import 'package:flutter/material.dart';

import 'package:collection/collection.dart';
import 'package:flutter_linkify/flutter_linkify.dart';

import 'package:fluffychat/pangea/common/utils/any_state_holder.dart';
import 'package:fluffychat/pangea/events/event_wrappers/pangea_message_event.dart';
import 'package:fluffychat/pangea/events/models/pangea_token_model.dart';
import 'package:fluffychat/pangea/events/utils/message_text_util.dart';
import 'package:fluffychat/pangea/message_token_text/message_token_button.dart';
import 'package:fluffychat/pangea/practice_activities/practice_selection.dart';
import 'package:fluffychat/pangea/practice_activities/practice_selection_repo.dart';
import 'package:fluffychat/pangea/toolbar/enums/message_mode_enum.dart';
import 'package:fluffychat/pangea/toolbar/enums/reading_assistance_mode_enum.dart';
import 'package:fluffychat/pangea/toolbar/utils/token_rendering_util.dart';
import 'package:fluffychat/pangea/toolbar/widgets/message_selection_overlay.dart';
import 'package:fluffychat/utils/url_launcher.dart';
import 'package:fluffychat/widgets/matrix.dart';

/// Question - does this need to be stateful or does this work?
/// Need to test.
///

class MessageTokenText extends StatelessWidget {
  final PangeaMessageEvent _pangeaMessageEvent;
  final TextStyle _style;

  final bool Function(PangeaToken)? _isSelected;
  final void Function(PangeaToken)? _onClick;
  final bool Function(PangeaToken)? _isHighlighted;
  final MessageOverlayController? _overlayController;
  final bool _isTransitionAnimation;
  final ReadingAssistanceMode? readingAssistanceMode;

  const MessageTokenText({
    super.key,
    required PangeaMessageEvent pangeaMessageEvent,
    required List<PangeaToken>? tokens,
    required TextStyle style,
    required void Function(PangeaToken)? onClick,
    bool Function(PangeaToken)? isSelected,
    bool Function(PangeaToken)? isHighlighted,
    MessageMode? messageMode,
    MessageOverlayController? overlayController,
    bool isTransitionAnimation = false,
    this.readingAssistanceMode,
  })  : _onClick = onClick,
        _isSelected = isSelected,
        _style = style,
        _pangeaMessageEvent = pangeaMessageEvent,
        _isHighlighted = isHighlighted,
        _overlayController = overlayController,
        _isTransitionAnimation = isTransitionAnimation;

  List<PangeaToken>? get _tokens =>
      _pangeaMessageEvent.messageDisplayRepresentation?.tokens;

  PracticeSelection? get messageAnalyticsEntry => _tokens != null
      ? PracticeSelectionRepo.get(
          _pangeaMessageEvent.messageDisplayLangCode,
          _tokens!,
        )
      : null;

  void callOnClick(TokenPosition tokenPosition) {
    _onClick != null && tokenPosition.token != null
        ? _onClick!(tokenPosition.token!)
        : null;
  }

  @override
  Widget build(BuildContext context) {
    if (_tokens == null) {
      return Text(
        _pangeaMessageEvent.messageDisplayText,
        style: _style,
        textScaler: TextScaler.noScaling,
      );
    }

    return MessageTextWidget(
      pangeaMessageEvent: _pangeaMessageEvent,
      existingStyle: _style,
      messageAnalyticsEntry: messageAnalyticsEntry,
      isSelected: _isSelected,
      onClick: callOnClick,
      isHighlighted: _isHighlighted,
      overlayController: _overlayController,
      isTransitionAnimation: _isTransitionAnimation,
      readingAssistanceMode: readingAssistanceMode,
    );
  }
}

class MessageTextWidget extends StatelessWidget {
  final PangeaMessageEvent pangeaMessageEvent;
  final TextStyle existingStyle;
  final PracticeSelection? messageAnalyticsEntry;
  final bool Function(PangeaToken)? isSelected;
  final void Function(TokenPosition tokenPosition)? onClick;
  final bool Function(PangeaToken)? isHighlighted;

  final bool? softWrap;
  final int? maxLines;
  final TextOverflow? overflow;

  final MessageOverlayController? overlayController;
  final bool isTransitionAnimation;
  final bool isMessage;
  final ReadingAssistanceMode? readingAssistanceMode;

  final TextScaler? textScaler;

  const MessageTextWidget({
    super.key,
    required this.pangeaMessageEvent,
    required this.existingStyle,
    this.messageAnalyticsEntry,
    this.isSelected,
    this.onClick,
    this.softWrap,
    this.maxLines,
    this.overflow,
    this.isHighlighted,
    this.overlayController,
    this.isTransitionAnimation = false,
    this.isMessage = true,
    this.readingAssistanceMode,
    this.textScaler,
  });

