From 8afdcd8f007af2c9c2df733d7e15e1e368327f1b Mon Sep 17 00:00:00 2001
From: Kevin Hahn <kevin_hahn@sil.org>
Date: Fri, 27 Sep 2024 11:42:45 +0700
Subject: [PATCH] Create MongoDbContext which provides the IMongoDatabase to
 other contexts.

Make it a scoped service so only 1 MongoClient is created per request. Use that to expose transactions which are now shared across all Repos.
---
 Backend/Contexts/BannerContext.cs         | 10 ++---
 Backend/Contexts/MergeBlacklistContext.cs | 11 ++----
 Backend/Contexts/MergeGraylistContext.cs  | 11 ++----
 Backend/Contexts/MongoDbContext.cs        | 47 +++++++++++++++++++++++
 Backend/Contexts/PasswordResetContext.cs  |  9 ++---
 Backend/Contexts/ProjectContext.cs        | 11 ++----
 Backend/Contexts/SemanticDomainContext.cs | 13 +++----
 Backend/Contexts/SpeakerContext.cs        | 12 +++---
 Backend/Contexts/UserContext.cs           | 11 ++----
 Backend/Contexts/UserEditContext.cs       | 11 ++----
 Backend/Contexts/UserRoleContext.cs       | 11 ++----
 Backend/Contexts/WordContext.cs           | 13 +++----
 Backend/Interfaces/IMongoDbContext.cs     | 17 ++++++++
 Backend/Startup.cs                        |  3 ++
 14 files changed, 114 insertions(+), 76 deletions(-)
 create mode 100644 Backend/Contexts/MongoDbContext.cs
 create mode 100644 Backend/Interfaces/IMongoDbContext.cs

diff --git a/Backend/Contexts/BannerContext.cs b/Backend/Contexts/BannerContext.cs
index ace2284f9f..15d123d25b 100644
--- a/Backend/Contexts/BannerContext.cs
+++ b/Backend/Contexts/BannerContext.cs
@@ -1,7 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
 using BackendFramework.Interfaces;
 using BackendFramework.Models;
-using Microsoft.Extensions.Options;
 using MongoDB.Driver;
 
 namespace BackendFramework.Contexts
@@ -9,14 +8,13 @@ namespace BackendFramework.Contexts
     [ExcludeFromCodeCoverage]
     public class BannerContext : IBannerContext
     {
-        private readonly IMongoDatabase _db;
+        private readonly IMongoDbContext _mongoDbContext;
 
-        public BannerContext(IOptions<Startup.Settings> options)
+        public BannerContext(IMongoDbContext mongoDbContext)
         {
-            var client = new MongoClient(options.Value.ConnectionString);
-            _db = client.GetDatabase(options.Value.CombineDatabase);
+            _mongoDbContext = mongoDbContext;
         }
 
-        public IMongoCollection<Banner> Banners => _db.GetCollection<Banner>("BannerCollection");
+        public IMongoCollection<Banner> Banners => _mongoDbContext.Db.GetCollection<Banner>("BannerCollection");
     }
 }
diff --git a/Backend/Contexts/MergeBlacklistContext.cs b/Backend/Contexts/MergeBlacklistContext.cs
index f977bf6d70..52c1c65f1c 100644
--- a/Backend/Contexts/MergeBlacklistContext.cs
+++ b/Backend/Contexts/MergeBlacklistContext.cs
@@ -1,7 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
 using BackendFramework.Interfaces;
 using BackendFramework.Models;
-using Microsoft.Extensions.Options;
 using MongoDB.Driver;
 
 namespace BackendFramework.Contexts
@@ -9,15 +8,13 @@ namespace BackendFramework.Contexts
     [ExcludeFromCodeCoverage]
     public class MergeBlacklistContext : IMergeBlacklistContext
     {
-        private readonly IMongoDatabase _db;
-
-        public MergeBlacklistContext(IOptions<Startup.Settings> options)
+        private readonly IMongoDbContext _mongoDbContext;
+        public MergeBlacklistContext(IMongoDbContext mongoDbContext)
         {
-            var client = new MongoClient(options.Value.ConnectionString);
-            _db = client.GetDatabase(options.Value.CombineDatabase);
+            _mongoDbContext = mongoDbContext;
         }
 
