// SPDX-License-Identifier: MIT
// Copyright (c) 2026 Incoprea
// Check installed package versions against requirements
// Not compiled or tested in-world
// Setup: Create a saved plain-text notecard named Data. Use package|minVersion rows. Edit INSTALLED package/version pairs in the script. 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. Both versions use three components 0–999. These are authored version labels, not an automatic security or compatibility guarantee.
// License: see LICENSE in this distribution.
// Original Incoprea example. MIT.
integer whole(string s)
{
    if(s=="" || llStringLength(s)>6)return FALSE;
    integer i;
    for(i=0;i<llStringLength(s);++i)if(llSubStringIndex("0123456789",llGetSubString(s,i,i))==-1)return FALSE;
    return TRUE;
}
integer validVersion(string s)
{
    list p=llParseStringKeepNulls(s,["."],[]);
    if(llGetListLength(p)!=3)return FALSE;
    integer i;
    for(i=0;i<3;++i)if(!whole(llList2String(p,i)) || llList2Integer(p,i)>999)return FALSE;
    return TRUE;
}
integer versionCode(string s)
{
    list p=llParseStringKeepNulls(s,["."],[]);
    return llList2Integer(p,0)*1000000+llList2Integer(p,1)*1000+llList2Integer(p,2);
}
list INSTALLED=["lighting","1.2.0","door","2.0.1"];
list lines;
integer lineNumber;
integer characters;
integer loaded;
key pending=NULL_KEY;
request()
{
    pending=llGetNotecardLine("Data",lineNumber);
    llSetTimerEvent(20);
}
run()
{
    if(llGetListLength(INSTALLED)%2)
    {
        llOwnerSay("Installed manifest malformed.");
        return;
    }
    list keys;
    integer i;
    for(i=0;i<llGetListLength(INSTALLED);i+=2)
    {
        if(!validVersion(llList2String(INSTALLED,i+1)) || llListFindList(keys,[llList2String(INSTALLED,i)])!=-1)
        {
            llOwnerSay("Invalid or duplicate installed package.");
            return;
        }
        keys += [llList2String(INSTALLED,i)];
    }
    for(i=0;i<llGetListLength(lines);++i)
    {
        list p=llParseStringKeepNulls(llList2String(lines,i),["|"],[]);
        if(llGetListLength(p)!=2 || !validVersion(llList2String(p,1)))
        {
            llOwnerSay("Invalid requirement.");
            return;
        }
        string name=llList2String(p,0);
        integer at=llListFindList(keys,[name]);
        if(at==-1)llOwnerSay("Missing package: "+name);
        else if(versionCode(llList2String(INSTALLED,at*2+1))<versionCode(llList2String(p,1)))llOwnerSay("Below required version: "+name);
        else llOwnerSay("Version meets declared minimum: "+name);
    }
}
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();
    }
}