add: user service with CRUD operations

Models/BlogDatabaseSettings.cs

@@ -0,0 +1,9 @@
+namespace backend.Models;
+
+public class BlogDatabaseSettings
+{
+    public string ConnectionString { get; set; } = null;
+    public string DatabaseName { get; set; } = null;
+    public string UsersCollectionName{ get; set; } = null;
+    public string PostsCollectionName { get; set; } = null;
+}

Program.cs

@@ -1,8 +1,11 @@
+using backend.Models;
+
 var builder = WebApplication.CreateBuilder(args);
 
 // Add services to the container.
 
 builder.Services.AddControllers();
+builder.Services.Configure<BlogDatabaseSettings>(builder.Configuration.GetSection("BlogDatabase"));
 // Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
 builder.Services.AddEndpointsApiExplorer();
 builder.Services.AddSwaggerGen();

Services/UserService.cs

@@ -1,6 +1,38 @@
+using backend.Models;
+using Microsoft.Extensions.Options;
+using MongoDB.Driver;
+
 namespace backend.Services;
 
 public class UserService
 {
+    private readonly IMongoCollection<User> _users;
+    
+    public UserService(IOptions<BlogDatabaseSettings> settings)
+    {
+        var client = new MongoClient(settings.Value.ConnectionString);
+        var database = client.GetDatabase(settings.Value.DatabaseName);
+        _users = database.GetCollection<User>(settings.Value.UsersCollectionName);
+    }
+    
+    public async Task<User?> GetAsync(string id)
+    {
+        var user = await _users.Find(user => user.Id == id).FirstOrDefaultAsync();
+        return user;
+    }
     
+    public async Task CreateAsync(User user)
+    {
+        await _users.InsertOneAsync(user);
+    }
+    
+    public async Task RemoveAsync(string id)
+    {
+        await _users.DeleteOneAsync(user => user.Id == id);
+    }
+    
+    public async Task UpdateAsync(string id, User userIn)
+    {
+        await _users.ReplaceOneAsync(user => user.Id == id, userIn);
+    }
 }

appsettings.json

@@ -1,4 +1,12 @@
 {
+  "BlogDatabase": {
+    "ConnectionString": "mongodb://localhost:27017",
+    "DatabaseName": "Blog",
+    "UserCollectionName": "Users",
+    "PostCollectionName": "Posts"
+    
+  },
+  
   "Logging": {
     "LogLevel": {
       "Default": "Information",