From 0c38a3ba9700bc16954bcaa6e3f862cde4a79782 Mon Sep 17 00:00:00 2001
From: Ryan McKinley <ryantxu@gmail.com>
Date: Tue, 20 Sep 2022 17:24:29 -0700
Subject: [PATCH] Search: Investigate frontend search options (again) (#55526)

---
 .../app/features/search/service/frontend.ts   | 104 ++++++++++++++++++
 .../app/features/search/service/searcher.ts   |   7 +-
 2 files changed, 110 insertions(+), 1 deletion(-)
 create mode 100644 public/app/features/search/service/frontend.ts

diff --git a/public/app/features/search/service/frontend.ts b/public/app/features/search/service/frontend.ts
new file mode 100644
index 00000000000..55a703c0229
--- /dev/null
+++ b/public/app/features/search/service/frontend.ts
@@ -0,0 +1,104 @@
+import { DataFrameView, SelectableValue, ArrayVector } from '@grafana/data';
+import { TermCount } from 'app/core/components/TagFilter/TagFilter';
+
+import { DashboardQueryResult, GrafanaSearcher, QueryResponse, SearchQuery } from '.';
+
+export class FrontendSearcher implements GrafanaSearcher {
+  readonly cache = new Map<string, FullResultCache>();
+
+  constructor(private parent: GrafanaSearcher) {}
+
+  async search(query: SearchQuery): Promise<QueryResponse> {
+    if (query.facet?.length) {
+      throw new Error('facets not supported!');
+    }
+    // Don't bother... not needed for this exercise
+    if (query.tags?.length || query.ds_uid?.length) {
+      return this.parent.search(query);
+    }
+
+    // TODO -- make sure we refresh after a while
+    const all = await this.getCache(query.kind);
+    const view = all.search(query.query);
+    return {
+      isItemLoaded: () => true,
+      loadMoreItems: async (startIndex: number, stopIndex: number): Promise<void> => {},
+      totalRows: view.length,
+      view,
+    };
+  }
+
+  async getCache(kind?: string[]): Promise<FullResultCache> {
+    const key = kind ? kind.join(',') : '*';
+    let res = this.cache.get(key);
+    if (res) {
+      return Promise.resolve(res);
+    }
+
+    const v = await this.parent.search({
+      kind, // match the request
+      limit: 5000, // max for now
+    });
+
+    res = new FullResultCache(v.view);
+    this.cache.set(key, res);
+    return res;
+  }
+
+  async starred(query: SearchQuery): Promise<QueryResponse> {
+    return this.parent.starred(query);
+  }
+
+  // returns the appropriate sorting options
+  async getSortOptions(): Promise<SelectableValue[]> {
+    return this.parent.getSortOptions();
+  }
+
+  async tags(query: SearchQuery): Promise<TermCount[]> {
+    return this.parent.tags(query);
+  }
+}
+
+class FullResultCache {
+  readonly lower: string[];
+  empty: DataFrameView<DashboardQueryResult>;
+
+  constructor(private full: DataFrameView<DashboardQueryResult>) {
+    this.lower = this.full.fields.name.values.toArray().map((v) => (v ? v.toLowerCase() : ''));
+
+    // Copy with empty values
+    this.empty = new DataFrameView<DashboardQueryResult>({
+      ...this.full.dataFrame, // copy folder metadata
+      fields: this.full.dataFrame.fields.map((v) => ({ ...v, values: new ArrayVector([]) })),
+      length: 0, // for now
+    });
+  }
+
+  // single instance that is mutated for each response (not great, but OK for now)
+  search(query?: string): DataFrameView<DashboardQueryResult> {
+    if (!query?.length || query === '*') {
+      return this.full;
+    }
+    const match = query.toLowerCase();
+    const allFields = this.full.dataFrame.fields;
+
+    // eslint-disable-next-line
+    const values = allFields.map((v) => [] as any[]); // empty value for each field
+
+    for (let i = 0; i < this.lower.length; i++) {
+      if (this.lower[i].indexOf(match) >= 0) {
+        for (let c = 0; c < allFields.length; c++) {
+          values[c].push(allFields[c].values.get(i));
+        }
+      }
+    }
+
+    // mutates the search object
+    this.empty.dataFrame.fields.forEach((f, idx) => {
+      f.values = new ArrayVector(values[idx]); // or just set it?
+    });
+    this.empty.dataFrame.length = this.empty.dataFrame.fields[0].values.length;
+
+    return this.empty;
+  }
+}
diff --git a/public/app/features/search/service/searcher.ts b/public/app/features/search/service/searcher.ts
index a43af21d386..fe017d1837f 100644
--- a/public/app/features/search/service/searcher.ts
+++ b/public/app/features/search/service/searcher.ts
@@ -1,16 +1,21 @@
 import { config } from '@grafana/runtime';
 
 import { BlugeSearcher } from './bluge';
+import { FrontendSearcher } from './frontend';
 import { SQLSearcher } from './sql';
 import { GrafanaSearcher } from './types';
 
 let searcher: GrafanaSearcher | undefined = undefined;
 
 export function getGrafanaSearcher(): GrafanaSearcher {
-  const sqlSearcher = new SQLSearcher();
   if (!searcher) {
+    const sqlSearcher = new SQLSearcher();
     const useBluge = config.featureToggles.panelTitleSearch;
     searcher = useBluge ? new BlugeSearcher(sqlSearcher) : sqlSearcher;
+
+    if (useBluge && location.search.indexOf('do-frontend-query')) {
+      searcher = new FrontendSearcher(searcher);
+    }
   }
   return searcher!;
 }