value suggestions server route -> data plugin (elastic#53191)

* value suggestions server route -> data plugin

Closes elastic#52842

* fix PR comments

* fix PR comments

src/legacy/core_plugins/kibana/index.js

@@ -27,7 +27,6 @@ import { exportApi } from './server/routes/api/export';
 import { homeApi } from './server/routes/api/home';
 import { managementApi } from './server/routes/api/management';
 import { scriptsApi } from './server/routes/api/scripts';
-import { registerSuggestionsApi } from './server/routes/api/suggestions';
 import { registerKqlTelemetryApi } from './server/routes/api/kql_telemetry';
 import { registerFieldFormats } from './server/field_formats/register';
 import { registerTutorials } from './server/tutorials/register';
@@ -331,7 +330,6 @@ export default function(kibana) {
       exportApi(server);
       homeApi(server);
       managementApi(server);
-      registerSuggestionsApi(server);
       registerKqlTelemetryApi(server);
       registerFieldFormats(server);
       registerTutorials(server);

src/plugins/data/common/index_patterns/types.ts

@@ -20,6 +20,7 @@
 import { IFieldType } from './fields';
 
 export interface IIndexPattern {
+  [key: string]: any;
   fields: IFieldType[];
   title: string;
   id?: string;

src/plugins/data/server/autocomplete/autocomplete_service.ts

@@ -0,0 +1,29 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { CoreSetup, Plugin } from 'kibana/server';
+import { registerRoutes } from './routes';
+
+export class AutocompleteService implements Plugin<void> {
+  public setup(core: CoreSetup) {
+    registerRoutes(core);
+  }
+
+  public start() {}
+}

src/legacy/core_plugins/kibana/server/routes/api/suggestions/index.js → src/plugins/data/server/autocomplete/index.ts

@@ -17,8 +17,4 @@
  * under the License.
  */
 
-import { registerValueSuggestions } from './register_value_suggestions';
-
-export function registerSuggestionsApi(server) {
-  registerValueSuggestions(server);
-}
+export { AutocompleteService } from './autocomplete_service';

src/plugins/data/server/autocomplete/routes.ts

@@ -0,0 +1,27 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { CoreSetup } from 'kibana/server';
+import { registerValueSuggestionsRoute } from './value_suggestions_route';
+
+export function registerRoutes({ http }: CoreSetup): void {
+  const router = http.createRouter();
+
+  registerValueSuggestionsRoute(router);
+}

src/plugins/data/server/autocomplete/value_suggestions_route.ts

@@ -0,0 +1,135 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { get, map } from 'lodash';
+import { schema } from '@kbn/config-schema';
+import { IRouter } from 'kibana/server';
+
+import { IFieldType, indexPatterns, esFilters } from '../index';
+
+export function registerValueSuggestionsRoute(router: IRouter) {
+  router.post(
+    {
+      path: '/api/kibana/suggestions/values/{index}',
+      validate: {
+        params: schema.object(
+          {
+            index: schema.string(),
+          },
+          { allowUnknowns: false }
+        ),
+        body: schema.object(
+          {
+            field: schema.string(),
+            query: schema.string(),
+            boolFilter: schema.maybe(schema.any()),
+          },
+          { allowUnknowns: false }
+        ),
+      },
+    },
+    async (context, request, response) => {
+      const { client: uiSettings } = context.core.uiSettings;
+      const { field: fieldName, query, boolFilter } = request.body;
+      const { index } = request.params;
+      const { dataClient } = context.core.elasticsearch;
+
+      const autocompleteSearchOptions = {
+        timeout: await uiSettings.get<number>('kibana.autocompleteTimeout'),
+        terminate_after: await uiSettings.get<number>('kibana.autocompleteTerminateAfter'),
+      };
+
+      const indexPattern = await indexPatterns.findIndexPatternById(
+        context.core.savedObjects.client,
+        index
+      );
+
+      const field = indexPattern && indexPatterns.getFieldByName(fieldName, indexPattern);
+      const body = await getBody(autocompleteSearchOptions, field || fieldName, query, boolFilter);
+
+      try {
+        const result = await dataClient.callAsCurrentUser('search', { index, body });
+
+        const buckets: any[] =
+          get(result, 'aggregations.suggestions.buckets') ||
+          get(result, 'aggregations.nestedSuggestions.suggestions.buckets');
+
+        return response.ok({ body: map(buckets || [], 'key') });
+      } catch (error) {
+        return response.internalError({ body: error });
+      }
+    }
+  );
+}
+
+async function getBody(
+  { timeout, terminate_after }: Record<string, any>,
+  field: IFieldType | string,
+  query: string,
+  boolFilter: esFilters.Filter[] = []
+) {
+  const isFieldObject = (f: any): f is IFieldType => Boolean(f && f.name);
+
+  // https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-regexp-query.html#_standard_operators
+  const getEscapedQuery = (q: string = '') =>
+    q.replace(/[.?+*|{}[\]()"\\#@&<>~]/g, match => `\\${match}`);
+
+  // Helps ensure that the regex is not evaluated eagerly against the terms dictionary
+  const executionHint = 'map';
+
+  // We don't care about the accuracy of the counts, just the content of the terms, so this reduces
+  // the amount of information that needs to be transmitted to the coordinating node
+  const shardSize = 10;
+  const body = {
+    size: 0,
+    timeout,
+    terminate_after,
+    query: {
+      bool: {
+        filter: boolFilter,
+      },
+    },
+    aggs: {
+      suggestions: {
+        terms: {
+          field: isFieldObject(field) ? field.name : field,
+          include: `${getEscapedQuery(query)}.*`,
+          execution_hint: executionHint,
+          shard_size: shardSize,
+        },
+      },
+    },
+  };
+
+  if (isFieldObject(field) && field.subType && field.subType.nested) {
+    return {
+      ...body,
+      aggs: {
+        nestedSuggestions: {
+          nested: {
+            path: field.subType.nested.path,
+          },
+          aggs: body.aggs,
+        },
+      },
+    };
+  }
+
+  return body;
+}

src/plugins/data/server/index.ts

@@ -57,6 +57,7 @@ export {
   IndexPatternsFetcher,
   FieldDescriptor,
   shouldReadFieldFromDocValues,
+  indexPatterns,
 } from './index_patterns';
 export * from './search';
 export {

src/plugins/data/server/index_patterns/index.ts

@@ -16,6 +16,8 @@
  * specific language governing permissions and limitations
  * under the License.
  */
+import * as indexPatterns from './utils';
 
 export { IndexPatternsFetcher, FieldDescriptor, shouldReadFieldFromDocValues } from './fetcher';
 export { IndexPatternsService } from './index_patterns_service';
+export { indexPatterns };