import 'dart:async';
import 'dart:convert';
import 'dart:developer' as log1;
import 'dart:io';
import 'dart:math';
import 'package:signalr_netcore/ihub_protocol.dart';
import 'package:signalr_netcore/signalr_client.dart';
import 'package:audioplayers/audioplayers.dart' as audioplayers;
import 'package:flutter/foundation.dart';
import 'package:flutter_sound/flutter_sound.dart' as sound;
import 'package:http/http.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:test_sa/controllers/api_routes/api_manager.dart';
import 'package:test_sa/controllers/api_routes/urls.dart';

import '../model/copilot_message_model.dart';

enum PttStatus { idle, connecting, recording, thinking, playingAudio, error }

class CopilotProvider extends ChangeNotifier {
  List<CopilotHistoryItem> history = [];
  bool historyLoading = false;
  List<CopilotMessage> messages = [];
  bool conversationLoading = false;
  bool isStreaming = false;
  bool isTranscribing = false;
  String? sessionId;
  String? errorMessage;
  StreamSubscription? _streamSub;

  HubConnection? _pttHub;
  PttStatus pttStatus = PttStatus.idle;
  String? pttErrorMessage;
  List<CopilotMessage> pttMessages = [];
  String? pttSessionId;
  bool _pttButtonHeld = false;

  final sound.FlutterSoundRecorder _pttRecorder = sound.FlutterSoundRecorder();
  bool _pttRecorderOpen = false;
  StreamController<Uint8List>? _pttMicStreamController;
  StreamSubscription? _pttMicSub;
  Future<void> _pttSendQueue = Future.value();
  int _pttChunkCount = 0;

  final audioplayers.AudioPlayer _pttAudioPlayer = audioplayers.AudioPlayer();
  final List<Uint8List> _pttAudioQueue = [];
  bool _pttIsPlayingAudio = false;
  CopilotMessage? _pttCurrentAssistantMsg;

  void _pttLog(String message) => log1.log('[PTT] $message');

  Future<void> loadHistory() async {
    historyLoading = true;
    errorMessage = null;
    notifyListeners();
    try {
      final res = await ApiManager.instance.get(
        URLs.copilotGetQueryHistory,
        enableToastMessage: false,
      );
      final decoded = jsonDecode(res.body);
      if (decoded is Map && decoded['isSuccess'] == true) {
        final List threads = decoded['data']?['threads'] ?? [];
        history = threads.map((e) => CopilotHistoryItem.fromJson(e)).toList();
      } else {
        errorMessage = (decoded is Map ? decoded['message'] : null) ?? "Failed to load history";
      }
    } catch (e) {
      errorMessage = "Failed to load history";
    } finally {
      historyLoading = false;
      notifyListeners();
    }
  }

  Future<void> deleteHistory(String threadId) async {
    final prevList = List<CopilotHistoryItem>.from(history);

    try {
      final res = await ApiManager.instance.delete(URLs.copilotDeleteQueryHistory(threadId), body: const {});
      final decoded = jsonDecode(res.body);
      final success = decoded is Map && decoded['isSuccess'] == true && decoded['data'] == true;
      if (success) {
        history.removeWhere((h) => h.threadId == threadId);
        notifyListeners();
      } else {
        history = prevList;
        errorMessage = (decoded is Map ? decoded['message'] : null) ?? "Failed to delete";
        notifyListeners();
      }
    } catch (e) {
      history = prevList;
      errorMessage = "Failed to delete";
      notifyListeners();
    }
  }

  Future<void> loadConversation(String threadId) async {
    conversationLoading = true;
    errorMessage = null;
    messages = [];
    sessionId = threadId;
    notifyListeners();
    try {
      final res = await ApiManager.instance.get(
        URLs.copilotGetConversationByThreadId(threadId),
        enableToastMessage: false,
      );
      final decoded = jsonDecode(res.body);
      if (decoded is Map && decoded['isSuccess'] == true) {
        final List rawMessages = decoded['data']?['messages'] ?? [];
        messages = rawMessages.map<CopilotMessage>((e) => CopilotMessage.fromHistoryJson(e)).toList();
      } else {
        errorMessage = (decoded is Map ? decoded['message'] : null) ?? "Failed to load conversation";
      }
    } catch (e) {
      errorMessage = "Failed to load conversation";
    } finally {
      conversationLoading = false;
      notifyListeners();
    }
  }

  void startNewConversation() {
    _streamSub?.cancel();
    sessionId = null;
    messages = [];
    errorMessage = null;
    isStreaming = false;
    notifyListeners();
  }

