/*
    HS_DollyCam - Menu Helper (HS_CamMenu.lsl)  [UX STABLE NAV]
    - Touch HUD -> llDialog menus
    - Stable pagination UX:
        * Always 12 buttons
        * Always shows: "<<", "Back", ">>" side-by-side
        * Blank filler buttons (" ") keep layout stable
        * Wrap-around: << on first page -> last, >> on last -> first
        * Back goes to previous menu level (not always main)
    - Save presets (1..N)
    - MoveTo presets (1..N) using configurable Duration
    - Play playlists: notecards starting with "shot_"
    - Settings: Mode linear/spline + Duration (ms)
    - Tour Builder: collect points -> run one tour

    Talks to Controller via:
      llMessageLinked(LINK_SET, MN_CMD, "TYPE|...", owner)

    Put this script into the prim(s) you want clickable.
*/

integer MN_CMD = 5200;

string  NC_PREFIX = "shot_";   // play menu shows only notecards starting with this (case-insensitive)
integer PRESET_MAX = 30;       // max preset slots shown in menus

// Stable 12-button layouts (no "Close"; viewer has Ignore)
integer SAVE_PER_PAGE = 9;     // 9 numbers + nav(3) = 12
integer MOVE_PER_PAGE = 8;     // 8 numbers + toggle(1) + nav(3) = 12
integer PLAY_PER_PAGE = 9;     // 9 cards + nav(3) = 12
integer TOUR_PER_PAGE = 9;     // 9 numbers + nav(3) = 12

// menu states
integer M_MAIN      = 0;
integer M_SAVE      = 1;
integer M_MOVETO    = 2;
integer M_PLAY      = 3;
integer M_SETTINGS  = 4;
integer M_SETMODE   = 5;
integer M_SETDUR    = 6;
integer M_TOUR      = 7;
integer M_TOUR_PICK = 8;

// ===== ADD: Follow/Lock Target Pick =====
integer M_FOLLOW_PICK = 9;
integer M_LOCK_PICK   = 10;

// Nearby config (leicht änderbar)
float   NEARBY_RANGE = 20.0;      // meters
integer AV_PER_PAGE  = 9;         // 9 entries + navRow(3) = 12 buttons stable

// LinksetData keys written by Controller (see Controller patch)
string  LSKEY_FOLLOW = "HS_FOLLOW"; // "on|uuid"
string  LSKEY_LOCK   = "HS_LOCK";   // "on|arg" (uuid or "<x,y,z>")

// runtime state (menu-side)
integer gFollowOn = FALSE;
string  gFollowArg = ""; // uuid (string) if ON
integer gLockOn = FALSE;
string  gLockArg = "";   // uuid or "<...>" if ON

// cached nearby lists for pick menus (kept across pages)
list gNearKeys;    // keys
list gNearNames;   // names
list gNearLabels;  // short labels shown in llDialog

key     gOwner;

integer gChan = 0;
integer gListen = 0;

// current menu state
integer gState = M_MAIN;
integer gPage = 0;

// previous menu stack: [state, page, state, page, ...]
list gBackStack;

// settings
integer gDurMs = 3000;         // used for MoveTo + Tour total
string  gMode = "linear";      // "linear" or "spline"
integer gGapMs = 0;            // optional for Play (kept simple)

// MoveTo toggle
integer gCutMode = FALSE;      // FALSE -> moveto, TRUE -> cut(load)

// Tour builder
list gTourIdx;                 // strings (idx)

// timeout
float MENU_TIMEOUT = 15.0;

// --- Marker toggle state (persisted in Linkset Data by Controller) ---
string  LSKEY_CAMS = "HS_CAMS"; // "shown|N" e.g. "1|12"
integer gCamsShown = FALSE;
integer gCamsN = 12;

camsLoadState()
{
    string s = llLinksetDataRead(LSKEY_CAMS);
    if (s == "") { gCamsShown = FALSE; gCamsN = 12; return; }

    list p = llParseString2List(s, ["|"], []);
    if (llGetListLength(p) >= 1) gCamsShown = (integer)llList2String(p, 0);

    if (llGetListLength(p) >= 2) {
        integer n = (integer)llList2String(p, 1);
        if (n < 1) n = 1;
        if (n > 30) n = 30;
        gCamsN = n;
    }
}

sendCamsShow()
{
    llMessageLinked(LINK_SET, MN_CMD, "CAMS|SHOW|" + (string)gCamsN, gOwner);
}

sendCamsHide()
{
    llMessageLinked(LINK_SET, MN_CMD, "CAMS|HIDE", gOwner);
}

// ---- small utils ----
say(string s) { llOwnerSay(s); }

integer isOwner(key k) { return (k == gOwner); }

integer startsWithNoCase(string s, string pref)
{
    s = llToLower(s);
    pref = llToLower(pref);
    return (llGetSubString(s, 0, llStringLength(pref)-1) == pref);
}

