Added Hangfire with LiteDB for a task running system. At the most basic, this allows us to monitor tasks running on the system (during dev only) and run tasks on a reoccuring or ad-hoc basis.

API/API.csproj

@@ -8,6 +8,9 @@
 
   <ItemGroup>
     <PackageReference Include="AutoMapper.Extensions.Microsoft.DependencyInjection" Version="8.1.0" />
+    <PackageReference Include="Hangfire" Version="1.7.18" />
+    <PackageReference Include="Hangfire.AspNetCore" Version="1.7.18" />
+    <PackageReference Include="Hangfire.LiteDB" Version="0.4.0" />
     <PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="5.0.1" NoWarn="NU1605" />
     <PackageReference Include="Microsoft.AspNetCore.Authentication.OpenIdConnect" Version="5.0.1" NoWarn="NU1605" />
     <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="5.0.1" />

API/Controllers/AccountController.cs

@@ -49,8 +49,6 @@ namespace API.Controllers
 
             if (!result.Succeeded) return BadRequest(result.Errors);
             
-
-            // TODO: Need a way to store Roles in enum and configure from there
             var role = registerDto.IsAdmin ? PolicyConstants.AdminRole : PolicyConstants.PlebRole;
             var roleResult = await _userManager.AddToRoleAsync(user, role);
 

API/Controllers/AdminController.cs

@@ -1,9 +1,6 @@
-using System.Collections.Generic;
+using System.Threading.Tasks;
-using System.Threading.Tasks;
-using API.DTOs;
 using API.Entities;
 using API.Interfaces;
-using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Identity;
 using Microsoft.AspNetCore.Mvc;
 

API/Controllers/LibraryController.cs

@@ -1,14 +1,13 @@
-using System.Collections.Generic;
+using System;
-using System.Collections.Immutable;
+using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using System.Threading.Tasks;
 using API.Data;
 using API.DTOs;
 using API.Entities;
-using API.Extensions;
 using API.Interfaces;
 using AutoMapper;
+using Hangfire;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.Logging;
@@ -18,23 +17,23 @@ namespace API.Controllers
     [Authorize]
     public class LibraryController : BaseApiController
     {
-        private readonly DataContext _context;
         private readonly IDirectoryService _directoryService;
         private readonly ILibraryRepository _libraryRepository;
         private readonly ILogger<LibraryController> _logger;
         private readonly IUserRepository _userRepository;
         private readonly IMapper _mapper;
+        private readonly ITaskScheduler _taskScheduler;
 
-        public LibraryController(DataContext context, IDirectoryService directoryService, 
+        public LibraryController(IDirectoryService directoryService, 
             ILibraryRepository libraryRepository, ILogger<LibraryController> logger, IUserRepository userRepository,
-            IMapper mapper)
+            IMapper mapper, ITaskScheduler taskScheduler)
         {
-            _context = context;
             _directoryService = directoryService;
             _libraryRepository = libraryRepository;
             _logger = logger;
             _userRepository = userRepository;
             _mapper = mapper;
+            _taskScheduler = taskScheduler;
         }
 
         /// <summary>
@@ -90,8 +89,8 @@ namespace API.Controllers
         public async Task<ActionResult> ScanLibrary(int libraryId)
         {
             var library = await _libraryRepository.GetLibraryForIdAsync(libraryId);
-
+            
-            _directoryService.ScanLibrary(library);
+            BackgroundJob.Enqueue(() => _directoryService.ScanLibrary(library));
 
             return Ok();
         }

API/Controllers/UsersController.cs

@@ -14,13 +14,11 @@ namespace API.Controllers
     [Authorize]
     public class UsersController : BaseApiController
     {
-        private readonly DataContext _context;
         private readonly IUserRepository _userRepository;
         private readonly ILibraryRepository _libraryRepository;
 
-        public UsersController(DataContext context, IUserRepository userRepository, ILibraryRepository libraryRepository)
+        public UsersController(IUserRepository userRepository, ILibraryRepository libraryRepository)
         {
-            _context = context;
             _userRepository = userRepository;
             _libraryRepository = libraryRepository;
         }
@@ -43,7 +41,7 @@ namespace API.Controllers
             // TODO: We probably need to clean the folders before we insert
             var library = new Library
             {
-                Name = createLibraryDto.Name, // TODO: Ensure code handles Library name always being lowercase
+                Name = createLibraryDto.Name.ToLower(),
                 Type = createLibraryDto.Type,
                 AppUsers = new List<AppUser>() { user }
             };

API/DTOs/CreateLibraryDto.cs

@@ -1,8 +1,6 @@
 using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
-using System.Text.Json.Serialization;
 using API.Entities;
-using Microsoft.EntityFrameworkCore.Storage.ValueConversion.Internal;
 
 namespace API.DTOs
 {

API/DTOs/MemberDto.cs

@@ -1,7 +1,5 @@
 using System;
-using System.Collections;
 using System.Collections.Generic;
-using API.Entities;
 
 namespace API.DTOs
 {

API/Data/DataContext.cs

@@ -1,5 +1,4 @@
-using System;
+using API.Entities;
-using API.Entities;
 using Microsoft.AspNetCore.Identity;
 using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore;

