From fb0b108c2198b56951f19cd65d0bf8bda8a12b1f Mon Sep 17 00:00:00 2001
From: jvyden <jvyden@jvyden.xyz>
Date: Thu, 20 Jan 2022 21:28:09 -0500
Subject: [PATCH] Automatically warmup website hot reload when starting up
 debug builds

---
 .../Startup/DebugWarmupLifetime.cs            | 52 +++++++++++++++++++
 ProjectLighthouse/Startup/Startup.cs          |  7 +++
 2 files changed, 59 insertions(+)
 create mode 100644 ProjectLighthouse/Startup/DebugWarmupLifetime.cs

diff --git a/ProjectLighthouse/Startup/DebugWarmupLifetime.cs b/ProjectLighthouse/Startup/DebugWarmupLifetime.cs
new file mode 100644
index 00000000..7f50ae6d
--- /dev/null
+++ b/ProjectLighthouse/Startup/DebugWarmupLifetime.cs
@@ -0,0 +1,52 @@
+using System;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+using Kettu;
+using LBPUnion.ProjectLighthouse.Logging;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Hosting.Internal;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+
+namespace LBPUnion.ProjectLighthouse.Startup;
+
+public class DebugWarmupLifetime : IHostLifetime
+{
+    public IHostApplicationLifetime ApplicationLifetime { get; }
+
+    private CancellationTokenRegistration applicationStartedRegistration;
+
+    private readonly ConsoleLifetime consoleLifetime;
+
+    public DebugWarmupLifetime
+    (
+        IOptions<ConsoleLifetimeOptions> options,
+        IHostEnvironment environment,
+        IHostApplicationLifetime applicationLifetime,
+        IOptions<HostOptions> hostOptions,
+        ILoggerFactory loggerFactory
+    )
+    {
+        this.consoleLifetime = new ConsoleLifetime(options, environment, applicationLifetime, hostOptions, loggerFactory);
+        this.ApplicationLifetime = applicationLifetime;
+    }
+
+    public static void OnApplicationStarted()
+    {
+        using HttpClient client = new();
+
+        Logger.Log("Warming up Hot Reload...", LoggerLevelStartup.Instance);
+        client.GetAsync("http://localhost:10060/").Wait();
+        Logger.Log("Hot Reload is ready to go!", LoggerLevelStartup.Instance);
+    }
+
+    public Task StopAsync(CancellationToken cancellationToken) => this.consoleLifetime.StopAsync(cancellationToken);
+
+    public Task WaitForStartAsync(CancellationToken cancellationToken)
+    {
+        this.applicationStartedRegistration = this.ApplicationLifetime.ApplicationStarted.Register((Action<object>)(_ => OnApplicationStarted()), (object)this);
+
+        return this.consoleLifetime.WaitForStartAsync(cancellationToken);
+    }
+}
\ No newline at end of file
diff --git a/ProjectLighthouse/Startup/Startup.cs b/ProjectLighthouse/Startup/Startup.cs
index c959a6af..20e0115a 100644
--- a/ProjectLighthouse/Startup/Startup.cs
+++ b/ProjectLighthouse/Startup/Startup.cs
@@ -12,6 +12,7 @@ using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.HttpOverrides;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Primitives;
 
 namespace LBPUnion.ProjectLighthouse.Startup;
@@ -53,6 +54,12 @@ public class Startup
                 options.ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto;
             }
         );
+
+        #if DEBUG
+        services.AddSingleton<IHostLifetime, DebugWarmupLifetime>();
+        #else
+        services.AddSingleton<IHostLifetime, ConsoleLifetime>();
+        #endif
     }
 
     // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.