frontend/src/screens/products/ImportPreview.tsx

@@ -1,5 +1,335 @@
-// Import preview (SD-0002 §5.4) — stub; Task 13 replaces this with the diff preview.
+// Import preview (SD-0002 §5.4) — the consent gate. Summary tiles filter a
-export default function ImportPreview({ draftId }: { draftId: number }) {
+// drill-in diff list; the sticky footer carries confirm (PUC-3) / cancel (PUC-3a).
-  void draftId;
+// Diff glyphs pair with color, never color alone (§6.6).
-  return null;
+import { useEffect, useState } from "react";
+import {
+  cancelDraft,
+  confirmDraft,
+  getDraft,
+  getDraftRecords,
+  type Draft,
+  type DraftRecord,
+  type FieldChange,
+  type RecordKind,
+  type VariantEntry,
+} from "../../productsApi";
+import { Banner } from "../../ui/kit";
+
+const PAGE = 100;
+
+function fmt(v: unknown): string {
+  if (v === null || v === undefined) return "—";
+  if (Array.isArray(v)) return v.length ? v.join(", ") : "—";
+  if (typeof v === "boolean") return v ? "TRUE" : "FALSE";
+  return String(v);
+}
+
+function KindChip({ kind }: { kind: RecordKind }) {
+  return <span className={`kindchip kindchip--${kind}`}>{kind}</span>;
+}
+
+function SetLine({ field, value }: { field: string; value: unknown }) {
+  return (
+    <div className="diffchange">
+      <span className="diffchange__glyph--add">+ </span>
+      {field}: {fmt(value)}
+    </div>
+  );
+}
+
+function ChangeRow({ change }: { change: FieldChange }) {
+  return (
+    <div className="diffchange">
+      {change.field}: <span className="diffchange__glyph--del">{fmt(change.before)}</span> →{" "}
+      <span className="diffchange__glyph--add">{fmt(change.after)}</span>
+    </div>
+  );
+}
+
+function variantLabel(v: VariantEntry): string {
+  const opts = v.options.filter((o): o is string => o != null);
+  return opts.length ? `Variant ${opts.join(" / ")}` : "Variant";
+}
+
+function RecordDetail({ record }: { record: DraftRecord }) {
+  const d = record.detail;
+  if (record.kind === "error") {
+    return (
+      <div>
+        {(d.errors ?? []).map((e, i) => (
+          <div className="diffchange" key={i}>
+            line {e.line}: {e.column != null && `'${e.column}' — `}
+            {e.message}
+          </div>
+        ))}
+      </div>
+    );
+  }
+  return (
+    <div>
+      {Object.entries(d.set ?? {}).map(([field, value]) => (
+        <SetLine key={field} field={field} value={value} />
+      ))}
+      {(d.changes ?? []).map((c, i) => (
+        <ChangeRow key={i} change={c} />
+      ))}
+      {(d.variants ?? []).map((v, i) => (
+        <div key={i}>
+          <div className="diffchange diffchange--head">
+            {variantLabel(v)}
+            {v.kind ? ` (${v.kind})` : ""}
+          </div>
+          {Object.entries(v.set ?? {}).map(([field, value]) => (
+            <SetLine key={field} field={field} value={value} />
+          ))}
+          {(v.changes ?? []).map((c, j) => (
+            <ChangeRow key={j} change={c} />
+          ))}
+        </div>
+      ))}
+      {(d.images ?? []).map((img, i) =>
+        img.kind && img.kind !== "add" ? (
+          <div key={i}>
+            <div className="diffchange diffchange--head">
+              image: {img.src} ({img.kind})
+            </div>
+            {(img.changes ?? []).map((c, j) => (
+              <ChangeRow key={j} change={c} />
+            ))}
+          </div>