// ===== ADD: Follow/Lock state from Controller (LinksetData) =====
followLockLoadState()
{
    // FOLLOW: "on|uuid"
    gFollowOn = FALSE;
    gFollowArg = "";
    string fs = llLinksetDataRead(LSKEY_FOLLOW);
    if (fs != "") {
        list p = llParseString2List(fs, ["|"], []);
        if (llGetListLength(p) >= 1) gFollowOn = (integer)llList2String(p, 0);
        if (llGetListLength(p) >= 2) gFollowArg = llList2String(p, 1);
    }

    // LOCK: "on|arg" (uuid or "<vec>")
    gLockOn = FALSE;
    gLockArg = "";
    string ls = llLinksetDataRead(LSKEY_LOCK);
    if (ls != "") {
        list q = llParseString2List(ls, ["|"], []);
        if (llGetListLength(q) >= 1) gLockOn = (integer)llList2String(q, 0);
        if (llGetListLength(q) >= 2) gLockArg = llList2String(q, 1);
    }
}

string shortNameFromArg(string arg)
{
    if (arg == "") return "";
    if (llGetSubString(arg, 0, 0) == "<") return "vec";
    string nm = llKey2Name((key)arg);
    if (nm != "") return nm;
    return llGetSubString(arg, 0, 7);
}

string followLockStatusLine()
{
    string f = "OFF";
    if (gFollowOn) f = "ON (" + shortNameFromArg(gFollowArg) + ")";

    string l = "OFF";
    if (gLockOn) l = "ON (" + shortNameFromArg(gLockArg) + ")";

    return "Follow: " + f + "\nLock: " + l;
}

// ===== ADD: Nearby list building (AGENT_LIST_REGION + distance filter) =====
string sanitizeName(string nm)
{
    if (nm == "") nm = "(unknown)";
    // avoid breaking our label format
    if (llSubStringIndex(nm, "|") != -1)
        nm = llDumpList2String(llParseString2List(nm, ["|"], []), ":");
    return nm;
}

string makeAgentLabel(string name, key agentId)
{
    // llDialog button limit -> short + uuid prefix
    string pref = llGetSubString((string)agentId, 0, 3); // 4 chars
    integer maxName = 24 - (1 + 4); // "name|abcd" => name max 19 chars
    if (llStringLength(name) > maxName) name = llGetSubString(name, 0, maxName - 1);

    string lbl = name + "|" + pref;

    // avoid reserved nav labels (paranoia)
    if (lbl == "Back" || lbl == "<<" || lbl == ">>") lbl = name + "_" + pref;
    return lbl;
}

buildNearbyLists()
{
    gNearKeys = [];
    gNearNames = [];
    gNearLabels = [];

    // Owner position for distance filter
    vector myPos = ZERO_VECTOR;
    list od = llGetObjectDetails(gOwner, [OBJECT_POS]);
    if (llGetListLength(od) >= 1) myPos = llList2Vector(od, 0);

    list agents = llGetAgentList(AGENT_LIST_REGION, []);

    // Ensure owner included
    if (llListFindList(agents, [gOwner]) == -1) agents += [gOwner];

    // build sortable stride list: [nameLower, uuidStr, name, label]...
    list tmp = [];
    integer i;
    for (i = 0; i < llGetListLength(agents); ++i)
    {
        key k = llList2Key(agents, i);

        list d = llGetObjectDetails(k, [OBJECT_POS]);
        if (llGetListLength(d) < 1) jump nextAgent;

        vector p = llList2Vector(d, 0);

        // distance filter; if owner pos is unavailable, include region agents
        if (myPos != ZERO_VECTOR)
        {
            if (llVecDist(p, myPos) > NEARBY_RANGE) jump nextAgent;
        }
        // else owner pos unknown; keep all region agents

        string nm = sanitizeName(llKey2Name(k));
        string lbl = makeAgentLabel(nm, k);

        tmp += [llToLower(nm), (string)k, nm, lbl];

