Add SpaceReorderDataModel and integrate drag-and-drop functionality in CommunityStructureCanvas for improved space management.

lib/pages/space_management_v2/main_module/models/space_reorder_data_model.dart

@@ -0,0 +1,14 @@
+import 'package:syncrow_web/pages/space_management_v2/modules/communities/domain/models/community_model.dart';
+import 'package:syncrow_web/pages/space_management_v2/modules/communities/domain/models/space_model.dart';
+
+class SpaceReorderDataModel {
+  const SpaceReorderDataModel({
+    required this.space,
+    this.parent,
+    this.community,
+  });
+
+  final SpaceModel space;
+  final SpaceModel? parent;
+  final CommunityModel? community;
+}

lib/pages/space_management_v2/main_module/widgets/community_structure_canvas.dart

@@ -1,12 +1,14 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:syncrow_web/pages/space_management_v2/main_module/models/space_connection_model.dart';
+import 'package:syncrow_web/pages/space_management_v2/main_module/models/space_reorder_data_model.dart';
 import 'package:syncrow_web/pages/space_management_v2/main_module/painters/spaces_connections_arrow_painter.dart';
 import 'package:syncrow_web/pages/space_management_v2/main_module/widgets/create_space_button.dart';
 import 'package:syncrow_web/pages/space_management_v2/main_module/widgets/space_card_widget.dart';
 import 'package:syncrow_web/pages/space_management_v2/main_module/widgets/space_cell.dart';
 import 'package:syncrow_web/pages/space_management_v2/modules/communities/domain/models/community_model.dart';
 import 'package:syncrow_web/pages/space_management_v2/modules/communities/domain/models/space_model.dart';
+import 'package:syncrow_web/pages/space_management_v2/modules/communities/presentation/bloc/communities_bloc.dart';
 import 'package:syncrow_web/pages/space_management_v2/modules/communities/presentation/communities_tree_selection_bloc/communities_tree_selection_bloc.dart';
 import 'package:syncrow_web/pages/space_management_v2/modules/space_details/presentation/helpers/space_details_dialog_helper.dart';
 import 'package:syncrow_web/utils/extension/build_context_x.dart';
@@ -35,6 +37,7 @@ class _CommunityStructureCanvasState extends State<CommunityStructureCanvas>
 
   late final TransformationController _transformationController;
   late final AnimationController _animationController;
+  SpaceReorderDataModel? _draggedData;
 
   @override
   void initState() {
@@ -99,7 +102,7 @@ class _CommunityStructureCanvasState extends State<CommunityStructureCanvas>
     final position = _positions[space.uuid];
     if (position == null) return;
 
-    const scale = 1.5;
+    const scale = 1;
     final viewSize = context.size;
     if (viewSize == null) return;
 
@@ -114,16 +117,33 @@ class _CommunityStructureCanvasState extends State<CommunityStructureCanvas>
     _runAnimation(matrix);
   }
 
+  void _onReorder(SpaceReorderDataModel data, int newIndex) {
+    final newCommunity = widget.community.copyWith();
+    final children = data.parent?.children ?? newCommunity.spaces;
+    final oldIndex = children.indexWhere((s) => s.uuid == data.space.uuid);
+    if (oldIndex != -1) {
+      final item = children.removeAt(oldIndex);
+      if (newIndex > oldIndex) {
+        children.insert(newIndex - 1, item);
+      } else {
+        children.insert(newIndex, item);
+      }
+    }
+    context.read<CommunitiesBloc>().add(
+          CommunitiesUpdateCommunity(newCommunity),
+        );
+  }
+
   void _onSpaceTapped(SpaceModel? space) {
     context.read<CommunitiesTreeSelectionBloc>().add(
           SelectSpaceEvent(community: widget.community, space: space),
         );
   }
 
-  void _resetSelectionAndZoom() {
+  void _resetSelectionAndZoom([CommunityModel? community]) {
     context.read<CommunitiesTreeSelectionBloc>().add(
           SelectSpaceEvent(
-            community: widget.community,
+            community: community ?? widget.community,
             space: null,
           ),
         );
@@ -196,7 +216,13 @@ class _CommunityStructureCanvasState extends State<CommunityStructureCanvas>
 
     final widgets = <Widget>[];
     final connections = <SpaceConnectionModel>[];
-    _generateWidgets(community.spaces, widgets, connections, highlightedUuids);
+    _generateWidgets(
+      widget.community.spaces,
+      widgets,
+      connections,
+      highlightedUuids,
+      community: widget.community,
+    );
 
     final createButtonX = levelXOffset[0] ?? 0.0;
     const createButtonY = 0.0;
@@ -225,22 +251,30 @@ class _CommunityStructureCanvasState extends State<CommunityStructureCanvas>
     List<SpaceModel> spaces,
     List<Widget> widgets,
     List<SpaceConnectionModel> connections,
-    Set<String> highlightedUuids,
-  ) {
-    for (final space in spaces) {
+    Set<String> highlightedUuids, {
+    CommunityModel? community,
+    SpaceModel? parent,
+  }) {
+    if (spaces.isNotEmpty) {
+      final firstChildPos = _positions[spaces.first.uuid]!;
+      final targetPos = Offset(
+        firstChildPos.dx - (_horizontalSpacing / 4),
+        firstChildPos.dy,
+      );
+      widgets.add(_buildDropTarget(parent, community, 0, targetPos));
+    }
+
+    for (var i = 0; i < spaces.length; i++) {
+      final space = spaces[i];
       final position = _positions[space.uuid];
-      if (position == null) continue;
+      if (position == null) {
+        continue;
+      }
 
       final isHighlighted = highlightedUuids.contains(space.uuid);
       final hasNoSelectedSpace = widget.selectedSpace == null;
 
