import 'dart:convert';
import 'dart:io';
import 'dart:math';
import 'package:flutter/cupertino.dart';
import 'package:http/http.dart' as http;
import 'package:provider/provider.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:html/parser.dart' as html_parser;
import 'package:html/dom.dart';

class GtiAuth extends ChangeNotifier {  // Add ChangeNotifier for reactive updates
  String? _SESSID;

  String? get sessionId => _SESSID;  // Dart convention: lowercase property names

  bool get isAuthenticated => _SESSID != null;

  static GtiAuth of(BuildContext context, {bool listen = false}) {  // Add listen parameter
    return Provider.of<GtiAuth>(context, listen: listen);
  }

  Future<void> init() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    String? storedSessionId = prefs.getString('PHPSESSID');

    if (storedSessionId != null) {
      _SESSID = storedSessionId;
      notifyListeners();  // Notify widgets that auth state changed
    }
  }

  Future<void> login(String username, String password, {bool remember = false}) async {
    try {
      final response = await http.post(
        Uri.parse('https://gti.fts-tech.co.uk/coordv2/login.php'),
        body: {
          'action': 'login',
          'user': username,
          'pass': password,
        },
      );

      // Check if login successful (response is "1")
      if (response.body.trim() != '1') {
        throw Exception('Invalid username or password');
      }

      // Extract PHPSESSID from cookies
      final cookies = response.headers['set-cookie'];
      if (cookies == null) {
        throw Exception('No session cookie received from server');
      }

      _SESSID = _extractSessionId(cookies);
      if (_SESSID == null) {
        throw Exception('Failed to extract PHPSESSID from cookies');
      }

      // If remember is true, use shared_preferences to store session persistently
      if (remember) {
        SharedPreferences prefs = await SharedPreferences.getInstance();
        await prefs.setString('PHPSESSID', _SESSID!);
      }

      notifyListeners();  // Notify widgets that auth state changed

    } catch (e) {
      if (e is Exception) {
        rethrow;
      }
      throw Exception('Login failed: $e');
    }
  }

  Future<void> logout() async {
    _SESSID = null;

    SharedPreferences prefs = await SharedPreferences.getInstance();
    await prefs.remove('PHPSESSID');

    notifyListeners();  // Notify widgets that auth state changed
  }

  // Validate if the current session is still valid
  Future<bool> validateSession() async {
    if (_SESSID == null) return false;

    try {
      final response = await getAuthenticatedPage(
          'https://gti.fts-tech.co.uk/coordv2/home.php'
      );

      // If redirected to login or unauthorized, session is invalid
      if (response.statusCode != 200 || response.body.contains('login')) {
        await logout();  // Clear invalid session
        return false;
      }

      return true;
    } catch (e) {
      await logout();  // Clear invalid session
      return false;
    }
  }

  String? _extractSessionId(String cookieHeader) {
    // Parse the Set-Cookie header to extract PHPSESSID
    // Example: "PHPSESSID=rm6rdoanhvcbo9cigsq1b5he17; path=/; HttpOnly"
    final cookies = cookieHeader.split(';');
    for (var cookie in cookies) {
      if (cookie.trim().startsWith('PHPSESSID=')) {
        return cookie.trim().substring('PHPSESSID='.length);
      }
    }
    return null;
  }

  // Helper method to create authenticated requests
  Map<String, String> getAuthHeaders() {
    if (_SESSID == null) {
      throw Exception('Not authenticated - SESSID is null');
    }
    return {
      'Cookie': 'PHPSESSID=$_SESSID',
    };
  }

  // Example authenticated request
  Future<http.Response> getAuthenticatedPage(String url) async {
    if (_SESSID == null) {
      throw Exception('Not authenticated');
    }

    return await http.get(
      Uri.parse(url),
      headers: getAuthHeaders(),
    );
  }

  Future<List<GtiStation>> searchStations(String term) async {
    if (term.length < 3) {
      return [];
    }

    final response = await http.get(
      Uri.parse('https://gti.fts-tech.co.uk/ajax/station_lookup_mobile.php?term=$term'),
      headers: {
        ...getAuthHeaders(),
        'accept': 'application/json, text/javascript, */*; q=0.01',
      },
    );

    if (response.statusCode != 200) {
      print('Search failed - Status: ${response.statusCode}');
      print('Response body: ${response.body}');
      print('Search term: $term');
      throw Exception('Failed to search stations');
    }

    try {
      final List<dynamic> data = jsonDecode(response.body);
      return data.map((json) => GtiStation.fromJson(json)).toList();
    } catch (e) {
      print('JSON parse error: $e');
      print('Response body: ${response.body}');
      rethrow;
    }
  }

