import 'dart:async';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import '../features/call/call_page.dart';
import '../features/call/incoming_call_page.dart';
import '../services/contact_service.dart';

class CallService {
  static const MethodChannel _channel = MethodChannel('call_service');
  static String? currentPhoneNumber;
  static String? currentDisplayName;
  static Uint8List? currentThumbnail;
  static bool _isCallPageVisible = false;
  static Map<String, dynamic>? _pendingCall;
  static bool wasPhoneLocked = false;
  static String? _activeCallNumber;
  static bool _isNavigating = false;
  final ContactService _contactService = ContactService();
  final _callStateController = StreamController<String>.broadcast();

  static final GlobalKey<NavigatorState> navigatorKey = GlobalKey<NavigatorState>();

  Stream<String> get callStateStream => _callStateController.stream;

  CallService() {
    _channel.setMethodCallHandler((call) async {
      final eventTime = DateTime.now().millisecondsSinceEpoch;
      final disconnectCause = call.arguments["disconnectCause"] ?? "none";
      print('CallService: [${eventTime}ms] Handling method call: ${call.method} with args: ${call.arguments}, disconnectCause: $disconnectCause');
      switch (call.method) {
        case "callAdded":
          final phoneNumber = call.arguments["callId"] as String?;
          final state = call.arguments["state"] as String?;
          if (phoneNumber == null || state == null) {
            print('CallService: [${eventTime}ms] Invalid callAdded args: $call.arguments');
            return;
          }
          final decodedPhoneNumber = Uri.decodeComponent(phoneNumber.replaceFirst('tel:', ''));
          print('CallService: [${eventTime}ms] Decoded phone number: $decodedPhoneNumber');
          if (_activeCallNumber != decodedPhoneNumber) {
            currentPhoneNumber = decodedPhoneNumber;
            if (currentDisplayName == null || currentDisplayName == currentPhoneNumber) {
              await _fetchContactInfo(decodedPhoneNumber);
            }
          }
          print('CallService: [${eventTime}ms] Call added, number: $currentPhoneNumber, displayName: $currentDisplayName, state: $state');
          _callStateController.add(state);
          if (state == "ringing") {
            _handleIncomingCall(decodedPhoneNumber);
          } else {
            _navigateToCallPage();
          }
          break;
        case "callStateChanged":
          final state = call.arguments["state"] as String?;
          wasPhoneLocked = call.arguments["wasPhoneLocked"] as bool? ?? false;
          if (state == null) {
            print('CallService: [${eventTime}ms] Invalid callStateChanged args: $call.arguments');
            return;
          }
          print('CallService: [${eventTime}ms] State changed to $state, wasPhoneLocked: $wasPhoneLocked, disconnectCause: $disconnectCause');
          _callStateController.add(state);
          if (state == "disconnected" || state == "disconnecting") {
            final closeStart = DateTime.now().millisecondsSinceEpoch;
            print('CallService: [${closeStart}ms] Initiating closeCallPage for state: $state');
            _closeCallPage();
            print('CallService: [${DateTime.now().millisecondsSinceEpoch}ms] closeCallPage completed');
            if (wasPhoneLocked) {
              await _channel.invokeMethod("callEndedFromFlutter");
            }
            _activeCallNumber = null;
          } else if (state == "active" || state == "dialing") {
            final phoneNumber = call.arguments["callId"] as String?;
            if (phoneNumber != null && _activeCallNumber != Uri.decodeComponent(phoneNumber.replaceFirst('tel:', ''))) {
              currentPhoneNumber = Uri.decodeComponent(phoneNumber.replaceFirst('tel:', ''));
              if (currentDisplayName == null || currentDisplayName == currentPhoneNumber) {
                await _fetchContactInfo(currentPhoneNumber!);
              }
            } else if (currentPhoneNumber != null && _activeCallNumber != currentPhoneNumber) {
              if (currentDisplayName == null || currentDisplayName == currentPhoneNumber) {
                await _fetchContactInfo(currentPhoneNumber!);
              }
            } else {
              print('CallService: [${eventTime}ms] Skipping fetch, active call: $_activeCallNumber, current: $currentPhoneNumber, displayName: $currentDisplayName');
            }
            _navigateToCallPage();
          } else if (state == "ringing") {
            final phoneNumber = call.arguments["callId"] as String?;
            if (phoneNumber == null) {
              print('CallService: [${eventTime}ms] Invalid ringing callId: $call.arguments');
              return;
            }
            final decodedPhoneNumber = Uri.decodeComponent(phoneNumber.replaceFirst('tel:', ''));
            if (_activeCallNumber != decodedPhoneNumber) {
              currentPhoneNumber = decodedPhoneNumber;
              if (currentDisplayName == null || currentDisplayName == currentPhoneNumber) {
                await _fetchContactInfo(decodedPhoneNumber);
              }
            }
            _handleIncomingCall(decodedPhoneNumber);
          }
          break;
        case "callEnded":
        case "callRemoved":
          wasPhoneLocked = call.arguments["wasPhoneLocked"] as bool? ?? false;
          print('CallService: [${eventTime}ms] Call ended/removed, wasPhoneLocked: $wasPhoneLocked, disconnectCause: $disconnectCause');
          _callStateController.add("disconnected");
          final closeStart = DateTime.now().millisecondsSinceEpoch;
          print('CallService: [${closeStart}ms] Initiating closeCallPage for callEnded/callRemoved');
          _closeCallPage();
          print('CallService: [${DateTime.now().millisecondsSinceEpoch}ms] closeCallPage completed');
          if (wasPhoneLocked) {
            await _channel.invokeMethod("callEndedFromFlutter");
          }
          currentPhoneNumber = null;
          currentDisplayName = null;
          currentThumbnail = null;
          _activeCallNumber = null;
          break;
        case "incomingCallFromNotification":
          final phoneNumber = call.arguments["phoneNumber"] as String?;
          wasPhoneLocked = call.arguments["wasPhoneLocked"] as bool? ?? false;
          if (phoneNumber == null) {
            print('CallService: [${eventTime}ms] Invalid incomingCallFromNotification args: $call.arguments');
            return;
          }
          final decodedPhoneNumber = Uri.decodeComponent(phoneNumber);
          if (_activeCallNumber != decodedPhoneNumber) {
            currentPhoneNumber = decodedPhoneNumber;
            if (currentDisplayName == null || currentDisplayName == currentPhoneNumber) {
              await _fetchContactInfo(decodedPhoneNumber);
            }
          }
          print('CallService: [${eventTime}ms] Incoming call from notification: $decodedPhoneNumber, displayName: $currentDisplayName, wasPhoneLocked: $wasPhoneLocked');
          _handleIncomingCall(decodedPhoneNumber);
          break;
        case "audioStateChanged":
          final route = call.arguments["route"] as int?;
          print('CallService: [${eventTime}ms] Audio state changed, route: $route');
          break;
      }
    });
  }

