// SPDX-License-Identifier: MIT
// Copyright (c) 2026 Incoprea
// Fill a private template from notecard variables
// Not compiled or tested in-world
// Setup: Create a saved plain-text notecard named Data. Use unique name|value lines. Edit TEMPLATE in the script. Values may not contain pipe. Touch as owner to load it; touch again to use the cached content.
// Stop / restore: Remove or disable. Reset or an inventory change discards the cache. No notecards are changed.
// Notes: At most 60 lines, 300 characters per line, and 6000 total characters; blank lines and # comments are omitted. Incomplete reads are rejected. Unknown or unclosed placeholders reject the preview. Literal braces outside {{...}} are preserved. Output is clipped by a conservative 800-character guard.
// License: see LICENSE in this distribution.
// Original Incoprea example. MIT.
string TEMPLATE="Welcome to {{place}}, made by {{creator}}.";
list lines;
integer lineNumber;
integer characters;
integer loaded;
key pending=NULL_KEY;
request()
{
    pending=llGetNotecardLine("Data",lineNumber);
    llSetTimerEvent(20);
}
run()
{
    list keys;
    list values;
    integer i;
    for(i=0;i<llGetListLength(lines);++i)
    {
        list p=llParseStringKeepNulls(llList2String(lines,i),["|"],[]);
        if(llGetListLength(p)!=2 || llList2String(p,0)=="" || llListFindList(keys,[llList2String(p,0)])!=-1)
        {
            llOwnerSay("Bad or duplicate variable row.");
            return;
        }
        keys += [llList2String(p,0)];
        values += [llList2String(p,1)];
    }
    string out="";
    integer pos;
    while(pos<llStringLength(TEMPLATE))
    {
        if(llGetSubString(TEMPLATE,pos,pos+1)=="{{")
        {
            integer start=pos+2;
            string tail="";
            if(start<llStringLength(TEMPLATE))tail=llGetSubString(TEMPLATE,start,-1);
            integer end=llSubStringIndex(tail,"}}");
            if(end<=0)
            {
                llOwnerSay("Unclosed or empty placeholder.");
                return;
            }
            string name=llGetSubString(tail,0,end-1);
            integer at=llListFindList(keys,[name]);
            if(at==-1)
            {
                llOwnerSay("Unknown variable: "+name);
                return;
            }
            out+=llList2String(values,at);
            pos=start+end+2;
        }
        else
        {
            out+=llGetSubString(TEMPLATE,pos,pos);
            ++pos;
        }
        if(llStringLength(out)>800)
        {
            llOwnerSay("Expanded text too long.");
            return;
        }
    }
    llOwnerSay(out);
}
default
{
    touch_start(integer touches)
    {
        if(llDetectedKey(0)!=llGetOwner())return;
        if(pending!=NULL_KEY)
        {
            llOwnerSay("Still loading.");
            return;
        }
        if(loaded)
        {
            run();
            return;
        }
        if(llGetInventoryType("Data")!=INVENTORY_NOTECARD)
        {
            llOwnerSay("Add a saved Data notecard.");
            return;
        }
        lines=[];
        lineNumber=0;
        characters=0;
        request();
    }
    dataserver(key query,string data)
    {
        if(query!=pending || pending==NULL_KEY)return;
        if(data==EOF)
        {
            pending=NULL_KEY;
            llSetTimerEvent(0);
            loaded=TRUE;
            run();
            return;
        }
        characters+=llStringLength(data);
        if(lineNumber>=60 || llStringLength(data)>300 || characters>6000)
        {
            pending=NULL_KEY;
            llSetTimerEvent(0);
            lines=[];
            llOwnerSay("Read rejected: card exceeds bounds.");
            return;
        }
        data=llStringTrim(data,STRING_TRIM);
        if(data!="" && llGetSubString(data,0,0)!="#")lines += [data];
        ++lineNumber;
        request();
    }
    timer()
    {
        pending=NULL_KEY;
        lines=[];
        llSetTimerEvent(0);
        llOwnerSay("Read timed out; touch to retry.");
    }
    changed(integer flags)
    {
        if(flags & (CHANGED_OWNER|CHANGED_INVENTORY))llResetScript();
    }
}