Hey! One Gift to a Customer!

//Roz Wright's "One Lollipop To a Customer" Script
//A combination of and a complete PG rewrite of NawtieNitey's
//"Candybags" script and Evie Moriguchi's "VaGatcha" scripts.

//Like "Candybags" and "VaGacha", this script can be placed in any
//non-rigged attachment, if you want a simple no-HUD on-touch sol-
//ution. The "Candybags" scripts are also now on pastebin.com.

//This script is designed to discourage visitors from abusing your
//free gift system by repeatedly clicking the dispenser. The script
//can randomly select between several gifts, or give the same gift
//to every visitor.  Type "alert" in the description field (in Edit)
//of the dispenser to be alerted to visitors touching the dispenser.

integer visitCycle = 60; //Try to keep this number reasonably low
// You want to discourage visitors from abusing the free gift system
// not store a list of partial avatar keys for eternity.

string curr_id;
string prev_id;
list past_users;
string itemName;
integer itemcount;
integer gift;

integer alertMe (string ObjDesc)
{
    //AlertMe checks to see if you have the word "alert" in your
    //dispenser's "description" field.  If you do, it returns a
    //TRUE value and you're alerted to someone touching your dis-
    //penser.
    integer giveAlert = FALSE;
    ObjDesc = llToLower(ObjDesc);
    //and here's where the magic happens...
    if (llSubStringIndex(ObjDesc, "alert") != -1) giveAlert = TRUE;
    //I don't need an "else" statement, giveAlert is already FALSE.
    return giveAlert;
    //llSubStringIndex and llGetObjectDesc are an easy way to allow
    //the user to change a simple single parameter without notecards,
    //menus, or opening a listen channel.
    //...and using llGetObjectDetails(id,[OBJECT_DESC]) is a nifty way
    //for an object to pull communication from other unlinked objects
    //without requiring a listen channel.  Just saying...
}

string ID_8 (key StoreID)
{
    //ID_8 only stores the first 8 characters of a key in a string to
    //save memory. It's good for speeding up key to list comparisons but
    //not for much else.
    return llList2String(llParseString2List((string)StoreID, ["-"], []),0);
    //Okay, I lied...It's also pretty good for creating key based indexes,
    //where you can look up a partial UUID in a list, which can direct you
    //to additional information stored in other lists.
}

default
{
    changed(integer change)
    //If you add or change gifts, this will let you know how many objects
    //are currently in your dispenser's inventory.
    {
        if (change & CHANGED_INVENTORY)
        {
            itemcount = llGetInventoryNumber(INVENTORY_OBJECT);
            llOwnerSay("There are now " + (string)itemcount + " objects in inventory.");
        }
    }

    touch_start(integer num_detected)
    {
        //Let's get the number of items in the dispenser
        itemcount = llGetInventoryNumber(INVENTORY_OBJECT);
        //Let's get the key for the avatar clicking the dispenser
        key commKey = llDetectedKey(0);
        //Let's prepare that key for comparison against a list of
        //recent visitors
        curr_id = ID_8 (commKey);
        //There are three conditionals that result in the visitor not
        //getting an item, so let's assume that the person may not be
        //getting a gift.
        gift = FALSE;
        //Check inventory and make sure there are actually items to give.
        if (itemcount==0)llInstantMessage(commKey, "Sorry, there are no items to give you at this time.");
        //Check to see if the visitor is repeatedly clicking the item.
        else if (curr_id == prev_id)llInstantMessage(commKey, "You have already been sent " + itemName +", please check your inventory.");

        //Check to see if the visitor has recently been given a gift.
        else if(~llListFindList(past_users, [curr_id]))
        {
            //singular
            if (itemcount==1)llInstantMessage(commKey, "Welcome back. This item is only available to new visitors at this time.");
            //plural
            else llInstantMessage(commKey, "Welcome back. These items are only available to new visitors at this time.");
        }

        //If this is a new visitor (or a really old one) give them a gift.
        else
        {
            //lets give our conditional a little buffer room so it doesn't have to move
            //around information in the list size every time it evaluates a new toucher.
            if (llGetListLength(past_users) > (visitCycle + 10)) llDeleteSubList(past_users, visitCycle, -1);
            //don't waste time on random gift selection if it's not neccessary.
            if (itemcount > 1)
            {
                integer randomIndex = (integer)llFrand(itemcount);
                itemName = llGetInventoryName(INVENTORY_OBJECT, randomIndex);
            }
            else itemName = llGetInventoryName(INVENTORY_OBJECT, 0);
            llInstantMessage (commKey, "Welcome, you are being sent " + itemName + " as our free gift!");
            llGiveInventory(commKey, itemName);
            //Let's set up a check to make sure the visitor isn't repeatedly
            //clicking the item.
            prev_id = curr_id;
            //Let's add their partial key to the list
            past_users = [prev_id] + past_users;
            //This person is getting a gift, let's set the "gift" flag to TRUE.
            gift = TRUE;
        }
        integer alert = alertMe (llGetObjectDesc());
        //Alert the owner that someone just received a gift.
        if (alert && gift) llInstantMessage(llGetOwner(),llDetectedName(0) + " was given " + itemName + ".");
        //Add a few slashes // to the next line if you don't want alerts on every touch
        else if (alert && !gift) llInstantMessage(llGetOwner(),llDetectedName(0) + " touched me.");
    }
}