
      thumbColor: WidgetStateProperty.resolveWith((states) {
        if (states.contains(WidgetState.selected)) {
          return accentYellow;
        }
        return textSecondary;
      }),
      trackColor: WidgetStateProperty.resolveWith((states) {
        if (states.contains(WidgetState.selected)) {
          return primaryBlack;
        }
        return textDisabledDark;
      }),
    ),
    checkboxTheme: CheckboxThemeData(
      fillColor: WidgetStateProperty.resolveWith((states) {
        if (states.contains(WidgetState.selected)) {
          return accentYellow;
        }
        return Colors.transparent;
      }),
      checkColor: WidgetStateProperty.all(primaryBlack),
      side: const BorderSide(color: textSecondary, width: 1),
    ),
    radioTheme: RadioThemeData(
      fillColor: WidgetStateProperty.resolveWith((states) {
        if (states.contains(WidgetState.selected)) {
          return accentYellow;
        }
        return textMediumEmphasisDark;
      }),
    ),
    progressIndicatorTheme: const ProgressIndicatorThemeData(
      color: accentYellow,
      linearTrackColor: textSecondary,
    ),
    sliderTheme: SliderThemeData(
      activeTrackColor: accentYellow,
      thumbColor: accentYellow,
      overlayColor: accentYellow.withValues(alpha: 0.2),
      inactiveTrackColor: textSecondary,
    ),
    tabBarTheme: TabBarThemeData(
      labelColor: accentYellow,
      unselectedLabelColor: textMediumEmphasisDark,
      indicatorColor: accentYellow,
      indicatorSize: TabBarIndicatorSize.tab,
      labelStyle: GoogleFonts.roboto(
        fontSize: 16,
        fontWeight: FontWeight.w500,
      ),
      unselectedLabelStyle: GoogleFonts.roboto(
        fontSize: 16,
        fontWeight: FontWeight.w400,
      ),
    ),
    tooltipTheme: TooltipThemeData(
      decoration: BoxDecoration(
        color: surfaceWhite,
        borderRadius: BorderRadius.circular(8),
      ),
      textStyle: GoogleFonts.openSans(
        color: primaryBlack,
        fontSize: 14,
        fontWeight: FontWeight.w400,
      ),
    ),
    snackBarTheme: SnackBarThemeData(
      backgroundColor: surfaceWhite,
      contentTextStyle: GoogleFonts.openSans(
        color: primaryBlack,
        fontSize: 16,
        fontWeight: FontWeight.w400,
      ),
      actionTextColor: primaryBlack,
      behavior: SnackBarBehavior.floating,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(8.0),
      ),
      elevation: 4,
    ), dialogTheme: DialogThemeData(backgroundColor: Color(0xFF1F2937)),
  );

  /// Helper method to build text theme based on brightness
  /// Uses Google Fonts for optimal Spanish character support and mobile readability
  static TextTheme _buildTextTheme({required bool isLight}) {
    final Color textHighEmphasis =
        isLight ? textHighEmphasisLight : textHighEmphasisDark;
    final Color textMediumEmphasis =
        isLight ? textMediumEmphasisLight : textMediumEmphasisDark;
    final Color textDisabled = isLight ? textDisabledLight : textDisabledDark;

    return TextTheme(
      // Display styles - Roboto for strong presence
      displayLarge: GoogleFonts.roboto(
        fontSize: 57,
        fontWeight: FontWeight.w700,
        color: textHighEmphasis,
        letterSpacing: -0.25,
      ),
      displayMedium: GoogleFonts.roboto(
        fontSize: 45,
        fontWeight: FontWeight.w700,
        color: textHighEmphasis,
      ),
      displaySmall: GoogleFonts.roboto(
        fontSize: 36,
        fontWeight: FontWeight.w500,
        color: textHighEmphasis,
      ),

      // Headline styles - Roboto for bus route names and times
      headlineLarge: GoogleFonts.roboto(
        fontSize: 32,
        fontWeight: FontWeight.w500,
        color: textHighEmphasis,
      ),
      headlineMedium: GoogleFonts.roboto(
        fontSize: 28,
        fontWeight: FontWeight.w500,
        color: textHighEmphasis,
      ),
      headlineSmall: GoogleFonts.roboto(
        fontSize: 24,
        fontWeight: FontWeight.w500,
        color: textHighEmphasis,
      ),

      // Title styles - Roboto for section headers
      titleLarge: GoogleFonts.roboto(
        fontSize: 22,
        fontWeight: FontWeight.w500,
        color: textHighEmphasis,
        letterSpacing: 0,
      ),
      titleMedium: GoogleFonts.roboto(
        fontSize: 16,
        fontWeight: FontWeight.w500,
        color: textHighEmphasis,
        letterSpacing: 0.15,
      ),
      titleSmall: GoogleFonts.roboto(
        fontSize: 14,
        fontWeight: FontWeight.w500,
        color: textHighEmphasis,
        letterSpacing: 0.1,
      ),

      // Body styles - Open Sans for extended reading
      bodyLarge: GoogleFonts.openSans(
        fontSize: 16,
        fontWeight: FontWeight.w400,
        color: textHighEmphasis,
        letterSpacing: 0.5,
      ),
      bodyMedium: GoogleFonts.openSans(
        fontSize: 14,
        fontWeight: FontWeight.w400,
        color: textHighEmphasis,
        letterSpacing: 0.25,
      ),
      bodySmall: GoogleFonts.openSans(
        fontSize: 12,
        fontWeight: FontWeight.w400,
        color: textMediumEmphasis,
        letterSpacing: 0.4,
      ),

      // Label styles - Inter for captions and small text
      labelLarge: GoogleFonts.inter(
        fontSize: 14,
        fontWeight: FontWeight.w500,
        color: textHighEmphasis,
        letterSpacing: 0.1,
      ),
      labelMedium: GoogleFonts.inter(
        fontSize: 12,
        fontWeight: FontWeight.w500,
        color: textMediumEmphasis,
        letterSpacing: 0.5,
      ),
      labelSmall: GoogleFonts.inter(
        fontSize: 11,
        fontWeight: FontWeight.w400,
        color: textDisabled,
        letterSpacing: 0.5,
      ),
    );
  }
}