Added logic of geo search workshops to db services

OutOfSchool/OutOfSchool.Common/GeoMathHelper.cs

@@ -0,0 +1,26 @@
+using System;
+
+namespace OutOfSchool.Common
+{
+    public static class GeoMathHelper
+    {
+        public static decimal GetDistanceFromLatLonInKm(double lat1, double lon1, double lat2, double lon2)
+        {
+            var r = 6371e3; // Radius of the earth in m
+            var dLat = Deg2rad(lat2 - lat1);  // Deg2rad below
+            var dLon = Deg2rad(lon2 - lon1);
+            var a =
+                    (Math.Sin(dLat / 2) * Math.Sin(dLat / 2)) +
+                    (Math.Cos(Deg2rad(lat1)) * Math.Cos(Deg2rad(lat2)) *
+                    Math.Sin(dLon / 2) * Math.Sin(dLon / 2));
+            var c = 2 * Math.Atan2(Math.Sqrt(a), Math.Sqrt(1 - a));
+            var d = r * c; // Distance in km
+            return (decimal)d;
+        }
+
+        public static double Deg2rad(double deg)
+        {
+            return deg * (Math.PI / 180);
+        }
+    }
+}

OutOfSchool/OutOfSchool.DataAccess/Models/Address.cs

@@ -1,5 +1,6 @@
 using System;
 using System.ComponentModel.DataAnnotations;
+using H3Lib;
 
 namespace OutOfSchool.Services.Models
 {
@@ -30,6 +31,9 @@ public class Address
 
         public double Longitude { get; set; }
 
+        // parameter r means size (resolution) of hexagon
+        public ulong GeoHash => H3Lib.Api.GeoToH3(new GeoCoord((decimal)Latitude, (decimal)Longitude), 6);
+
         public override bool Equals(object obj)
         {
             if (obj == null)

OutOfSchool/OutOfSchool.DataAccess/OutOfSchool.DataAccess.csproj

@@ -23,6 +23,7 @@
     </ItemGroup>
 
     <ItemGroup>
+      <PackageReference Include="H3Lib" Version="3.7.2" />
       <PackageReference Include="Microsoft.AspNetCore.DataProtection.EntityFrameworkCore" Version="5.0.2" />
       <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="5.0.2" />
       <PackageReference Include="Microsoft.EntityFrameworkCore" Version="5.0.2" />

OutOfSchool/OutOfSchool.ElasticsearchData/ESWorkshopProvider.cs

@@ -9,7 +9,8 @@
 namespace OutOfSchool.ElasticsearchData
 {
     /// <inheritdoc/>
-    public class ESWorkshopProvider : ElasticsearchProvider<WorkshopES, WorkshopFilterES>, IElasticsearchProvider<WorkshopES, WorkshopFilterES>
+    public class ESWorkshopProvider : ElasticsearchProvider<WorkshopES, WorkshopFilterES>,
+        IElasticsearchProvider<WorkshopES, WorkshopFilterES>
     {
         public ESWorkshopProvider(ElasticClient elasticClient)
             : base(elasticClient)
@@ -26,14 +27,16 @@ public override async Task<SearchResultES<WorkshopES>> Search(WorkshopFilterES f
 
             var query = this.CreateQueryFromFilter(filter);
             var sorts = this.CreateSortFromFilter(filter);
-
-            var resp = await ElasticClient.SearchAsync<WorkshopES>(new SearchRequest<WorkshopES>()
+            var req = new SearchRequest<WorkshopES>()
             {
                 Query = query,
                 Sort = sorts,
                 From = filter.From,
                 Size = filter.Size,
-            });
+
+            };
+
+            var resp = await ElasticClient.SearchAsync<WorkshopES>(req);
 
             return new SearchResultES<WorkshopES>() { TotalAmount = (int)resp.Total, Entities = resp.Documents };
         }
@@ -164,6 +167,20 @@ private QueryContainer CreateQueryFromFilter(WorkshopFilterES filter)
                     },
                 };
             }
+
+            if (Equals(OrderBy.Nearest.ToString(), filter.OrderByField))
+            {
+                queryContainer &= new GeoDistanceQuery()
+                {
+                    Boost = 1.1,
+                    Name = "named_query",
+                    Field = Infer.Field<WorkshopES>(w => w.Address.Point),
+                    DistanceType = GeoDistanceType.Arc,
+                    Location = new GeoLocation((double)filter.Latitude, (double)filter.Longitude),
+                    Distance = "5000m",
+                    ValidationMethod = GeoValidationMethod.IgnoreMalformed,
+                };
+            }
 
