From 3aae76416c7b35523aebe40cc25db569d7b0c523 Mon Sep 17 00:00:00 2001
From: Marc Riera <marc@marcriera.cat>
Date: Sun, 13 Oct 2024 13:03:44 +0200
Subject: [PATCH] Train stop

---
 src/Devices/TrainStop.cs | 115 +++++++++++++++++++++++++++++++++++++++
 src/Train/Train.cs       |   8 ++-
 2 files changed, 122 insertions(+), 1 deletion(-)

diff --git a/src/Devices/TrainStop.cs b/src/Devices/TrainStop.cs
index f2797cd..a56b083 100644
--- a/src/Devices/TrainStop.cs
+++ b/src/Devices/TrainStop.cs
@@ -1,10 +1,125 @@
 using System;
+using OpenBveApi.Runtime;
 
 namespace OpenbveFcmbTrainPlugin
 {
     /// <summary>A train stop device to stop the train if a stop signal is passed.</summary>
     internal class TrainStop : Device
     {
+        /// <summary>Represents the state of the device.</summary>
+        private enum DeviceStates
+        {
+            /// <summary>The device is inactive.</summary>
+            Inactive,
+            /// <summary>The device is active.</summary>
+            Active,
+            /// <summary>The device is in emergency state.</summary>
+            Emergency,
+        }
 
+        /// <summary>The current state of the device.</summary>
+        private DeviceStates DeviceState;
+
+        /// <summary>Is called when the device state should be updated.</summary>
+        /// <param name="train">The current train.</param>
+        /// <param name="route">The current route.</param>
+        /// <param name="init">Whether the device should initialize.</param>
+        /// <param name="elapsedTime">The time elapsed since the previous call.</param>
+        internal override void Update(Train train, Route route, bool init, Time elapsedTime)
+        {
+            if (init)
+            {
+                // Activate the device during initialization
+                DeviceState = DeviceStates.Active;
+            }
+
+            if (train.VigilanceOverride)
+            {
+                // If the train requires a vigilance override, deactivate the device
+                DeviceState = DeviceStates.Inactive;
+            }
+            else if (DeviceState != DeviceStates.Emergency)
+            {
+                // Activate the device if there is no emergency
+                DeviceState = DeviceStates.Active;
+            }
+
+            switch (DeviceState)
+            {
+                case DeviceStates.Emergency:
+                    // Emergency stop required, potential SPAD
+                    RequestedBrakeNotch = train.Specs.BrakeNotches + 1;
+                    break;
+                default:
+                    RequestedBrakeNotch = -1;
+                    break;
+            }
+        }
+
+
+        /// <summary>Is called when the state of a key changes.</summary>
+        /// <param name="key">The key.</param>
+        /// <param name="pressed">Whether the key is pressed or released.</param>
+        /// <param name="train">The current train.</param>
+        internal override void KeyChange(VirtualKeys key, bool pressed, Train train)
+        {
+            if (pressed)
+            {
+                switch (key)
+                {
+                    case VirtualKeys.C2:
+                        // Reset the train stop device
+                        if (!OpenbveFcmbTrainPlugin.KeysPressed[(int)key])
+                        {
+                            // Reset only possible with train stopped
+                            if (train.State.Speed.KilometersPerHour < 0.05)
+                            {
+                                if (DeviceState == DeviceStates.Emergency)
+                                {
+                                    DeviceState = DeviceStates.Active;
+                                }
+                            }
+                        }
+                        break;
+                }
+            }
+        }
+
+        /// <summary>Is called when a beacon is passed.</summary>
+        /// <param name="beacon">The beacon data.</param>
+        internal override void SetBeacon(BeaconData beacon)
+        {
+            switch (beacon.Type)
+            {
+                // Accidental departure beacon/transponder
+                case 2:
+                    // Check if there is a potential SPAD and change to emergency mode
+                    if (beacon.Signal.Aspect == 0)
+                    {
+                        if (DeviceState == DeviceStates.Active)
+                        {
+                            DeviceState = DeviceStates.Emergency;
+                        }
+                    }
+                    break;
+            }
+        }
+
+
+        /// <summary>Is called when the device should perform the AI.</summary>
+        /// <param name="data">The AI data.</param>
+        /// <param name="train">The current train.</param>
+        /// <param name="route">The current route.</param>
+        internal override void PerformAI(AIData data, Train train, Route route)
+        {
+            // Reset device in case of emergency, once the train has stopped
+            if (DeviceState == DeviceStates.Emergency && train.State.Speed.KilometersPerHour < 0.05)
+            {
+                data.Handles.BrakeNotch = train.Specs.BrakeNotches;
+                KeyChange(VirtualKeys.C2, true, train);
+                data.Response = AIResponse.Long;
+                KeyChange(VirtualKeys.C2, false, train);
+            }
+        }
     }
 }
diff --git a/src/Train/Train.cs b/src/Train/Train.cs
index daf2898..cf62add 100644
--- a/src/Train/Train.cs
+++ b/src/Train/Train.cs
@@ -137,7 +137,13 @@ namespace OpenbveFcmbTrainPlugin
 
         /// <summary>Is called when a beacon is passed.</summary>
         /// <param name="beacon">The beacon data.</param>
-        internal void SetBeacon(BeaconData beacon) { }
+        internal void SetBeacon(BeaconData beacon)
+        {
+            foreach (Device dev in Devices)
+            {
+                dev.SetBeacon(beacon);
+            }
+        }
 
         /// <summary>Is called when the plugin should perform the AI.</summary>
         /// <param name="data">The AI data.</param>