-        public IMongoCollection<MergeWordSet> MergeBlacklist => _db.GetCollection<MergeWordSet>(
+        public IMongoCollection<MergeWordSet> MergeBlacklist => _mongoDbContext.Db.GetCollection<MergeWordSet>(
             "MergeBlacklistCollection");
     }
 }
diff --git a/Backend/Contexts/MergeGraylistContext.cs b/Backend/Contexts/MergeGraylistContext.cs
index d9ea381829..35b0f8caf9 100644
--- a/Backend/Contexts/MergeGraylistContext.cs
+++ b/Backend/Contexts/MergeGraylistContext.cs
@@ -1,7 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
 using BackendFramework.Interfaces;
 using BackendFramework.Models;
-using Microsoft.Extensions.Options;
 using MongoDB.Driver;
 
 namespace BackendFramework.Contexts
@@ -9,15 +8,13 @@ namespace BackendFramework.Contexts
     [ExcludeFromCodeCoverage]
     public class MergeGraylistContext : IMergeGraylistContext
     {
-        private readonly IMongoDatabase _db;
-
-        public MergeGraylistContext(IOptions<Startup.Settings> options)
+        private readonly IMongoDbContext _mongoDbContext;
+        public MergeGraylistContext(IMongoDbContext mongoDbContext)
         {
-            var client = new MongoClient(options.Value.ConnectionString);
-            _db = client.GetDatabase(options.Value.CombineDatabase);
+            _mongoDbContext = mongoDbContext;
         }
 
-        public IMongoCollection<MergeWordSet> MergeGraylist => _db.GetCollection<MergeWordSet>(
+        public IMongoCollection<MergeWordSet> MergeGraylist => _mongoDbContext.Db.GetCollection<MergeWordSet>(
             "MergeGraylistCollection");
     }
 }
diff --git a/Backend/Contexts/MongoDbContext.cs b/Backend/Contexts/MongoDbContext.cs
new file mode 100644
index 0000000000..60785b5cbe
--- /dev/null
+++ b/Backend/Contexts/MongoDbContext.cs
@@ -0,0 +1,47 @@
+using System.Threading.Tasks;
+using BackendFramework.Interfaces;
+using Microsoft.Extensions.Options;
+using MongoDB.Driver;
+
+namespace BackendFramework.Contexts;
+
+public class MongoDbContext : IMongoDbContext
+{
+    public IMongoDatabase Db { get; }
+
+    public MongoDbContext(IOptions<Startup.Settings> options)
+    {
+        var client = new MongoClient(options.Value.ConnectionString);
+        Db = client.GetDatabase(options.Value.CombineDatabase);
+    }
+
+    public async Task<IMongoTransaction> BeginTransaction()
+    {
+        return new MongoTransactionWrapper(await Db.Client.StartSessionAsync());
+    }
+
+    private class MongoTransactionWrapper : IMongoTransaction
+    {
+        private readonly IClientSessionHandle _session;
+
+        public MongoTransactionWrapper(IClientSessionHandle session)
+        {
+            _session = session;
+        }
+
+        public Task CommitTransactionAsync()
+        {
+            return _session.CommitTransactionAsync();
+        }
+
+        public Task AbortTransactionAsync()
+        {
+            return _session.AbortTransactionAsync();
+        }
+
+        public void Dispose()
+        {
+            _session.Dispose();
+        }
+    }
+}
\ No newline at end of file
diff --git a/Backend/Contexts/PasswordResetContext.cs b/Backend/Contexts/PasswordResetContext.cs
index dbcc4041c0..84aebc7eed 100644
--- a/Backend/Contexts/PasswordResetContext.cs
+++ b/Backend/Contexts/PasswordResetContext.cs
@@ -10,17 +10,16 @@ namespace BackendFramework.Contexts
     [ExcludeFromCodeCoverage]
     public class PasswordResetContext : IPasswordResetContext
     {
-        private readonly IMongoDatabase _db;
+        private readonly IMongoDbContext _mongoDbContext;
         public int ExpireTime { get; }
 