             if (filter.MinStartTime.TotalMinutes > 0 || filter.MaxStartTime.Hours < 23)
             {
@@ -198,31 +215,60 @@ private List<ISort> CreateSortFromFilter(WorkshopFilterES filter)
             switch (filter.OrderByField)
             {
                 case nameof(OrderBy.Rating):
-                    sorts.Add(new FieldSort() { Field = Infer.Field<WorkshopES>(w => w.Rating), Order = SortOrder.Descending });
+                    sorts.Add(new FieldSort()
+                    {
+                        Field = Infer.Field<WorkshopES>(w => w.Rating),
+                        Order = SortOrder.Descending,
+                    });
                     break;
 
                 case nameof(OrderBy.Statistic):
-                    sorts.Add(new FieldSort() { Field = Infer.Field<WorkshopES>(w => w.Rating), Order = SortOrder.Descending });
+                    sorts.Add(new FieldSort()
+                    {
+                        Field = Infer.Field<WorkshopES>(w => w.Rating),
+                        Order = SortOrder.Descending,
+                    });
                     break;
 
                 case nameof(OrderBy.PriceAsc):
-                    sorts.Add(new FieldSort() { Field = Infer.Field<WorkshopES>(w => w.Price), Order = SortOrder.Ascending });
+                    sorts.Add(new FieldSort()
+                    {
+                        Field = Infer.Field<WorkshopES>(w => w.Price),
+                        Order = SortOrder.Ascending,
+                    });
                     break;
 
                 case nameof(OrderBy.PriceDesc):
-                    sorts.Add(new FieldSort() { Field = Infer.Field<WorkshopES>(w => w.Price), Order = SortOrder.Descending });
+                    sorts.Add(new FieldSort()
+                    {
+                        Field = Infer.Field<WorkshopES>(w => w.Price),
+                        Order = SortOrder.Descending,
+                    });
                     break;
 
                 case nameof(OrderBy.Alphabet):
-                    sorts.Add(new FieldSort() { Field = "title.keyword", Order = SortOrder.Ascending });
+                    sorts.Add(new FieldSort()
+                    {
+                        Field = "title.keyword",
+                        Order = SortOrder.Ascending,
+                    });
                     break;
 
                 case nameof(OrderBy.Nearest):
-                    sorts.Add(new FieldSort() { Field = Infer.Field<WorkshopES>(w => w.Rating), Order = SortOrder.Descending });
+                    sorts.Add(new GeoDistanceSort()
+                    {
+                        Field = Infer.Field<WorkshopES>(w => w.Address.Point),
+                        Points = new[] { new GeoLocation((double)filter.Latitude, (double)filter.Longitude) },
+                        Order = SortOrder.Ascending,
+                    });
                     break;
 
                 default:
-                    sorts.Add(new FieldSort() { Field = Infer.Field<WorkshopES>(w => w.Id), Order = SortOrder.Ascending });
+                    sorts.Add(new FieldSort()
+                    {
+                        Field = Infer.Field<WorkshopES>(w => w.Id),
+                        Order = SortOrder.Ascending,
+                    });
                     break;
             }
 

OutOfSchool/OutOfSchool.ElasticsearchData/Models/AddressES.cs

@@ -1,4 +1,6 @@
-namespace OutOfSchool.ElasticsearchData.Models
+using Nest;
+
+namespace OutOfSchool.ElasticsearchData.Models
 {
     public class AddressES
     {
@@ -14,8 +16,8 @@ public class AddressES
 
         public string BuildingNumber { get; set; }
 
-        public double Latitude { get; set; }
+        [GeoPoint]
+        public GeoLocation Point { get; set; }
 
-        public double Longitude { get; set; }
     }
 }

OutOfSchool/OutOfSchool.ElasticsearchData/Models/WorkshopFilterES.cs

@@ -38,5 +38,9 @@ public class WorkshopFilterES
         public int Size { get; set; } = 12;
 
         public int From { get; set; } = 0;
+
+        public decimal Latitude { get; set; } = 0;
+
+        public decimal Longitude { get; set; } = 0;
     }
 }