  void dispose() {
    _callStateController.close();
  }

  Future<void> _fetchContactInfo(String phoneNumber) async {
    try {
      print('CallService: Fetching contact info for $phoneNumber');
      final contacts = await _contactService.fetchContacts();
      print('CallService: Retrieved ${contacts.length} contacts');
      final normalizedPhoneNumber = _normalizePhoneNumber(phoneNumber);
      print('CallService: Normalized phone number: $normalizedPhoneNumber');
      for (var contact in contacts) {
        for (var phone in contact.phones) {
          final normalizedContactNumber = _normalizePhoneNumber(phone.number);
          print('CallService: Comparing $normalizedPhoneNumber with contact number $normalizedContactNumber');
          if (normalizedContactNumber == normalizedPhoneNumber) {
            currentDisplayName = contact.displayName;
            currentThumbnail = contact.thumbnail;
            print('CallService: Found contact - displayName: $currentDisplayName, thumbnail: ${currentThumbnail != null ? "present" : "null"}');
            return;
          }
        }
      }
      currentDisplayName = phoneNumber;
      currentThumbnail = null;
      print('CallService: No contact match, using phoneNumber as displayName: $currentDisplayName');
    } catch (e) {
      print('CallService: Error fetching contact info: $e');
      currentDisplayName = phoneNumber;
      currentThumbnail = null;
    }
  }

