From 0d472dccb1125bf6df6def1bdcbe54a4a8c6eaf3 Mon Sep 17 00:00:00 2001
From: whitlocktech <whitlocktech@gmail.com>
Date: Fri, 28 Nov 2025 23:33:51 -0600
Subject: [PATCH] Lesson 01: add host engine and core domain models

---
 src/NetPulse.Core/Domain/PingResult.cs | 34 ++++++++++++++++++++++++++
 src/NetPulse.Core/Domain/PingTarget.cs | 27 ++++++++++++++++++++
 src/NetPulse.Core/EngineLoop.cs        | 33 +++++++++++++++++++------
 src/NetPulse.Core/Program.cs           | 11 +++++----
 4 files changed, 92 insertions(+), 13 deletions(-)
 create mode 100644 src/NetPulse.Core/Domain/PingResult.cs
 create mode 100644 src/NetPulse.Core/Domain/PingTarget.cs

diff --git a/src/NetPulse.Core/Domain/PingResult.cs b/src/NetPulse.Core/Domain/PingResult.cs
new file mode 100644
index 0000000..5d796b7
--- /dev/null
+++ b/src/NetPulse.Core/Domain/PingResult.cs
@@ -0,0 +1,34 @@
+namespace NetPulse.Core.Domain;
+
+///<summary>
+/// Result of a ping check against a Ping Target.
+/// </summary>
+public class PingResult
+{
+    public Guid Id { get; init; } = Guid.NewGuid();
+
+    /// <summary>
+    /// The Target this result belongs to.
+    /// </summary>
+    public Guid TargetId { get; init; }
+
+    /// <summary>
+    /// When the check was performed (UTC).
+    /// </summary>
+    public DateTime TimeStampUtc { get; init; }
+
+    /// <summary>
+    /// If the ping succeeded.
+    /// </summary>
+    public bool Success { get; init; }
+
+    /// <summary>
+    /// Round-trip in milliseconds, if check succeeded.
+    /// </summary>
+    public double? LatencyMs { get; init; }
+
+    /// <summary>
+    /// Error detail if the pin failed.
+    /// </summary>
+    public string? ErrorMessage { get; init; } 
+}
\ No newline at end of file
diff --git a/src/NetPulse.Core/Domain/PingTarget.cs b/src/NetPulse.Core/Domain/PingTarget.cs
new file mode 100644
index 0000000..fdb4096
--- /dev/null
+++ b/src/NetPulse.Core/Domain/PingTarget.cs
@@ -0,0 +1,27 @@
+namespace NetPulse.Core.Domain;
+
+/// <summary>
+/// A host or service that NetPulse should Monitor
+/// </summary>
+public class PingTarget
+{
+    /// <summary>
+    /// Internal Identifier (map to db key later)
+    /// </summary>
+    public Guid Id { get; init; } = Guid.NewGuid();
+
+    /// <summary>
+    /// Display name for the target
+    /// </summary>
+    public string Name { get; init; } = string.Empty;
+
+    /// <summary>
+    /// Hostname or Ip address to ping.
+    /// </summary>
+    public string Host { get; init; } = string.Empty;
+
+    /// <summary>
+    /// Whether this target is currently enabled for monitoring.
+    /// </summary>
+    public bool isEnabled { get; init; } = true;
+}
\ No newline at end of file
diff --git a/src/NetPulse.Core/EngineLoop.cs b/src/NetPulse.Core/EngineLoop.cs
index e087518..e08f13a 100644
--- a/src/NetPulse.Core/EngineLoop.cs
+++ b/src/NetPulse.Core/EngineLoop.cs
@@ -1,5 +1,6 @@
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
+using NetPulse.Core.Domain;
 
 namespace NetPulse.Core;
 
@@ -8,6 +9,12 @@ public class EngineLoop : BackgroundService
     private readonly ILogger<EngineLoop> _logger;
     private readonly TimeSpan _interval = TimeSpan.FromSeconds(2);
 
+    private readonly List<PingTarget> _targets = new()
+    {
+        new PingTarget { Name = "Router", Host = "192.168.0.1" },
+        new PingTarget { Name = "Cloudflare", Host = "1.1.1.1"}
+    };
+
     public EngineLoop(ILogger<EngineLoop> logger)
     {
         _logger = logger;
@@ -17,16 +24,26 @@ public class EngineLoop : BackgroundService
     {
         _logger.LogInformation("EngineLoop started.");
 
-        while(!stoppingToken.IsCancellationRequested)
+        while (!stoppingToken.IsCancellationRequested)
         {
             try
             {
-                // ===== Core Heartbeat =====
-                _logger.LogInformation("Hearbeat at {time}", DateTime.UtcNow);
 
-                // Future: metrics Collection
-                // Future: dispatch events
-                // Future: run modules
+                // ===== Core Heartbeat =====
+                _logger.LogInformation("Heartbeat at {time}", DateTime.UtcNow);
+
+                foreach (var target in _targets)
+                {
+                    _logger.LogInformation(
+                        "Target {name} at {host} is configured (enabled = {enabled})",
+                        target.Name,
+                        target.Host,
+                        target.isEnabled);
+                }
+
+                /// Future: metrics Collection
+                /// Future: dispatch events
+                /// Future: run modules
 
                 await Task.Delay(_interval, stoppingToken);
             }
@@ -36,10 +53,10 @@ public class EngineLoop : BackgroundService
             }
             catch (Exception ex)
             {
-                _logger.LogError(ex, "Unexpected Engine error.");
+                _logger.LogError(ex, "Unexpected engine error.");
             }
         }
 
-        _logger.LogInformation("EngineLoop Stopping");
+        _logger.LogInformation("EngineLoop stopping.");
     }
 }
\ No newline at end of file
diff --git a/src/NetPulse.Core/Program.cs b/src/NetPulse.Core/Program.cs
index 5e2eef8..9f64c7d 100644
--- a/src/NetPulse.Core/Program.cs
+++ b/src/NetPulse.Core/Program.cs
@@ -1,6 +1,7 @@
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
-using Microsoft.Extensions.Configuration;
 
 namespace NetPulse.Core;
 
@@ -11,23 +12,23 @@ public class Program
         using IHost host = Host.CreateDefaultBuilder(args)
             .ConfigureAppConfiguration(config =>
             {
-                config.AddJsonFile("appsettings.json", optional: true, reloadOnChange: true);
+                config.AddJsonFile("appsettings.json", optional: true, reloadOnChange:true);
             })
-            .ConfigureLogging(logging =>
+            .ConfigureLogging(logging=>
             {
                 logging.ClearProviders();
                 logging.AddSimpleConsole(options =>
                 {
-                    options.TimestampFormat = "HH:MM:SS";
+                    options.TimestampFormat = "HH:mm:ss ";
                     options.IncludeScopes = true;
                 });
-
             })
             .ConfigureServices((context, services) =>
             {
                 services.AddHostedService<EngineLoop>();
             })
             .Build();
+
         await host.RunAsync();
     }
 }
\ No newline at end of file