// SPDX-License-Identifier: MIT
// Copyright (c) 2026 Incoprea
// Sequential component lesson
// Not compiled or tested in-world
// Setup: Name up to12 children lesson and put short ASCII descriptions in them. Link order is lesson order; root owner-touch advances.
// Stop / restore: After the last component, one more touch restores every original label.
// Notes: Use a spare modifiable build. Snapshot state is held only in script memory; restore before reset/removal. Do not relink during a preview. One-at-a-time labels reduce visual clutter without changing geometry. This is an owner-paced exhibit rehearsal.
// License: see LICENSE in this distribution.
// Original Incoprea. MIT. Not compiled or tested in-world.
list links;
list saved;
list captions;
integer step=-1;
integer valid=TRUE;
restore()
{
    integer i;
    for(i=0;i<llGetListLength(links);++i)llSetLinkPrimitiveParamsFast(llList2Integer(links,i),[PRIM_TEXT]+llList2List(saved,i*3,i*3+2));
}
default
{
    state_entry()
    {
        integer i;
        for(i=2;i<=llGetObjectPrimCount(llGetKey())&&llGetListLength(links)<12;++i)if(llGetLinkName(i)=="lesson")
        {
            links+=[i];
            saved+=llGetLinkPrimitiveParams(i,[PRIM_TEXT]);
            captions+=llGetLinkPrimitiveParams(i,[PRIM_DESC]);
        }
    }
    touch_start(integer n)
    {
        if(llDetectedKey(0)!=llGetOwner()||llGetLinkNumber()>1||!valid)return;
        ++step;
        if(step>=llGetListLength(links))
        {
            step=-1;
            restore();
            return;
        }
        integer i;
        for(i=0;i<llGetListLength(links);++i)
        {
            string text="";
            if(i==step)text=llGetSubString(llList2String(captions,i),0,99);
            llSetLinkPrimitiveParamsFast(llList2Integer(links,i),[PRIM_TEXT,text,<1.0,1.0,1.0>,1.0]);
        }
    }
    changed(integer change)
    {
        if(change&CHANGED_LINK)valid=FALSE;
    }
}