Add ambient music (#16829)

Content.Shared/Audio/AmbientMusicPrototype.cs

@@ -0,0 +1,39 @@
+using Content.Shared.Random;
+using Robust.Shared.Audio;
+using Robust.Shared.Prototypes;
+using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom.Prototype;
+
+namespace Content.Shared.Audio;
+
+/// <summary>
+/// Attaches a rules prototype to sound files to play ambience.
+/// </summary>
+[Prototype("ambientMusic")]
+public sealed class AmbientMusicPrototype : IPrototype
+{
+    [IdDataField] public string ID { get; } = string.Empty;
+
+    /// <summary>
+    /// Traditionally you'd prioritise most rules to least as priority but in our case we'll just be explicit.
+    /// </summary>
+    [ViewVariables(VVAccess.ReadWrite), DataField("priority")]
+    public int Priority = 0;
+
+    /// <summary>
+    /// Can we interrupt this ambience for a better prototype if possible?
+    /// </summary>
+    [ViewVariables(VVAccess.ReadWrite), DataField("interruptable")]
+    public bool Interruptable = false;
+
+    /// <summary>
+    /// Do we fade-in. Useful for songs.
+    /// </summary>
+    [ViewVariables(VVAccess.ReadWrite), DataField("fadeIn")]
+    public bool FadeIn;
+
+    [ViewVariables(VVAccess.ReadWrite), DataField("sound", required: true)]
+    public SoundSpecifier Sound = default!;
+
+    [ViewVariables(VVAccess.ReadWrite), DataField("rules", required: true, customTypeSerializer:typeof(PrototypeIdSerializer<RulesPrototype>))]
+    public string Rules = string.Empty;
+}