From 6b3dbb59a5d32ff5264f28e1c82195007c5f52c6 Mon Sep 17 00:00:00 2001
From: Jay Quan <a331998513@gmail.com>
Date: Tue, 5 Dec 2023 14:04:24 +0100
Subject: [PATCH 1/3] added mongo query .sort() to sort ES query result

---
 src/datasets/datasets.service.ts | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/datasets/datasets.service.ts b/src/datasets/datasets.service.ts
index 08ff92f73..ade96cf8a 100644
--- a/src/datasets/datasets.service.ts
+++ b/src/datasets/datasets.service.ts
@@ -122,9 +122,12 @@ export class DatasetsService {
         filter.fields as IDatasetFields,
         modifiers.limit,
         modifiers.skip,
+        modifiers.sort,
       );
+
       datasets = await this.datasetModel
         .find({ _id: { $in: esResult.data } })
+        .sort(modifiers.sort)
         .exec();
     }
 

From 8815cbc53921d4adafeee91b04ec10daf29e491a Mon Sep 17 00:00:00 2001
From: Jay Quan <a331998513@gmail.com>
Date: Tue, 5 Dec 2023 14:06:58 +0100
Subject: [PATCH 2/3] explicitly added scientificMetadata.runNumber.value to
 the field mapping for sorting purpose

---
 src/elastic-search/configuration/datasetFieldMapping.ts | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/elastic-search/configuration/datasetFieldMapping.ts b/src/elastic-search/configuration/datasetFieldMapping.ts
index 20c849e67..24c78ec15 100644
--- a/src/elastic-search/configuration/datasetFieldMapping.ts
+++ b/src/elastic-search/configuration/datasetFieldMapping.ts
@@ -32,6 +32,15 @@ export const datasetMappings: MappingObject = {
   scientificMetadata: {
     type: "nested",
     dynamic: true,
+    properties: {
+      runNumber: {
+        properties: {
+          value: {
+            type: "long",
+          },
+        },
+      },
+    },
   },
   history: {
     type: "nested",

From f41c963d5794507324f42cb7d929e2cbb719a1b1 Mon Sep 17 00:00:00 2001
From: Jay Quan <a331998513@gmail.com>
Date: Tue, 5 Dec 2023 14:09:35 +0100
Subject: [PATCH 3/3] added sort query to the elasticsearch

---
 src/elastic-search/elastic-search.service.ts | 41 +++++++++++++++++++-
 src/elastic-search/providers/fields.enum.ts  |  7 ++++
 2 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/src/elastic-search/elastic-search.service.ts b/src/elastic-search/elastic-search.service.ts
index dd6a3b5c1..ca2e7be42 100644
--- a/src/elastic-search/elastic-search.service.ts
+++ b/src/elastic-search/elastic-search.service.ts
@@ -12,6 +12,7 @@ import {
   SearchTotalHits,
   SearchRequest,
   AggregationsAggregate,
+  SortOrder,
 } from "@elastic/elasticsearch/lib/api/types";
 import { IDatasetFields } from "src/datasets/interfaces/dataset-filters.interface";
 import {
@@ -31,6 +32,8 @@ import {
   transformFacets,
 } from "./helpers/utils";
 
+import { SortFields } from "./providers/fields.enum";
+
 @Injectable()
 export class ElasticSearchService implements OnModuleInit {
   private esService: Client;
@@ -255,6 +258,7 @@ export class ElasticSearchService implements OnModuleInit {
     searchParam: IDatasetFields,
     limit = 20,
     skip = 0,
+    sort?: Record<string, SortOrder>,
   ): Promise<{ totalCount: number; data: string[] }> {
     const defaultMinScore = searchParam.text ? 1 : 0;
 
@@ -263,15 +267,48 @@ export class ElasticSearchService implements OnModuleInit {
 
       const searchOptions = {
         track_scores: true,
-        body: searchQuery,
+        sort: [{ _score: { order: "desc" } }],
+        query: searchQuery.query,
         from: skip,
         size: limit,
-        sort: [{ _score: { order: "desc" } }],
         min_score: defaultMinScore,
         track_total_hits: true,
         _source: [""],
       } as SearchRequest;
 
+      if (sort) {
+        const sortField = Object.keys(sort)[0];
+        const sortDirection = Object.values(sort)[0];
+
+        // NOTE: To sort datasetName field we need to use datasetName.keyword field,
+        // as elasticsearch does not have good support for text type field sorting
+        const isDatasetName = sortField === SortFields.DatasetName;
+        const fieldForSorting = isDatasetName
+          ? SortFields.DatasetNameKeyword
+          : sortField;
+
+        const isNestedField = fieldForSorting.includes(
+          SortFields.ScientificMetadata,
+        );
+
+        if (isNestedField) {
+          searchOptions.sort = [
+            {
+              [`${SortFields.ScientificMetadataRunNumberValue}`]: {
+                order: sortDirection,
+                nested: {
+                  path: SortFields.ScientificMetadata,
+                },
+              },
+            },
+          ];
+        } else {
+          searchOptions.sort = [
+            { [fieldForSorting]: { order: sortDirection } },
+          ];
+        }
+      }
+
       const body = await this.esService.search(searchOptions);
 
       const totalCount = (body.hits.total as SearchTotalHits)?.value || 0;
diff --git a/src/elastic-search/providers/fields.enum.ts b/src/elastic-search/providers/fields.enum.ts
index f5b691e5d..7cf919dc0 100644
--- a/src/elastic-search/providers/fields.enum.ts
+++ b/src/elastic-search/providers/fields.enum.ts
@@ -22,3 +22,10 @@ export enum QueryFields {
   DatasetName = "datasetName",
   Description = "description",
 }
+
+export enum SortFields {
+  DatasetName = "datasetName",
+  DatasetNameKeyword = "datasetName.keyword",
+  ScientificMetadata = "scientificMetadata",
+  ScientificMetadataRunNumberValue = "scientificMetadata.runnumber.value",
+}