refactor(editor): decouple QueryaCodeEditor from highlight controller lifecycle and manage at session level

lib/core/editor/querya_code_editor.dart

@@ -60,212 +60,93 @@ class QueryaCodeEditor extends StatefulWidget {
 }
 
 class _QueryaCodeEditorState extends State<QueryaCodeEditor> {
-  material.TextEditingController? _plainController;
-  QueryaHighlightController? _highlightController;
-  bool _ownsPlainController = false;
-  bool _ownsHighlightController = false;
-  bool _syncing = false;
-  QueryaEditorTheme? _highlightEditorTheme;
-  QueryaCodeLanguage? _highlightLanguage;
-  int _highlightTokenColorsHash = 0;
+  material.TextEditingController? _internalController;
+  QueryaEditorTheme? _lastEditorTheme;
+  int _lastTokenColorsHash = 0;
 
-  material.TextEditingController get _activeController =>
-      _highlightController ?? _plainController!;
-
-  bool get _useHighlighting =>
-      widget.enableHighlighting &&
-      widget.language != QueryaCodeLanguage.plain &&
-      SyntaxHighlightService.isInitialized;
+  material.TextEditingController get _effectiveController =>
+      widget.controller ?? _internalController!;
 
   @override
   void initState() {
     super.initState();
-    if (!_useHighlighting) {
-      _initPlainController(widget.controller);
-      _plainController!.addListener(_onTextChanged);
-    }
+    _initControllerIfNeeded();
+    _attachListener();
   }
 
-  void _initPlainController(material.TextEditingController? external) {
-    if (external == null) {
-      _plainController = material.TextEditingController();
-      _ownsPlainController = true;
-    } else {
-      _plainController = external;
-      _ownsPlainController = false;
+  void _initControllerIfNeeded() {
+    if (widget.controller == null) {
+      _internalController = material.TextEditingController();
     }
   }
 
-  void _onTextChanged() {
-    widget.onChanged?.call(_activeController.text);
+  void _attachListener() {
+    _effectiveController.addListener(_onTextChanged);
   }
 
-  void _syncFromExternal() {
-    final external = widget.controller;
-    final highlight = _highlightController;
-    if (external == null || highlight == null || _syncing) return;
-    if (external.text == highlight.text &&
-        external.selection == highlight.selection) {
-      return;
-    }
-    _syncing = true;
-    highlight.value = external.value;
-    _syncing = false;
+  void _detachListener([material.TextEditingController? target]) {
+    (target ?? _effectiveController).removeListener(_onTextChanged);
   }
 
-  void _syncToExternal() {
-    final external = widget.controller;
-    final highlight = _highlightController;
-    if (external == null || highlight == null || _syncing) return;
-    if (external.text == highlight.text &&
-        external.selection == highlight.selection) {
-      return;
-    }
-    _syncing = true;
-    external.value = highlight.value;
-    _syncing = false;
-  }
-
-  void _disposeHighlight([material.TextEditingController? externalToDetach]) {
-    final highlight = _highlightController;
-    if (highlight == null) return;
-    highlight.removeListener(_onTextChanged);
-    highlight.removeListener(_syncToExternal);
-    (externalToDetach ?? widget.controller)?.removeListener(_syncFromExternal);
-    if (_ownsHighlightController) {
-      highlight.dispose();
-    }
-    _highlightController = null;
-    _highlightEditorTheme = null;
-    _highlightLanguage = null;
-    _highlightTokenColorsHash = 0;
+  void _onTextChanged() {
+    widget.onChanged?.call(_effectiveController.text);
   }
 
-  void _ensureHighlightController(QueryaTheme queryaTheme) {
-    if (!_useHighlighting) return;
+  void _syncThemeIfNeeded(QueryaTheme queryaTheme) {
+    final controller = _effectiveController;
+    if (controller is! QueryaHighlightController) return;
 
     final editor = queryaTheme.editor;
     final tokenHash = Object.hashAll(queryaTheme.tokenColors);
-    if (_highlightController != null &&
-        _highlightEditorTheme == editor &&
-        _highlightLanguage == widget.language &&
-        _highlightTokenColorsHash == tokenHash) {
+    if (_lastEditorTheme == editor && _lastTokenColorsHash == tokenHash) {
       return;
     }
 
+    _lastEditorTheme = editor;
+    _lastTokenColorsHash = tokenHash;
+
     final pair = SyntaxHighlightService.createPair(
-      language: widget.language,
+      language: controller.language,
       queryaTheme: queryaTheme,
     );
 
