Drop on slip fix (#160)

# Description
Fixes the DropOnSlipSystem to actually work now.
It also improves it, so now your items go flying when you drop them! :)

Requires #113 


# Changelog

:cl:
- add: Added fun!
- tweak: Tweaked fun!
- fix: Fixed fun!
- remove: Removed fun!

Content.Server/SimpleStation14/Slippery/DropOnSlipComponent.cs

@@ -1,13 +1,16 @@
-namespace Content.Server.Slippery
+namespace Content.Server.SimpleStation14.Slippery;
+
+/// <summary>
+///     Uses provided chance to try and drop the item when slipped, if equipped.
+/// </summary>
+[RegisterComponent]
+public sealed class DropOnSlipComponent : Component
 {
-    /// <summary>
-    ///     Uses provided chance to try and drop the item when slipped, if equipped.
-    /// </summary>
-    [RegisterComponent]
-    public sealed class DropOnSlipComponent : Component
-    {
-        [DataField("chance")]
-        [ViewVariables(VVAccess.ReadWrite)]
-        public int Chance = 20;
-    }
+    [DataField("chance")]
+    [ViewVariables(VVAccess.ReadWrite)]
+    public int Chance = 20;
+
+    [DataField("chanceToThrow")]
+    [ViewVariables(VVAccess.ReadWrite)]
+    public int ChanceToThrow = 40;
 }

Content.Server/SimpleStation14/Slippery/DropOnSlipSystem.cs

@@ -0,0 +1,97 @@
+using Content.Shared.Administration.Logs;
+using Content.Shared.Database;
+using Content.Shared.Inventory;
+using Robust.Shared.Random;
+using Content.Server.Popups;
+using Content.Shared.Popups;
+using Content.Shared.Slippery;
+using Content.Shared.Interaction.Components;
+using Robust.Shared.Physics.Systems;
+using Robust.Shared.Physics.Components;
+using Content.Shared.Throwing;
+
+namespace Content.Server.SimpleStation14.Slippery;
+
+public sealed class DropOnSlipSystem : EntitySystem
+{
+    [Dependency] private readonly ISharedAdminLogManager _adminLogger = default!;
+    [Dependency] private readonly PopupSystem _popup = default!;
+    [Dependency] private readonly IRobustRandom _random = default!;
+    [Dependency] private readonly InventorySystem _invSystem = default!;
+    [Dependency] private readonly SharedPhysicsSystem _physics = default!;
+    [Dependency] private readonly ThrowingSystem _throwing = default!;
+
+    private static readonly float PocketDropChance = 10f;
+    private static readonly float PocketThrowChance = 5f;
+
+    private static readonly float ClumsyDropChance = 5f;
+    private static readonly float ClumsyThrowChance = 90f;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+
+        SubscribeLocalEvent<InventoryComponent, ParkSlipEvent>(HandleSlip);
+    }
+
+
+    private void HandleSlip(EntityUid entity, InventoryComponent invComp, ParkSlipEvent args)
+    {
+        if (!_invSystem.TryGetSlots(entity, out var slotDefinitions, invComp))
+            return;
+
+        foreach (var slot in slotDefinitions)
+        {
+            if (!_invSystem.TryGetSlotEntity(entity, slot.Name, out var item))
+                continue;
+
+            // A check for DropOnSlipComponent.
+            if (slot.Name != "pocket1" && slot.Name != "pocket2" && EntityManager.TryGetComponent<DropOnSlipComponent>(item, out var dropComp) && _random.NextFloat(0, 100) < dropComp.Chance)
+            {
+                var popupString = Loc.GetString("system-drop-on-slip-text-component", ("name", entity), ("item", item));
+
+                Drop(entity, item.Value, slot.Name, popupString);
+                continue;
+            }
+
+            // A check for any items in pockets.
+            if (slot.Name == "pocket1" | slot.Name == "pocket2" && _random.NextFloat(0, 100) < PocketDropChance)
+            {
+                var popupString = Loc.GetString("system-drop-on-slip-text-pocket", ("name", entity), ("item", item));
+
+                Drop(entity, item.Value, slot.Name, popupString);
+                continue;
+            }
+
+            // A check for ClumsyComponent.
+            if (slot.Name != "jumpsuit" && _random.NextFloat(0, 100) < ClumsyDropChance && HasComp<ClumsyComponent>(entity))
+            {
+                var popupString = Loc.GetString("system-drop-on-slip-text-clumsy", ("name", entity), ("item", item));
+
+                Drop(entity, item.Value, slot.Name, popupString);
+                continue;
+            }
+        }
+    }
+
+    private void Drop(EntityUid entity, EntityUid item, string slot, string popupString)
+    {
+        if (!_invSystem.TryUnequip(entity, slot, false, true))
+            return;
+
+        EntityManager.TryGetComponent<PhysicsComponent>(entity, out var entPhysComp);
+
+        if (entPhysComp != null)
+        {
+            var strength = entPhysComp.LinearVelocity.Length / 1.5f;
+            Vector2 direction = (_random.Next(-8, 8), _random.Next(-8, 8));
+
+            _throwing.TryThrow(item, direction, strength, entity);
+        }
+
+        _popup.PopupEntity(popupString, item, PopupType.MediumCaution);
+
+        var logMessage = Loc.GetString("system-drop-on-slip-log", ("entity", ToPrettyString(entity)), ("item", ToPrettyString(item)));
+        _adminLogger.Add(LogType.Slip, LogImpact.Low, $"{logMessage}");
+    }
+}

Content.Shared/Slippery/SlipperySystem.cs

@@ -106,6 +106,8 @@ private void TrySlip(EntityUid uid, SlipperyComponent component, EntityUid other
 
         _stun.TryParalyze(other, TimeSpan.FromSeconds(component.ParalyzeTime), true);
 
+        RaiseLocalEvent(other, new ParkSlipEvent(uid)); // Parkstation-DropOnSlip
+
         // Preventing from playing the slip sound when you are already knocked down.
         if (playSound)
         {
@@ -138,3 +140,10 @@ public sealed class SlipAttemptEvent : CancellableEntityEventArgs, IInventoryRel
 /// </summary>
 [ByRefEvent]
 public readonly record struct SlipEvent(EntityUid Slipped);
+
+// Parkstation-DropOnSlip-Start
+/// <summary>
+///     This is an event raised on an entity after they slip. Duh.
+/// </summary>
+public readonly record struct ParkSlipEvent(EntityUid Tripper);
+// Parkstation-DropOnSlip-End

Resources/Locale/en-US/SimpleStation14/Content/Slippery/dropOnSlip.ftl

@@ -1,3 +1,5 @@
 system-drop-on-slip-text-component = {$name}'s {$item} slips off!
 system-drop-on-slip-text-pocket = Something falls out of {$name}'s pocket!
 system-drop-on-slip-text-clumsy = The {$item} tumbles off of {$name}!
+
+system-drop-on-slip-log = {$entity} dropped {$item} when slipping.