// SPDX-License-Identifier: MIT
// Copyright (c) 2026 Incoprea
// Domino chain table
// Not compiled or tested in-world
// Setup: Enter tile index 1-6 to append it to the right. A used tile cannot be selected again. Owner-touch starts a fresh game; type reset to restart. Input times out after 90 seconds.
// Stop / restore: Let the input timeout expire or remove the script. No world geometry, avatar or inventory is changed.
// Notes: Original compact educational game. Owner-only local input; no scores or avatar identities are sent to a service. Output is short ASCII text. Not a competition authority.
// License: see LICENSE in this distribution.
// Original Incoprea. MIT. Not compiled or tested in-world.
integer channel;
integer handle;
list tiles;
list used;
integer end;
string chain;
close()
{
    if(handle)llListenRemove(handle);
    handle=0;
    llSetTimerEvent(0.0);
}
start()
{
    tiles=[0,1,2,3,1,2,3,0,0,2,2,2];
    used=[];
    end=0;
    chain="[0]";
}
string board()
{
    string s="";
    integer i;
    for(i=0;i<6;++i)if(llListFindList(used,[i])<0)s+=(string)(i+1)+":"+llList2String(tiles,i*2)+"-"+llList2String(tiles,i*2+1)+" ";
    return chain+" | available "+s;
}
show()
{
    llOwnerSay(board());
    if(!handle)
    {
        channel=-1000-(integer)llFrand(1000000.0);
        handle=llListen(channel,"",llGetOwner(),"");
    }
    llTextBox(llGetOwner(),"Enter tile index 1-6 to append it to the right. A used tile cannot be selected again. Type reset to restart.",channel);
    llSetTimerEvent(90.0);
}
default
{
    touch_start(integer n)
    {
        if(llDetectedKey(0)!=llGetOwner())return;
        close();
        start();
        show();
    }
    listen(integer incomingChannel,string name,key id,string input)
    {
        if(!handle||incomingChannel!=channel||id!=llGetOwner())return;
        input=llToLower(llStringTrim(input,STRING_TRIM));
        if(input=="reset")start();
        else
        {
            if(llStringLength(input)==1)
            {
                integer p=llSubStringIndex("123456",input);
                if(p>=0&&llListFindList(used,[p])<0)
                {
                    integer a=llList2Integer(tiles,p*2);
                    integer b=llList2Integer(tiles,p*2+1);
                    if(a==end||b==end)
                    {
                        if(a==end)end=b;
                        else end=a;
                        used+=[p];
                        chain+="-"+(string)end;
                        if(llGetListLength(used)==6)llOwnerSay("All tiles used.");
                    }
                    else llOwnerSay("No matching endpoint.");
                }
            }
        }
        show();
    }
    timer()
    {
        close();
    }
}