-    final external = widget.controller;
-    final text = external?.text ?? _highlightController?.text ?? '';
-
-    _disposeHighlight();
-
-    _highlightController = QueryaHighlightController(
-      text: text,
-      language: widget.language,
+    controller.updateTheme(
       lightHighlighter: pair.light,
       darkHighlighter: pair.dark,
       lightThemeConfig: pair.lightThemeConfig,
       darkThemeConfig: pair.darkThemeConfig,
-      grammarJson: pair.grammarJson,
       wrapperColor: editor.foreground,
     );
-    _ownsHighlightController = external == null;
-    _highlightEditorTheme = editor;
-    _highlightLanguage = widget.language;
-    _highlightTokenColorsHash = tokenHash;
-
-    _highlightController!.addListener(_onTextChanged);
-    if (external != null) {
-      external.addListener(_syncFromExternal);
-      _highlightController!.addListener(_syncToExternal);
-    }
-  }
-
-  void _switchToPlain(material.TextEditingController? external) {
-    _disposeHighlight();
-    final text = external?.text ?? _plainController?.text ?? '';
-    if (_plainController != null) {
-      _plainController!.removeListener(_onTextChanged);
-      if (_ownsPlainController) {
-        _plainController!.dispose();
-      }
-    }
-    _initPlainController(external);
-    if (_ownsPlainController && text.isNotEmpty) {
-      _plainController!.text = text;
-    }
-    _plainController!.addListener(_onTextChanged);
   }
 
   @override
   void didChangeDependencies() {
     super.didChangeDependencies();
-    final queryaTheme = context.queryaTheme;
-    if (_useHighlighting) {
-      if (_plainController != null) {
-        _plainController!.removeListener(_onTextChanged);
-        if (_ownsPlainController) {
-          _plainController!.dispose();
-        }
-        _plainController = null;
-        _ownsPlainController = false;
-      }
-      _ensureHighlightController(queryaTheme);
-    } else if (_highlightController != null) {
-      _highlightController!.removeListener(_onTextChanged);
-      _switchToPlain(widget.controller);
-    } else if (_plainController == null) {
-      _initPlainController(widget.controller);
-      _plainController!.addListener(_onTextChanged);
-    }
+    _syncThemeIfNeeded(context.queryaTheme);
   }
 
   @override
   void didUpdateWidget(QueryaCodeEditor oldWidget) {
     super.didUpdateWidget(oldWidget);
     if (oldWidget.controller != widget.controller) {
-      _highlightController?.removeListener(_onTextChanged);
-      _plainController?.removeListener(_onTextChanged);
-      _disposeHighlight(oldWidget.controller);
-      if (_plainController != null) {
-        _plainController!.removeListener(_onTextChanged);
-        if (_ownsPlainController) {
-          _plainController!.dispose();
-        }
-        _plainController = null;
-      }
-      if (_useHighlighting) {
-        _ensureHighlightController(context.queryaTheme);
-      } else {
-        _initPlainController(widget.controller);
-        _plainController!.addListener(_onTextChanged);
-      }
-    } else if (oldWidget.language != widget.language ||
-        oldWidget.enableHighlighting != widget.enableHighlighting) {
-      _highlightEditorTheme = null;
-      _highlightLanguage = null;
-      _highlightTokenColorsHash = 0;
-      if (_useHighlighting) {
-        _ensureHighlightController(context.queryaTheme);
-      } else {
-        _switchToPlain(widget.controller);
+      _detachListener(oldWidget.controller ?? _internalController);
+      if (oldWidget.controller == null && widget.controller != null) {
+        _internalController?.dispose();
+        _internalController = null;
+      } else if (widget.controller == null && _internalController == null) {
+        _internalController = material.TextEditingController();
       }
+      _lastEditorTheme = null;
+      _lastTokenColorsHash = 0;
+      _attachListener();
+      _syncThemeIfNeeded(context.queryaTheme);
     }
   }
 
   @override
   void dispose() {
-    _disposeHighlight();
-    if (_plainController != null) {
-      _plainController!.removeListener(_onTextChanged);
-      if (_ownsPlainController) {
-        _plainController!.dispose();
-      }
-    }
+    _detachListener();
+    _internalController?.dispose();
     super.dispose();
   }
 
@@ -293,14 +174,10 @@ class _QueryaCodeEditorState extends State<QueryaCodeEditor> {
 
   @override
   Widget build(BuildContext context) {
-    if (_useHighlighting) {
-      _ensureHighlightController(context.queryaTheme);
-    }
-
     final editor = context.editorTheme;
     final style = _textStyle(editor);
     final placeholder = _resolvedPlaceholder();
-    final controller = _highlightController ?? _plainController!;
+    final controller = _effectiveController;
 
     if (widget.variant == QueryaCodeEditorVariant.material) {
       return material.TextField(

lib/core/editor/querya_highlight_controller.dart

@@ -23,12 +23,31 @@ class QueryaHighlightController extends TextEditingController {
   });
 
   final QueryaCodeLanguage language;
-  final Highlighter lightHighlighter;
-  final Highlighter darkHighlighter;
-  final String lightThemeConfig;
-  final String darkThemeConfig;
+  Highlighter lightHighlighter;
+  Highlighter darkHighlighter;
+  String lightThemeConfig;
+  String darkThemeConfig;
   final String grammarJson;
-  final Color wrapperColor;
+  Color wrapperColor;
+
+  /// Updates highlighters and theme configs when application theme changes.
+  void updateTheme({
+    required Highlighter lightHighlighter,
+    required Highlighter darkHighlighter,
+    required String lightThemeConfig,
+    required String darkThemeConfig,
+    required Color wrapperColor,
+  }) {
+    this.lightHighlighter = lightHighlighter;
+    this.darkHighlighter = darkHighlighter;
+    this.lightThemeConfig = lightThemeConfig;
+    this.darkThemeConfig = darkThemeConfig;
+    this.wrapperColor = wrapperColor;
+    _cachedSpan = null;
+    _cachedText = null;
+    _cachedBrightness = null;
+    notifyListeners();
+  }
 
