Implements sandstorm

Plugins/PkmnLib.Plugin.Gen7/Scripts/Weather/Sandstorm.cs

@@ -3,5 +3,39 @@ namespace PkmnLib.Plugin.Gen7.Scripts.Weather;
 [Script(ScriptCategory.Weather, "sandstorm")]
 public class Sandstorm : Script
 {
-    // TODO: Implement Sandstorm
+    /// <inheritdoc />
+    public override void OnEndTurn(IScriptSource owner, IBattle battle)
+    {
+        foreach (var pokemon in battle.Sides.SelectMany(x => x.Pokemon).WhereNotNull())
+        {
+            if (!pokemon.IsUsable)
+                continue;
+            if (pokemon.Types.Any(x => x.Name == "rock" || x.Name == "ground" || x.Name == "steel"))
+            {
+                // Rock, Ground, and Steel types are immune to Sandstorm damage.
+                continue;
+            }
+            var bypassSandstormArgs = new CustomTriggers.BypassSandstormDamageArgs(pokemon);
+            pokemon.RunScriptHook(x => x.CustomTrigger(CustomTriggers.BypassSandstormDamage, bypassSandstormArgs));
+            if (bypassSandstormArgs.Bypass)
+                continue;
+
+            pokemon.Damage(pokemon.MaxHealth / 16, DamageSource.Weather);
+        }
+    }
+
+    /// <inheritdoc />
+    public override void ChangeDefensiveStatValue(IExecutingMove move, IPokemon target, byte hit, uint offensiveStat,
+        ImmutableStatisticSet<uint> targetStats, Statistic stat, ref uint value)
+    {
+        if (stat == Statistic.SpecialDefense && target.Types.Any(x => x.Name == "rock"))
+            value = value.MultiplyOrMax(1.5f);
+    }
+
+    /// <inheritdoc />
+    public override void ChangeBasePower(IExecutingMove move, IPokemon target, byte hit, ref ushort basePower)
+    {
+        if (move.UseMove.Name == "solar_beam")
+            basePower /= 2;
+    }
 }