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

class AppConfig {
  // ─── API Configuration ────────────────────────────────────────────────────
  //
  // Dual-Mode Configuration:
  // - If public ngrok is running and active, the app will use it automatically.
  // - If ngrok is down/inactive or unreachable, it falls back to the LAN/Local URL.
  //

  // LAN / WiFi / Emulator URL (port 8000 = nginx gateway)
  // - Physical Device on same Wi-Fi: use 'http://192.168.70.7:8000/api/v1'
  // - Android Emulator: use 'http://10.0.2.2:8000/api/v1'
  // - iOS Simulator: use 'http://localhost:8000/api/v1'
  static const String _lanBaseUrl = 'http://192.168.70.7:8000/api/v1';

  // Ngrok public tunnel URL (update ini setiap ngrok di-restart)
  static const String _ngrokBaseUrl = 'https://unlocated-waylon-potently.ngrok-free.dev/api/v1';

  // Dynamic Base URL determined at startup
  static String apiBaseUrl = _lanBaseUrl;

  /// Dynamic URL resolver: Checks if the Ngrok tunnel is active.
  /// If it returns a valid response (not 502/503/504), we use Ngrok.
  /// Otherwise, we fall back to the LAN/Local base URL.
  static Future<void> initializeApiBaseUrl() async {
    final client = HttpClient();
    client.connectionTimeout = const Duration(seconds: 2);
    try {
      debugPrint('AppConfig: Checking public Ngrok tunnel at $_ngrokBaseUrl/auth/login...');
      final uri = Uri.parse('$_ngrokBaseUrl/auth/login');
      final request = await client.postUrl(uri);
      
      // Add headers to bypass the ngrok browser warning page
      request.headers.add('ngrok-skip-browser-warning', 'true');
      request.headers.contentType = ContentType.json;
      request.write('{}');
      
      final response = await request.close();
      
      final contentType = response.headers.contentType?.mimeType ?? '';
      final ngrokErrorCode = response.headers.value('ngrok-error-code');

      debugPrint('AppConfig: Ngrok response status: ${response.statusCode}, Content-Type: $contentType, Ngrok-Error-Code: $ngrokErrorCode');

      // An active tunnel connected to our backend:
      // 1. Should not return an ngrok-error-code header.
      // 2. The response content-type should be JSON (our login API returns JSON).
      // 3. Status code should not be 502, 503, or 504.
      if (ngrokErrorCode == null && 
          contentType.contains('json') && 
          response.statusCode != 502 && 
          response.statusCode != 503 && 
          response.statusCode != 504) {
        apiBaseUrl = _ngrokBaseUrl;
        debugPrint('AppConfig: Ngrok tunnel is ACTIVE and backend responded. API Base URL: $apiBaseUrl');
        return;
      } else {
        debugPrint('AppConfig: Ngrok is offline, inactive, or returned an error page.');
      }
    } catch (e) {
      debugPrint('AppConfig: Ngrok connection failed or timed out: $e');
    } finally {
      client.close();
    }
    
    apiBaseUrl = _lanBaseUrl;
    debugPrint('AppConfig: Using Local/LAN API Base URL: $apiBaseUrl');
  }

  static const String loginEndpoint = '/auth/login';
  static const String uploadDocumentEndpoint = '/documents/upload';
  static const String fetchDocumentsEndpoint = '/documents';

  
  // App Constants
  static const String appName = 'Prima Mart Scanner';
  static const String appVersion = '1.0.0';

  // Colors - Prima Fresh Mart Theme
  static const Color primaryColor = Color(0xFF6EBE4A); // Prima Green
  static const Color secondaryColor = Color(0xFF005DAA); // Prima Blue
  static const Color accentColor = Color(0xFFFFCC00); // Prima Yellow
  static const Color backgroundColor = Color(0xFFF8F9FA); // Off-white
  static const Color surfaceColor = Colors.white;
  static const Color errorColor = Color(0xFFD32F2F);
  static const Color successColor = Color(0xFF388E3C);
  
  // Text Colors
  static const Color textPrimary = Color(0xFF212121);
  static const Color textSecondary = Color(0xFF757575);
  static const Color textOnPrimary = Colors.white;

  // Typography Config
  // Using Google Fonts - Inter for clean, modern look
  static TextStyle get h1 => GoogleFonts.inter(
        fontSize: 32,
        fontWeight: FontWeight.bold,
        color: textPrimary,
      );

  static TextStyle get h2 => GoogleFonts.inter(
        fontSize: 24,
        fontWeight: FontWeight.w600,
        color: textPrimary,
      );

  static TextStyle get h3 => GoogleFonts.inter(
        fontSize: 20,
        fontWeight: FontWeight.w600,
        color: textPrimary,
      );

  static TextStyle get bodyLarge => GoogleFonts.inter(
        fontSize: 16,
        fontWeight: FontWeight.normal,
        color: textPrimary,
      );

  static TextStyle get bodyMedium => GoogleFonts.inter(
        fontSize: 14,
        fontWeight: FontWeight.normal,
        color: textPrimary,
      );

  static TextStyle get bodySmall => GoogleFonts.inter(
        fontSize: 12,
        fontWeight: FontWeight.normal,
        color: textSecondary,
      );

  // Theme Data Builder
  static ThemeData get lightTheme {
    return ThemeData(
      primaryColor: primaryColor,
      scaffoldBackgroundColor: backgroundColor,
      colorScheme: const ColorScheme.light(
        primary: primaryColor,
        secondary: secondaryColor,
        surface: surfaceColor,
        error: errorColor,
      ),
      appBarTheme: AppBarTheme(
        backgroundColor: surfaceColor,
        elevation: 0,
        centerTitle: true,
        iconTheme: const IconThemeData(color: textPrimary),
        titleTextStyle: h2.copyWith(color: textPrimary),
      ),
      elevatedButtonTheme: ElevatedButtonThemeData(
        style: ElevatedButton.styleFrom(
          backgroundColor: primaryColor,
          foregroundColor: textOnPrimary,
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(12),
          ),
          padding: const EdgeInsets.symmetric(vertical: 16, horizontal: 24),
          textStyle: bodyLarge.copyWith(fontWeight: FontWeight.w600),
        ),
      ),
      inputDecorationTheme: InputDecorationTheme(
        filled: true,
        fillColor: surfaceColor,
        contentPadding: const EdgeInsets.symmetric(horizontal: 16, vertical: 16),
        border: OutlineInputBorder(
          borderRadius: BorderRadius.circular(12),
          borderSide: BorderSide(color: Colors.grey.shade300),
        ),
        enabledBorder: OutlineInputBorder(
          borderRadius: BorderRadius.circular(12),
          borderSide: BorderSide(color: Colors.grey.shade300),
        ),
        focusedBorder: OutlineInputBorder(
          borderRadius: BorderRadius.circular(12),
          borderSide: const BorderSide(color: primaryColor, width: 2),
        ),
        labelStyle: bodyMedium.copyWith(color: textSecondary),
      ),
    );
  }
}