   TextSpan? _cachedSpan;
   String? _cachedText;

lib/core/editor/syntax_highlight_service.dart

@@ -7,6 +7,7 @@ import 'package:syntax_highlight/syntax_highlight.dart';
 
 import 'highlighter_theme_from_querya.dart';
 import 'querya_code_language.dart';
+import 'querya_highlight_controller.dart';
 
 /// Global syntax highlighter setup for [QueryaCodeEditor].
 abstract final class SyntaxHighlightService {
@@ -112,6 +113,30 @@ abstract final class SyntaxHighlightService {
     );
   }
 
+  /// Creates a [QueryaHighlightController] initialized with highlighters and grammar for [language].
+  /// If syntax highlighting is not initialized or [language] is plain, falls back to a plain [TextEditingController].
+  static TextEditingController createHighlightController({
+    required QueryaCodeLanguage language,
+    String? text,
+    QueryaTheme? queryaTheme,
+  }) {
+    if (!_initialized || language == QueryaCodeLanguage.plain) {
+      return TextEditingController(text: text);
+    }
+    final theme = queryaTheme ?? QueryaTheme.darkDefault;
+    final pair = createPair(language: language, queryaTheme: theme);
+    return QueryaHighlightController(
+      text: text,
+      language: language,
+      lightHighlighter: pair.light,
+      darkHighlighter: pair.dark,
+      lightThemeConfig: pair.lightThemeConfig,
+      darkThemeConfig: pair.darkThemeConfig,
+      grammarJson: pair.grammarJson,
+      wrapperColor: theme.editor.foreground,
+    );
+  }
+
   static void _assertInitialized() {
     assert(
       _initialized,

lib/features/workspace/sql_query_tab_session.dart

@@ -1,6 +1,8 @@
 import 'package:flutter/material.dart' as material;
 import 'package:querya_desktop/core/actions/sql_script_format.dart';
 import 'package:querya_desktop/core/database/table_schema_meta.dart';
+import 'package:querya_desktop/core/editor/querya_code_language.dart';
+import 'package:querya_desktop/core/editor/syntax_highlight_service.dart';
 import 'package:querya_desktop/features/workspace/query_plan.dart';
 import 'package:querya_desktop/core/unsaved_work_registry.dart';
 import 'package:querya_desktop/features/workspace/data_grid_staging_buffer.dart';
@@ -17,7 +19,12 @@ class SqlQueryTabSession {
     this.filePath,
     double initialFraction = 0.65,
     this.isDiagram = false,
-  })  : controller = material.TextEditingController(text: initialSql ?? ''),
+    material.TextEditingController? customController,
+  })  : controller = customController ??
+            SyntaxHighlightService.createHighlightController(
+              language: QueryaCodeLanguage.sql,
+              text: initialSql ?? '',
+            ),
         _savedSql = initialSql ?? '',
         topFraction = material.ValueNotifier<double>(initialFraction) {
     controller.addListener(_onTextChanged);

test/core/editor/querya_code_editor_test.dart

@@ -63,16 +63,19 @@ void main() {
     expect(field.style?.color, const Color(0xFFABCDEF));
   });
 
-  testWidgets('SQL highlighting keeps external controller in sync',
+  testWidgets('SQL highlight controller works directly in QueryaCodeEditor',
       (tester) async {
-    final external = material.TextEditingController();
+    final controller = SyntaxHighlightService.createHighlightController(
+      language: QueryaCodeLanguage.sql,
+      text: '',
+    );
     await tester.pumpWidget(
       queryaThemeTestShell(
         child: material.SizedBox(
           width: 400,
           height: 200,
           child: QueryaCodeEditor(
-            controller: external,
+            controller: controller,
             language: QueryaCodeLanguage.sql,
           ),
         ),
@@ -83,8 +86,8 @@ void main() {
     await tester.enterText(find.byType(material.EditableText), 'SELECT 1');
     await tester.pump();
     await pumpSyntaxHighlightDebounce(tester);
-    expect(external.text, 'SELECT 1');
-    external.text = 'UPDATE x';
+    expect(controller.text, 'SELECT 1');
+    controller.text = 'UPDATE x';
     await tester.pump();
     await pumpSyntaxHighlightDebounce(tester);
     expect(