/* ── User-defined set structure dialog (ADR 0016) ────────────────────────────
   Lets the user define which line belongs to which set (and how deep) instead of relying only
   on the implicit "everything after a Set header until the next Set" derivation that
   fds__prepInvoice delivers as the initial structure. The dialog is a pure view of the
   authoritative server state (state.req[].itm — the co shape with SetItmId + lvl): every action
   posts ONE delta (set.assign / set.level / set.create) via $inv.d.sync, the server rewrites the
   cached block (parent links, depth-first order, levels) and the normal draftReady/dstate
   refresh re-renders both the editor rows and this dialog (applyState -> $inv.sets.render).
   The browser never restructures anything itself (ADR 0006/0008). */
$inv.sets = {
    o: null,        /* open dialog handle ($ocms.dlg result) or null */
    c: null,        /* dialog content container */
    drag: null,     /* { id, bid } of the row currently being dragged */
    /* Reorder = set.move (▲▼ or drag before/after a row), membership = set.assign (drag into a set /
       root zone), depth = set.level (◀▶). Folding is purely a view state kept in $inv.sets.collapsed. */
    isOpen: () => !!$inv.sets.o,
    open: function () {
        let tbl = $inv.d.tbl();
        if (tbl.length < 1 || $inv.sets.isOpen()) { return; }
        if ($inv.d.token() === '' && !tbl.data('dstate')) { return; }   /* no draft session (e.g. reminder editor) — nothing to structure */
        let c = $$.dc('setstruct');
        $inv.sets.c = c;
        $inv.sets.o = $ocms.dlg(c, {
            title: $ict.setst, size: [-1, 960], exclusive: false,
            close: () => { $inv.sets.o = null; $inv.sets.c = null; $inv.sets.drag = null; }
        });
        let state = tbl.data('dstate');
        if (state) { $inv.sets.render(state); } else { $inv.d.refresh(); }
    },
    /* plain-text title of a co line (co.t is HTML for text lines / titles) */
    title: (co) => {
        let t = $$.d().html(co.t || '').text().replace(/\s+/g, ' ').trim();
        return t !== '' ? t : ($ict.setsNoTitle || '');
    },
    typLbl: (co) => {
        let k = (co.typ || '').toString().toLowerCase();
        return ($ict.settyp || {})[k] || co.typ || '';
    },
    isSet: (co) => (co.typ || '').toString().toLowerCase() === 'set',
    /* Normalised parent id of a line, mirroring InvoiceSetStructure.ParentOf: SetItmId when it
       names ANOTHER set line of the same block; '' for top level / self-reference / unknown. */
    parentOf: (co, byId) => {
        let p = (co.SetItmId == null ? '' : co.SetItmId).toString(), id = (co.id || '').toString();
        if (p === '' || p === id) { return ''; }
        let t = byId[p];
        return (t && $inv.sets.isSet(t)) ? p : '';
    },
    isDescendant: (candidateId, ancestorId, byId) => {
        let seen = {}, cur = byId[candidateId];
        while (cur) {
            let p = $inv.sets.parentOf(cur, byId);
            if (p === '' || seen[p]) { return false; }
            if (p === ancestorId) { return true; }
            seen[p] = true; cur = byId[p];
        }
        return false;
    },
    /* Whether a line may be dropped onto the given target set (same block, not itself, no cycle). */
    canDrop: (drag, targetId, bid, byId) =>
        !!drag && drag.bid === bid && drag.id !== targetId && !$inv.sets.isDescendant(targetId, drag.id, byId),
    sync: (delta) => {
        if ($inv.sets.c) { $inv.sets.c.aC('busy'); }
        return $inv.d.sync(delta);
    },
    render: function (state) {
        let c = $inv.sets.c; if (!c) { return; }
        let bdy = c.closest('.modal-body'), scroll = bdy.length ? bdy.scrollTop() : 0;
        c.empty().rC('busy');
        $$.dc('shint', c).text($ict.setsHint || '');
        (state.req || []).forEach((b) => {
            if (!b) { return; }
            let bid = (b.Id || '').toString(); if (bid === '') { return; }
            let itms = (b.itm || []).filter((co) => co && (co.id || '') !== ''), byId = {};
            itms.forEach((co) => { byId[(co.id || '').toString()] = co; });