  Future<void> sendText(String query, String language) async {
    if (isStreaming || query.trim().isEmpty) return;
    sessionId ??= _generateSessionId();

    messages.add(CopilotMessage(id: UniqueKey().toString(), role: CopilotRole.user, content: query, timestamp: DateTime.now()));
    final assistantMsg = CopilotMessage(id: UniqueKey().toString(), role: CopilotRole.assistant, isStreaming: true, timestamp: DateTime.now());
    messages.add(assistantMsg);
    isStreaming = true;
    errorMessage = null;
    notifyListeners();

    try {
      final streamedResponse = await ApiManager.instance.postFormDataStreaming(
        URLs.copilotQueryStream,
        body: {
          "sessionId": sessionId!,
          "isAudio": "false",
          "langId": "$language",
          'isFromMobile': 'true',
          "query": query,
        },
      );
      await _consumeStream(streamedResponse, assistantMsg, null);
    } catch (e) {
      _onStreamError(assistantMsg, e);
    }
  }

  Future<void> sendAudio(File audioFile, String language) async {
    if (isStreaming) return;
    sessionId ??= _generateSessionId();
    final humanAudioMsg = CopilotMessage(id: UniqueKey().toString(), role: CopilotRole.user, localAudioPath: audioFile.path, timestamp: DateTime.now());
    messages.add(humanAudioMsg);
    final assistantMsg = CopilotMessage(id: UniqueKey().toString(), role: CopilotRole.assistant, isStreaming: true, timestamp: DateTime.now());
    messages.add(assistantMsg);
    isStreaming = true;
    errorMessage = null;
    notifyListeners();

    try {
      final streamedResponse = await ApiManager.instance.postFormDataStreamingWithFile(
        URLs.copilotQueryStream,
        fields: {
          "sessionId": sessionId!,
          "isAudio": "true",
          "langId": "$language",
          'isFromMobile': 'true',
        },
        fileFieldName: "AudioFile",
        file: audioFile,
        filename: audioFile.path.split('/').last,
      );
      await _consumeStream(streamedResponse, assistantMsg, humanAudioMsg);
    } catch (e) {
      _onStreamError(assistantMsg, e);
    }
  }

  Future<String?> transcribeAudio(File audioFile, String language) async {
    isTranscribing = true;
    errorMessage = null;
    notifyListeners();
    final exists = await audioFile.exists();
    final sizeBytes = exists ? await audioFile.length() : 0;
    if (!exists || sizeBytes == 0) {
      errorMessage = "Recording file is empty or missing";
      isTranscribing = false;
      notifyListeners();
      return null;
    }

    try {
      final response = await ApiManager.instance.multiPart(
        URLs.copilotAudioTranscription,
        body: {
          "langId": language,
        },
        showToast: false,
        files: [
          MultipartFile.fromPath("AudioFile", audioFile.path, filename: audioFile.path.split('/').last),
        ],
      );

      if (response.statusCode < 200 || response.statusCode >= 300) {
        errorMessage = "Failed to transcribe audio";
        return null;
      }

      return _extractTranscriptionText(response.body);
    } catch (e) {
      errorMessage = "Failed to transcribe audio";
      return null;
    } finally {
      isTranscribing = false;
      notifyListeners();
    }
  }

