Public Transit (#850)

* public transportation

* priority dock prototypes

* map changes

* bug fixes

* comments and cleanup

Content.Server/_NF/PublicTransit/Components/StationTransitComponent.cs

@@ -0,0 +1,9 @@
+namespace Content.Server._NF.PublicTransit.Components;
+
+/// <summary>
+/// Added to a station that is available for public transit.
+/// </summary>
+[RegisterComponent, Access(typeof(PublicTransitSystem))]
+public sealed partial class StationTransitComponent : Component
+{
+}

Content.Server/_NF/PublicTransit/Components/TransitShuttleComponent.cs

@@ -0,0 +1,18 @@
+using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom;
+
+namespace Content.Server._NF.PublicTransit.Components;
+
+/// <summary>
+/// Added to a grid to have it act as an automated public transit bus.
+/// Public Transit system will add this procedurally to any grid designated as a 'bus' through the CVAR
+/// Mappers may add it to their shuttle if they wish, but this is going to force it's use and function as a public transit bus
+/// </summary>
+[RegisterComponent, Access(typeof(PublicTransitSystem))]
+public sealed partial class TransitShuttleComponent : Component
+{
+    [DataField("nextStation")]
+    public EntityUid NextStation;
+
+    [DataField("nextTransfer", customTypeSerializer:typeof(TimeOffsetSerializer))]
+    public TimeSpan NextTransfer;
+}