@nextAgent;
    }

    if (llGetListLength(tmp) > 0)
        tmp = llListSort(tmp, 4, TRUE);

    for (i = 0; i < llGetListLength(tmp); i += 4)
    {
        gNearKeys   += [(key)llList2String(tmp, i + 1)];
        gNearNames  += [llList2String(tmp, i + 2)];
        gNearLabels += [llList2String(tmp, i + 3)];
    }
}

menuClose()
{
    if (gListen) llListenRemove(gListen);
    gListen = 0;
    llSetTimerEvent(0.0);
}

menuOpenListen()
{
    menuClose();
    gChan = (integer)(llFrand(1000000.0) + 1000.0) * -1;
    gListen = llListen(gChan, "", gOwner, "");
    llSetTimerEvent(MENU_TIMEOUT);
}

pushBack(integer st, integer pg)
{
    gBackStack += [st, pg];
}

integer popBack()
{
    integer n = llGetListLength(gBackStack);
    if (n < 2) return FALSE;

    integer prevPage = llList2Integer(gBackStack, n - 1);
    integer prevState = llList2Integer(gBackStack, n - 2);

    gBackStack = llDeleteSubList(gBackStack, n - 2, n - 1);

    gState = prevState;
    gPage = prevPage;

    return TRUE;
}

// Returns a list padded with filler " " to exactly wantLen entries.
list padTo(list items, integer wantLen)
{
    integer n = llGetListLength(items);
    while (n < wantLen) {
        items += [" "];
        ++n;
    }
    if (n > wantLen) items = llList2List(items, 0, wantLen - 1);
    return items;
}

// Stable nav row: always present, always same order.
list navRow()
{
    return ["<<", "Back", ">>"];
}

// Wrap-around paging
integer wrapPrev(integer page, integer pages)
{
    page -= 1;
    if (page < 0) page = pages - 1;
    return page;
}

integer wrapNext(integer page, integer pages)
{
    page += 1;
    if (page >= pages) page = 0;
    return page;
}

// ---- inventory listing ----
list getShotNotecards()
{
    list out = [];
    integer n = llGetInventoryNumber(INVENTORY_NOTECARD);
    integer i;
    for (i = 0; i < n; ++i) {
        string name = llGetInventoryName(INVENTORY_NOTECARD, i);
        if (startsWithNoCase(name, NC_PREFIX)) out += [name];
    }
    return out;
}

// ---- controller triggers ----
sendSave(integer idx)
{
    llMessageLinked(LINK_SET, MN_CMD, "SAVE|" + (string)idx, gOwner);
}

sendMoveTo(integer idx)
{
    llMessageLinked(LINK_SET, MN_CMD, "MOVETO|" + (string)idx + "|" + (string)gDurMs, gOwner);
}

sendLoad(integer idx)
{
    llMessageLinked(LINK_SET, MN_CMD, "LOAD|" + (string)idx, gOwner);
}

sendPlay(string card)
{
    llMessageLinked(LINK_SET, MN_CMD, "PLAY|" + card + "|" + (string)gGapMs, gOwner);
}

sendStop()
{
    llMessageLinked(LINK_SET, MN_CMD, "STOP", gOwner);
}

sendTourRun()
{
    integer n = llGetListLength(gTourIdx);
    if (n < 2) {
        say("Tour Builder: add at least 2 points.");
        return;
    }

    // TOURRUN|totalMs|mode|count|idx1|idx2|...
    list parts = ["TOURRUN", (string)gDurMs, gMode, (string)n];
    integer i;
    for (i = 0; i < n; ++i) parts += [llList2String(gTourIdx, i)];

    llMessageLinked(LINK_SET, MN_CMD, llDumpList2String(parts, "|"), gOwner);
}

// ---- UI strings ----
string settingsLine()
{
    return "Mode: " + llToUpper(gMode) + "\nDuration: " + (string)gDurMs + " ms";
}

string tourListLine()
{
    integer n = llGetListLength(gTourIdx);
    if (n < 1) return "(none)";
    string s = "";
    integer i;
    for (i = 0; i < n; ++i) {
        s += llList2String(gTourIdx, i);
        if (i < n - 1) s += ", ";
        if (llStringLength(s) > 200) { s += " ..."; jump done; }
    }
@done;
    return s;
}