  String? _extractTranscriptionText(String rawBody) {
    final trimmedRaw = rawBody.trim();
    if (trimmedRaw.isEmpty) return null;

    try {
      final decoded = jsonDecode(trimmedRaw);
      if (decoded is String) {
        return decoded.trim();
      } else if (decoded is Map) {
        final map = Map<String, dynamic>.from(decoded);
        final lowerKeyMap = {for (final entry in map.entries) entry.key.toLowerCase(): entry.value};
        final text = lowerKeyMap['transcription'] ?? lowerKeyMap['data'] ?? lowerKeyMap['text'] ?? lowerKeyMap['result'];
        if (text is Map) {
          return _extractTranscriptionText(jsonEncode(text));
        }
        if (text != null) return text.toString().trim();
      }
    } catch (_) {}

    return trimmedRaw;
  }

  String _generateSessionId() {
    final rand = Random();
    final bytes = List<int>.generate(16, (_) => rand.nextInt(256));
    bytes[6] = (bytes[6] & 0x0F) | 0x40;
    bytes[8] = (bytes[8] & 0x3F) | 0x80;
    String byteHex(int i) => bytes[i].toRadixString(16).padLeft(2, '0');
    final hex = List.generate(16, byteHex).join();
    return '${hex.substring(0, 8)}-${hex.substring(8, 12)}-${hex.substring(12, 16)}-${hex.substring(16, 20)}-${hex.substring(20, 32)}';
  }

  Future<void> _consumeStream(dynamic streamedResponse, CopilotMessage assistantMsg, CopilotMessage? humanAudioMsg) async {
    if (streamedResponse.statusCode < 200 || streamedResponse.statusCode >= 300) {
      _onStreamError(assistantMsg, "Server error ${streamedResponse.statusCode}");
      return;
    }

    String buffer = '';
    _streamSub = streamedResponse.stream.transform(utf8.decoder).listen(
      (rawChunk) {
        buffer += rawChunk;
        while (buffer.contains('\n\n')) {
          final idx = buffer.indexOf('\n\n');
          final rawEvent = buffer.substring(0, idx);
          buffer = buffer.substring(idx + 2);
          _handleSseEvent(rawEvent, assistantMsg, humanAudioMsg);
        }
      },
      onDone: () {
        if (buffer.trim().isNotEmpty) {
          _handleSseEvent(buffer, assistantMsg, humanAudioMsg);
        }
        assistantMsg.isStreaming = false;
        isStreaming = false;
        notifyListeners();
      },
      onError: (e) => _onStreamError(assistantMsg, e),
      cancelOnError: true,
    );
  }

  void _handleSseEvent(String rawEvent, CopilotMessage assistantMsg, CopilotMessage? humanAudioMsg) {
    final dataLines = rawEvent.split('\n').where((line) => line.startsWith('data:')).map((line) => line.substring(5).trim()).toList();
    if (dataLines.isEmpty) return;

    final payload = dataLines.join('\n');

    if (payload == '[DONE]') {
      assistantMsg.isStreaming = false;
      isStreaming = false;
      notifyListeners();
      return;
    }

    try {
      final json = jsonDecode(payload);
      final event = CopilotStreamEvent.fromJson(json);
      if (event.type == 'response' && event.content != null) {
        assistantMsg.content = event.content!.answer ?? '';
        assistantMsg.documentAnswer = event.content!.documentAnswer;
        assistantMsg.websiteAnswer = event.content!.websiteAnswer;
        assistantMsg.images = event.content!.images;
      } else if (event.type == 'error') {
        _onStreamError(assistantMsg, event.content?.answer ?? 'Something went wrong');
        return;
      }
      if (event.type == 'transcription' && event.transcriptionContent != null) {
        humanAudioMsg?.content = event.transcriptionContent ?? '';
        humanAudioMsg?.localAudioPath = null;
      }
      notifyListeners();
    } catch (_) {}
  }

  void _onStreamError(CopilotMessage assistantMsg, Object e) {
    assistantMsg.isStreaming = false;
    assistantMsg.isError = true;
    if (assistantMsg.content.isEmpty) {
      assistantMsg.content = "Something went wrong. Please try again.";
    }
    isStreaming = false;
    errorMessage = "Failed to get a response";
    notifyListeners();
  }

  void cancelStreaming() {
    _streamSub?.cancel();
    isStreaming = false;
    if (messages.isNotEmpty && messages.last.role == CopilotRole.assistant) {
      messages.last.isStreaming = false;
    }
  }