            let blk = $$.dc('sblock', c).data({ bid: bid });
            $inv.sets.rootZone($$.dc('sbhd', blk).append($$.sc('nme', b.text || b.nme || bid)), bid, byId);
            let ts = $$.tblset({ class: 'stbl' }, blk);
            let thr = $$.tr(ts.hd);
            ($ict.setsHR || []).forEach((h) => $$.th(thr, h));
            itms.forEach((co) => $inv.sets.row(ts.bdy, co, bid, itms, byId));
            $inv.sets.rootZone($$.dc('sroot', blk).text($ict.setsRoot || ''), bid, byId);
            $inv.sets.createBar(blk, bid, itms, byId);
        });
        if (bdy.length) { bdy.scrollTop(scroll); }
    },
    /* Ancestor-collapsed test: a row is hidden while any set above it is folded. */
    collapsed: {},   /* set id -> true (survives re-renders; default: everything expanded) */
    hiddenByCollapse: function (co, byId) {
        let seen = {}, cur = co;
        while (cur) {
            let p = $inv.sets.parentOf(cur, byId);
            if (p === '' || seen[p]) { return false; }
            if ($inv.sets.collapsed[p]) { return true; }
            seen[p] = true; cur = byId[p];
        }
        return false;
    },
    /* Drop zone of a pointer position within a row: top edge = before, bottom edge = after,
       middle = into (sets only; for other rows the middle counts as "after"). */
    zone: function (ev, tr, isSet) {
        let oe = ev.originalEvent || ev, r = tr[0].getBoundingClientRect(), y = (oe.clientY || 0) - r.top, h = r.height || 1;
        if (y < h * 0.3) { return 'before'; }
        if (y > h * 0.7 || !isSet) { return 'after'; }
        return 'into';
    },
    clearDrop: () => { $('.setstruct .dropok, .setstruct .dropbefore, .setstruct .dropafter').rC('dropok dropbefore dropafter'); },
    /* One line of the structure table: drag handle, fold toggle, pos, type, qty, indented title,
       order buttons (▲▼ among siblings) and level buttons (◀▶). */
    row: function (tbody, co, bid, itms, byId) {
        let id = (co.id || '').toString(), lvl = parseInt(co.lvl || 0, 10) || 0, isSet = $inv.sets.isSet(co);
        let parent = $inv.sets.parentOf(co, byId), folded = isSet && !!$inv.sets.collapsed[id];
        let tr = $$.tr(tbody, { draggable: 'true' }).aC('srow lvl' + lvl).tC('isset', isSet).tC('folded', folded).data({ id: id, bid: bid });
        if ($inv.sets.hiddenByCollapse(co, byId)) { tr.aC('hid'); }
        $$.tdc('grip', tr).append(gi('move')).attr('title', $rct.mR);
        $$.tdc('pos', tr).text(co.p != null ? co.p : '');
        let typ = $$.tdc('typ', tr);
        if (isSet) {   /* fold toggle sits in the type column, in front of "Set" */
            typ.append($$.sc('fold').attr('title', folded ? $ict.setsExpand : $ict.setsCollapse).append(gi(folded ? 'triangle-right' : 'triangle-bottom')).click((ev) => {
                ev.stopPropagation();
                if (folded) { delete $inv.sets.collapsed[id]; } else { $inv.sets.collapsed[id] = true; }
                let state = $inv.d.tbl().data('dstate'); if (state) { $inv.sets.render(state); }
            }));
        }
        typ.append($$.s($inv.sets.typLbl(co)));
        $$.tdc('qty', tr).text(co.q || '');
        let ttl = $$.tdc('ttl', tr);
        if (parent !== '') { ttl.append($$.sc('seti', $inv.sets.title(byId[parent]))); }
        ttl.append($$.sc('txt', $inv.sets.title(co)).click(function (ev) { ev.stopPropagation(); $(this).tC('exp'); }));
        if (isSet) {
            let n = itms.filter((x) => $inv.sets.parentOf(x, byId) === id).length;
            ttl.append($$.sc('cnt', ' (' + n + ')'));
        }
        /* siblings (same parent, current order) drive the ▲▼ buttons; a preceding sibling set drives ▶ */
        let sibs = itms.filter((x) => $inv.sets.parentOf(x, byId) === parent), si = sibs.findIndex((x) => (x.id || '').toString() === id);
        let hasSibSet = sibs.slice(0, si).some((x) => $inv.sets.isSet(x));
        let act = $$.tdc('act', tr);
        let btn = (cls, glyph, title, enabled, delta) => $$.dc('ibtn ' + cls, act, { title: title }).append(gi(glyph)).tC('disabled', !enabled)
            .click(() => { if (enabled) { $inv.sets.sync(delta); } });