  String _normalizePhoneNumber(String number) {
    return number.replaceAll(RegExp(r'[\s\-\(\)]'), '').replaceFirst(RegExp(r'^\+'), '');
  }

  void _handleIncomingCall(String phoneNumber) {
    if (_activeCallNumber == phoneNumber && _isCallPageVisible) {
      print('CallService: Incoming call for $phoneNumber already active, skipping');
      return;
    }
    _activeCallNumber = phoneNumber;

    final context = navigatorKey.currentContext;
    if (context == null) {
      print('CallService: Context is null, queuing incoming call: $phoneNumber');
      _pendingCall = {"phoneNumber": phoneNumber};
      Future.delayed(Duration(milliseconds: 500), () => _checkPendingCall());
    } else {
      _navigateToIncomingCallPage(context);
    }
  }

  Future<void> _checkPendingCall() async {
    if (_pendingCall == null) {
      print('CallService: No pending call to process');
      return;
    }

    final phoneNumber = _pendingCall!["phoneNumber"];
    if (_activeCallNumber == phoneNumber && _isCallPageVisible) {
      print('CallService: Pending call for $phoneNumber already active, clearing');
      _pendingCall = null;
      return;
    }

    final context = navigatorKey.currentContext;
    if (context != null) {
      print('CallService: Processing queued call: $phoneNumber');
      currentPhoneNumber = phoneNumber;
      _activeCallNumber = phoneNumber;
      await _fetchContactInfo(phoneNumber);
      _navigateToIncomingCallPage(context);
      _pendingCall = null;
    } else {
      print('CallService: Context still null, retrying...');
      Future.delayed(Duration(milliseconds: 500), () => _checkPendingCall());
    }
  }

  void _navigateToCallPage() {
    if (_isNavigating) {
      print('CallService: Navigation already in progress, skipping');
      return;
    }
    _isNavigating = true;

    final context = navigatorKey.currentContext;
    if (context == null) {
      print('CallService: Cannot navigate to CallPage, context is null');
      _isNavigating = false;
      return;
    }
    final currentRoute = ModalRoute.of(context)?.settings.name ?? 'unknown';
    print('CallService: Navigating to CallPage, Visible: $_isCallPageVisible, Current Route: $currentRoute, Active Call: $_activeCallNumber, DisplayName: $currentDisplayName');
    if (_isCallPageVisible && currentRoute == '/call' && _activeCallNumber == currentPhoneNumber) {
      print('CallService: CallPage already visible for $_activeCallNumber, skipping navigation');
      _isNavigating = false;
      return;
    }
    if (_isCallPageVisible && currentRoute == '/incoming_call' && _activeCallNumber == currentPhoneNumber) {
      print('CallService: Popping IncomingCallPage before navigating to CallPage');
      Navigator.pop(context);
      _isCallPageVisible = false;
    }
    if (currentPhoneNumber == null) {
      print('CallService: Cannot navigate to CallPage, currentPhoneNumber is null');
      _isNavigating = false;
      return;
    }
    _activeCallNumber = currentPhoneNumber;
    Navigator.pushReplacement(
      context,
      MaterialPageRoute(
        settings: const RouteSettings(name: '/call'),
        builder: (context) => CallPage(
          displayName: currentDisplayName ?? currentPhoneNumber!,
          phoneNumber: currentPhoneNumber!,
          thumbnail: currentThumbnail,
        ),
      ),
    ).then((_) {
      _isCallPageVisible = false;
      _isNavigating = false;
      print('CallService: CallPage popped, _isCallPageVisible set to false');
    });
    _isCallPageVisible = true;
  }

  void _navigateToIncomingCallPage(BuildContext context) {
    if (_isNavigating) {
      print('CallService: Navigation already in progress, skipping');
      return;
    }
    _isNavigating = true;