Content.Server/_NF/PublicTransit/PublicTransitSystem.cs

@@ -0,0 +1,255 @@
+using Content.Server._NF.PublicTransit.Components;
+using Content.Server.GameTicking;
+using Content.Server.Shuttles.Components;
+using Content.Server.Shuttles.Events;
+using Content.Server.Shuttles.Systems;
+using Content.Shared.NF14.CCVar;
+using Content.Shared.Shuttles.Components;
+using Content.Shared.Tiles;
+using Robust.Server.GameObjects;
+using Robust.Shared.Configuration;
+using Robust.Shared.Map;
+using Robust.Shared.Timing;
+using TimedDespawnComponent = Robust.Shared.Spawners.TimedDespawnComponent;
+
+namespace Content.Server._NF.PublicTransit;
+
+/// <summary>
+/// If enabled, spawns a public trasnport grid as definied by cvar, to act as an automatic transit shuttle between designated grids
+/// </summary>
+public sealed class PublicTransitSystem : EntitySystem
+{
+    [Dependency] private readonly IConfigurationManager _cfgManager = default!;
+    [Dependency] private readonly IGameTiming _timing = default!;
+    [Dependency] private readonly GameTicker _ticker = default!;
+    [Dependency] private readonly IMapManager _mapManager = default!;
+    [Dependency] private readonly MapLoaderSystem _loader = default!;
+    [Dependency] private readonly ShuttleSystem _shuttles = default!;
+
+    /// <summary>
+    /// If enabled then spawns the bus and sets up the bus line.
+    /// </summary>
+    public bool Enabled { get; private set; }
+    public float FlyTime = 50f;
+    public int Counter = 0;
+    public List<EntityUid> StationList = new();
+
+    public override void Initialize()
+    {
+        base.Initialize();
+
+        SubscribeLocalEvent<StationTransitComponent, ComponentStartup>(OnStationStartup);
+        SubscribeLocalEvent<StationTransitComponent, ComponentShutdown>(OnStationShutdown);
+        SubscribeLocalEvent<TransitShuttleComponent, ComponentStartup>(OnShuttleStartup);
+        SubscribeLocalEvent<TransitShuttleComponent, EntityUnpausedEvent>(OnShuttleUnpaused);
+        SubscribeLocalEvent<TransitShuttleComponent, FTLTagEvent>(OnShuttleTag);
+
+        Enabled = _cfgManager.GetCVar(NF14CVars.PublicTransit);
+        FlyTime = _cfgManager.GetCVar(NF14CVars.PublicTransitFlyTime);
+        Counter = 0;
+        StationList.Clear();
+        _cfgManager.OnValueChanged(NF14CVars.PublicTransit, SetTransit);
+        _cfgManager.OnValueChanged(NF14CVars.PublicTransitFlyTime, SetFly);
+    }
+
+    /// <summary>
+    /// Hardcoded snippit to intercept FTL events. It catches the transit shuttle and ensures its looking for the "DockTransit" priority dock.
+    /// </summary>
+    private void OnShuttleTag(EntityUid uid, TransitShuttleComponent component, ref FTLTagEvent args)
+    {
+        if (args.Handled)
+            return;
+
+        // Just saves mappers forgetting, or ensuring that a non-standard grid forced to be a bus will prioritize the "DockTransit" tagged docks
+        args.Handled = true;
+        args.Tag = "DockTransit";
+    }
+
+    public override void Shutdown()
+    {
+        base.Shutdown();
+        _cfgManager.UnsubValueChanged(NF14CVars.PublicTransitFlyTime, SetFly);
+        _cfgManager.UnsubValueChanged(NF14CVars.PublicTransit, SetTransit);
+    }
+
+    /// <summary>
+    /// Checks to make sure the grid is on the appropriate playfield, i.e., not in mapping space being worked on.
+    /// If so, adds the grid to the list of bus stops, but only if its not already there
+    /// </summary>
+    private void OnStationStartup(EntityUid uid, StationTransitComponent component, ComponentStartup args)
+    {
+        if (Transform(uid).MapID == _ticker.DefaultMap) //best solution i could find because of componentinit/mapinit race conditions
+        {
+            if (!StationList.Contains(uid)) //if the grid isnt already in
+                StationList.Add(uid); //add it to the list
+            if (Enabled) //and just in case this has been added dynamically mid-round, lets do a setup check
+                SetupPublicTransit();
+        }
+    }
+
+    /// <summary>
+    /// When a bus stop gets deleted in-game, we need to remove it from the list of bus stops, or else we get FTL problems
+    /// </summary>
+    private void OnStationShutdown(EntityUid uid, StationTransitComponent component, ComponentShutdown args)
+    {
+        if (StationList.Contains(uid))
+            StationList.Remove(uid);
+    }
+
+    /// <summary>
+    /// Again, this can and likely should be instructed to mappers to do, but just in case it was either forgotten or we are doing admemes,
+    /// we make sure that the bus is (mostly) griefer protected and that it cant be hijacked
+    /// </summary>
+    private void OnShuttleStartup(EntityUid uid, TransitShuttleComponent component, ComponentStartup args)
+    {
+        EnsureComp<PreventPilotComponent>(uid);
+        EnsureComp<ProtectedGridComponent>(uid);
+    }
+
+    /// <summary>
+    /// ensuring that pausing the shuttle for any reason doesnt mess up our timing
+    /// </summary>
+    private void OnShuttleUnpaused(EntityUid uid, TransitShuttleComponent component, ref EntityUnpausedEvent args)
+    {
+        component.NextTransfer += args.PausedTime;
+    }
+
+    /// <summary>
+    /// Here is our bus stop list handler. Theres probably a better way...
+    /// First, sets our output to null just in case
+    /// then, makes sure that our counter/index isnt out of range (reaching the end of the list will force you back to the beginning, like a loop)
+    /// Then, it checks to make sure that there even is anything in the list
+    /// and if so, we return the next station, and then increment our counter for the next time its ran
+    /// </summary>
+    private bool TryGetNextStation(out EntityUid? station)
+    {
+        station = null;
+
+        if (Counter >= StationList.Count)
+            Counter = 0;
+
+        if (!(StationList.Count > 0))
+            return false;
+
+        station = StationList[Counter];
+        Counter++;
+        return true;
+    }
+
+    /// <summary>
+    /// We check the current time every tick, and if its not yet time, we just ignore.
+    /// If the timer is ready, we send the shuttle on an FTL journey to the destination it has saved
+    /// then we check our bus list, and if it returns true with the next station, we cache it on the component and reset the timer
+    /// if it returns false or gives a bad grid, we are just going to FTL back to where we are and try again until theres a proper destination
+    /// This could cause unintended behavior, if a destination is deleted while it's next in the cache, the shuttle is going to be stuck in FTL space
+    /// However the timer is going to force it to FTL to the next bus stop
+    /// If it happens that all bus stops are deleted and we never get a valid stop again, we are going to be stuck FTL'ing forever in ftl space
+    /// but at that point, theres nowhere to return to anyway
+    /// </summary>
+    public override void Update(float frameTime)
+    {
+        base.Update(frameTime);
+
+        var query = EntityQueryEnumerator<TransitShuttleComponent, ShuttleComponent>();
+        var curTime = _timing.CurTime;
+
+        while (query.MoveNext(out var uid, out var comp, out var shuttle))
+        {
+            if (comp.NextTransfer > curTime)
+                continue;
+
+            _shuttles.FTLTravel(uid, shuttle, comp.NextStation, hyperspaceTime: FlyTime, dock: true);
+
+            if (TryGetNextStation(out var nextStation) && nextStation is {Valid : true} destination)
+                comp.NextStation = destination;
+
+            comp.NextTransfer += TimeSpan.FromSeconds(FlyTime + _cfgManager.GetCVar(NF14CVars.PublicTransitWaitTime));
+        }
+    }
+
+    /// <summary>
+    /// Here is handling a simple CVAR change to enable/disable the system
+    /// if the cvar is changed to enabled, we setup the transit system
+    /// if its changed to disabled, we delete any bus grids that exist
+    /// along with anyone/thing riding the bus
+    /// you've been warned
+    /// </summary>
+    private void SetTransit(bool obj)
+    {
+        Enabled = obj;
+
+        if (Enabled)
+        {
+            SetupPublicTransit();
+        }
+        else
+        {
+            var shuttleQuery = AllEntityQuery<TransitShuttleComponent>();
+
+            while (shuttleQuery.MoveNext(out var uid, out _))
+            {
+                QueueDel(uid);
+            }
+        }
+    }
+
+    /// <summary>
+    /// Simple cache reflection
+    /// </summary>
+    private void SetFly(float obj)
+    {
+        FlyTime = obj;
+    }
+
+    /// <summary>
+    /// Here is where we handle setting up the transit system, including sanity checks.
+    /// This is called multiple times, from a few different sources, to ensure that if the system is activated dynamically
+    /// it will still function as intended
+    /// </summary>
+    private void SetupPublicTransit()
+    {
+        // If a public bus alraedy exists, we simply return. No need to set up the system again.
+        var query = EntityQueryEnumerator<TransitShuttleComponent>();
+        while (query.MoveNext(out var euid, out _))
+        {
+            if (!Deleted(euid))
+                return;
+        }
+
+        // Spawn the bus onto a dummy map
+        var dummyMap = _mapManager.CreateMap();
+        var busMap = _cfgManager.GetCVar(NF14CVars.PublicTransitBusMap);
+        if (_loader.TryLoad(dummyMap, busMap, out var shuttleUids))
+        {
+            var shuttleComp = Comp<ShuttleComponent>(shuttleUids[0]);
+            // Here we are making sure that the shuttle has the TransitShuttle comp onto it, in case of dynamically changing the bus grid
+            var transitComp = EnsureComp<TransitShuttleComponent>(shuttleUids[0]);
+
+            //We run our bus station function to try to get a valid station to FTL to. If for some reason, there are no bus stops, we will instead just delete the shuttle
+            if (TryGetNextStation(out var station) && station is { Valid : true } destination)
+            {
+                //we set up a default in case the second time we call it fails for some reason
+                transitComp.NextStation = destination;
+                _shuttles.FTLTravel(shuttleUids[0], shuttleComp, destination, hyperspaceTime: 5f, dock: true);
+                transitComp.NextTransfer = _timing.CurTime + TimeSpan.FromSeconds(_cfgManager.GetCVar(NF14CVars.PublicTransitWaitTime));
+
+                //since the initial cached value of the next station is actually the one we are 'starting' from, we need to run the
+                //bus stop list code one more time so that our first trip isnt just Frontier - Frontier
+                if (TryGetNextStation(out var firstStop) && firstStop is { Valid : true } firstDestination)
+                    transitComp.NextStation = firstDestination;
+            }
+            else
+            {
+                foreach (var shuttle in shuttleUids)
+                {
+                    QueueDel(shuttle);
+                }
+            }
+        }
+
+        // the FTL sequence takes a few seconds to warm up and send the grid, so we give the temp dummy map
+        // some buffer time before calling a self-delete
+        var timer = AddComp<TimedDespawnComponent>(_mapManager.GetMapEntityId(dummyMap));
+        timer.Lifetime = 15f;
+    }
+}