// ---- show menus ----
showMainEx(integer doLoad)
{
    camsLoadState();
    if (doLoad) followLockLoadState(); // nur wenn wir "frisch" aus LSD lesen wollen

    gState = M_MAIN;
    gPage = 0;
    gCutMode = FALSE;
    gBackStack = []; // root
    menuOpenListen();

    string camsBtn = "Show Cams";
    if (gCamsShown) camsBtn = "Hide Cams";

    string msg =
        "HS DollyCam Menu\n\n"
        + settingsLine()
        + "\n\n"
        + followLockStatusLine()
        + "\n\nSelect:";

    list buttons = ["Follow","Lock", "Settings", "Tour", camsBtn, "Stop", "Save","MoveTo","Play"];
    llDialog(gOwner, msg, buttons, gChan);
}

showMain()
{
    showMainEx(TRUE);
}

showSave(integer page)
{
    pushBack(gState, gPage);
    gState = M_SAVE;
    gPage = page;
    gCutMode = FALSE;
    menuOpenListen();

    integer pages = (PRESET_MAX + SAVE_PER_PAGE - 1) / SAVE_PER_PAGE;
    if (pages < 1) pages = 1;
    if (gPage < 0) gPage = 0;
    if (gPage >= pages) gPage = pages - 1;

    integer start = gPage * SAVE_PER_PAGE + 1;
    integer end = start + SAVE_PER_PAGE - 1;
    if (end > PRESET_MAX) end = PRESET_MAX;

    list btn = [];
    integer i;
    for (i = start; i <= end; ++i) btn += [(string)i];

    btn = padTo(btn, SAVE_PER_PAGE);
    btn += navRow(); // total 12

    string msg =
        "Save preset:\n"
        + "(Select a slot)\n\n"
        + "Page " + (string)(gPage + 1) + "/" + (string)pages
        + "\nRange: " + (string)start + "-" + (string)end;

    llDialog(gOwner, msg, btn, gChan);
}

showMoveTo(integer page)
{
    pushBack(gState, gPage);
    gState = M_MOVETO;
    gPage = page;
    menuOpenListen();

    integer pages = (PRESET_MAX + MOVE_PER_PAGE - 1) / MOVE_PER_PAGE;
    if (pages < 1) pages = 1;
    if (gPage < 0) gPage = 0;
    if (gPage >= pages) gPage = pages - 1;

    integer start = gPage * MOVE_PER_PAGE + 1;
    integer end = start + MOVE_PER_PAGE - 1;
    if (end > PRESET_MAX) end = PRESET_MAX;

    list btn = [];
    integer i;
    for (i = start; i <= end; ++i) btn += [(string)i];

    btn = padTo(btn, MOVE_PER_PAGE);

    // Toggle button (always present, stable position)
    if (gCutMode) btn += ["Move"];
    else btn += ["Cut"];

    btn += navRow(); // total 12

    string modeLine;
    if (gCutMode) modeLine = "Selection action: CUT (load)";
    else modeLine = "Selection action: MOVETO";

    string msg =
        "MoveTo preset:\n"
        + "Duration: " + (string)gDurMs + " ms\n"
        + modeLine + "\n\n"
        + "Page " + (string)(gPage + 1) + "/" + (string)pages
        + "\nRange: " + (string)start + "-" + (string)end;

    llDialog(gOwner, msg, btn, gChan);
}

showPlay(integer page)
{
    pushBack(gState, gPage);
    gState = M_PLAY;
    gPage = page;
    gCutMode = FALSE;
    menuOpenListen();

    list cards = getShotNotecards();
    integer total = llGetListLength(cards);

    if (total < 1) {
        // Keep stable 12 buttons: 9 blanks + nav
        list btn = padTo([], PLAY_PER_PAGE);
        btn += navRow();

        string msg =
            "Play playlist:\n"
            + "No notecards found with prefix '" + NC_PREFIX + "'.\n\n"
            + "Press Back to return.";
        llDialog(gOwner, msg, btn, gChan);
        return;
    }

    integer pages = (total + PLAY_PER_PAGE - 1) / PLAY_PER_PAGE;
    if (pages < 1) pages = 1;
    if (gPage < 0) gPage = 0;
    if (gPage >= pages) gPage = pages - 1;

