CheckWeight fully implemented

BUILDIN_FUNC(checkweight)
{
    int nameid=0,amount,i,count=0;
    unsigned long weight;
    TBL_PC *sd;
    struct script_data *data;

    sd = script_rid2sd(st);
    if( sd == NULL )
        return 0;

    data=script_getdata(st,2);
    get_val(st,data);
    if( data_isstring(data) ){
        const char *name=conv_str(st,data);
        struct item_data *item_data = itemdb_searchname(name);
        if( item_data )
            nameid=item_data->nameid;
    }else
        nameid=conv_num(st,data);

    amount=script_getnum(st,3);
    if ( amount<=0 || nameid<500 ) { //if get wrong item ID or amount<=0, don't count weight of non existing items
        script_pushint(st,0);
        ShowError("buildin_checkweight: Wrong item ID or amount.\n");
        return 1;
    }

    weight = itemdb_weight(nameid)*amount;
    if(amount > MAX_AMOUNT || weight + sd->weight > sd->max_weight){
        script_pushint(st,0);
    } else {
        //Check if the inventory ain't full.
        //[VoidLess] implemented full checks
        if(itemdb_isstackable(nameid)){
            i = pc_search_inventory(sd,nameid); //Look for same items
            if(i >= 0)
                if(sd->status.inventory[i].amount + amount > MAX_AMOUNT)
                    script_pushint(st,0); //Can't take, total will be more than max
                else
                    script_pushint(st,1);
            else { //There is no same items, look for spaces
                i = pc_search_inventory(sd,0);
                if(i >= 0)
                    script_pushint(st,1);
                else //Inventory full
                    script_pushint(st,0);
            }
        } else { //Not stackable
            for(i = 0; i < MAX_INVENTORY; i++)
                if(sd->status.inventory[i].nameid == 0)
                    count++; //Counting empty slots
            if (count >= amount)
                script_pushint(st,1);
            else //Not enough slots
                script_pushint(st,0);
        }
            
    }

    return 0;
}