API/Data/Migrations/20201224155621_MiscCleanup.cs

@@ -1,5 +1,4 @@
-using System;
+using Microsoft.EntityFrameworkCore.Migrations;
-using Microsoft.EntityFrameworkCore.Migrations;
 
 namespace API.Data.Migrations
 {

API/Data/Migrations/DataContextModelSnapshot.cs

@@ -1,9 +1,7 @@
 // <auto-generated />
 using System;
-using API.Data;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore.Infrastructure;
-using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
 
 namespace API.Data.Migrations
 {

API/Data/Seed.cs

@@ -12,8 +12,8 @@ namespace API.Data
         {
             var roles = new List<AppRole>
             {
-                new AppRole {Name = PolicyConstants.AdminRole},
+                new() {Name = PolicyConstants.AdminRole},
-                new AppRole {Name = PolicyConstants.PlebRole}
+                new() {Name = PolicyConstants.PlebRole}
             };
 
             foreach (var role in roles)

API/Extensions/ApplicationServiceExtensions.cs

@@ -3,6 +3,8 @@ using API.Helpers;
 using API.Interfaces;
 using API.Services;
 using AutoMapper;
+using Hangfire;
+using Hangfire.LiteDB;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
@@ -14,6 +16,7 @@ namespace API.Extensions
         public static IServiceCollection AddApplicationServices(this IServiceCollection services, IConfiguration config)
         {
             services.AddAutoMapper(typeof(AutoMapperProfiles).Assembly);
+            services.AddScoped<ITaskScheduler, TaskScheduler>();
             services.AddScoped<IUserRepository, UserRepository>();
             services.AddScoped<ITokenService, TokenService>();
             services.AddScoped<IDirectoryService, DirectoryService>();
@@ -23,6 +26,14 @@ namespace API.Extensions
                 options.UseSqlite(config.GetConnectionString("DefaultConnection"));
             });
 
+            services.AddHangfire(configuration => configuration
+                .UseSimpleAssemblyNameTypeSerializer()
+                .UseRecommendedSerializerSettings()
+                .UseLiteDbStorage());
+            
+            // Add the processing server as IHostedService
+            services.AddHangfireServer();
+
             return services;
         }
     }

API/Helpers/AutoMapperProfiles.cs

@@ -1,5 +1,4 @@
-using System;
+using System.Linq;
-using System.Linq;
 using API.DTOs;
 using API.Entities;
 using AutoMapper;

API/Interfaces/IDirectoryService.cs

@@ -1,7 +1,5 @@
 using System.Collections.Generic;
-using System.Threading.Tasks;
 using API.DTOs;
-using API.Entities;
 
 namespace API.Interfaces
 {

API/Interfaces/ITaskScheduler.cs

@@ -0,0 +1,7 @@
+namespace API.Interfaces
+{
+    public interface ITaskScheduler
+    {
+        
+    }
+}

API/Interfaces/IUserRepository.cs

@@ -1,5 +1,4 @@
-using System.Collections;
+using System.Collections.Generic;
-using System.Collections.Generic;
 using System.Threading.Tasks;
 using API.DTOs;
 using API.Entities;

API/Services/DirectoryService.cs

@@ -29,7 +29,7 @@ namespace API.Services
         /// <returns>List of folder names</returns>
         public IEnumerable<string> ListDirectory(string rootPath)
         {
-            // TODO: Put some checks in here along with API to ensure that we aren't passed a file, folder exists, etc.
+           if (!Directory.Exists(rootPath)) return ImmutableList<string>.Empty;
             
             var di = new DirectoryInfo(rootPath);
             var dirs = di.GetDirectories()
@@ -137,7 +137,7 @@ namespace API.Services
                   else {
                      Parallel.ForEach(files, () => 0, (file, loopState, localCount) =>
                                                   { action(file);
-                                                    return (int) ++localCount;
+                                                    return ++localCount;
                                                   },
                                       (c) => {
                                                 Interlocked.Add(ref fileCount, c);

API/Services/TaskScheduler.cs

@@ -0,0 +1,17 @@
+using API.Interfaces;
+using Hangfire;
+
+namespace API.Services
+{
+    public class TaskScheduler : ITaskScheduler
+    {
+        private readonly BackgroundJobServer _client;
+        
+        public TaskScheduler()
+        {
+            _client = new BackgroundJobServer();
+        }
+        
+        
+    }
+}

API/Startup.cs

@@ -1,5 +1,7 @@
+using System;
 using API.Extensions;
 using API.Middleware;
+using Hangfire;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.Configuration;
@@ -33,7 +35,7 @@ namespace API
         }
 
         // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
-        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
+        public void Configure(IApplicationBuilder app, IBackgroundJobClient backgroundJobs, IWebHostEnvironment env)
         {
             app.UseMiddleware<ExceptionMiddleware>();
             
@@ -42,6 +44,9 @@ namespace API
                 app.UseSwagger();
                 app.UseSwaggerUI(c => c.SwaggerEndpoint("/swagger/v1/swagger.json", "API v1"));
             }
+            
+            app.UseHangfireDashboard();
+            backgroundJobs.Enqueue(() => Console.WriteLine("Hello world from Hangfire!"));
 
             app.UseHttpsRedirection();
 
@@ -57,6 +62,7 @@ namespace API
             app.UseEndpoints(endpoints =>
             {
                 endpoints.MapControllers();
+                endpoints.MapHangfireDashboard();
             });
         }
     }

API/appsettings.Development.json

@@ -1,13 +1,15 @@
 {
   "ConnectionStrings": {
-    "DefaultConnection": "Data source=kavita.db"
+    "DefaultConnection": "Data source=kavita.db",
+    "HangfireConnection": "Data source=hangfire.db"
   },
   "TokenKey": "super secret unguessable key",
   "Logging": {
     "LogLevel": {
       "Default": "Debug",
       "Microsoft": "Information",
-      "Microsoft.Hosting.Lifetime": "Information"
+      "Microsoft.Hosting.Lifetime": "Information",
+      "Hangfire": "Information"
     }
   }
 }