        btn('up', 'arrow-up', $ict.setsUp, si > 0, { Target: 'set.move', Ref: id, Value: -1 });
        btn('down', 'arrow-down', $ict.setsDown, si >= 0 && si < sibs.length - 1, { Target: 'set.move', Ref: id, Value: 1 });
        btn('out', 'chevron-left', $ict.setsOut, lvl > 0, { Target: 'set.level', Ref: id, Value: -1 });
        btn('in', 'chevron-right', $ict.setsIn, hasSibSet, { Target: 'set.level', Ref: id, Value: 1 });

        tr.on('dragstart', (ev) => {
            $inv.sets.drag = { id: id, bid: bid };
            tr.aC('dragging');
            try { ev.originalEvent.dataTransfer.setData('text/plain', id); ev.originalEvent.dataTransfer.effectAllowed = 'move'; } catch (e) { /* ignore */ }
        }).on('dragend', () => { tr.rC('dragging'); $inv.sets.drag = null; $inv.sets.clearDrop(); });
        /* Every row is a target: before / after (reorder, become the anchor's sibling — works on a
           folded set too, its subtree travels along) and, for sets, into (become its last member). */
        let ok = () => $inv.sets.canDrop($inv.sets.drag, id, bid, byId);
        tr.on('dragover', (ev) => {
            if (!ok()) { return; }
            ev.preventDefault();
            let z = $inv.sets.zone(ev, tr, isSet);
            tr.rC('dropok dropbefore dropafter').aC(z === 'into' ? 'dropok' : (z === 'before' ? 'dropbefore' : 'dropafter'));
        }).on('dragleave', () => { tr.rC('dropok dropbefore dropafter'); }).on('drop', (ev) => {
            ev.preventDefault(); $inv.sets.clearDrop();
            let d = $inv.sets.drag; $inv.sets.drag = null;
            if (!$inv.sets.canDrop(d, id, bid, byId)) { return; }
            let z = $inv.sets.zone(ev, tr, isSet);
            if (z === 'into') { $inv.sets.sync({ Target: 'set.assign', Ref: d.id, Value: { parent: id } }); }
            else { $inv.sets.sync({ Target: 'set.move', Ref: d.id, Value: { anchor: id, where: z } }); }
        });
        return tr;
    },
    /* Drop target for "pull out of its set" (top level of the block). */
    rootZone: function (el, bid, byId) {
        let ok = () => { let d = $inv.sets.drag; return !!d && d.bid === bid && !!byId[d.id] && $inv.sets.parentOf(byId[d.id], byId) !== ''; };
        el.on('dragover', (ev) => { if (ok()) { ev.preventDefault(); el.aC('dropok'); } })
          .on('dragleave', () => { el.rC('dropok'); })
          .on('drop', (ev) => {
              ev.preventDefault(); el.rC('dropok');
              let d = $inv.sets.drag; $inv.sets.drag = null;
              if (d && d.bid === bid && byId[d.id] && $inv.sets.parentOf(byId[d.id], byId) !== '') {
                  $inv.sets.sync({ Target: 'set.assign', Ref: d.id, Value: { parent: '' } });
              }
          });
        return el;
    },
    /* "New line" bar per block: type (Set/Text), target set (top level or any set), title. */
    createBar: function (blk, bid, itms, byId) {
        let bar = $$.dc('screate', blk);
        let typ = $('<select></select>').attr({ name: 'typ' }).append([$$.opt('set', $ict.settyp.set), $$.opt('text', $ict.settyp.text)]);
        let par = $('<select></select>').attr({ name: 'parent' }).append($$.opt('', $ict.setsTop));
        itms.forEach((co) => {
            if (!$inv.sets.isSet(co)) { return; }
            let lvl = parseInt(co.lvl || 0, 10) || 0;
            par.append($$.opt((co.id || '').toString(), ' '.repeat(lvl * 3) + $inv.sets.title(co)));
        });
        let ttl = $('<input type="text" />').attr({ name: 'title', placeholder: $ict.setsTitle, maxlength: 250 });
        let add = () => {
            let t = (ttl.val() || '').toString().trim();
            if (t === '') { ttl.focus(); return; }
            $inv.sets.sync({ Target: 'set.create', Ref: bid, Value: { typ: typ.val(), title: t, parent: par.val() || '' } });
            ttl.val('');
        };
        ttl.on('keydown', (ev) => { if (ev.key === 'Enter') { ev.preventDefault(); add(); } });
        bar.append([$$.sc('lbl', $ict.setsNew), typ, $$.sc('lbl', $ict.setsInto), par, ttl, $$.bbtn($ict.setsAdd, 'sadd').click(add)]);
        return bar;
    }
};