From bf1ead29205878526573496653554ae81c3ebde7 Mon Sep 17 00:00:00 2001
From: Kevin Dockx <kevin.dockx@gmail.com>
Date: Tue, 25 Sep 2018 16:16:57 +0200
Subject: [PATCH] Improve DI for legacy sample

---
 .../Books.Api/Controllers/BooksController.cs  | 19 ++++++++++++-------
 .../Migrations/InitialMigration.Designer.cs   |  2 +-
 Books/Books.Api/Services/BooksRepository.cs   |  3 +--
 Books/Books.Api/Startup.cs                    |  3 +++
 4 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/Books/Books.Api/Controllers/BooksController.cs b/Books/Books.Api/Controllers/BooksController.cs
index ee74428..1292571 100644
--- a/Books/Books.Api/Controllers/BooksController.cs
+++ b/Books/Books.Api/Controllers/BooksController.cs
@@ -1,6 +1,7 @@
 using AutoMapper;
 using Books.Api.Models;
 using Books.Api.Services;
+using Books.Legacy;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.Logging;
 using System;
@@ -15,14 +16,18 @@ public class BooksController : ControllerBase
         private readonly IBooksRepository _booksRepository;
         private readonly IMapper _mapper;
         private readonly ILogger<BooksController> _logger;
+        private readonly ComplicatedPageCalculator _complicatedPageCalculator;
 
         public BooksController(IBooksRepository booksRepository,
-            IMapper mapper,  ILogger<BooksController> logger)
+            IMapper mapper,  ILogger<BooksController> logger,
+            ComplicatedPageCalculator complicatedPageCalculator)
         {
             _booksRepository = booksRepository 
                 ?? throw new ArgumentNullException(nameof(booksRepository));
             _mapper = mapper ?? throw new ArgumentNullException(nameof(mapper));
             _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+            _complicatedPageCalculator = complicatedPageCalculator ?? 
+                throw new ArgumentNullException(nameof(complicatedPageCalculator)); 
         }
  
         [HttpGet]
@@ -39,12 +44,12 @@ public async Task<IActionResult> GetBook(Guid id)
 
             // calculate the book pages 
             // DON'T DO THIS, this is sample code for a bad practice!
-            _logger.LogInformation($"ThreadId when entering GetBookAsync: {System.Threading.Thread.CurrentThread.ManagedThreadId}");
+            _logger.LogInformation($"ThreadId when entering GetBook: " +
+                $"{System.Threading.Thread.CurrentThread.ManagedThreadId}");
             var bookPages = await GetBookPages(id);
 
             // good way to call legacy computational-bound code is by NOT offloading it to the background
-            //var pageCalculator = new Books.Legacy.ComplicatedPageCalculator();
-            //var bookPages = pageCalculator.CalculateBookPages(id);
+            //var bookPages = _complicatedPageCalculator.CalculateBookPages(id);
 
             return Ok(_mapper.Map<Models.Book>(bookEntity));
         }
@@ -59,10 +64,10 @@ private Task<int> GetBookPages(Guid id)
         {
             return Task.Run(() =>
             {
-                _logger.LogInformation($"ThreadId when calculating the amount of pages: {System.Threading.Thread.CurrentThread.ManagedThreadId}");
+                _logger.LogInformation($"ThreadId when calculating the amount of pages: " +
+                    $"{System.Threading.Thread.CurrentThread.ManagedThreadId}");
 
-                var pageCalculator = new Books.Legacy.ComplicatedPageCalculator();
-                return pageCalculator.CalculateBookPages(id);
+                return _complicatedPageCalculator.CalculateBookPages(id);
             });
         }
 
diff --git a/Books/Books.Api/Migrations/InitialMigration.Designer.cs b/Books/Books.Api/Migrations/InitialMigration.Designer.cs
index 010d933..79b80f2 100644
--- a/Books/Books.Api/Migrations/InitialMigration.Designer.cs
+++ b/Books/Books.Api/Migrations/InitialMigration.Designer.cs
@@ -10,7 +10,7 @@
 namespace Books.Api.Migrations
 {
     [DbContext(typeof(BooksContext))]
-    [Migration("20180717132912_InitialMigration")]
+    [Migration("InitialMigration")]
     partial class InitialMigration
     {
         protected override void BuildTargetModel(ModelBuilder modelBuilder)
diff --git a/Books/Books.Api/Services/BooksRepository.cs b/Books/Books.Api/Services/BooksRepository.cs
index 84f37bf..34d6ce6 100644
--- a/Books/Books.Api/Services/BooksRepository.cs
+++ b/Books/Books.Api/Services/BooksRepository.cs
@@ -3,7 +3,6 @@
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
 using System;
-using System.Net.Http;
 using System.Threading.Tasks;
 
 namespace Books.Api.Services
@@ -13,7 +12,7 @@ public class BooksRepository : IBooksRepository, IDisposable
         private BooksContext _context;
         private readonly ILogger<BooksRepository> _logger;
 
-        public BooksRepository(BooksContext context, IHttpClientFactory httpClientFactory,
+        public BooksRepository(BooksContext context,  
               ILogger<BooksRepository> logger)
         {
             _context = context ?? throw new ArgumentNullException(nameof(context));
diff --git a/Books/Books.Api/Startup.cs b/Books/Books.Api/Startup.cs
index b496f6c..1536a4a 100644
--- a/Books/Books.Api/Startup.cs
+++ b/Books/Books.Api/Startup.cs
@@ -1,6 +1,7 @@
 using AutoMapper;
 using Books.Api.Contexts;
 using Books.Api.Services;
+using Books.Legacy;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Mvc;
@@ -32,6 +33,8 @@ public void ConfigureServices(IServiceCollection services)
 
             services.AddScoped<IBooksRepository, BooksRepository>();
 
+            services.AddTransient<ComplicatedPageCalculator>();
+
             services.AddAutoMapper(); 
         }