package tokarotik.giftapi.NBT.pages;

import net.minecraft.server.v1_6_R3.NBTTagList;
import org.bukkit.inventory.ItemStack;

public class PagesManager
{
    private NBTTagList tag;
    private int current_page = 0;
    private int count_pages = 0;
    private final int items_slots;
    public PagesManager(NBTTagList tag, int items_slots)
    {
        this.items_slots = items_slots;
        this.tag = tag;
        setCountPages();
    }

    public PagesManager(int items_slots)
    {
        this.items_slots = items_slots;
        this.tag = new NBTTagList("giftapi");
    }

    public synchronized void add(ItemStack item)
    {
        PagesUtil.add(item, this.tag);
        setCountPages();
    }

    public synchronized void remove(ItemStack item)
    {
        this.tag = PagesUtil.remove(item, this.tag);
        setCountPages();
    }

    public synchronized NBTTagList getTag() { return this.tag; }

    public synchronized ItemStack[] getList() { return PagesUtil.getRawList(this.tag); }

    public synchronized int getCurrentPage() { return this.current_page; }

    public synchronized int getCountPages() { return this.count_pages; }
    public synchronized void nextPage()
    {
        if (getCountPages() > getCurrentPage())
        {
            this.current_page++;
        }
    }

    public synchronized void backPage()
    {
        if (0 < getCurrentPage())
        {
            this.current_page -= 1;
        }
    }

    private synchronized void setCountPages() {
        int tag_size = this.tag.size();
        if (tag_size == 0) { this.count_pages = 0; }

        this.count_pages = Math.floorDiv(tag_size, this.items_slots);
    }

}