  Future<List<GtiService>> getServicesForStation(GtiStation station, {String filter = ''}) async {
    // Step 1: Set station context by navigating to home.php (as a page load, not AJAX)
    print('Setting station to ${station.label} (${station.crs})...');

    final homeUri = Uri.https(
      'gti.fts-tech.co.uk',
      '/coordv2/home.php',
      {
        'crs': station.crs,
        'stationpc': station.postcode,
        'stationname': station.label,
        'stationloc': '${station.stationName},${station.postcode}',
      },
    );

    final homeResponse = await http.get(
      homeUri,
      headers: {
        ...getAuthHeaders(),
        'accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8',
        'referer': 'https://gti.fts-tech.co.uk/coordv2/home.php',
        'user-agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/143.0.0.0 Safari/537.36',
      },
    );

    print('home.php status: ${homeResponse.statusCode}');

    // Extract any new cookies from the response
    String cookieHeader = getAuthHeaders()['Cookie']!;
    final setCookie = homeResponse.headers['set-cookie'];
    if (setCookie != null) {
      print('Got new cookies: $setCookie');
      // Append new cookies to existing ones
      cookieHeader += '; $setCookie';
    }

    // Step 2: Now fetch services via AJAX with updated cookies
    final random = Random().nextInt(1000000000);
    print('Fetching services...');
    final response = await http.post(
      Uri.parse('https://gti.fts-tech.co.uk/coordv2/station_adlist_quick.php?nocache=$random&filter=$filter'),
      headers: {
        'Cookie': cookieHeader,
        'accept': '*/*',
        'referer': 'https://gti.fts-tech.co.uk/coordv2/home.php',
        'origin': 'https://gti.fts-tech.co.uk',
        'user-agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/143.0.0.0 Safari/537.36',
        'x-requested-with': 'XMLHttpRequest',
      },
    );

    print('Services response status: ${response.statusCode}');
    print('Response length: ${response.body.length}');

    final services = _parseServicesFromHtml(response.body);
    print('Parsed ${services.length} services');

    return services;
  }

  Future<bool> saveAudit({
    required String time,
    required String crs,
    required String vehicleId,
    required String auditId,
    required String vehicleReg,
    required String seats,
    required String pax,
    required String luggage,
    required String paceNotes,
    required String vehicleTracking,
    required String destBanner,
    required String callingPatternFront,
    required String callingPatternMiddle,
    required String callingPatternRear,
    required String audioEquipment,
    required String audioWorking,
    required String wheelchair,
    required String exemption,
  }) async {
    try {
      final requestBody = {
        'txtVehicleReg': vehicleReg,
        'cboSeats1': seats[0],
        'cboSeats2': seats[1],
        'cboPax1': pax[0],
        'cboPax2': pax[1],
        'cboLuggage': luggage,
        'cboPaceNotes': paceNotes,
        'cboVehicleTracking': vehicleTracking,
        'cboDestBanner': destBanner,
        'cboCallingPatternFront': callingPatternFront,
        'cboCallingPatternMiddle': callingPatternMiddle,
        'cboCallingPatternRear': callingPatternRear,
        'cboAudioEquipment': audioEquipment,
        'cboAudioWorking': audioWorking,
        'cboWheelchair': wheelchair,
        'cboExemption': exemption,
        'time': time,
        'crs': crs,
        'vid': vehicleId,
        'audit_id': auditId,
      };

      print('=== AUDIT SAVE DEBUG ===');
      print('URL: https://gti.fts-tech.co.uk/coordv2/update_audit_psvair.php');
      print('Request body:');
      requestBody.forEach((key, value) {
        print('  $key: $value');
      });

      final response = await http.post(
        Uri.parse('https://gti.fts-tech.co.uk/coordv2/update_audit_psvair.php'),
        headers: {
          ...getAuthHeaders(),
          'Content-Type': 'application/x-www-form-urlencoded',
        },
        body: requestBody,
      );

      print('Response status: ${response.statusCode}');
      print('Response body: ${response.body}');
      print('======================');

      if (response.statusCode == 200) {
        // Check if response is a positive integer (success)
        final result = int.tryParse(response.body.trim());
        final success = result != null && result > 0;
        print('Parse result: $result, Success: $success');
        return success;
      }

      print('Non-200 status code: ${response.statusCode}');
      return false;
    } catch (e) {
      print('Error saving audit: $e');
      return false;
    }
  }
}

class GtiStation {
  final String label;           // "Redhill (RDH)"
  final String stationName;     // "Redhill"
  final String area;            // "Redstone Hill"
  final String town;            // "Redhill"
  final String county;          // "Surrey"
  final String postcode;        // "RH1 1RB"
  final String crs;             // "RDH"