+        ) : (
+          <div className="diffchange" key={i}>
+            <span className="diffchange__glyph--add">+ </span>image: {img.src}
+          </div>
+        ),
+      )}
+    </div>
+  );
+}
+
+function ErrorTable({ records }: { records: DraftRecord[] }) {
+  const rows = records.flatMap((r) => r.detail.errors ?? []);
+  if (rows.length === 0) return null;
+  return (
+    <table className="errortable">
+      <thead>
+        <tr>
+          <th>Line</th>
+          <th>Column</th>
+          <th>Problem</th>
+        </tr>
+      </thead>
+      <tbody>
+        {rows.map((e, i) => (
+          <tr key={i}>
+            <td>{e.line}</td>
+            <td>{e.column ?? "—"}</td>
+            <td>{e.message}</td>
+          </tr>
+        ))}
+      </tbody>
+    </table>
+  );
+}
+
+export default function ImportPreview({ draftId }: { draftId: number }) {
+  const [draft, setDraft] = useState<Draft | null>(null);
+  const [loadFail, setLoadFail] = useState<"gone" | "expired" | "failed" | null>(null);
+  const [filter, setFilter] = useState<RecordKind | null>(null);
+  const [records, setRecords] = useState<DraftRecord[] | null>(null);
+  const [hasMore, setHasMore] = useState(false);
+  const [moreBusy, setMoreBusy] = useState(false);
+  const [confirming, setConfirming] = useState(false);
+  const [cancelling, setCancelling] = useState(false);
+  const [stale, setStale] = useState(false);
+  const [nothingNote, setNothingNote] = useState(false);
+  const [confirmError, setConfirmError] = useState<string | null>(null);
+
+  async function loadDraft() {
+    setLoadFail(null);
+    const resp = await getDraft(draftId);
+    if (!resp.ok) {
+      setLoadFail(resp.status === 404 ? "gone" : resp.status === 410 ? "expired" : "failed");
+      return;
+    }
+    setDraft(resp.value);
+  }
+  useEffect(() => {
+    void loadDraft();
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [draftId]);
+
+  useEffect(() => {
+    if (!draft) return;
+    let gone = false;
+    setRecords(null);
+    setHasMore(false);
+    void getDraftRecords(draftId, filter ?? undefined, PAGE, 0).then((resp) => {
+      if (gone || !resp.ok) return;
+      setRecords(resp.value);
+      setHasMore(resp.value.length === PAGE);
+    });
+    return () => {
+      gone = true;
+    };
+  }, [draft, draftId, filter]);
+
+  async function showMore() {
+    if (!records) return;
+    setMoreBusy(true);
+    const resp = await getDraftRecords(draftId, filter ?? undefined, PAGE, records.length);
+    setMoreBusy(false);
+    if (!resp.ok) return;
+    setRecords([...records, ...resp.value]);
+    setHasMore(resp.value.length === PAGE);
+  }
+
+  async function onConfirm() {
+    setConfirming(true);
+    setConfirmError(null);
+    const resp = await confirmDraft(draftId);
+    if (resp.ok) {
+      window.location.hash = `#/products/imports/runs/${resp.value.run_id}`;
+      return;
+    }
+    setConfirming(false);
+    if ((resp.status === 409 && resp.error.code === "preview_stale") || resp.status === 410) {
+      setStale(true);
+    } else if (resp.status === 409 && resp.error.code === "nothing_to_apply") {
+      setNothingNote(true);
+    } else {
+      setConfirmError(resp.error.message);
+    }
+  }
+
+  async function onCancel() {
+    setCancelling(true);
+    // PUC-3a — cancel even on draft-gone (404) still navigates home.
