ModernUO/Projects/Scripts/Context Menus/AddToSpellbookEntry.cs

using Server.Items;
using Server.Network;
using Server.Targeting;

namespace Server.ContextMenus
{
  public class AddToSpellbookEntry : ContextMenuEntry
  {
    public AddToSpellbookEntry() : base(6144, 3)
    {
    }

    public override void OnClick()
    {
      if (Owner.From.CheckAlive() && Owner.Target is SpellScroll scroll)
        Owner.From.Target = new InternalTarget(scroll);
    }

    private class InternalTarget : Target
    {
      private SpellScroll m_Scroll;

      public InternalTarget(SpellScroll scroll) : base(3, false, TargetFlags.None) => m_Scroll = scroll;

      protected override void OnTarget(Mobile from, object targeted)
      {
        if (targeted is Spellbook book)
          if (from.CheckAlive() && !m_Scroll.Deleted && m_Scroll.Movable && m_Scroll.Amount >= 1 &&
              m_Scroll.CheckItemUse(from))
          {
            SpellbookType type = Spellbook.GetTypeForSpell(m_Scroll.SpellID);

            if (type != book.SpellbookType)
            {
            }
            else if (book.HasSpell(m_Scroll.SpellID))
              from.SendLocalizedMessage(500179); // That spell is already present in that spellbook.
            else
            {
              int val = m_Scroll.SpellID - book.BookOffset;

              if (val >= 0 && val < book.BookCount)
              {
                book.Content |= (ulong)1 << val;

                m_Scroll.Consume();

                Packets.SendPlaySound(from.NetState, 0x249, book.GetWorldLocation());
              }
            }
          }
      }
    }
  }
}