mod_turn_battle_base/src/BattleSetCoreAction.cs

using Cthangover.Core.Actions;

namespace Cthangover.Core.Battle
{
    /// <summary>
    /// Selects which battle core (combat ruleset) the next battle will use.
    /// The "core" variable maps to a <see cref="BattleCoreRegistry"/> entry by
    /// string ID. Must be called before a battle starts, as
    /// <see cref="BattleService.Init"/> reads the active core at initialization time.
    /// </summary>
    public class BattleSetCoreAction : IScenarioAction
    {
        /// <summary>
        /// Registered as "battle.set_core" — selects the combat ruleset
        /// for the next battle encounter. If "core" is empty or missing, logs a
        /// warning and returns without modifying the registry.
        /// </summary>
        public string Name => "battle.set_core";

        /// <summary>
        /// Reads the "core" variable and sets it as the active battle core
        /// via <see cref="BattleCoreRegistry.SetActive"/>. The core determines
        /// combat mechanics (turn order, ability system, etc.) for the
        /// next initiated battle.
        /// </summary>
        public void Run(IActionContext ctx)
        {
            var core = ctx.GetParam("core");
            if (string.IsNullOrEmpty(core))
            {
                ctx.Log("EVENT", "BattleSetCoreAction: missing 'core' variable");
                return;
            }

            BattleCoreRegistry.Instance.SetActive(core);
            ctx.Log("EVENT", $"BattleSetCoreAction: battle core set to '{core}'");
        }
    }
}