    integer start = gPage * PLAY_PER_PAGE;
    integer end = start + PLAY_PER_PAGE - 1;
    if (end > total - 1) end = total - 1;

    list btn2 = [];
    integer i;
    for (i = start; i <= end; ++i) btn2 += [llList2String(cards, i)];

    btn2 = padTo(btn2, PLAY_PER_PAGE);
    btn2 += navRow();

    string msg2 =
        "Play playlist:\n"
        + "(Notecards starting with '" + NC_PREFIX + "')\n"
        + "gap: " + (string)gGapMs + " ms\n\n"
        + "Page " + (string)(gPage + 1) + "/" + (string)pages;

    llDialog(gOwner, msg2, btn2, gChan);
}

showSettings()
{
    pushBack(gState, gPage);
    gState = M_SETTINGS;
    gPage = 0;
    gCutMode = FALSE;
    menuOpenListen();

    string msg =
        "Settings\n\n"
        + settingsLine()
        + "\n\nSelect:";
    list btn = ["Mode","Duration","Back"];
    llDialog(gOwner, msg, btn, gChan);
}

showSetMode()
{
    pushBack(gState, gPage);
    gState = M_SETMODE;
    gPage = 0;
    gCutMode = FALSE;
    menuOpenListen();

    string msg =
        "Set Tour Mode\n\n"
        + "Current: " + llToUpper(gMode) + "\n"
        + "(Used for Tours)\n";

    // Keep it simple: one screen, no pagination needed
    list btn = ["LINEAR","SPLINE","EASE_IN","EASE_OUT","EASE_IN_OUT","Back"];
    llDialog(gOwner, msg, btn, gChan);
}


showSetDur()
{
    pushBack(gState, gPage);
    gState = M_SETDUR;
    gPage = 0;
    gCutMode = FALSE;
    menuOpenListen();

    string msg =
        "Set Duration (ms)\n\n"
        + "Current: " + (string)gDurMs + "\n"
        + "Used for MoveTo + Tour total.\n";
    list btn = ["1500","2500","3000","4000","6000","Custom","Back"];
    llDialog(gOwner, msg, btn, gChan);
}

showTour()
{
    pushBack(gState, gPage);
    gState = M_TOUR;
    gPage = 0;
    gCutMode = FALSE;
    menuOpenListen();

    string msg =
        "Tour Builder\n\n"
        + "Mode: " + llToUpper(gMode) + "\n"
        + "Total: " + (string)gDurMs + " ms\n"
        + "Points: " + tourListLine()
        + "\n\nSelect:";
    list btn = ["Add","Run","Clear","Back"];
    llDialog(gOwner, msg, btn, gChan);
}

showTourPick(integer page)
{
    pushBack(gState, gPage);
    gState = M_TOUR_PICK;
    gPage = page;
    gCutMode = FALSE;
    menuOpenListen();

    integer pages = (PRESET_MAX + TOUR_PER_PAGE - 1) / TOUR_PER_PAGE;
    if (pages < 1) pages = 1;
    if (gPage < 0) gPage = 0;
    if (gPage >= pages) gPage = pages - 1;

    integer start = gPage * TOUR_PER_PAGE + 1;
    integer end = start + TOUR_PER_PAGE - 1;
    if (end > PRESET_MAX) end = PRESET_MAX;

    list btn = [];
    integer i;
    for (i = start; i <= end; ++i) btn += [(string)i];

    btn = padTo(btn, TOUR_PER_PAGE);
    btn += navRow();

    string msg =
        "Add Tour Point\n\n"
        + "Select preset index to add.\n"
        + "Current points: " + tourListLine()
        + "\n\n"
        + "Page " + (string)(gPage + 1) + "/" + (string)pages
        + "\nRange: " + (string)start + "-" + (string)end;

    llDialog(gOwner, msg, btn, gChan);
}

// ===== ADD: Follow/Lock pick menus =====
showFollowPickInternal(integer page, integer rebuild)
{
    pushBack(gState, gPage);
    gState = M_FOLLOW_PICK;
    gPage = page;
    gCutMode = FALSE;
    menuOpenListen();

    if (rebuild) buildNearbyLists();
    integer total = llGetListLength(gNearLabels);