  Future<void> connectPushToTalkHub() async {
    if (_pttHub != null && _pttHub!.state == HubConnectionState.Connected) {
      _pttLog('connectPushToTalkHub: already connected, skipping');
      return;
    }
    await disconnectPushToTalkHub();

    // final token = URLs.chatApiKey;
    final token = ApiManager.instance.user?.token ?? '';
    final userId = ApiManager.instance.user?.id ?? '';
    // final url = "${URLs.copilotHubUrl}?access_token=$token";
    final url = "https://atomsmuat.hmg.com/VoiceWebSocket?access_token=$token";
    // final url = "${URLs.copilotHubUrl}?id=$userId&access_token=$token";
    _pttLog('connectPushToTalkHub: building connection url=$url');
    final httpOp = HttpConnectionOptions(skipNegotiation: false, logMessageContent: true,headers: MessageHeaders()..setHeaderValue('Authorization', 'Bearer $token'));
    _pttHub = HubConnectionBuilder().withUrl(url,transportType:HttpTransportType.LongPolling ).withAutomaticReconnect(retryDelays: <int>[2000, 5000, 10000, 20000]).build();

    _pttHub!.on("RecordingStarted", _onRecordingStarted);
    _pttHub!.on("RecordingStopped", _onRecordingStopped);
    _pttHub!.on("RecordingCancelled", _onRecordingCancelled);
    _pttHub!.on("TranscriptionReceived", _onTranscriptionReceived);
    _pttHub!.on("ResponseReceived", _onResponseReceived);
    _pttHub!.on("AudioReceived", _onAudioReceived);
    _pttHub!.on("RecordingError", _onRecordingError);

    try {
      await _pttHub!.start();
      _pttLog('connectPushToTalkHub: connected, state=${_pttHub!.state}');
    } catch (e) {
      _pttLog('connectPushToTalkHub: failed error=$e');
      pttErrorMessage = "Failed to connect to push-to-talk service";
      pttStatus = PttStatus.error;
      _pttHub = null;
      notifyListeners();
      rethrow;
    }
  }

  Future<void> disconnectPushToTalkHub() async {
    _pttLog('disconnectPushToTalkHub: stopping');
    try {
      await _abortMicStreaming();
      if (_pttHub != null) {
        await _pttHub!.stop();
      }
    } catch (e) {
      _pttLog('disconnectPushToTalkHub: error=$e');
    } finally {
      _pttHub = null;
      pttStatus = PttStatus.idle;
    }
  }

  void startNewPttConversation() {
    pttSessionId = null;
    pttMessages = [];
    pttErrorMessage = null;
    pttStatus = PttStatus.idle;
    notifyListeners();
  }

  Future<void> beginPushToTalk(String language) async {
    if (pttStatus != PttStatus.idle && pttStatus != PttStatus.error) return;
    pttSessionId ??= _generateSessionId();
    _pttButtonHeld = true;
    pttErrorMessage = null;
    pttStatus = PttStatus.connecting;
    notifyListeners();

    try {
      if (_pttHub == null || _pttHub!.state != HubConnectionState.Connected) {
        await connectPushToTalkHub();
      }
      final args = [
        // pttSessionId ?? '',
        sessionId ?? '',
        ApiManager.instance.user?.id ?? '',
        (ApiManager.instance.assetGroup?.id ?? '').toString(),
        // language,
        "1",
        false,
      ];
      _pttLog('beginPushToTalk: invoking StartRecording args=$args');
      await _pttHub!.invoke("StartRecording", args: args);
      _pttLog('beginPushToTalk: StartRecording invoked, waiting for RecordingStarted event');
    } catch (e) {
      _pttLog('beginPushToTalk: failed error=$e');
      pttStatus = PttStatus.error;
      pttErrorMessage = "Failed to start recording";
      _pttButtonHeld = false;
      notifyListeners();
    }
  }

  Future<void> endPushToTalk() async {
    _pttButtonHeld = false;
    if (pttStatus != PttStatus.recording) {
      notifyListeners();
      return;
    }