  GtiStation({
    required this.label,
    required this.stationName,
    required this.area,
    required this.town,
    required this.county,
    required this.postcode,
    required this.crs,
  });

  factory GtiStation.fromJson(Map<String, dynamic> json) {
    // Format: "StationName|Area|Town|County|Postcode|CRS"
    final parts = (json['id'] as String).split('|');

    return GtiStation(
      label: json['label'],
      stationName: parts[0],
      area: parts[1],
      town: parts[2],
      county: parts[3],
      postcode: parts[4],
      crs: parts[5],
    );
  }

  // Build the URL that the web portal uses
  String getHomeUrl() {
    return 'https://gti.fts-tech.co.uk/coordv2/home.php?'
        'crs=$crs&'
        'stationpc=$postcode&'
        'stationname=${Uri.encodeComponent(label)}&'
        'stationloc=${Uri.encodeComponent('$stationName,$postcode')}';
  }

  @override
  String toString() => label;
}

class GtiService {
  final String time;           // "14:13"
  final String type;           // "T" (Type - possibly Train replacement?)
  final String coach;          // "3" (Coach/diagram number)
  final String vehicleType;    // "Wheelchair Coach"
  final String customer;       // "Great Western Railway"
  final String destination;    // "GTWU - Gatwick Airport (Upper Level)"
  final String operator;       // "Passenger Plus Ltd"
  final String vrm;            // "YT23BTY" (Vehicle Registration Mark)
  final int passengers;        // 0-99
  final String vehicleId;      // "3314973"
  final String timeKey;        // "1413"
  final String? auditId;       // "438769" (if service has been audited)
  final bool hasGps;           // Whether GPS tracking is available
  final bool hasStandbys;      // Whether there are standby services
  final List<CallingPoint> callingPattern;  // List of stops

  GtiService({
    required this.time,
    required this.type,
    required this.coach,
    required this.vehicleType,
    required this.customer,
    required this.destination,
    required this.operator,
    required this.vrm,
    required this.passengers,
    required this.vehicleId,
    required this.timeKey,
    this.auditId,
    required this.hasGps,
    required this.hasStandbys,
    required this.callingPattern,
  });

  Map<String, dynamic> toJson() {
    return {
      'time': time,
      'type': type,
      'coach': coach,
      'vehicleType': vehicleType,
      'customer': customer,
      'destination': destination,
      'operator': operator,
      'vrm': vrm,
      'passengers': passengers,
      'vehicleId': vehicleId,
      'timeKey': timeKey,
      'hasGps': hasGps,
      'hasStandbys': hasStandbys,
      'callingPattern': callingPattern.map((cp) => cp.toJson()).toList(),
      'auditId': auditId,
    };
  }

  factory GtiService.fromJson(Map<String, dynamic> json) {
    return GtiService(
      time: json['time'] ?? '',
      type: json['type'] ?? '',
      coach: json['coach'] ?? '',
      vehicleType: json['vehicleType'] ?? '',
      customer: json['customer'] ?? '',
      destination: json['destination'] ?? '',
      operator: json['operator'] ?? '',
      vrm: json['vrm'] ?? '',
      passengers: json['passengers'] ?? 0,
      vehicleId: json['vehicleId'] ?? '',
      timeKey: json['timeKey'] ?? '',
      hasGps: json['hasGps'] ?? false,
      hasStandbys: json['hasStandbys'] ?? false,
      callingPattern: (json['callingPattern'] as List?)
          ?.map((cp) => CallingPoint.fromJson(cp))
          .toList() ?? [],
      auditId: json['auditId'],
    );
  }
}

class CallingPoint {
  final String time;
  final String location;
  final String postcode;

  CallingPoint({
    required this.time,
    required this.location,
    required this.postcode,
  });