    integer pages = (total + AV_PER_PAGE - 1) / AV_PER_PAGE;
    if (pages < 1) pages = 1;
    if (gPage < 0) gPage = 0;
    if (gPage >= pages) gPage = pages - 1;

    integer start = gPage * AV_PER_PAGE;
    integer end = start + AV_PER_PAGE - 1;
    if (end > total - 1) end = total - 1;

    list btn = [];
    integer i;
    for (i = start; i <= end; ++i) btn += [llList2String(gNearLabels, i)];

    btn = padTo(btn, AV_PER_PAGE);
    btn += navRow();

    string msg =
        "Select Follow Target\n"
        + "Range: " + (string)NEARBY_RANGE + " m\n"
        + "Found: " + (string)total + "\n"
        + "Page " + (string)(gPage + 1) + "/" + (string)pages;

    llDialog(gOwner, msg, btn, gChan);
}

showFollowPick(integer page)
{
    showFollowPickInternal(page, TRUE);
}

showFollowPickCached(integer page)
{
    showFollowPickInternal(page, FALSE);
}

showLockPickInternal(integer page, integer rebuild)
{
    pushBack(gState, gPage);
    gState = M_LOCK_PICK;
    gPage = page;
    gCutMode = FALSE;
    menuOpenListen();

    if (rebuild) buildNearbyLists();
    integer total = llGetListLength(gNearLabels);

    integer pages = (total + AV_PER_PAGE - 1) / AV_PER_PAGE;
    if (pages < 1) pages = 1;
    if (gPage < 0) gPage = 0;
    if (gPage >= pages) gPage = pages - 1;

    integer start = gPage * AV_PER_PAGE;
    integer end = start + AV_PER_PAGE - 1;
    if (end > total - 1) end = total - 1;

    list btn = [];
    integer i;
    for (i = start; i <= end; ++i) btn += [llList2String(gNearLabels, i)];

    btn = padTo(btn, AV_PER_PAGE);
    btn += navRow();

    string msg =
        "Lock Ziel wählen\n"
        + "Reichweite: " + (string)NEARBY_RANGE + " m\n"
        + "Gefunden: " + (string)total + "\n"
        + "Seite " + (string)(gPage + 1) + "/" + (string)pages;

    llDialog(gOwner, msg, btn, gChan);
}

showLockPick(integer page)
{
    showLockPickInternal(page, TRUE);
}

showLockPickCached(integer page)
{
    showLockPickInternal(page, FALSE);
}

// ---- navigation dispatcher (previous menu) ----
showByState(integer st, integer pg)
{
    integer beforeN = llGetListLength(gBackStack);

    if (st == M_MAIN) { showMain(); return; }
    else if (st == M_SAVE) { showSave(pg); }
    else if (st == M_MOVETO) { showMoveTo(pg); }
    else if (st == M_PLAY) { showPlay(pg); }
    else if (st == M_SETTINGS) { showSettings(); }
    else if (st == M_SETMODE) { showSetMode(); }
    else if (st == M_SETDUR) { showSetDur(); }
    else if (st == M_TOUR) { showTour(); }
    else if (st == M_TOUR_PICK) { showTourPick(pg); }
    else if (st == M_FOLLOW_PICK) { showFollowPickCached(pg); }
    else if (st == M_LOCK_PICK)   { showLockPickCached(pg); }
    else { showMain(); return; }

    integer afterN = llGetListLength(gBackStack);
    if (afterN == beforeN + 2) {
        gBackStack = llDeleteSubList(gBackStack, afterN - 2, afterN - 1);
    }
}

// ---- LSL events ----
default
{
    state_entry()
    {
        gOwner = llGetOwner();
    }

    on_rez(integer sp)
    {
        gOwner = llGetOwner();
    }

    attach(key id)
    {
        gOwner = llGetOwner();
        if (id == NULL_KEY) menuClose();
    }

    touch_start(integer n)
    {
        key who = llDetectedKey(0);
        if (!isOwner(who)) return;
        showMain();
    }

    timer()
    {
        menuClose();
    }

    listen(integer channel, string name, key id, string msg)
    {
        if (channel != gChan) return;
        if (!isOwner(id)) return;

        // IMPORTANT: keep blanks " " non-functional:
        // the trim turns " " into "", which we ignore.
        msg = llStringTrim(msg, STRING_TRIM);
        if (msg == "") return;

