Lots more work on implementing battling

PkmnLib.Dynamic/Events/StatBoostEvent.cs

@@ -0,0 +1,47 @@
+using PkmnLib.Dynamic.Models;
+using PkmnLib.Static;
+
+namespace PkmnLib.Dynamic.Events;
+
+/// <summary>
+/// Triggered when a Pokemon's stat boost is changed, either positively or negatively.
+/// </summary>
+public class StatBoostEvent : IEventData
+{
+    /// <inheritdoc cref="StatBoostEvent" />
+    public StatBoostEvent(IPokemon pokemon, Statistic statistic, sbyte oldBoost, sbyte newBoost)
+    {
+        Pokemon = pokemon;
+        Statistic = statistic;
+        OldBoost = oldBoost;
+        NewBoost = newBoost;
+    }
+
+    /// <summary>
+    /// The Pokemon that had its stat boosted.
+    /// </summary>
+    public IPokemon Pokemon { get; }
+
+    /// <summary>
+    /// The statistic that was boosted.
+    /// </summary>
+    public Statistic Statistic { get; }
+
+    /// <summary>
+    /// The old boost value.
+    /// </summary>
+    public sbyte OldBoost { get; }
+
+    /// <summary>
+    /// The new boost value.
+    /// </summary>
+    public sbyte NewBoost { get; }
+
+    /// <summary>
+    /// The difference between the new and old boost values.
+    /// </summary>
+    public sbyte BoostDifference => (sbyte)(NewBoost - OldBoost);
+
+    /// <inheritdoc />
+    public EventBatchId BatchId { get; init; }
+}