import 'dart:async';
import 'dart:convert';
import 'dart:developer';

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

import 'package:collection/collection.dart';
import 'package:flutter_tts/flutter_tts.dart' as flutter_tts;
import 'package:just_audio/just_audio.dart';
import 'package:matrix/matrix.dart';
import 'package:sentry_flutter/sentry_flutter.dart';

import 'package:fluffychat/l10n/l10n.dart';
import 'package:fluffychat/pages/chat/chat.dart';
import 'package:fluffychat/pages/chat/events/audio_player.dart';
import 'package:fluffychat/pangea/bot/utils/bot_style.dart';
import 'package:fluffychat/pangea/common/utils/overlay.dart';
import 'package:fluffychat/pangea/common/widgets/card_header.dart';
import 'package:fluffychat/pangea/events/models/pangea_token_text_model.dart';
import 'package:fluffychat/pangea/instructions/instructions_enum.dart';
import 'package:fluffychat/pangea/languages/language_constants.dart';
import 'package:fluffychat/pangea/phonetic_transcription/pt_v2_disambiguation.dart';
import 'package:fluffychat/pangea/phonetic_transcription/pt_v2_repo.dart';
import 'package:fluffychat/pangea/text_to_speech/text_to_speech_repo.dart';
import 'package:fluffychat/pangea/text_to_speech/text_to_speech_request_model.dart';
import 'package:fluffychat/pangea/text_to_speech/text_to_speech_response_model.dart';
import 'package:fluffychat/widgets/future_loading_dialog.dart';
import 'package:fluffychat/widgets/matrix.dart';

import 'package:fluffychat/pangea/common/utils/error_handler.dart'
    as error_handler;

class TtsController {
  static List<String> _availableLangCodes = [];

  static final _tts = flutter_tts.FlutterTts();
  static final StreamController<bool> loadingChoreoStream =
      StreamController<bool>.broadcast();

  static AudioPlayer? audioPlayer;

  static Future<void> _onError(dynamic message) async {
    if (message != 'canceled' && message != 'interrupted') {
      error_handler.ErrorHandler.logError(
        e: 'TTS error',
        data: {'message': message},
      );
    }
  }

  static Future<void> setAvailableLanguages() async {
    try {
      await _tts.awaitSpeakCompletion(true);
      await _setAvailableBaseLanguages();
    } catch (e, s) {
      debugger(when: kDebugMode);
      error_handler.ErrorHandler.logError(e: e, s: s, data: {});
    }
  }

  static Future<void> _setAvailableBaseLanguages() async {
    final voices = (await _tts.getVoices) as List?;
    _availableLangCodes = (voices ?? [])
        .map((v) {
          // on iOS / web, the codes are in 'locale', but on Android, they are in 'name'
          final nameCode = v['name'];
          final localeCode = v['locale'];
          return localeCode.contains("-") ? localeCode : nameCode;
        })
        .toSet()
        .cast<String>()
        .toList();
  }

  static Future<void> _setSpeakingLanguage(String langCode) async {
    String? selectedLangCode;
    final langCodeShort = langCode.split("-").first;
    if (_availableLangCodes.contains(langCode)) {
      selectedLangCode = langCode;
    } else {
      selectedLangCode = _availableLangCodes.firstWhereOrNull(
        (code) => code.startsWith(langCodeShort),
      );
    }

    if (selectedLangCode != null) {
      await (_tts.setLanguage(selectedLangCode));
    } else {
      final jsonData = {
        'langCode': langCode,
        'availableLangCodes': _availableLangCodes,
      };
      debugPrint("TTS: Language not supported: $jsonData");
      Sentry.addBreadcrumb(Breadcrumb.fromJson(jsonData));
    }
  }

  static Future<void> stop() async {
    try {
      // return type is dynamic but apparent its supposed to be 1
      // https://pub.dev/packages/flutter_tts
      final result = await (_tts.stop());
      audioPlayer?.stop();

      if (result != 1) {
        error_handler.ErrorHandler.logError(
          m: 'Unexpected result from tts.stop',
          data: {'result': result},
        );
      }
    } catch (e, s) {
      debugger(when: kDebugMode);
      error_handler.ErrorHandler.logError(e: e, s: s, data: {});
    }
  }

  static VoidCallback? _onStop;

