ArachnaeSwarm/Source/ArachnaeSwarm/Plants/Plant_Transforming.cs

using RimWorld;
using Verse;

namespace ArachnaeSwarm
{
    // Define a DefModExtension to hold our custom properties in XML
    public class PlantTransformExtension : DefModExtension
    {
        public ThingDef buildingDef;
        public float transformAtGrowth = 0.8f;
    }

    public class Plant_Transforming : Plant
    {
        private PlantTransformExtension extension;
        private bool transformed = false;

        // Caching the extension for performance
        public PlantTransformExtension Extension
        {
            get
            {
                if (extension == null)
                {
                    extension = this.def.GetModExtension<PlantTransformExtension>();
                }
                return extension;
            }
        }
        
        public override void ExposeData()
        {
            base.ExposeData();
            Scribe_Values.Look(ref transformed, "transformed", false);
        }

        public override void TickLong()
        {
            base.TickLong(); // Execute base plant logic first

            if (transformed || this.Destroyed || Extension == null)
            {
                return;
            }

            if (this.Growth >= Extension.transformAtGrowth)
            {
                TryTransform();
                transformed = true;
            }
        }

        private void TryTransform()
        {
            if (this.Destroyed || Extension.buildingDef == null) return;

            Map map = this.Map;
            IntVec3 position = this.Position;
            
            Faction factionToSet = null;
            Zone zone = map.zoneManager.ZoneAt(position);
            if (zone is Zone_Growing) factionToSet = Faction.OfPlayer;
            if (factionToSet == null && map.IsPlayerHome) factionToSet = Faction.OfPlayer;
            
            Thing building = ThingMaker.MakeThing(Extension.buildingDef, null);
            if (factionToSet != null && building.def.CanHaveFaction)
            {
                building.SetFaction(factionToSet);
            }

            this.Destroy(DestroyMode.Vanish);
            GenSpawn.Spawn(building, position, map, WipeMode.Vanish);
        }
    }
}