    _pttLog('endPushToTalk: stopping mic and flushing $_pttChunkCount chunks sent so far');
    try {
      await _stopMicStreamingAndFlush();
      pttStatus = PttStatus.thinking;
      notifyListeners();
      _pttLog('endPushToTalk: invoking StopRecording');
      await _pttHub?.invoke("StopRecording");
    } catch (e) {
      _pttLog('endPushToTalk: failed error=$e');
      pttStatus = PttStatus.error;
      pttErrorMessage = "Failed to stop recording";
      notifyListeners();
    }
  }

  Future<void> cancelPushToTalk() async {
    _pttButtonHeld = false;
    _pttLog('cancelPushToTalk: invoking CancelRecording');
    try {
      await _abortMicStreaming();
      await _pttHub?.invoke("CancelRecording");
    } catch (e) {
      _pttLog('cancelPushToTalk: error=$e');
    }
    pttStatus = PttStatus.idle;
    notifyListeners();
  }

  Future<void> _startMicStreaming() async {
    final micStatus = await Permission.microphone.request();
    if (!micStatus.isGranted) {
      _pttLog('_startMicStreaming: microphone permission denied');
      pttStatus = PttStatus.error;
      pttErrorMessage = "Microphone permission denied";
      notifyListeners();
      await cancelPushToTalk();
      return;
    }

    if (!_pttRecorderOpen) {
      await _pttRecorder.openRecorder();
      _pttRecorderOpen = true;
    }
    await _pttRecorder.setSubscriptionDuration(const Duration(milliseconds: 100));

    _pttMicStreamController = StreamController<Uint8List>();
    _pttSendQueue = Future.value();
    _pttChunkCount = 0;

    _pttMicSub = _pttMicStreamController!.stream.listen((chunk) {
      _pttChunkCount++;
      _pttLog('mic chunk #$_pttChunkCount captured bytes=${chunk.length}');
      _enqueueChunkSend(chunk);
    });

    await _pttRecorder.startRecorder(
      toStream: _pttMicStreamController!.sink,
      codec: sound.Codec.pcm16,
      numChannels: 1,
      sampleRate: 48000,
    );

    _pttLog('_startMicStreaming: recorder started');
    pttStatus = PttStatus.recording;
    notifyListeners();
  }

  Future<void> _stopMicStreamingAndFlush() async {
    try {
      if (_pttRecorderOpen) {
        await _pttRecorder.stopRecorder();
      }
    } catch (e) {
      _pttLog('_stopMicStreamingAndFlush: stopRecorder error=$e');
    }
    await Future.delayed(const Duration(milliseconds: 50));
    await _pttMicSub?.cancel();
    _pttMicSub = null;
    await _pttMicStreamController?.close();
    _pttMicStreamController = null;
    await _pttSendQueue;
    _pttLog('_stopMicStreamingAndFlush: done, total chunks sent=$_pttChunkCount');
  }

  Future<void> _abortMicStreaming() async {
    try {
      if (_pttRecorderOpen) {
        await _pttRecorder.stopRecorder();
      }
    } catch (e) {
      _pttLog('_abortMicStreaming: stopRecorder error=$e');
    }
    await _pttMicSub?.cancel();
    _pttMicSub = null;
    await _pttMicStreamController?.close();
    _pttMicStreamController = null;
    _pttSendQueue = Future.value();
  }

  void _enqueueChunkSend(Uint8List chunk) {
    _pttSendQueue = _pttSendQueue.then((_) => _sendAudioChunk(chunk));
  }