    final currentRoute = ModalRoute.of(context)?.settings.name ?? 'unknown';
    print('CallService: Navigating to IncomingCallPage, Visible: $_isCallPageVisible, Current Route: $currentRoute, Active Call: $_activeCallNumber, DisplayName: $currentDisplayName');
    if (_isCallPageVisible && currentRoute == '/incoming_call' && _activeCallNumber == currentPhoneNumber) {
      print('CallService: IncomingCallPage already visible for $_activeCallNumber, skipping navigation');
      _isNavigating = false;
      return;
    }
    if (_isCallPageVisible && currentRoute == '/call') {
      print('CallService: CallPage visible, not showing IncomingCallPage');
      _isNavigating = false;
      return;
    }
    if (currentPhoneNumber == null) {
      print('CallService: Cannot navigate to IncomingCallPage, currentPhoneNumber is null');
      _isNavigating = false;
      return;
    }
    Navigator.push(
      context,
      MaterialPageRoute(
        settings: const RouteSettings(name: '/incoming_call'),
        builder: (context) => IncomingCallPage(
          displayName: currentDisplayName ?? currentPhoneNumber!,
          phoneNumber: currentPhoneNumber!,
          thumbnail: currentThumbnail,
        ),
      ),
    ).then((_) {
      _isCallPageVisible = false;
      _isNavigating = false;
      print('CallService: IncomingCallPage popped, _isCallPageVisible set to false');
    });
    _isCallPageVisible = true;
  }

  void _closeCallPage() {
    final context = navigatorKey.currentContext;
    if (context == null) {
      print('CallService: Cannot close page, context is null');
      return;
    }
    final currentRoute = ModalRoute.of(context)?.settings.name ?? 'unknown';
    print('CallService: Closing call page, _isCallPageVisible: $_isCallPageVisible, Current Route: $currentRoute');
    if (_isCallPageVisible && (currentRoute == '/call' || currentRoute == '/incoming_call')) {
      print('CallService: Popping call page');
      Navigator.pop(context);
    } else {
      print('CallService: No call page to pop, _isCallPageVisible: $_isCallPageVisible, Current Route: $currentRoute');
    }
    _isCallPageVisible = false;
    _activeCallNumber = null;
  }

  Future<Map<String, dynamic>> makeGsmCall(
    BuildContext context, {
    required String phoneNumber,
    String? displayName,
    Uint8List? thumbnail,
  }) async {
    try {
      if (_activeCallNumber == phoneNumber && _isCallPageVisible) {
        print('CallService: Call already active for $phoneNumber, skipping');
        return {"status": "already_active", "message": "Call already in progress"};
      }
      currentPhoneNumber = phoneNumber;
      currentDisplayName = displayName ?? phoneNumber;
      currentThumbnail = thumbnail;
      if (displayName == null || thumbnail == null) {
        await _fetchContactInfo(phoneNumber);
      }
      print('CallService: Making GSM call to $phoneNumber, displayName: $currentDisplayName');
      final result = await _channel.invokeMethod('makeGsmCall', {"phoneNumber": phoneNumber});
      print('CallService: makeGsmCall result: $result');
      final resultMap = Map<String, dynamic>.from(result as Map);
      if (resultMap["status"] != "calling") {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text("Failed to initiate call")),
        );
      }
      return resultMap;
    } catch (e) {
      print("CallService: Error making call: $e");
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text("Error making call: $e")),
      );
      return {"status": "error", "message": e.toString()};
    }
  }

  Future<Map<String, dynamic>> hangUpCall(BuildContext context) async {
    try {
      print('CallService: Hanging up call');
      final result = await _channel.invokeMethod('hangUpCall');
      print('CallService: hangUpCall result: $result');
      final resultMap = Map<String, dynamic>.from(result as Map);
      if (resultMap["status"] == "ended") {
        final closeStart = DateTime.now().millisecondsSinceEpoch;
        print('CallService: [${closeStart}ms] Initiating closeCallPage for hangUpCall');
        _closeCallPage();
        print('CallService: [${DateTime.now().millisecondsSinceEpoch}ms] closeCallPage completed');
      } else {
        print('CallService: Hang up failed, status: ${resultMap["status"]}');
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text("Failed to end call")),
        );
      }
      return resultMap;
    } catch (e) {
      print("CallService: Error hanging up call: $e");
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text("Error hanging up call: $e")),
      );
      _closeCallPage();
      return {"status": "error", "message": e.toString()};
    }
  }
}