-        public PasswordResetContext(IOptions<Startup.Settings> options)
+        public PasswordResetContext(IOptions<Startup.Settings> options, IMongoDbContext mongoDbContext)
         {
-            var client = new MongoClient(options.Value.ConnectionString);
-            _db = client.GetDatabase(options.Value.CombineDatabase);
+            _mongoDbContext = mongoDbContext;
             ExpireTime = options.Value.PassResetExpireTime;
         }
 
-        private IMongoCollection<PasswordReset> PasswordResets => _db.GetCollection<PasswordReset>(
+        private IMongoCollection<PasswordReset> PasswordResets => _mongoDbContext.Db.GetCollection<PasswordReset>(
             "PasswordResetCollection");
 
         public Task ClearAll(string email)
diff --git a/Backend/Contexts/ProjectContext.cs b/Backend/Contexts/ProjectContext.cs
index 696a8a35da..0901b6b0e4 100644
--- a/Backend/Contexts/ProjectContext.cs
+++ b/Backend/Contexts/ProjectContext.cs
@@ -1,7 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
 using BackendFramework.Interfaces;
 using BackendFramework.Models;
-using Microsoft.Extensions.Options;
 using MongoDB.Driver;
 
 namespace BackendFramework.Contexts
@@ -9,14 +8,12 @@ namespace BackendFramework.Contexts
     [ExcludeFromCodeCoverage]
     public class ProjectContext : IProjectContext
     {
-        private readonly IMongoDatabase _db;
-
-        public ProjectContext(IOptions<Startup.Settings> options)
+        private readonly IMongoDbContext _mongoDbContext;
+        public ProjectContext(IMongoDbContext mongoDbContext)
         {
-            var client = new MongoClient(options.Value.ConnectionString);
-            _db = client.GetDatabase(options.Value.CombineDatabase);
+            _mongoDbContext = mongoDbContext;
         }
 
-        public IMongoCollection<Project> Projects => _db.GetCollection<Project>("ProjectsCollection");
+        public IMongoCollection<Project> Projects => _mongoDbContext.Db.GetCollection<Project>("ProjectsCollection");
     }
 }
diff --git a/Backend/Contexts/SemanticDomainContext.cs b/Backend/Contexts/SemanticDomainContext.cs
index 5ad11cac28..66fa39acd0 100644
--- a/Backend/Contexts/SemanticDomainContext.cs
+++ b/Backend/Contexts/SemanticDomainContext.cs
@@ -1,7 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
 using BackendFramework.Interfaces;
 using BackendFramework.Models;
-using Microsoft.Extensions.Options;
 using MongoDB.Driver;
 
 namespace BackendFramework.Contexts
@@ -9,15 +8,13 @@ namespace BackendFramework.Contexts
     [ExcludeFromCodeCoverage]
     public class SemanticDomainContext : ISemanticDomainContext
     {
-        private readonly IMongoDatabase _db;
-
-        public SemanticDomainContext(IOptions<Startup.Settings> options)
+        private readonly IMongoDbContext _mongoDbContext;
+        public SemanticDomainContext(IMongoDbContext mongoDbContext)
         {
-            var client = new MongoClient(options.Value.ConnectionString);
-            _db = client.GetDatabase(options.Value.CombineDatabase);
+            _mongoDbContext = mongoDbContext;
         }
 
-        public IMongoCollection<SemanticDomainTreeNode> SemanticDomains => _db.GetCollection<SemanticDomainTreeNode>("SemanticDomainTree");
-        public IMongoCollection<SemanticDomainFull> FullSemanticDomains => _db.GetCollection<SemanticDomainFull>("SemanticDomains");
+        public IMongoCollection<SemanticDomainTreeNode> SemanticDomains => _mongoDbContext.Db.GetCollection<SemanticDomainTreeNode>("SemanticDomainTree");
+        public IMongoCollection<SemanticDomainFull> FullSemanticDomains => _mongoDbContext.Db.GetCollection<SemanticDomainFull>("SemanticDomains");
     }
 }
diff --git a/Backend/Contexts/SpeakerContext.cs b/Backend/Contexts/SpeakerContext.cs
index f65c3e08c0..fb413f8f6b 100644
--- a/Backend/Contexts/SpeakerContext.cs
+++ b/Backend/Contexts/SpeakerContext.cs
@@ -1,7 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
 using BackendFramework.Interfaces;
 using BackendFramework.Models;
-using Microsoft.Extensions.Options;
 using MongoDB.Driver;
 