  Future<void> _sendAudioChunk(Uint8List chunk) async {
    try {
      await _pttHub?.invoke("SendAudioChunk", args: [base64Encode(chunk)]);
    } catch (e) {
      _pttLog('_sendAudioChunk: failed error=$e');
    }
  }

  void _onRecordingStarted(List<Object?>? params) async {
    _pttLog('event RecordingStarted params=$params');
    try {
      if (!_pttButtonHeld) {
        _pttLog('RecordingStarted received but button already released, cancelling');
        try {
          await _pttHub?.invoke("CancelRecording");
        } catch (_) {}
        pttStatus = PttStatus.idle;
        notifyListeners();
        return;
      }
      await _startMicStreaming();
    } catch (e) {
      _pttLog('_onRecordingStarted: failed error=$e');
      pttStatus = PttStatus.error;
      pttErrorMessage = "Failed to start recording";
      notifyListeners();
    }
  }

  void _onRecordingStopped(List<Object?>? params) {
    _pttLog('event RecordingStopped params=$params');
  }

  void _onRecordingCancelled(List<Object?>? params) {
    _pttLog('event RecordingCancelled params=$params');
    pttStatus = PttStatus.idle;
    notifyListeners();
  }

  void _onTranscriptionReceived(List<Object?>? params) {
    _pttLog('event TranscriptionReceived params=$params');
    final data = _firstArgAsMap(params);
    final text = data?['text']?.toString() ?? '';
    if (text.isEmpty) return;
    pttMessages.add(CopilotMessage(id: UniqueKey().toString(), role: CopilotRole.user, content: text, timestamp: DateTime.now()));
    notifyListeners();
  }

  void _onResponseReceived(List<Object?>? params) {
    _pttLog('event ResponseReceived params=$params');
    final data = _firstArgAsMap(params);
    final text = data?['voiceAnswer']?.toString() ?? '';
    _pttCurrentAssistantMsg = CopilotMessage(id: UniqueKey().toString(), role: CopilotRole.assistant, content: text, timestamp: DateTime.now());
    pttMessages.add(_pttCurrentAssistantMsg!);
    notifyListeners();
  }

  void _onAudioReceived(List<Object?>? params) {
    if (params == null || params.isEmpty || params.first == null) return;
    try {
      final bytes = base64Decode(params.first.toString());
      _pttLog('event AudioReceived bytes=${bytes.length}');
      _pttCurrentAssistantMsg?.ttsAudioClips.add(bytes);
      _pttAudioQueue.add(bytes);
      notifyListeners();
      _playNextTtsClipIfIdle();
    } catch (e) {
      _pttLog('_onAudioReceived: failed to decode error=$e');
    }
  }

  void _onRecordingError(List<Object?>? params) {
    final msg = (params != null && params.isNotEmpty) ? params.first?.toString() : null;
    _pttLog('event RecordingError message=$msg');
    pttErrorMessage = msg ?? "Recording error occurred";
    pttStatus = PttStatus.error;
    _abortMicStreaming();
    notifyListeners();
  }

  Map<String, dynamic>? _firstArgAsMap(List<Object?>? params) {
    if (params == null || params.isEmpty || params.first == null) return null;
    final first = params.first;
    if (first is Map) return Map<String, dynamic>.from(first);
    try {
      final decoded = jsonDecode(jsonEncode(first));
      if (decoded is Map) return Map<String, dynamic>.from(decoded);
    } catch (_) {}
    return null;
  }

  Future<void> _playNextTtsClipIfIdle() async {
    if (_pttIsPlayingAudio) return;
    if (_pttAudioQueue.isEmpty) return;
    _pttIsPlayingAudio = true;
    pttStatus = PttStatus.playingAudio;
    notifyListeners();

    while (_pttAudioQueue.isNotEmpty) {
      final clip = _pttAudioQueue.removeAt(0);
      final completer = Completer<void>();
      late StreamSubscription sub;
      sub = _pttAudioPlayer.onPlayerComplete.listen((_) {
        sub.cancel();
        if (!completer.isCompleted) completer.complete();
      });
      try {
        await _pttAudioPlayer.play(audioplayers.BytesSource(clip, mimeType: 'audio/wav'));
        await completer.future;
      } catch (_) {
        sub.cancel();
      }
    }

    _pttIsPlayingAudio = false;
    pttStatus = PttStatus.idle;
    notifyListeners();
  }


  @override
  void dispose() {
    _streamSub?.cancel();
    _abortMicStreaming();
    if (_pttRecorderOpen) {
      _pttRecorder.closeRecorder();
    }
    _pttAudioPlayer.dispose();
    _pttHub?.stop();
    super.dispose();
  }
}