Add envelopes (#30298)

* Add envelopes

* oops

* Remove unused loc string

* comments and fixes

Content.Shared/Paper/EnvelopeComponent.cs

@@ -0,0 +1,63 @@
+using Content.Shared.DoAfter;
+using Robust.Shared.Audio;
+using Robust.Shared.GameStates;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.Paper;
+
+[RegisterComponent, NetworkedComponent, AutoGenerateComponentState(true)]
+public sealed partial class EnvelopeComponent : Component
+{
+    /// <summary>
+    /// The current open/sealed/torn state of the envelope
+    /// </summary>
+    [ViewVariables, DataField, AutoNetworkedField]
+    public EnvelopeState State = EnvelopeState.Open;
+
+    [DataField, ViewVariables]
+    public string SlotId = "letter_slot";
+
+    /// <summary>
+    /// Stores the current sealing/tearing doafter of the envelope
+    /// to prevent doafter spam/prediction issues
+    /// </summary>
+    [DataField, ViewVariables]
+    public DoAfterId? EnvelopeDoAfter;
+
+    /// <summary>
+    /// How long it takes to seal the envelope closed
+    /// </summary>
+    [DataField, ViewVariables]
+    public TimeSpan SealDelay = TimeSpan.FromSeconds(1);
+
+    /// <summary>
+    /// How long it takes to tear open the envelope
+    /// </summary>
+    [DataField, ViewVariables]
+    public TimeSpan TearDelay = TimeSpan.FromSeconds(1);
+
+    /// <summary>
+    /// The sound to play when the envelope is sealed closed
+    /// </summary>
+    [DataField, ViewVariables]
+    public SoundPathSpecifier? SealSound = new SoundPathSpecifier("/Audio/Effects/packetrip.ogg");
+
+    /// <summary>
+    /// The sound to play when the envelope is torn open
+    /// </summary>
+    [DataField, ViewVariables]
+    public SoundPathSpecifier? TearSound = new SoundPathSpecifier("/Audio/Effects/poster_broken.ogg");
+
+    [Serializable, NetSerializable]
+    public enum EnvelopeState : byte
+    {
+        Open,
+        Sealed,
+        Torn
+    }
+}
+
+[Serializable, NetSerializable]
+public sealed partial class EnvelopeDoAfterEvent : SimpleDoAfterEvent
+{
+}