✨ Gateway readiness check

DysonNetwork.Gateway/Health/GatewayReadinessStore.cs

@@ -0,0 +1,76 @@
+using NodaTime;
+
+namespace DysonNetwork.Gateway.Health;
+
+public record ServiceHealthState(
+    string ServiceName,
+    bool IsHealthy,
+    Instant LastChecked,
+    string? Error
+);
+
+public record GatewayReadinessState(
+    bool IsReady,
+    IReadOnlyDictionary<string, ServiceHealthState> Services,
+    Instant LastUpdated
+);
+
+public class GatewayReadinessStore
+{
+    private readonly Lock _lock = new();
+
+    private readonly Dictionary<string, ServiceHealthState> _services = new();
+
+    public GatewayReadinessState Current { get; private set; } = new(
+        IsReady: false,
+        Services: new Dictionary<string, ServiceHealthState>(),
+        LastUpdated: SystemClock.Instance.GetCurrentInstant()
+    );
+
+    public IReadOnlyCollection<string> ServiceNames => _services.Keys;
+
+    public GatewayReadinessStore()
+    {
+        InitializeServices(GatewayConstant.ServiceNames);
+    }
+
+    private void InitializeServices(IEnumerable<string> serviceNames)
+    {
+        lock (_lock)
+        {
+            _services.Clear();
+
+            foreach (var name in serviceNames)
+            {
+                _services[name] = new ServiceHealthState(
+                    name,
+                    IsHealthy: false,
+                    LastChecked: SystemClock.Instance.GetCurrentInstant(),
+                    Error: "Not checked yet"
+                );
+            }
+
+            RecalculateLocked();
+        }
+    }
+
+    public void Update(ServiceHealthState state)
+    {
+        lock (_lock)
+        {
+            _services[state.ServiceName] = state;
+            RecalculateLocked();
+        }
+    }
+
+    private void RecalculateLocked()
+    {
+        var isReady = _services.Count > 0 && _services.Values.All(s => s.IsHealthy);
+
+        Current = new GatewayReadinessState(
+            IsReady: isReady,
+            Services: new Dictionary<string, ServiceHealthState>(_services),
+            LastUpdated: SystemClock.Instance.GetCurrentInstant()
+        );
+    }
+}