import 'dart:developer';

import 'package:fluffychat/pangea/models/pangea_match_model.dart';
import 'package:fluffychat/pangea/models/pangea_token_model.dart';
import 'package:fluffychat/pangea/models/span_card_model.dart';
import 'package:fluffychat/pangea/utils/error_handler.dart';
import 'package:fluffychat/pangea/utils/overlay.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';
import 'package:matrix/matrix.dart';
import 'package:sentry_flutter/sentry_flutter.dart';

import '../constants/model_keys.dart';
import '../widgets/igc/span_card.dart';
import 'language_detection_model.dart';

// import 'package:language_tool/language_tool.dart';

class IGCTextData {
  List<LanguageDetection> detections;
  String originalInput;
  String? fullTextCorrection;
  List<PangeaToken> tokens;
  List<PangeaMatch> matches;
  String userL1;
  String userL2;
  bool enableIT;
  bool enableIGC;
  bool loading = false;

  IGCTextData({
    required this.detections,
    required this.originalInput,
    required this.fullTextCorrection,
    required this.tokens,
    required this.matches,
    required this.userL1,
    required this.userL2,
    required this.enableIT,
    required this.enableIGC,
  });

  factory IGCTextData.fromJson(Map<String, dynamic> json) {
    return IGCTextData(
      tokens: (json[_tokensKey] as Iterable)
          .map<PangeaToken>(
            (e) => PangeaToken.fromJson(e as Map<String, dynamic>),
          )
          .toList()
          .cast<PangeaToken>(),
      matches: json[_matchesKey] != null
          ? (json[_matchesKey] as Iterable)
              .map<PangeaMatch>(
                (e) {
                  return PangeaMatch.fromJson(e as Map<String, dynamic>);
                },
              )
              .toList()
              .cast<PangeaMatch>()
          : [],
      detections: (json[_detectionsKey] as Iterable)
          .map<LanguageDetection>(
            (e) => LanguageDetection.fromJson(e as Map<String, dynamic>),
          )
          .toList()
          .cast<LanguageDetection>(),
      originalInput: json["original_input"],
      fullTextCorrection: json["full_text_correction"],
      userL1: json[ModelKey.userL1],
      userL2: json[ModelKey.userL2],
      enableIT: json["enable_it"],
      enableIGC: json["enable_igc"],
    );
  }

  static const String _tokensKey = "tokens";
  static const String _matchesKey = "matches";
  static const String _detectionsKey = "detections";

  Map<String, dynamic> toJson() => {
        _detectionsKey: detections.map((e) => e.toJson()).toList(),
        "original_input": originalInput,
        "full_text_correction": fullTextCorrection,
        _tokensKey: tokens.map((e) => e.toJson()).toList(),
        _matchesKey: matches.map((e) => e.toJson()).toList(),
        ModelKey.userL1: userL1,
        ModelKey.userL2: userL2,
        "enable_it": enableIT,
        "enable_igc": enableIGC,
      };

  // reconstruct fullText based on accepted match
  //update offsets in existing matches to reflect the change
  //if existing matches overlap with the accepted one, remove them??
  void acceptReplacement(
    int matchIndex,
    int choiceIndex,
  ) async {
    //should be already added to choreoRecord
    //TODO - that should be done in the same function to avoid error potential
    final PangeaMatch pangeaMatch = matches[matchIndex];

    if (pangeaMatch.match.choices == null) {
      debugger(when: kDebugMode);
      ErrorHandler.logError(
        m: "pangeaMatch.match.choices is null in acceptReplacement",
      );
      return;
    }

    final String replacement = pangeaMatch.match.choices![choiceIndex].value;

    originalInput = originalInput.replaceRange(
      pangeaMatch.match.offset,
      pangeaMatch.match.offset + pangeaMatch.match.length,
      replacement,
    );

    //update offsets in existing matches to reflect the change
    //Question - remove matches that overlap with the accepted one?
    // see case of "quiero ver un fix"
    matches.removeAt(matchIndex);

    for (final match in matches) {
      final matchOffset = match.match.offset;
      final matchLength = match.match.length;
      match.match.fullText = originalInput;
      if (match.match.offset > pangeaMatch.match.offset) {
        match.match.offset += replacement.length - pangeaMatch.match.length;
      }
    }
    //quiero ver un fix
    //match offset zero and length of full text or 16
    //fix is repplaced by arreglo and now the length needs to be 20
    //if the accepted span is within another span, then the length of that span needs
    //needs to be increased by the difference between the new and old length
    //if the two spans are overlapping, what happens?
    //------
    //   ----- -> ---
    //if there is any overlap, maybe igc needs to run again?
  }

  void removeMatchByOffset(int offset) {
    final int index = getTopMatchIndexForOffset(offset);
    if (index != -1) {
      matches.removeAt(index);
    }
  }

  int tokenIndexByOffset(cursorOffset) => tokens.indexWhere(
        (token) =>
            token.text.offset <= cursorOffset && cursorOffset <= token.end,
      );