  /// Look up the PT v2 cache for [text] and return tts_phoneme if the word is a
  /// heteronym that can be disambiguated. Returns null for single-pronunciation
  /// words or when no PT data is cached.
  static String? _resolveTtsPhonemeFromCache(
    String text,
    String langCode, {
    String? pos,
    Map<String, String>? morph,
  }) {
    final userL1 = MatrixState.pangeaController.userController.userL1Code;
    if (userL1 == null) return null;

    final ptResponse = PTV2Repo.getCachedResponse(text, langCode, userL1);
    debugPrint(
      '[TTS-DEBUG] _resolveTtsPhonemeFromCache: text="$text" lang=$langCode cached=${ptResponse != null} count=${ptResponse?.pronunciations.length ?? 0} pos=$pos morph=$morph',
    );
    if (ptResponse == null || ptResponse.pronunciations.length <= 1) {
      return null;
    }

    final result = disambiguate(
      ptResponse.pronunciations,
      pos: pos,
      morph: morph,
    );
    return result.ttsPhoneme;
  }

  static Future<void> tryToSpeak(
    String text, {
    required String langCode,
    // Target ID for where to show warning popup
    String? targetID,
    BuildContext? context,
    ChatController? chatController,
    VoidCallback? onStart,
    VoidCallback? onStop,

    /// When provided, skip device TTS and use choreo with phoneme tags.
    /// If omitted, the PT v2 cache is checked automatically.
    String? ttsPhoneme,

    /// POS tag for disambiguation when resolving tts_phoneme from cache.
    String? pos,

    /// Morph features for disambiguation when resolving tts_phoneme from cache.
    Map<String, String>? morph,
  }) async {
    // Auto-resolve tts_phoneme from PT cache if not explicitly provided.
    final explicitPhoneme = ttsPhoneme;
    ttsPhoneme ??= _resolveTtsPhonemeFromCache(
      text,
      langCode,
      pos: pos,
      morph: morph,
    );
    debugPrint(
      '[TTS-DEBUG] tryToSpeak: text="$text" explicitPhoneme=$explicitPhoneme resolvedPhoneme=$ttsPhoneme pos=$pos morph=$morph',
    );

    final prevOnStop = _onStop;
    _onStop = onStop;

    if (_availableLangCodes.isEmpty) {
      await setAvailableLanguages();
    }

    _tts.setErrorHandler((message) {
      _onError(message);
      prevOnStop?.call();
    });

    onStart?.call();

    await _tryToSpeak(
      text,
      langCode: langCode,
      targetID: targetID,
      context: context,
      chatController: chatController,
      onStart: onStart,
      onStop: onStop,
      ttsPhoneme: ttsPhoneme,
    );
  }

  /// A safer version of speak, that handles the case of
  /// the language not being supported by the TTS engine
  static Future<void> _tryToSpeak(
    String text, {
    required String langCode,
    // Target ID for where to show warning popup
    String? targetID,
    BuildContext? context,
    ChatController? chatController,
    VoidCallback? onStart,
    VoidCallback? onStop,
    String? ttsPhoneme,
  }) async {
    chatController?.stopMediaStream.add(null);
    MatrixState.pangeaController.matrixState.audioPlayer?.stop();

    await _setSpeakingLanguage(langCode);

    final enableTTS = MatrixState
        .pangeaController
        .userController
        .profile
        .toolSettings
        .enableTTS;

    if (enableTTS) {
      final token = PangeaTokenText(
        offset: 0,
        content: text,
        length: text.length,
      );

      onStart?.call();

      // When tts_phoneme is provided, skip device TTS and use choreo with phoneme tags.
      if (ttsPhoneme != null) {
        await _speakFromChoreo(text, langCode, [token], ttsPhoneme: ttsPhoneme);
      } else {
        await (_isLangFullySupported(langCode)
            ? _speak(text, langCode, [token])
            : _speakFromChoreo(text, langCode, [token]));
      }
    } else if (targetID != null && context != null) {
      await _showTTSDisabledPopup(context, targetID);
    }

    onStop?.call();
  }

  static Future<void> _speak(
    String text,
    String langCode,
    List<PangeaTokenText> tokens,
  ) async {
    try {
      await stop();
      text = text.toLowerCase();