  Map<String, dynamic> toJson() {
    return {
      'Time': time,
      'Loc': location,
      'Postcode': postcode,
    };
  }

  factory CallingPoint.fromJson(Map<String, dynamic> json) {
    return CallingPoint(
      time: json['Time'],
      location: json['Loc'],
      postcode: json['Postcode'],
    );
  }
}



List<GtiService> _parseServicesFromHtml(String htmlContent) {
  final document = html_parser.parse(htmlContent);
  final services = <GtiService>[];

  // Extract calling patterns from script tags
  final callingPatterns = <String, List<CallingPoint>>{};
  final scripts = document.querySelectorAll('script');

  for (final script in scripts) {
    final text = script.text;
    final cpMatch = RegExp(r"aCP\['(\d+-\d+)'\] = '(\[.*?\])'").firstMatch(text);
    if (cpMatch != null) {
      try {
        final key = cpMatch.group(1)!;
        final jsonStr = cpMatch.group(2)!;
        final List<dynamic> data = jsonDecode(jsonStr);
        callingPatterns[key] = data.map((cp) => CallingPoint.fromJson(cp)).toList();
      } catch (e) {
        // Skip invalid JSON
        print('Failed to parse calling pattern: $e');
      }
    }
  }

  // Parse each service list item
  final listItems = document.querySelectorAll('li.list-group-item-action');
  print('Found ${listItems.length} list items');

  for (final item in listItems) {
    try {
      final table = item.querySelector('table');
      if (table == null) continue;

      final rows = table.querySelectorAll('tr');

      // Extract data from table rows
      String? time, type, coach, vehicleType, customer, destination, operator, vrm;
      int passengers = 0;
      String? vehicleId, auditId;
      bool hasGps = false;
      bool hasStandbys = false;

      for (final row in rows) {
        // Get all labels and values in this row (some rows have multiple pairs)
        final labels = row.querySelectorAll('.adlabel');
        final values = row.querySelectorAll('.adtext');

        // Process each label-value pair in this row
        for (int i = 0; i < labels.length && i < values.length; i++) {
          final label = labels[i].text.trim();
          final value = values[i].text.trim();

          switch (label) {
            case 'Time:':
              time = value;
              break;
            case 'Type:':
              type = value;
              break;
            case 'Coach:':
              coach = value;
              break;
            case 'Vehicle Type:':
              vehicleType = value;
              break;
            case 'Customer:':
              customer = value;
              break;
            case 'Destination:':
              destination = value;
              break;
            case 'Operator:':
              operator = value;
              break;
            case 'VRM:':
              vrm = value;
              break;
          }
        }

        // Check for GPS button
        if (row.text.contains('btn-opengps')) {
          hasGps = true;
        }

        // Check for standbys
        if (row.text.contains('Standbys')) {
          hasStandbys = true;
        }

        // Extract passenger count from selects
        final select1 = row.querySelector('select[id^="cboPax1_"]');
        final select2 = row.querySelector('select[id^="cboPax2_"]');
        if (select1 != null && select2 != null) {
          final pax1 = select1.querySelector('option[selected]')?.attributes['value'] ?? '0';
          final pax2 = select2.querySelector('option[selected]')?.attributes['value'] ?? '0';
          passengers = int.parse(pax1 + pax2);

          // Extract vehicle ID from onchange attribute
          final onChange = select1.attributes['onchange'];
          if (onChange != null) {
            final vidMatch = RegExp(r"'(\d+)'").allMatches(onChange).toList();
            if (vidMatch.length >= 2) {
              auditId = vidMatch[0].group(1);
              vehicleId = vidMatch[1].group(1);
            }
          }
        }
      }

      if (time != null && type != null && coach != null) {
        final timeKey = time.replaceAll(':', '');
        final cpKey = '$vehicleId-$timeKey';

        services.add(GtiService(
          time: time,
          type: type,
          coach: coach,
          vehicleType: vehicleType ?? '',
          customer: customer ?? '',
          destination: destination ?? '',
          operator: operator ?? '',
          vrm: vrm ?? '',
          passengers: passengers,
          vehicleId: vehicleId ?? '',
          timeKey: timeKey,
          auditId: auditId,
          hasGps: hasGps,
          hasStandbys: hasStandbys,
          callingPattern: callingPatterns[cpKey] ?? [],
        ));
      } else {
        print('Skipping service - time: $time, type: $type, coach: $coach');
      }
    } catch (e) {
      // Skip malformed items
      continue;
    }
  }

  return services;
}