        // Back goes to previous menu level
        if (msg == "Back") {
            if (!popBack()) { showMain(); return; }
            showByState(gState, gPage);
            return;
        }

        // Stable paging nav for paginated menus only
        if (msg == "<<" || msg == ">>") {
            integer pages = 1;

            if (gState == M_SAVE) {
                pages = (PRESET_MAX + SAVE_PER_PAGE - 1) / SAVE_PER_PAGE;
                if (pages < 1) pages = 1;
                if (msg == "<<") gPage = wrapPrev(gPage, pages);
                else gPage = wrapNext(gPage, pages);
                showByState(M_SAVE, gPage);
                return;
            }

            if (gState == M_MOVETO) {
                pages = (PRESET_MAX + MOVE_PER_PAGE - 1) / MOVE_PER_PAGE;
                if (pages < 1) pages = 1;
                if (msg == "<<") gPage = wrapPrev(gPage, pages);
                else gPage = wrapNext(gPage, pages);
                showByState(M_MOVETO, gPage);
                return;
            }

            if (gState == M_PLAY) {
                list cards = getShotNotecards();
                integer total = llGetListLength(cards);
                pages = (total + PLAY_PER_PAGE - 1) / PLAY_PER_PAGE;
                if (pages < 1) pages = 1;
                if (msg == "<<") gPage = wrapPrev(gPage, pages);
                else gPage = wrapNext(gPage, pages);
                showByState(M_PLAY, gPage);
                return;
            }

            if (gState == M_TOUR_PICK) {
                pages = (PRESET_MAX + TOUR_PER_PAGE - 1) / TOUR_PER_PAGE;
                if (pages < 1) pages = 1;
                if (msg == "<<") gPage = wrapPrev(gPage, pages);
                else gPage = wrapNext(gPage, pages);
                showByState(M_TOUR_PICK, gPage);
                return;
            }

            if (gState == M_FOLLOW_PICK) {
                integer totalF = llGetListLength(gNearLabels);
                pages = (totalF + AV_PER_PAGE - 1) / AV_PER_PAGE;
                if (pages < 1) pages = 1;
                if (msg == "<<") gPage = wrapPrev(gPage, pages);
                else gPage = wrapNext(gPage, pages);
                showByState(M_FOLLOW_PICK, gPage);
                return;
            }

            if (gState == M_LOCK_PICK) {
                integer totalL = llGetListLength(gNearLabels);
                pages = (totalL + AV_PER_PAGE - 1) / AV_PER_PAGE;
                if (pages < 1) pages = 1;
                if (msg == "<<") gPage = wrapPrev(gPage, pages);
                else gPage = wrapNext(gPage, pages);
                showByState(M_LOCK_PICK, gPage);
                return;
            }

            // if not a paginated menu, ignore
            return;
        }

        // ---- main ----
        if (gState == M_MAIN) {
            if (msg == "Save") { showSave(0); return; }
            if (msg == "MoveTo") { showMoveTo(0); return; }
            if (msg == "Play") { showPlay(0); return; }
            if (msg == "Settings") { showSettings(); return; }
            if (msg == "Tour") { showTour(); return; }

            if (msg == "Show Cams") {
                sendCamsShow();
                gCamsShown = TRUE;
                showMain(); // refresh label
                return;
            }
            if (msg == "Hide Cams") {
                sendCamsHide();
                gCamsShown = FALSE;
                showMain(); // refresh label
                return;
            }

            if (msg == "Stop") { sendStop(); return; }
            
            if (msg == "Follow") {
                // lokalen Status nutzen (nicht sofort LSD neu lesen)
                followLockLoadState();

                if (gFollowOn) {
                    llMessageLinked(LINK_SET, MN_CMD, "FOLLOW|OFF", gOwner);

                    // sofort UI-korrekt
                    gFollowOn = FALSE; gFollowArg = "";
                    showMainEx(FALSE);
                } else {
                    showFollowPick(0);
                }
                return;
            }

            if (msg == "Lock") {
                followLockLoadState();

                if (gLockOn) {
                    llMessageLinked(LINK_SET, MN_CMD, "LOCK|OFF", gOwner);

                    // sofort UI-korrekt
                    gLockOn = FALSE; gLockArg = "";
                    showMainEx(FALSE);
                } else {
                    showLockPick(0);
                }
                return;
            }