Content.Shared/_NF/CCVars/CCVars.cs

@@ -28,4 +28,31 @@ public sealed class NF14CVars
     /// </summary>
     public static readonly CVarDef<float> CryoExpirationTime =
         CVarDef.Create("nf14.uncryo.maxtime", 60 * 60f, CVar.SERVER | CVar.REPLICATED);
+
+    /*
+     *  Public Transit
+     */
+    /// <summary>
+    /// Whether public transit is enabled.
+    /// </summary>
+    public static readonly CVarDef<bool> PublicTransit =
+        CVarDef.Create("nf14.publictransit.enabled", true, CVar.SERVERONLY);
+
+    /// <summary>
+    /// The map to use for the public bus.
+    /// </summary>
+    public static readonly CVarDef<string> PublicTransitBusMap =
+        CVarDef.Create("nf14.publictransit.bus_map", "/Maps/_NF/Shuttles/publicts.yml", CVar.SERVERONLY);
+
+    /// <summary>
+    /// The amount of time the bus waits at a station.
+    /// </summary>
+    public static readonly CVarDef<float> PublicTransitWaitTime =
+        CVarDef.Create("nf14.publictransit.wait_time", 150f, CVar.SERVERONLY);
+
+    /// <summary>
+    /// The amount of time the flies through FTL space.
+    /// </summary>
+    public static readonly CVarDef<float> PublicTransitFlyTime =
+        CVarDef.Create("nf14.publictransit.fly_time", 145f, CVar.SERVERONLY);
 }