 namespace BackendFramework.Contexts
@@ -9,14 +8,13 @@ namespace BackendFramework.Contexts
     [ExcludeFromCodeCoverage]
     public class SpeakerContext : ISpeakerContext
     {
-        private readonly IMongoDatabase _db;
-
-        public SpeakerContext(IOptions<Startup.Settings> options)
+        private readonly IMongoDbContext _mongoDbContext;
+        
+        public SpeakerContext(IMongoDbContext mongoDbContext)
         {
-            var client = new MongoClient(options.Value.ConnectionString);
-            _db = client.GetDatabase(options.Value.CombineDatabase);
+            _mongoDbContext = mongoDbContext;
         }
 
-        public IMongoCollection<Speaker> Speakers => _db.GetCollection<Speaker>("SpeakersCollection");
+        public IMongoCollection<Speaker> Speakers => _mongoDbContext.Db.GetCollection<Speaker>("SpeakersCollection");
     }
 }
diff --git a/Backend/Contexts/UserContext.cs b/Backend/Contexts/UserContext.cs
index 46122c146c..92778f02d7 100644
--- a/Backend/Contexts/UserContext.cs
+++ b/Backend/Contexts/UserContext.cs
@@ -1,7 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
 using BackendFramework.Interfaces;
 using BackendFramework.Models;
-using Microsoft.Extensions.Options;
 using MongoDB.Driver;
 
 namespace BackendFramework.Contexts
@@ -9,14 +8,12 @@ namespace BackendFramework.Contexts
     [ExcludeFromCodeCoverage]
     public class UserContext : IUserContext
     {
-        private readonly IMongoDatabase _db;
-
-        public UserContext(IOptions<Startup.Settings> options)
+        private readonly IMongoDbContext _mongoDbContext;
+        public UserContext(IMongoDbContext mongoDbContext)
         {
-            var client = new MongoClient(options.Value.ConnectionString);
-            _db = client.GetDatabase(options.Value.CombineDatabase);
+            _mongoDbContext = mongoDbContext;
         }
 
-        public IMongoCollection<User> Users => _db.GetCollection<User>("UsersCollection");
+        public IMongoCollection<User> Users => _mongoDbContext.Db.GetCollection<User>("UsersCollection");
     }
 }
diff --git a/Backend/Contexts/UserEditContext.cs b/Backend/Contexts/UserEditContext.cs
index 7487d78ec0..d0de83a1a6 100644
--- a/Backend/Contexts/UserEditContext.cs
+++ b/Backend/Contexts/UserEditContext.cs
@@ -1,7 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
 using BackendFramework.Interfaces;
 using BackendFramework.Models;
-using Microsoft.Extensions.Options;
 using MongoDB.Driver;
 
 namespace BackendFramework.Contexts
@@ -9,14 +8,12 @@ namespace BackendFramework.Contexts
     [ExcludeFromCodeCoverage]
     public class UserEditContext : IUserEditContext
     {
-        private readonly IMongoDatabase _db;
-
-        public UserEditContext(IOptions<Startup.Settings> options)
+        private readonly IMongoDbContext _mongoDbContext;
+        public UserEditContext(IMongoDbContext mongoDbContext)
         {
-            var client = new MongoClient(options.Value.ConnectionString);
-            _db = client.GetDatabase(options.Value.CombineDatabase);
+            _mongoDbContext = mongoDbContext;
         }
 
