YHTMod/Items/KatanaRedo.cs

using System.Collections.Generic;
using Microsoft.Xna.Framework;
using Terraria;
using Terraria.ID;
using Terraria.ModLoader;

namespace YHTMod.Items;

public class KatanaRedo : GlobalItem
{
    public override void ModifyTooltips(Item item, List<TooltipLine> tooltips)
    {
        if (item.type != ItemID.Katana) return;
        tooltips.Insert(5, new TooltipLine(YHTMod.GetInstance(), "flavor", "Nothing personel kid."));
        tooltips.Insert(6, new TooltipLine(YHTMod.GetInstance(), "usage", "Right click to teleport behind them."));
    }

    public override bool AltFunctionUse(Item item, Player player)
    {
        return item.type == ItemID.Katana || base.AltFunctionUse(item, player);
    }

    public override bool? UseItem(Item item, Player player)
    {
        if (item.type != ItemID.Katana || player.altFunctionUse != 2) return null;
        var yhtPlayer = player.GetModPlayer<YhtPlayer>();

        if (yhtPlayer.KatanaTeleportCooldown > 0) return null;
        yhtPlayer.KatanaTeleportCooldown = 300;

        for (var i = 0; i < Main.maxNPCs; i++)
        {
            var npc = Main.npc[i];
            if (!npc.CanBeChasedBy()) continue;

            var between = Vector2.Distance(npc.Center, player.Center);
            var inRange = between < 650;

            var lineOfSight = Collision.CanHitLine(player.position, player.width, player.height, npc.position,
                npc.width, npc.height);

            if (!inRange || !lineOfSight) continue;
            var tpPos = npc.position;
            tpPos.X += -(npc.direction * npc.width + (player.width * 2));

            if (Collision.TileCollision(tpPos, Vector2.Zero, player.width, player.height) != Vector2.Zero) return true;

            player.Teleport(tpPos, TeleportationStyleID.RodOfDiscord);
            player.velocity = Vector2.Zero;
            player.NinjaDodge();
            return true;
        }

        return null;
    }
}