  @override
  Widget build(BuildContext context) {
    final renderer = TokenRenderingUtil(
      pangeaMessageEvent: pangeaMessageEvent,
      readingAssistanceMode: readingAssistanceMode,
      existingStyle: existingStyle,
      overlayController: overlayController,
      isTransitionAnimation: isTransitionAnimation,
    );

    final Characters messageCharacters =
        pangeaMessageEvent.messageDisplayText.characters;

    final tokenPositions = MessageTextUtil.getTokenPositions(
      pangeaMessageEvent,
      messageAnalyticsEntry: messageAnalyticsEntry,
      isSelected: isSelected,
      isHighlighted: isHighlighted,
    );

    if (tokenPositions == null) {
      return Text(
        pangeaMessageEvent.messageDisplayText,
        style: renderer.style(context),
        softWrap: softWrap,
        maxLines: maxLines,
        overflow: overflow,
        textScaler: textScaler,
      );
    }

    final theme = Theme.of(context);
    final ownMessage =
        pangeaMessageEvent.senderId == Matrix.of(context).client.userID;
    final linkColor = theme.brightness == Brightness.light
        ? theme.colorScheme.primary
        : ownMessage
            ? theme.colorScheme.onPrimary
            : theme.colorScheme.onSurface;

    return RichText(
      softWrap: softWrap ?? true,
      maxLines: maxLines,
      overflow: overflow ?? TextOverflow.clip,
      textScaler: textScaler ?? TextScaler.noScaling,
      text: TextSpan(
        children:
            tokenPositions.mapIndexed((int i, TokenPosition tokenPosition) {
          final substring = messageCharacters
              .skip(tokenPosition.start)
              .take(tokenPosition.end - tokenPosition.start)
              .toString();

          if (tokenPosition.token?.pos == 'SPACE') {
            return const TextSpan(text: '\n');
          }

          if (tokenPosition.token != null) {
            // if the tokenPosition is a combination of the token and preceding / following punctuation
            // split them so that only the token itself is highlighted when clicked
            String start = '';
            String middle = '';
            String end = '';

            final startSplitIndex =
                tokenPosition.tokenStart - tokenPosition.start;
            final endSplitIndex = tokenPosition.tokenEnd - tokenPosition.start;

            start = substring.characters.take(startSplitIndex).toString();
            end = substring.characters.skip(endSplitIndex).toString();
            middle = substring.characters
                .skip(startSplitIndex)
                .take(endSplitIndex - startSplitIndex)
                .toString();

            final token = tokenPosition.token!;

            final tokenWidth = renderer.tokenTextWidthForContainer(
              context,
              token.text.content,
            );