            
            return;
        }

        // ---- save ----
        if (gState == M_SAVE) {
            integer idx = (integer)msg;
            if (idx >= 1 && idx <= PRESET_MAX) {
                sendSave(idx);
                return;
            }
            return;
        }

        // ---- moveto ----
        if (gState == M_MOVETO) {
            if (msg == "Cut") { gCutMode = TRUE; showByState(M_MOVETO, gPage); return; }
            if (msg == "Move") { gCutMode = FALSE; showByState(M_MOVETO, gPage); return; }

            integer idx2 = (integer)msg;
            if (idx2 >= 1 && idx2 <= PRESET_MAX) {
                if (gCutMode) {
                    sendLoad(idx2);
                    gCutMode = FALSE;
                } else {
                    sendMoveTo(idx2);
                }
                return;
            }
            return;
        }

        // ---- play ----
        if (gState == M_PLAY) {
            // msg is notecard name button
            if (llGetInventoryType(msg) == INVENTORY_NOTECARD) {
                sendPlay(msg);
                return;
            }
            return;
        }

        // ---- settings ----
        if (gState == M_SETTINGS) {
            if (msg == "Mode") { showSetMode(); return; }
            if (msg == "Duration") { showSetDur(); return; }
            return;
        }

        // ---- set mode ----
        if (gState == M_SETMODE) {
            if (msg == "LINEAR") gMode = "linear";
            else if (msg == "SPLINE") gMode = "spline";
            else if (msg == "EASE_IN") gMode = "ease_in";
            else if (msg == "EASE_OUT") gMode = "ease_out";
            else if (msg == "EASE_IN_OUT") gMode = "ease_in_out";

            // go back one level
            if (!popBack()) { showMain(); return; }
            showByState(gState, gPage);
            return;
        }

        // ---- set duration ----
        if (gState == M_SETDUR) {
            if (msg == "Custom") {
                llTextBox(gOwner, "Enter duration in ms (e.g. 3000):", gChan);
                return;
            }

            integer d = (integer)msg;
            if (d >= 200 && d <= 60000) gDurMs = d;

            // return to previous level
            if (!popBack()) { showMain(); return; }
            showByState(gState, gPage);
            return;
        }

        // ---- tour builder ----
        if (gState == M_TOUR) {
            if (msg == "Add") { showTourPick(0); return; }
            if (msg == "Clear") { gTourIdx = []; showByState(M_TOUR, 0); return; }
            if (msg == "Run") { sendTourRun(); return; }
            return;
        }

        // ---- tour pick ----
        if (gState == M_TOUR_PICK) {
            integer idxT = (integer)msg;
            if (idxT >= 1 && idxT <= PRESET_MAX) {
                gTourIdx += [(string)idxT];

                // Go back one level (to Tour builder) after adding
                if (!popBack()) { showMain(); return; }
                showByState(gState, gPage);
                return;
            }
            return;
        }
        
        // ---- follow pick ----
        if (gState == M_FOLLOW_PICK) {
            integer idxF = llListFindList(gNearLabels, [msg]);
            if (idxF < 0) return;

            key kF = llList2Key(gNearKeys, idxF);
            string nmF = llList2String(gNearNames, idxF);

            say("Gewählt: " + nmF + " | UUID: " + (string)kF);
            llMessageLinked(LINK_SET, MN_CMD, "FOLLOW|ON|" + (string)kF, gOwner);

            // sofort UI korrekt + Mutual Exclusion im Menü
            gFollowOn = TRUE;  gFollowArg = (string)kF;
            gLockOn   = FALSE; gLockArg = "";

            showMainEx(FALSE);
            return;
        }

        // ---- lock pick ----
        if (gState == M_LOCK_PICK) {
            integer idxL = llListFindList(gNearLabels, [msg]);
            if (idxL < 0) return;

            key kL = llList2Key(gNearKeys, idxL);
            string nmL = llList2String(gNearNames, idxL);

            say("Gewählt: " + nmL + " | UUID: " + (string)kL);
            llMessageLinked(LINK_SET, MN_CMD, "LOCK|ON|" + (string)kL, gOwner);

            // sofort UI korrekt + Mutual Exclusion im Menü
            gLockOn   = TRUE;  gLockArg = (string)kL;
            gFollowOn = FALSE; gFollowArg = "";

            showMainEx(FALSE);
            return;
        }

        // If we got here, ignore.
    }
}