Add under-pressure lockout to air vents (#9824)

* Add under-pressure lockout to vent pumps

* Add examine text showing UPLO

Content.Server/Atmos/Piping/Unary/Components/GasVentPumpComponent.cs

@@ -33,6 +33,17 @@ namespace Content.Server.Atmos.Piping.Unary.Components
         [DataField("pressureChecks")]
         public VentPressureBound PressureChecks { get; set; } = VentPressureBound.ExternalBound;
 
+        [ViewVariables(VVAccess.ReadOnly)]
+        [DataField("underPressureLockout")]
+        public bool UnderPressureLockout { get; set; } = false;
+
+        /// <summary>
+        ///     In releasing mode, do not pump when environment pressure is below this limit.
+        /// </summary>
+        [ViewVariables(VVAccess.ReadWrite)]
+        [DataField("underPressureLockoutThreshold")]
+        public float UnderPressureLockoutThreshold = 1;
+
         [ViewVariables(VVAccess.ReadWrite)]
         [DataField("externalPressureBound")]
         public float ExternalPressureBound

Content.Server/Atmos/Piping/Unary/EntitySystems/GasVentPumpSystem.cs

@@ -16,6 +16,7 @@ using Content.Shared.Atmos.Monitor;
 using Content.Shared.Atmos.Piping.Unary.Components;
 using Content.Shared.Atmos.Visuals;
 using Content.Shared.Audio;
+using Content.Shared.Examine;
 using JetBrains.Annotations;
 using Robust.Shared.Timing;
 
@@ -41,6 +42,7 @@ namespace Content.Server.Atmos.Piping.Unary.EntitySystems
             SubscribeLocalEvent<GasVentPumpComponent, PowerChangedEvent>(OnPowerChanged);
             SubscribeLocalEvent<GasVentPumpComponent, DeviceNetworkPacketEvent>(OnPacketRecv);
             SubscribeLocalEvent<GasVentPumpComponent, ComponentInit>(OnInit);
+            SubscribeLocalEvent<GasVentPumpComponent, ExaminedEvent>(OnExamine);
             SubscribeLocalEvent<GasVentPumpComponent, SignalReceivedEvent>(OnSignalReceived);
         }
 
@@ -83,6 +85,13 @@ namespace Content.Server.Atmos.Piping.Unary.EntitySystems
                 if (environment.Pressure > vent.MaxPressure)
                     return;
 
+                if (environment.Pressure < vent.UnderPressureLockoutThreshold)
+                {
+                    vent.UnderPressureLockout = true;
+                    return;
+                }
+                vent.UnderPressureLockout = false;
+
                 if ((vent.PressureChecks & VentPressureBound.ExternalBound) != 0)
                     pressureDelta = MathF.Min(pressureDelta, vent.ExternalPressureBound - environment.Pressure);
 
@@ -255,5 +264,18 @@ namespace Content.Server.Atmos.Piping.Unary.EntitySystems
                 appearance.SetData(VentPumpVisuals.State, VentPumpState.Welded);
             }
         }
+
+        private void OnExamine(EntityUid uid, GasVentPumpComponent component, ExaminedEvent args)
+        {
+            if (!TryComp<GasVentPumpComponent>(uid, out var pumpComponent))
+                return;
+            if (args.IsInDetailsRange)
+            {
+                if (pumpComponent.UnderPressureLockout)
+                {
+                    args.PushMarkup(Loc.GetString("gas-vent-pump-uvlo"));
+                }
+            }
+        }
     }
 }

Resources/Locale/en-US/atmos/gas-vent-pump.ftl

@@ -0,0 +1 @@
+gas-vent-pump-uvlo = It is in [color=red]under-pressure lock out[/color].