fluffychat/lib/pangea/widgets/chat/message_selection_overlay.dart

import 'package:fluffychat/config/themes.dart';
import 'package:fluffychat/pages/chat/chat.dart';
import 'package:fluffychat/pangea/matrix_event_wrappers/pangea_message_event.dart';
import 'package:fluffychat/pangea/utils/any_state_holder.dart';
import 'package:fluffychat/pangea/utils/error_handler.dart';
import 'package:fluffychat/pangea/widgets/chat/message_toolbar.dart';
import 'package:fluffychat/pangea/widgets/chat/overlay_footer.dart';
import 'package:fluffychat/pangea/widgets/chat/overlay_header.dart';
import 'package:fluffychat/pangea/widgets/chat/overlay_message.dart';
import 'package:fluffychat/utils/platform_infos.dart';
import 'package:fluffychat/widgets/matrix.dart';
import 'package:flutter/material.dart';

class MessageSelectionOverlay extends StatelessWidget {
  final ChatController controller;
  final ToolbarDisplayController toolbarController;
  final Function closeToolbar;
  final Widget toolbar;
  final PangeaMessageEvent pangeaMessageEvent;
  final bool ownMessage;
  final bool immersionMode;
  final String targetId;

  const MessageSelectionOverlay({
    required this.controller,
    required this.closeToolbar,
    required this.toolbar,
    required this.pangeaMessageEvent,
    required this.immersionMode,
    required this.ownMessage,
    required this.targetId,
    required this.toolbarController,
    super.key,
  });

  @override
  Widget build(BuildContext context) {
    final LayerLinkAndKey layerLinkAndKey =
        MatrixState.pAnyState.layerLinkAndKey(targetId);
    final targetRenderBox =
        layerLinkAndKey.key.currentContext?.findRenderObject();

    double center = 290;
    double? left;
    double? right;
    bool showDown = false;
    final double footerSize = PlatformInfos.isMobile
        ? PlatformInfos.isIOS
            ? 128
            : 108
        : 143;
    final double headerSize = PlatformInfos.isMobile
        ? PlatformInfos.isIOS
            ? 121
            : 84
        : 77;
    final double stackSize =
        MediaQuery.of(context).size.height - footerSize - headerSize;

    try {
      if (targetRenderBox != null) {
        final Size transformTargetSize = (targetRenderBox as RenderBox).size;
        final Offset targetOffset =
            (targetRenderBox).localToGlobal(Offset.zero);
        if (ownMessage) {
          right = MediaQuery.of(context).size.width -
              targetOffset.dx -
              transformTargetSize.width;
        } else {
          left =
              targetOffset.dx - (FluffyThemes.isColumnMode(context) ? 425 : 1);
        }

        showDown = targetOffset.dy + transformTargetSize.height / 2 <=
            headerSize + stackSize / 2;

        center = targetOffset.dy -
            headerSize +
            (showDown ? transformTargetSize.height + 3 : (-3));
        // If top of selected message extends below header
        if (targetOffset.dy <= headerSize) {
          center = transformTargetSize.height + 3;
          showDown = true;
        }
        // If bottom of selected message extends below footer
        else if (targetOffset.dy + transformTargetSize.height >=
            headerSize + stackSize) {
          center = stackSize - transformTargetSize.height - 3;
        }
        final double midpoint = headerSize + stackSize / 2;
        // If message is too long,
        // use default location to make full use of screen
        if (transformTargetSize.height >= stackSize / 2 - 30) {
          center = stackSize / 2 + (showDown ? -30 : 30);
        }
        // If message is not too long, but too close
        // to center of screen, scroll closer to edges
        else if (targetOffset.dy + transformTargetSize.height > midpoint - 30 &&
            targetOffset.dy < midpoint + 30) {
          final double scrollUp = midpoint + 30 - targetOffset.dy;
          final double scrollDown =
              targetOffset.dy + transformTargetSize.height - (midpoint - 30);
          final double minScroll =
              controller.scrollController.position.minScrollExtent;
          final double maxScroll =
              controller.scrollController.position.maxScrollExtent;
          final double currentOffset = controller.scrollController.offset;

          // If can scroll up, scroll up
          if (currentOffset + scrollUp < maxScroll) {
            controller.scrollController.animateTo(
              currentOffset + scrollUp,
              duration: FluffyThemes.animationDuration,
              curve: FluffyThemes.animationCurve,
            );
            showDown = false;
            center = stackSize / 2 + 27;
          }

          // Else if can scroll down, scroll down
          else if (currentOffset - scrollDown > minScroll) {
            controller.scrollController.animateTo(
              currentOffset - scrollDown,
              duration: FluffyThemes.animationDuration,
              curve: FluffyThemes.animationCurve,
            );
            showDown = true;
            center = stackSize / 2 - 27;
          }

          // Neither scrolling works; leave message as-is,
          // and use centered toolbar location
          else {
            center = stackSize / 2 + (showDown ? -30 : 30);
          }
        }
      }
    } catch (err) {
      MatrixState.pAnyState.closeAllOverlays();
      ErrorHandler.logError(e: err, s: StackTrace.current);
      // throw L10n.of(context)!.toolbarError;
      return const SizedBox();
    }

    final Widget overlayMessage = OverlayMessage(
      pangeaMessageEvent.event,
      timeline: pangeaMessageEvent.timeline,
      immersionMode: immersionMode,
      ownMessage: pangeaMessageEvent.ownMessage,
      toolbarController: toolbarController,
      width: 290,
      showDown: showDown,
    );

    return Expanded(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        mainAxisSize: MainAxisSize.max,
        crossAxisAlignment:
            ownMessage ? CrossAxisAlignment.end : CrossAxisAlignment.start,
        children: [
          OverlayHeader(
            controller: controller,
            closeToolbar: closeToolbar,
          ),
          SizedBox(
            height: PlatformInfos.isAndroid ? 3 : 6,
          ),
          Flexible(
            child: Stack(
              children: [
                Positioned(
                  left: left,
                  right: right,
                  bottom: stackSize - center + 3,
                  child: showDown ? overlayMessage : toolbar,
                ),
                Positioned(
                  left: left,
                  right: right,
                  top: center + 3,
                  child: showDown ? toolbar : overlayMessage,
                ),
              ],
            ),
          ),
          SizedBox(
            height: PlatformInfos.isAndroid ? 3 : 6,
          ),
          OverlayFooter(controller: controller),
        ],
      ),
    );
  }
}