            return WidgetSpan(
              child: CompositedTransformTarget(
                link: renderer.assignTokenKey
                    ? MatrixState.pAnyState
                        .layerLinkAndKey(token.text.uniqueKey)
                        .link
                    : LayerLinkAndKey(token.hashCode.toString()).link,
                child: Column(
                  key: renderer.assignTokenKey
                      ? MatrixState.pAnyState
                          .layerLinkAndKey(token.text.uniqueKey)
                          .key
                      : null,
                  children: [
                    if (renderer.showCenterStyling)
                      MessageTokenButton(
                        token: token,
                        overlayController: overlayController,
                        textStyle: renderer.style(context),
                        width: tokenWidth,
                        animateIn: isTransitionAnimation,
                        practiceTargetForToken: overlayController
                                    ?.toolbarMode.associatedActivityType !=
                                null
                            ? overlayController?.practiceSelection
                                ?.activities(
                                  overlayController!
                                      .toolbarMode.associatedActivityType!,
                                )
                                .firstWhereOrNull(
                                  (a) => a.tokens.contains(token),
                                )
                            : null,
                      ),
                    MouseRegion(
                      cursor: SystemMouseCursors.click,
                      child: GestureDetector(
                        behavior: HitTestBehavior.translucent,
                        onTap: onClick != null
                            ? () => onClick?.call(tokenPosition)
                            : null,
                        child: RichText(
                          text: TextSpan(
                            children: [
                              if (start.isNotEmpty)
                                LinkifySpan(
                                  text: start,
                                  style: renderer.style(
                                    context,
                                    color: renderer.backgroundColor(
                                      context,
                                      tokenPosition.selected,
                                    ),
                                  ),
                                  linkStyle: TextStyle(
                                    decoration: TextDecoration.underline,
                                    color: linkColor,
                                  ),
                                  onOpen: (url) =>
                                      UrlLauncher(context, url.url).launchUrl(),
                                ),
                              // tokenPosition.hideContent
                              //     ? WidgetSpan(
                              //         alignment: PlaceholderAlignment.middle,
                              //         child: GestureDetector(
                              //           onTap: onClick != null
                              //               ? () => onClick?.call(tokenPosition)
                              //               : null,
                              //           child: HiddenText(
                              //             text: middle,
                              //             style: style(context),
                              //           ),
                              //         ),
                              //       )
                              //     :
                              LinkifySpan(
                                text: middle,
                                style: renderer.style(
                                  context,
                                  color: renderer.backgroundColor(
                                    context,
                                    tokenPosition.selected,
                                  ),
                                ),
                                linkStyle: TextStyle(
                                  decoration: TextDecoration.underline,
                                  color: linkColor,
                                ),
                                onOpen: (url) =>
                                    UrlLauncher(context, url.url).launchUrl(),
                              ),
                              if (end.isNotEmpty)
                                LinkifySpan(
                                  text: end,
                                  style: renderer.style(
                                    context,
                                    color: renderer.backgroundColor(
                                      context,
                                      tokenPosition.selected,
                                    ),
                                  ),
                                  linkStyle: TextStyle(
                                    decoration: TextDecoration.underline,
                                    color: linkColor,
                                  ),
                                  onOpen: (url) =>
                                      UrlLauncher(context, url.url).launchUrl(),
                                ),
                            ],
                          ),
                        ),
                      ),
                    ),
                    // AnimatedContainer(
                    //   duration: const Duration(
                    //     milliseconds: AppConfig.overlayAnimationDuration,
                    //   ),
                    //   height: overlayController != null && isTransitionAnimation
                    //       ? 4
                    //       : 0,
                    //   width: tokenWidth,
                    //   child: Container(
                    //     color: backgroundColor(context, tokenPosition),
                    //   ),
                    // ),
                  ],
                ),
              ),
            );
          } else {
            // if ((i > 0 || i < tokenPositions.length - 1) &&
            //     tokenPositions[i + 1].hideContent &&
            //     tokenPositions[i - 1].hideContent) {
            //   return WidgetSpan(
            //     child: GestureDetector(
            //       onTap: onClick != null
            //           ? () => onClick?.call(tokenPosition)
            //           : null,
            //       child: HiddenText(
            //         text: substring,
            //         style: style(context),
            //       ),
            //     ),
            //   );
            // }
            return LinkifySpan(
              text: substring,
              style: renderer.style(context),
              options: const LinkifyOptions(humanize: false),
              linkStyle: TextStyle(
                decoration: TextDecoration.underline,
                color: Theme.of(context).colorScheme.primary,
              ),
              onOpen: (url) => UrlLauncher(context, url.url).launchUrl(),
            );
          }
        }).toList(),
      ),
    );
  }
}

// class HiddenText extends StatelessWidget {
//   final String text;
//   final TextStyle style;

//   const HiddenText({
//     super.key,
//     required this.text,
//     required this.style,
//   });

//   @override
//   Widget build(BuildContext context) {
//     final TextPainter textPainter = TextPainter(
//       text: TextSpan(text: text, style: style),
//       textDirection: TextDirection.ltr,
//     )..layout();

//     final textWidth = textPainter.size.width;
//     final textHeight = textPainter.size.height;

//     textPainter.dispose();

//     return SizedBox(
//       height: textHeight,
//       child: Stack(
//         children: [
//           Container(
//             width: textWidth,
//             height: textHeight,
//             color: Colors.transparent,
//           ),
//           Positioned(
//             bottom: 0,
//             child: Container(
//               width: textWidth,
//               height: 1,
//               color: style.color,
//             ),
//           ),
//         ],
//       ),
//     );
//   }
// }