      Logs().i('Speaking: $text, langCode: $langCode');
      final result = await Future(
        () => (_tts.speak(text)),
        //     .timeout(
        //   const Duration(seconds: 5),
        //   // onTimeout: () {
        //   //   ErrorHandler.logError(
        //   //     e: "Timeout on tts.speak",
        //   //     data: {"text": text},
        //   //   );
        //   // },
        // ),
      );
      Logs().i('Finished speaking: $text, result: $result');

      // return type is dynamic but apparent its supposed to be 1
      // https://pub.dev/packages/flutter_tts
      // if (result != 1 && !kIsWeb) {
      //   ErrorHandler.logError(
      //     m: 'Unexpected result from tts.speak',
      //     data: {
      //       'result': result,
      //       'text': text,
      //     },
      //     level: SentryLevel.warning,
      //   );
      // }
    } catch (e, s) {
      debugger(when: kDebugMode);
      error_handler.ErrorHandler.logError(e: e, s: s, data: {'text': text});
      await _speakFromChoreo(text, langCode, tokens);
    } finally {
      stop();
    }
  }

  static Future<void> _speakFromChoreo(
    String text,
    String langCode,
    List<PangeaTokenText> tokens, {
    String? ttsPhoneme,
  }) async {
    debugPrint(
      '[TTS-DEBUG] _speakFromChoreo: text="$text" ttsPhoneme=$ttsPhoneme',
    );
    TextToSpeechResponseModel? ttsRes;

    loadingChoreoStream.add(true);
    final result = await TextToSpeechRepo.get(
      MatrixState.pangeaController.userController.accessToken,
      TextToSpeechRequestModel(
        text: text,
        langCode: langCode,
        tokens: tokens,
        userL1:
            MatrixState.pangeaController.userController.userL1Code ??
            LanguageKeys.unknownLanguage,
        userL2:
            MatrixState.pangeaController.userController.userL2Code ??
            LanguageKeys.unknownLanguage,
        ttsPhoneme: ttsPhoneme,
        speakingRate: 1.0,
      ),
    );
    loadingChoreoStream.add(false);
    if (result.isError) return;
    ttsRes = result.result!;

    try {
      Logs().i('Speaking from choreo: $text, langCode: $langCode');
      final audioContent = base64Decode(ttsRes.audioContent);
      audioPlayer?.dispose();
      audioPlayer = AudioPlayer();
      await audioPlayer!.setAudioSource(
        BytesAudioSource(audioContent, ttsRes.mimeType),
      );
      await audioPlayer!.play();
    } catch (e, s) {
      error_handler.ErrorHandler.logError(
        e: 'Error playing audio',
        s: s,
        data: {'error': e.toString(), 'text': text},
      );
    } finally {
      audioPlayer?.dispose();
      audioPlayer = null;
    }
  }

  static bool _isLangFullySupported(String langCode) {
    if (_availableLangCodes.contains(langCode)) {
      return true;
    }

    final langCodeShort = langCode.split("-").first;
    if (langCodeShort.isEmpty) {
      return false;
    }

    return _availableLangCodes.any((lang) => lang.startsWith(langCodeShort));
  }

  static Future<void> _showTTSDisabledPopup(
    BuildContext context,
    String targetID,
  ) async => OverlayUtil.showPositionedCard(
    context: context,
    backDropToDismiss: false,
    cardToShow: Column(
      spacing: 12.0,
      mainAxisAlignment: MainAxisAlignment.spaceBetween,
      children: [
        CardHeader(InstructionsEnum.ttsDisabled.title(L10n.of(context))),
        Padding(
          padding: const EdgeInsets.all(6.0),
          child: Text(
            InstructionsEnum.ttsDisabled.body(L10n.of(context)),
            style: BotStyle.text(context),
          ),
        ),
      ],
    ),
    maxHeight: 300,
    maxWidth: 300,
    transformTargetId: targetID,
    closePrevOverlay: false,
    overlayKey: InstructionsEnum.ttsDisabled.toString(),
  );
}