From 3d59836d0cbb866c4bffedceaa3c840adf4f3cc3 Mon Sep 17 00:00:00 2001
From: mrhid6 <mrhid6@gmail.com>
Date: Tue, 4 Aug 2026 17:13:50 +0100
Subject: [PATCH] feat: dual list box for workflow target servers

---
 web/components/workflows/DualListBox.tsx      | 152 ++++++++++++++++++
 .../workflows/EditWorkflowModal.tsx           |  31 ++--
 2 files changed, 166 insertions(+), 17 deletions(-)
 create mode 100644 web/components/workflows/DualListBox.tsx

diff --git a/web/components/workflows/DualListBox.tsx b/web/components/workflows/DualListBox.tsx
new file mode 100644
index 0000000..a1bbff3
--- /dev/null
+++ b/web/components/workflows/DualListBox.tsx
@@ -0,0 +1,152 @@
+"use client";
+
+import { useMemo, useState } from "react";
+
+/*
+ * A two-pane picker: everything available on the left, everything chosen on the
+ * right, moved across with the four buttons between them.
+ *
+ * The panes are divs rather than <select multiple>. A native multi-select draws
+ * its selected rows with the platform's own highlight colour, which cannot be
+ * restyled reliably across browsers — on a dark ground it renders as a pale
+ * band that belongs to no palette. Rebuilding the widget is the only way to
+ * keep it inside the token system.
+ */
+
+export interface DualItem {
+    id: string;
+    label: string;
+    hint?: string;
+}
+
+function Pane({
+    items,
+    marked,
+    onToggle,
+    onCommit,
+    empty,
+}: {
+    items: DualItem[];
+    marked: string[];
+    onToggle: (id: string, additive: boolean) => void;
+    onCommit: (id: string) => void;
+    empty: string;
+}) {
+    return (
+        <div className="h-56 overflow-y-auto rounded-lg border border-border bg-surface-2" role="listbox" aria-multiselectable>
+            {items.length === 0 ? (
+                <p className="px-3 py-2 text-xs text-text-tertiary">{empty}</p>
+            ) : (
+                items.map((it) => {
+                    const on = marked.includes(it.id);
+                    return (
+                        <button
+                            key={it.id}
+                            type="button"
+                            role="option"
+                            aria-selected={on}
+                            onClick={(e) => onToggle(it.id, e.ctrlKey || e.metaKey || e.shiftKey)}
+                            onDoubleClick={() => onCommit(it.id)}
+                            className={`flex w-full items-baseline gap-2 px-3 py-1.5 text-left text-sm transition-colors focus:outline-none focus-visible:ring-1 focus-visible:ring-inset focus-visible:ring-accent ${
+                                on ? "bg-accent text-accent-ink" : "text-text-primary hover:bg-surface"
+                            }`}
+                        >
+                            <span className="truncate">{it.label}</span>
+                            {it.hint && <span className={`truncate font-mono text-[11px] ${on ? "opacity-70" : "text-text-tertiary"}`}>{it.hint}</span>}
+                        </button>
+                    );
+                })
+            )}
+        </div>
+    );
+}
+
+function MoveButton({ children, onClick, disabled, label }: { children: React.ReactNode; onClick: () => void; disabled: boolean; label: string }) {
+    return (
+        <button
+            type="button"
+            onClick={onClick}
+            disabled={disabled}
+            aria-label={label}
+            title={label}
+            className="rounded-lg border border-border bg-surface-2 px-3 py-1.5 text-sm text-text-secondary transition-colors hover:border-accent/40 hover:text-text-primary focus:outline-none focus-visible:ring-2 focus-visible:ring-accent disabled:cursor-not-allowed disabled:opacity-40 disabled:hover:border-border disabled:hover:text-text-secondary"
+        >
+            {children}
+        </button>
+    );
+}
+
+export function DualListBox({
+    items,
+    selected,
+    onChange,
+    availableLabel = "Available",
+    selectedLabel = "Selected",
+    emptyAvailable = "Nothing left to add.",
+    emptySelected = "Nothing selected.",
+}: {
+    items: DualItem[];
+    selected: string[];
+    onChange: (next: string[]) => void;
+    availableLabel?: string;
+    selectedLabel?: string;
+    emptyAvailable?: string;
+    emptySelected?: string;
+}) {
+    // Which rows are highlighted in each pane, not which are chosen. Highlight
+    // is transient and per-pane; membership is the `selected` prop.
+    const [markedLeft, setMarkedLeft] = useState<string[]>([]);
+    const [markedRight, setMarkedRight] = useState<string[]>([]);
+
+    const byLabel = (a: DualItem, b: DualItem) => a.label.localeCompare(b.label);
+    const available = useMemo(() => items.filter((i) => !selected.includes(i.id)).sort(byLabel), [items, selected]);
+    // Ordered by the same rule as the left pane rather than by the order things
+    // were clicked, so a workflow's targets read the same way every time.
+    const chosen = useMemo(() => items.filter((i) => selected.includes(i.id)).sort(byLabel), [items, selected]);
+
+    const mark = (setter: typeof setMarkedLeft) => (id: string, additive: boolean) =>
+        setter((m) => (additive ? (m.includes(id) ? m.filter((x) => x !== id) : [...m, id]) : m.length === 1 && m[0] === id ? [] : [id]));
+
+    const add = (ids: string[]) => {
+        if (ids.length === 0) return;
+        onChange([...selected, ...ids.filter((id) => !selected.includes(id))]);
+        setMarkedLeft([]);
+    };
+
+    const remove = (ids: string[]) => {
+        if (ids.length === 0) return;
+        onChange(selected.filter((id) => !ids.includes(id)));
+        setMarkedRight([]);
+    };
+
+    return (
+        <div className="grid grid-cols-[1fr_auto_1fr] items-start gap-3">
+            <div>
+                <p className="mb-1 text-[11px] uppercase tracking-wide text-text-tertiary">{availableLabel}</p>
+                <Pane items={available} marked={markedLeft} onToggle={mark(setMarkedLeft)} onCommit={(id) => add([id])} empty={emptyAvailable} />
+            </div>
+
+            <div className="flex flex-col gap-2 pt-6">
+                <MoveButton label={`Add all to ${selectedLabel}`} disabled={available.length === 0} onClick={() => add(available.map((i) => i.id))}>
+                    »
+                </MoveButton>
+                <MoveButton label={`Add to ${selectedLabel}`} disabled={markedLeft.length === 0} onClick={() => add(markedLeft)}>
+                    ›
+                </MoveButton>
+                <MoveButton label={`Remove from ${selectedLabel}`} disabled={markedRight.length === 0} onClick={() => remove(markedRight)}>
+                    ‹
+                </MoveButton>
+                <MoveButton label={`Remove all from ${selectedLabel}`} disabled={chosen.length === 0} onClick={() => remove(chosen.map((i) => i.id))}>
+                    «
+                </MoveButton>
+            </div>
+
+            <div>
+                <p className="mb-1 text-[11px] uppercase tracking-wide text-text-tertiary">
+                    {selectedLabel} · {chosen.length}
+                </p>
+                <Pane items={chosen} marked={markedRight} onToggle={mark(setMarkedRight)} onCommit={(id) => remove([id])} empty={emptySelected} />
+            </div>
+        </div>
+    );
+}
diff --git a/web/components/workflows/EditWorkflowModal.tsx b/web/components/workflows/EditWorkflowModal.tsx
index 2d8cb2a..632d3f5 100644
--- a/web/components/workflows/EditWorkflowModal.tsx
+++ b/web/components/workflows/EditWorkflowModal.tsx
@@ -6,6 +6,7 @@ import { useQuery } from "@tanstack/react-query";
 import { api, Workflow } from "@/lib/api";
 import { Button, Modal } from "@/components/ui";
 import { ScheduleCard } from "./ScheduleCard";
+import { DualListBox } from "./DualListBox";
 
