Let the last exchange be retried, edited or dropped, and stop losing drafts to a tab swap

Plugin/unraid/include/ai_chat.php

@@ -162,6 +162,13 @@ function vv_ai_chat_assets(): void {
 /* ── Code cards ─────────────────────────────────────────────────────────────
    Controls are always visible, never hover-revealed. The Monitor and Scheduler run full-time on
    15" panels with no pointer near them, so a control that only exists on hover does not exist. */
+/* Sits directly above the composer, so what it acts on — the exchange just above — reads left to
+   right into the box you would retype it in. */
+.vv-ai-last { display:flex; gap:10px; padding:0 2px 4px; }
+.vv-ai-lnk { background:none; border:none; padding:0; font-size:10px; color:#4a4a4a;
+             cursor:pointer; text-decoration:underline; text-underline-offset:2px; }
+.vv-ai-lnk:hover { color:#8a8a8a; }
+
 .vv-ai-code { margin:8px 0; border:1px solid #222; border-radius:4px; overflow:hidden; }
 .vv-ai-code pre { margin:0; border:none; border-radius:0; }
 .vv-ai-code-h { display:flex; align-items:center; gap:8px; padding:3px 8px;
@@ -714,6 +721,77 @@ vv_ai_profiles_script();
       setTimeout(() => { btn.textContent = was; btn.classList.remove('ok'); }, 1100);
     }
 
+    // ── Last-exchange controls ───────────────────────────────────────────
+    // Shown only when there is a completed exchange and nothing in flight. Hidden rather than
+    // disabled: a disabled control still occupies a line on a 15" panel to advertise something
+    // that cannot be done.
+    function syncLast() {
+      const box = $('last');
+      if (!box) return;
+      box.hidden = busy || lastUserIndex() < 0;
+    }
+
+    // Index of the most recent user message. Everything from it to the end is one exchange —
+    // the question, its answer, and any offer that answer carried.
+    function lastUserIndex() {
+      for (let i = messages.length - 1; i >= 0; i--) if (messages[i].role === 'user') return i;
+      return -1;
+    }
+
+    // Truncates to just before the last question and returns what it was. The DOM is rebuilt from
+    // messages rather than patched, because an error bubble renders as a message but was never
+    // stored — so anything counting elements would drift the first time a turn failed.
+    function dropLastExchange() {
+      const i = lastUserIndex();
+      if (i < 0) return '';
+      const q = messages[i].content;
+      messages.length = i;
+      render();
+      save();
+      syncLast();
+      return q;
+    }
+
+    function lastAction(what) {
+      if (busy) return;
+      if (what === 'edit') {
+        const q = dropLastExchange();
+        if (!q) return;
+        const inp = $('input');
+        if (inp) { inp.value = q; inp.focus(); inp.setSelectionRange(q.length, q.length); saveDraft(); }
+        return;
+      }
+      if (what === 'drop') { dropLastExchange(); return; }
+      if (what === 'retry') {
+        const q = dropLastExchange();
+        if (!q) return;
+        const inp = $('input');
+        if (inp) inp.value = q;
+        send();
+      }
+    }
+
+    // ── Draft persistence ────────────────────────────────────────────────
+    // Unraid swaps tabs by replacing the DOM, which destroys anything typed and not sent. Losing a
+    // carefully worded question to a stray tab click is the kind of small loss that stops people
+    // using a tool. Keyed per instance so the three surfaces do not share one draft.
+    const DRAFT_KEY = 'vvAiDraft:' + P;
+    function saveDraft() {
+      try {
+        const v = ($('input') || {}).value || '';
+        if (v.trim()) localStorage.setItem(DRAFT_KEY, v); else localStorage.removeItem(DRAFT_KEY);
+      } catch (_) {}
+    }
+    function restoreDraft() {
+      try {
+        const v = localStorage.getItem(DRAFT_KEY);
+        const inp = $('input');
+        // Never over an existing value: resume may have put something there first.
+        if (v && inp && !inp.value) inp.value = v;
+      } catch (_) {}
+    }
+    function clearDraft() { try { localStorage.removeItem(DRAFT_KEY); } catch (_) {} }
+
     // ── Ask / poll ───────────────────────────────────────────────────────
     function send() {
       // Never fail silently on a stuck flag. A turn that ends without finish() — a throw, a poll
@@ -741,6 +819,8 @@ vv_ai_profiles_script();
       setSendMode('stop');
       addUser(q);
       $('input').value = '';
+      clearDraft();
+      syncLast();
       addPending();
 
       // Wrapped: a synchronous throw here — from building the request, or from a fetch wrapper
@@ -819,6 +899,7 @@ vv_ai_profiles_script();
       curToken = null;
       setSendMode('ask');
       clearInterval(pendingTimer);
+      syncLast();
     }
 
     // The token of the turn in flight. Held so Stop knows what to cancel, and cleared by finish()
@@ -939,6 +1020,7 @@ vv_ai_profiles_script();
                        + (m.offer ? offerHtml(m.offer, i) : '') + `</div>`));
       });
       scroll();
+      syncLast();
     }
 
     // ── Offers ───────────────────────────────────────────────────────────
@@ -983,6 +1065,9 @@ vv_ai_profiles_script();
 
     function reset() {
       chatEl().innerHTML = `<div class="vv-ai-empty">${esc(o.empty || 'Ask Varaverk about itself.')}</div>`;
+      // An emptied transcript has no last exchange. render() funnels here when messages run out,
+      // and New Chat calls it directly, so both paths are covered by putting it here.
+      syncLast();
     }
 
     function loadChat(id) {
@@ -1141,6 +1226,19 @@ vv_ai_profiles_script();
     // One button, two jobs — which one is decided by busy rather than by what the label happens to
     // say, so a stale label can never send a question into a turn already running.
     $('send').addEventListener('click', () => { busy ? stopTurn() : send(); });
+
+    const lastBox = $('last');
+    if (lastBox) {
+      lastBox.addEventListener('click', e => {
+        const b = e.target.closest('[data-last]');
+        if (b) lastAction(b.dataset.last);
+      });
+    }
+
+    // input, not change: change only fires on blur, and a tab swap does not blur first.
+    $('input').addEventListener('input', saveDraft);
+    restoreDraft();
+    syncLast();
     const newBtn = $('new'); if (newBtn) newBtn.addEventListener('click', newChat);
 
     // ── Expand / collapse ────────────────────────────────────────────────
@@ -1613,6 +1711,15 @@ function vv_ai_chat_markup(string $prefix, array $o = []): void {
   </div>
 
   <div class="vv-ai-composer">
+    <!-- Acts on the last exchange only, and is hidden until there is one. Redoing the previous turn
+         is nearly the whole of what conversation control means in practice, and a row of buttons
+         under every message would spend a line each to serve the rare case. -->
+    <div class="vv-ai-last" id="<?= $p ?>-last" hidden>
+      <button type="button" class="vv-ai-lnk" data-last="retry">Retry</button>
+      <button type="button" class="vv-ai-lnk" data-last="edit">Edit question</button>
+      <button type="button" class="vv-ai-lnk" data-last="drop">Delete exchange</button>
+    </div>
+
     <textarea class="vv-ai-input" id="<?= $p ?>-input" rows="<?= $compact ? 1 : 2 ?>"
               title="Ctrl+Enter to send"
               placeholder="<?= htmlspecialchars($o['placeholder'] ?? 'Ask anything — questions about this install route to the assistant on their own.', ENT_QUOTES) ?>"></textarea>