-        public IMongoCollection<UserEdit> UserEdits => _db.GetCollection<UserEdit>("UserEditsCollection");
+        public IMongoCollection<UserEdit> UserEdits => _mongoDbContext.Db.GetCollection<UserEdit>("UserEditsCollection");
     }
 }
diff --git a/Backend/Contexts/UserRoleContext.cs b/Backend/Contexts/UserRoleContext.cs
index 086c2ffe57..92b7c6506f 100644
--- a/Backend/Contexts/UserRoleContext.cs
+++ b/Backend/Contexts/UserRoleContext.cs
@@ -1,7 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
 using BackendFramework.Interfaces;
 using BackendFramework.Models;
-using Microsoft.Extensions.Options;
 using MongoDB.Driver;
 
 namespace BackendFramework.Contexts
@@ -9,14 +8,12 @@ namespace BackendFramework.Contexts
     [ExcludeFromCodeCoverage]
     public class UserRoleContext : IUserRoleContext
     {
-        private readonly IMongoDatabase _db;
-
-        public UserRoleContext(IOptions<Startup.Settings> options)
+        private readonly IMongoDbContext _mongoDbContext;
+        public UserRoleContext(IMongoDbContext mongoDbContext)
         {
-            var client = new MongoClient(options.Value.ConnectionString);
-            _db = client.GetDatabase(options.Value.CombineDatabase);
+            _mongoDbContext = mongoDbContext;
         }
 
-        public IMongoCollection<UserRole> UserRoles => _db.GetCollection<UserRole>("UserRolesCollection");
+        public IMongoCollection<UserRole> UserRoles => _mongoDbContext.Db.GetCollection<UserRole>("UserRolesCollection");
     }
 }
diff --git a/Backend/Contexts/WordContext.cs b/Backend/Contexts/WordContext.cs
index 32876c6af2..d8989de00e 100644
--- a/Backend/Contexts/WordContext.cs
+++ b/Backend/Contexts/WordContext.cs
@@ -1,7 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
 using BackendFramework.Interfaces;
 using BackendFramework.Models;
-using Microsoft.Extensions.Options;
 using MongoDB.Driver;
 
 namespace BackendFramework.Contexts
@@ -9,15 +8,13 @@ namespace BackendFramework.Contexts
     [ExcludeFromCodeCoverage]
     public class WordContext : IWordContext
     {
-        private readonly IMongoDatabase _db;
-
-        public WordContext(IOptions<Startup.Settings> options)
+        private readonly IMongoDbContext _mongoDbContext;
+        public WordContext(IMongoDbContext mongoDbContext)
         {
-            var client = new MongoClient(options.Value.ConnectionString);
-            _db = client.GetDatabase(options.Value.CombineDatabase);
+            _mongoDbContext = mongoDbContext;
         }
 
-        public IMongoCollection<Word> Words => _db.GetCollection<Word>("WordsCollection");
-        public IMongoCollection<Word> Frontier => _db.GetCollection<Word>("FrontierCollection");
+        public IMongoCollection<Word> Words => _mongoDbContext.Db.GetCollection<Word>("WordsCollection");
+        public IMongoCollection<Word> Frontier => _mongoDbContext.Db.GetCollection<Word>("FrontierCollection");
     }
 }
diff --git a/Backend/Interfaces/IMongoDbContext.cs b/Backend/Interfaces/IMongoDbContext.cs
new file mode 100644
index 0000000000..cfd1363286
--- /dev/null
+++ b/Backend/Interfaces/IMongoDbContext.cs
@@ -0,0 +1,17 @@
+using System;
+using System.Threading.Tasks;
+using MongoDB.Driver;
+
+namespace BackendFramework.Interfaces;
+
+public interface IMongoDbContext
+{
+    IMongoDatabase Db { get; }
+    Task<IMongoTransaction> BeginTransaction();
+}
+
+public interface IMongoTransaction : IDisposable
+{
+    Task CommitTransactionAsync();
+    Task AbortTransactionAsync();
+}
\ No newline at end of file
diff --git a/Backend/Startup.cs b/Backend/Startup.cs
index 8bdad6da05..95f56f9260 100644
--- a/Backend/Startup.cs
+++ b/Backend/Startup.cs
@@ -287,6 +287,9 @@ public void ConfigureServices(IServiceCollection services)
             services.AddTransient<IWordContext, WordContext>();
             services.AddTransient<IWordRepository, WordRepository>();
             services.AddTransient<IWordService, WordService>();
+            
+            // mongo context, scoped so it is shared across a single request
+            services.AddScoped<IMongoDbContext, MongoDbContext>();
         }
 
         /// <summary> This method gets called by the runtime. Use this method to configure the HTTP request pipeline.