Loki: Respect pre-selected filters in adhoc filter queries (#89022)

* Loki: In adhoc filters, respect pre-selected filters

* improve test,fix quotes

* Refactor

public/app/plugins/datasource/loki/datasource.test.ts

@@ -19,6 +19,7 @@ import {
   ToggleFilterAction,
   DataQueryRequest,
   ScopedVars,
+  AdHocVariableFilter,
 } from '@grafana/data';
 import {
   BackendSrv,
@@ -1701,6 +1702,67 @@ describe('LokiDatasource', () => {
       expect(ds.applyTemplateVariables).toHaveBeenCalledWith(expect.objectContaining(query), scopedVars, filters);
     });
   });
+
+  describe('getTagKeys', () => {
+    it('should pass timeRange and filters to the request', async () => {
+      const ds = createLokiDatasource();
+      const filters = [
+        { key: 'foo', operator: '=', value: 'bar' },
+        { key: 'foo2', operator: '=', value: 'bar2' },
+      ];
+      const spy = jest.spyOn(ds.languageProvider, 'fetchLabels').mockResolvedValue([]);
+
+      await ds.getTagKeys({ filters, timeRange: mockTimeRange });
+      expect(spy).toHaveBeenCalledWith({ streamSelector: '{foo="bar", foo2="bar2"}', timeRange: mockTimeRange });
+    });
+
+    it('should pass regex filters', async () => {
+      const ds = createLokiDatasource();
+      const filters = [
+        { key: 'foo', operator: '=~', value: 'abc|def' },
+        { key: 'foo2', operator: '=', value: 'bar2' },
+      ];
+      const spy = jest.spyOn(ds.languageProvider, 'fetchLabels').mockResolvedValue([]);
+
+      await ds.getTagKeys({ filters, timeRange: mockTimeRange });
+      expect(spy).toHaveBeenCalledWith({ streamSelector: '{foo=~"abc|def", foo2="bar2"}', timeRange: mockTimeRange });
+    });
+
+    it('should pass empty stream selector when no filters', async () => {
+      const ds = createLokiDatasource();
+      const filters: AdHocVariableFilter[] = [];
+      const spy = jest.spyOn(ds.languageProvider, 'fetchLabels').mockResolvedValue([]);
+
+      await ds.getTagKeys({ filters, timeRange: mockTimeRange });
+      expect(spy).toHaveBeenCalledWith({ streamSelector: '{}', timeRange: mockTimeRange });
+    });
+  });
+
+  describe('getTagValues', () => {
+    it('should pass timeRange and filters to the request', async () => {
+      const ds = createLokiDatasource();
+      const filters = [
+        { key: 'foo', operator: '=', value: 'bar' },
+        { key: 'foo2', operator: '=', value: 'bar2' },
+      ];
+      const spy = jest.spyOn(ds.languageProvider, 'fetchLabelValues').mockResolvedValue([]);
+
+      await ds.getTagValues({ key: 'label1', filters, timeRange: mockTimeRange });
+      expect(spy).toHaveBeenCalledWith('label1', {
+        streamSelector: '{foo="bar", foo2="bar2"}',
+        timeRange: mockTimeRange,
+      });
+    });
+
+    it('should pass empty stream selector when no filters', async () => {
+      const ds = createLokiDatasource();
+      const filters: AdHocVariableFilter[] = [];
+      const spy = jest.spyOn(ds.languageProvider, 'fetchLabelValues').mockResolvedValue([]);
+
+      await ds.getTagValues({ key: 'label1', filters, timeRange: mockTimeRange });
+      expect(spy).toHaveBeenCalledWith('label1', { streamSelector: '{}', timeRange: mockTimeRange });
+    });
+  });
 });
 
 describe('applyTemplateVariables', () => {

public/app/plugins/datasource/loki/datasource.ts

@@ -743,7 +743,11 @@ export class LokiDatasource
    * @returns A Promise that resolves to an array of label names represented as MetricFindValue objects.
    */
   async getTagKeys(options?: DataSourceGetTagKeysOptions<LokiQuery>): Promise<MetricFindValue[]> {
-    const result = await this.languageProvider.fetchLabels({ timeRange: options?.timeRange });
+    let streamSelector = '{}';
+    for (const filter of options?.filters ?? []) {
+      streamSelector = addLabelToQuery(streamSelector, filter.key, filter.operator, filter.value);
+    }
+    const result = await this.languageProvider.fetchLabels({ timeRange: options?.timeRange, streamSelector });
     return result.map((value: string) => ({ text: value }));
   }
 
@@ -752,7 +756,14 @@ export class LokiDatasource
    * @returns A Promise that resolves to an array of label values represented as MetricFindValue objects
    */
   async getTagValues(options: DataSourceGetTagValuesOptions<LokiQuery>): Promise<MetricFindValue[]> {
-    const result = await this.languageProvider.fetchLabelValues(options.key, { timeRange: options.timeRange });
+    let streamSelector = '{}';
+    for (const filter of options?.filters ?? []) {
+      streamSelector = addLabelToQuery(streamSelector, filter.key, filter.operator, filter.value);
+    }
+    const result = await this.languageProvider.fetchLabelValues(options.key, {
+      timeRange: options.timeRange,
+      streamSelector,
+    });
     return result.map((value: string) => ({ text: value }));
   }