feat(query-editor): enhance current statement framing

apps/desktop/src/lib/sql/executableStatementRangeCache.ts

@@ -6,6 +6,7 @@ export interface ExecutableStatementRangeCache {
   doc: Text;
   databaseType?: DatabaseType;
   byStart: Map<number, SqlTextRange>;
+  ranges: SqlTextRange[];
 }
 
 export type ExecutableStatementRangeParser = (sql: string, databaseType?: DatabaseType) => SqlTextRange[];
@@ -14,12 +15,59 @@ export function executableStatementRangeCacheForDoc(cache: ExecutableStatementRa
   if (cache?.doc === doc && cache.databaseType === databaseType) return cache;
 
   const byStart = new Map<number, SqlTextRange>();
-  for (const range of parse(doc.toString(), databaseType)) {
+  const ranges = parse(doc.toString(), databaseType);
+  for (const range of ranges) {
     byStart.set(range.from, range);
   }
-  return { doc, databaseType, byStart };
+  return { doc, databaseType, byStart, ranges };
 }
 
 export function executableStatementRangeStartingAt(cache: ExecutableStatementRangeCache, lineFrom: number): SqlTextRange | null {
   return cache.byStart.get(lineFrom) ?? null;
 }
+
+export function executableStatementRangeAtCursor(cache: ExecutableStatementRangeCache, cursorPos: number): SqlTextRange | null {
+  const pos = Math.max(0, Math.min(cursorPos, cache.doc.length));
+  const line = cache.doc.lineAt(pos);
+  const lineText = line.text.trim();
+  if (!lineText || lineText.startsWith("--") || lineText.startsWith("#") || isCursorOnLeadingBlockComment(line.text, pos - line.from)) return null;
+
+  for (let index = 0; index < cache.ranges.length; index += 1) {
+    const range = cache.ranges[index];
+    if (pos >= range.from && pos <= range.to) return range;
+
+    if (pos < range.from && range.from <= line.to && cache.doc.sliceString(pos, range.from).trim() === "") {
+      return range;
+    }
+
+    const next = cache.ranges[index + 1];
+    if (pos > range.to && (!next || pos < next.from) && range.to >= line.from && range.to <= line.to && cursorRemainsOnRangeLine(cache.doc, range.to, pos)) {
+      return range;
+    }
+  }
+
+  return null;
+}
+
+function isCursorOnLeadingBlockComment(lineText: string, lineOffset: number): boolean {
+  const commentStart = lineText.search(/\S/);
+  if (commentStart < 0 || !lineText.startsWith("/*", commentStart)) return false;
+
+  const commentEnd = lineText.indexOf("*/", commentStart + 2);
+  if (commentEnd < 0) return true;
+  const afterComment = lineText.slice(commentEnd + 2);
+  if (!afterComment.trim()) return true;
+
+  return lineOffset <= commentEnd + 2;
+}
+
+function cursorRemainsOnRangeLine(doc: Text, rangeTo: number, cursorPos: number): boolean {
+  const between = doc.sliceString(rangeTo, cursorPos);
+  if (between.includes("\n")) return false;
+  const delimiterIndex = between.lastIndexOf(";");
+  if (delimiterIndex === -1) return between.trim() === "";
+
+  const beforeDelimiter = between.slice(0, delimiterIndex);
+  const afterDelimiter = between.slice(delimiterIndex + 1);
+  return beforeDelimiter.trim() === "" && afterDelimiter.trim() === "";
+}