  List<int> matchIndicesByOffset(int offset) {
    final List<int> matchesForOffset = [];
    for (final (index, match) in matches.indexed) {
      if (match.isOffsetInMatchSpan(offset)) {
        matchesForOffset.add(index);
      }
    }
    return matchesForOffset;
  }

  int getTopMatchIndexForOffset(int offset) {
    final List<int> matchesForToken = matchIndicesByOffset(offset);
    final int matchIndex = matchesForToken.indexWhere((matchIndex) {
      final match = matches[matchIndex];
      return (enableIT && (match.isITStart || match.isl1SpanMatch)) ||
          (enableIGC && match.isGrammarMatch);
    });
    if (matchIndex == -1) return -1;
    return matchesForToken[matchIndex];
  }

  PangeaMatch? getTopMatchForToken(PangeaToken token) {
    final int topMatchIndex = getTopMatchIndexForOffset(token.text.offset);
    if (topMatchIndex == -1) return null;
    return matches[topMatchIndex];
  }

  int getAfterTokenSpacingByIndex(int tokenIndex) {
    final int endOfToken = tokens[tokenIndex].end;

    if (tokenIndex + 1 < tokens.length) {
      final spaceBetween = tokens[tokenIndex + 1].text.offset - endOfToken;

      if (spaceBetween < 0) {
        Sentry.addBreadcrumb(
          Breadcrumb.fromJson(
            {
              "fullText": originalInput,
              "tokens": tokens.map((e) => e.toJson()).toString(),
            },
          ),
        );
        ErrorHandler.logError(
          m: "weird token lengths for ${tokens[tokenIndex].text.content} and ${tokens[tokenIndex + 1].text.content}",
        );
        return 0;
      }
      return spaceBetween;
    } else {
      return originalInput.length - endOfToken;
    }
  }

  static TextStyle underlineStyle(Color color) => TextStyle(
        decoration: TextDecoration.underline,
        decorationColor: color,
        decorationThickness: 5,
      );

  List<MatchToken> getMatchTokens() {
    final List<MatchToken> matchTokens = [];
    int? endTokenIndex;
    PangeaMatch? topMatch;
    for (final (i, token) in tokens.indexed) {
      if (endTokenIndex != null) {
        if (i <= endTokenIndex) {
          matchTokens.add(
            MatchToken(
              token: token,
              match: topMatch,
            ),
          );
          continue;
        }
        endTokenIndex = null;
      }
      topMatch = getTopMatchForToken(token);
      if (topMatch != null) {
        endTokenIndex = tokens.indexWhere((e) => e.end >= topMatch!.end, i);
      }
      matchTokens.add(
        MatchToken(
          token: token,
          match: topMatch,
        ),
      );
    }
    return matchTokens;
  }

  //PTODO - handle multitoken spans
  List<TextSpan> constructTokenSpan({
    required BuildContext context,
    TextStyle? defaultStyle,
    required SpanCardModel? spanCardModel,
    required bool handleClick,
    required String transformTargetId,
    required Room room,
  }) {
    final List<TextSpan> items = [];

    if (loading) {
      return [
        TextSpan(
          text: originalInput,
          style: defaultStyle,
        ),
      ];
    }

    final List<MatchToken> matchTokens = getMatchTokens();

    for (int tokenIndex = 0; tokenIndex < matchTokens.length; tokenIndex++) {
      final MatchToken matchToken = matchTokens[tokenIndex];
      final Widget? cardToShow =
          matchToken.match != null && spanCardModel != null
              ? SpanCard(scm: spanCardModel)
              : null;

      int nextTokenIndex = matchTokens.indexWhere(
        (e) => matchToken.match != null
            ? e.match != matchToken.match
            : e.match != null,
        tokenIndex,
      );

      if (nextTokenIndex < 0) {
        nextTokenIndex = matchTokens.length;
      }

      String matchText;
      try {
        matchText = originalInput.substring(
          matchTokens[tokenIndex].token.text.offset,
          matchTokens[nextTokenIndex - 1].token.end,
        );
      } catch (err) {
        return [
          TextSpan(
            text: originalInput,
            style: defaultStyle,
          ),
        ];
      }

      items.add(
        TextSpan(
          text: matchText,
          style: matchTokens[tokenIndex].match?.textStyle(defaultStyle) ??
              defaultStyle,
          recognizer: handleClick && cardToShow != null
              ? (TapGestureRecognizer()
                ..onTapDown = (details) => OverlayUtil.showPositionedCard(
                      context: context,
                      cardToShow: cardToShow,
                      cardSize:
                          matchTokens[tokenIndex].match?.isITStart ?? false
                              ? const Size(350, 220)
                              : const Size(350, 400),
                      transformTargetId: transformTargetId,
                    ))
              : null,
        ),
      );

      final String beforeNextToken = originalInput.substring(
        matchTokens[nextTokenIndex - 1].token.end,
        nextTokenIndex < matchTokens.length
            ? matchTokens[nextTokenIndex].token.text.offset
            : originalInput.length,
      );

      if (beforeNextToken.isNotEmpty) {
        items.add(
          TextSpan(
            text: beforeNextToken,
            style: defaultStyle,
          ),
        );
      }

      tokenIndex = nextTokenIndex - 1;
    }

    return items;
  }
}

class MatchToken {
  final PangeaToken token;
  final PangeaMatch? match;

  MatchToken({required this.token, this.match});
}