 const inputClass = "w-full rounded-lg border border-border bg-surface-2 px-3 py-2 text-sm text-text-primary focus:border-signal focus:outline-none focus:ring-1 focus:ring-signal";
 
@@ -24,8 +25,6 @@ export function EditWorkflowModal({ open, workflow, onSaved, onClose }: { open:
         }
     }, [open, workflow]);
 
-    const toggle = (id: string) => setTargets((t) => (t.includes(id) ? t.filter((x) => x !== id) : [...t, id]));
-
     const save = async () => {
         setBusy(true);
         setError(null);
@@ -63,21 +62,19 @@ export function EditWorkflowModal({ open, workflow, onSaved, onClose }: { open:
                 </div>
                 <div>
                     <label className="mb-1 block text-xs uppercase text-text-secondary">Target servers</label>
-                    <div className="flex flex-wrap gap-2">
-                        {servers?.map((s) => {
-                            const on = targets.includes(s.server_id);
-                            return (
-                                <label
-                                    key={s.server_id}
-                                    className={`flex cursor-pointer items-center gap-2 rounded-lg border px-2 py-1 text-sm ${on ? "border-signal bg-signal/10 text-text-primary" : "border-border text-text-secondary"}`}
-                                >
-                                    <input type="checkbox" className="accent-signal" checked={on} onChange={() => toggle(s.server_id)} />
-                                    {s.hostname}
-                                </label>
-                            );
-                        })}
-                        {servers && servers.length === 0 && <p className="text-xs text-text-secondary">No servers registered.</p>}
-                    </div>
+                    {servers && servers.length === 0 ? (
+                        <p className="text-xs text-text-secondary">No servers registered.</p>
+                    ) : (
+                        <DualListBox
+                            items={(servers ?? []).map((s) => ({ id: s.server_id, label: s.hostname, hint: s.status === "active" ? undefined : s.status }))}
+                            selected={targets}
+                            onChange={setTargets}
+                            selectedLabel="Targets"
+                            emptyAvailable="Every server is a target."
+                            emptySelected="No servers targeted."
+                        />
+                    )}
+                    <p className="mt-1.5 text-[11px] text-text-tertiary">Click to highlight, ctrl-click for several, double-click to move. Tag selectors are set on the workflow page.</p>
                 </div>
                 {/* The schedule saves through its own endpoint, so it sits above
                     the footer rather than under it — the footer's Save covers the