-      widgets.add(
-        Positioned(
-          left: position.dx,
-          top: position.dy,
-          width: _cardWidth,
-          height: _cardHeight,
-          child: SpaceCardWidget(
+      final spaceCard = SpaceCardWidget(
         buildSpaceContainer: () {
           return Opacity(
             opacity: hasNoSelectedSpace || isHighlighted ? 1.0 : 0.5,
@@ -259,19 +293,128 @@ class _CommunityStructureCanvasState extends State<CommunityStructureCanvas>
           context,
           communityUuid: widget.community.uuid,
         ),
+      );
+
+      final reorderData = SpaceReorderDataModel(
+        space: space,
+        parent: parent,
+        community: community,
+      );
+
+      widgets.add(
+        Positioned(
+          left: position.dx,
+          top: position.dy,
+          width: _cardWidth,
+          height: _cardHeight,
+          child: Draggable<SpaceReorderDataModel>(
+            data: reorderData,
+            feedback: Material(
+              color: Colors.transparent,
+              child: Opacity(
+                opacity: 0.2,
+                child: SizedBox(
+                  width: _cardWidth,
+                  height: _cardHeight,
+                  child: spaceCard,
+                ),
+              ),
+            ),
+            onDragStarted: () => setState(() => _draggedData = reorderData),
+            onDragEnd: (_) => setState(() => _draggedData = null),
+            onDraggableCanceled: (_, __) => setState(() => _draggedData = null),
+            childWhenDragging: Opacity(opacity: 0.4, child: spaceCard),
+            child: spaceCard,
           ),
         ),
       );
 
+      final targetPos = Offset(
+        position.dx + _cardWidth + (_horizontalSpacing / 4) - 20,
+        position.dy,
+      );
+      widgets.add(_buildDropTarget(parent, community, i + 1, targetPos));
+
       for (final child in space.children) {
-        connections.add(
-          SpaceConnectionModel(from: space.uuid, to: child.uuid),
+        connections.add(SpaceConnectionModel(from: space.uuid, to: child.uuid));
+      }
+
+      if (space.children.isNotEmpty) {
+        _generateWidgets(
+          space.children,
+          widgets,
+          connections,
+          highlightedUuids,
+          parent: space,
         );
       }
-      _generateWidgets(space.children, widgets, connections, highlightedUuids);
     }
   }
 
+  Widget _buildDropTarget(
+    SpaceModel? parent,
+    CommunityModel? community,
+    int index,
+    Offset position,
+  ) {
+    return Positioned(
+      left: position.dx,
+      top: position.dy,
+      width: 40,
+      height: _cardHeight,
+      child: DragTarget<SpaceReorderDataModel>(
+        builder: (context, candidateData, rejectedData) {
+          if (_draggedData == null) {
+            return const SizedBox();
+          }
+
+          final isTargetForDragged = (_draggedData?.parent?.uuid == parent?.uuid &&
+                  _draggedData?.community == null) ||
+              (_draggedData?.community?.uuid == community?.uuid &&
+                  _draggedData?.parent == null);
+
+          if (!isTargetForDragged) {
+            return const SizedBox();
+          }
+
+          return Container(
+            width: 40,
+            height: _cardHeight,
+            decoration: BoxDecoration(
+              color: context.theme.colorScheme.primary.withValues(
+                alpha: candidateData.isNotEmpty ? 0.7 : 0.3,
+              ),
+              borderRadius: BorderRadius.circular(8),
+            ),
+            child: Icon(
+              Icons.add,
+              color: context.theme.colorScheme.onPrimary,
+            ),
+          );
+        },
+        onWillAcceptWithDetails: (data) {
+          final children = parent?.children ?? community?.spaces ?? [];
+          final isSameParent = (data.data.parent?.uuid == parent?.uuid &&
+                  data.data.community == null) ||
+              (data.data.community?.uuid == community?.uuid &&
+                  data.data.parent == null);
+
+          if (!isSameParent) {
+            return false;
+          }
+
+          final oldIndex =
+              children.indexWhere((s) => s.uuid == data.data.space.uuid);
+          if (oldIndex == index || oldIndex == index - 1) {
+            return false;
+          }
+          return true;
+        },
+        onAcceptWithDetails: (data) => _onReorder(data.data, index),
+      ),
+    );
+  }
+
   @override
   Widget build(BuildContext context) {
     final treeWidgets = _buildTreeWidgets();