+    await cancelDraft(draftId);
+    window.location.hash = "#/products";
+  }
+
+  if (loadFail === "gone") {
+    return (
+      <Banner tone="attn" title="This preview is gone">
+        <a href="#/products">Back to Products</a>
+      </Banner>
+    );
+  }
+  if (loadFail === "expired") {
+    return (
+      <Banner tone="attn" title="This preview expired — upload the file again">
+        <a href="#/products/import">Upload the file again</a>
+      </Banner>
+    );
+  }
+  if (loadFail === "failed") {
+    return (
+      <Banner tone="attn" title="Couldn't load this preview">
+        Something went wrong on our side.{" "}
+        <button type="button" className="linklike" onClick={() => void loadDraft()}>
+          Retry
+        </button>
+      </Banner>
+    );
+  }
+  if (!draft) return <p className="note">Loading…</p>;
+
+  const { summary } = draft;
+  const tiles: { kind: RecordKind; num: number; label: string }[] = [
+    { kind: "add", num: summary.adds, label: "to add" },
+    { kind: "update", num: summary.updates, label: "to update" },
+    { kind: "unchanged", num: summary.unchanged, label: "unchanged" },
+    { kind: "error", num: summary.errors, label: "errors" },
+  ];
+  const toApply = summary.adds + summary.updates;
+
+  return (
+    <div className="products">
+      <p className="note">
+        <a href="#/products">← Products</a>
+      </p>
+      <h1>Import preview — {draft.file_name}</h1>
+      <p className="note">{draft.dialect === "canonical" ? "Canonical format" : draft.dialect}</p>
+      {draft.unknown_columns.length > 0 && (
+        <Banner tone="info" title="Columns not imported">
+          {draft.unknown_columns.join(", ")}
+        </Banner>
+      )}
+      <div className="tiles">
+        {tiles.map((t) => (
+          <button
+            key={t.kind}
+            type="button"
+            className={`tile tile--${t.kind}${filter === t.kind ? " tile--active" : ""}`}
+            aria-pressed={filter === t.kind}
+            onClick={() => setFilter(filter === t.kind ? null : t.kind)}
+          >
+            <span className="tile__num">{t.num.toLocaleString()}</span>
+            <span className="tile__label">{t.label}</span>
+          </button>
+        ))}
+      </div>
+      {filter === "error" && records && <ErrorTable records={records} />}
+      {records === null ? (
+        <p className="note">Loading…</p>
+      ) : records.length === 0 ? (
+        <p className="note">Nothing to show here.</p>
+      ) : (
+        <div className="difflist">
+          {records.map((r, i) => (
+            <details className="difflist__item" key={`${r.handle}-${i}`}>
+              <summary>
+                <span className="difflist__handle">{r.handle}</span> · {r.title} ·{" "}
+                <KindChip kind={r.kind} /> · {r.variant_count}{" "}
+                {r.variant_count === 1 ? "variant" : "variants"}
+              </summary>
+              <RecordDetail record={r} />
+            </details>
+          ))}
+        </div>
+      )}
+      {hasMore && (
+        <p>
+          <button type="button" className="btn-secondary" disabled={moreBusy} onClick={() => void showMore()}>
+            {moreBusy ? "Loading…" : "Show more"}
+          </button>
+        </p>
+      )}
+      <div className="sticky-footer">
+        {stale ? (
+          <Banner tone="attn" title="Your catalog changed since this preview — upload the file again">
+            <a href="#/products/import">Upload the file again</a>
+          </Banner>
+        ) : (
+          <>
+            <button
+              type="button"
+              className="btn-primary"
+              disabled={toApply === 0 || confirming || cancelling}
+              onClick={() => void onConfirm()}
+            >
+              {confirming ? "Importing…" : `Import ${toApply.toLocaleString()} products`}
+            </button>
+            <button
+              type="button"
+              className="btn-secondary"
+              disabled={confirming || cancelling}
+              onClick={() => void onCancel()}
+            >
+              Cancel
+            </button>
+            {(toApply === 0 || nothingNote) && (
+              <span className="note">Nothing to change — your catalog already matches this file</span>
+            )}
+            {confirmError && (
+              <span className="note note--attn" role="alert">
+                {confirmError}
+              </span>
+            )}
+          </>
+        )}
+      </div>
+    </div>
+  );
 }

frontend/src/styles/products.css

@@ -161,15 +161,48 @@
 /* ── diff list (preview records, Task 13) ───────────────────────────────────── */
 .difflist { list-style: none; margin: 0; padding: 0; }
 .difflist > li { padding: 12px 4px; border-bottom: 1px solid var(--border-soft); }
+.difflist__item { padding: 12px 4px; border-bottom: 1px solid var(--border-soft); }
+.difflist__item > summary {
+  cursor: pointer;
+  font-size: 14px;
+  color: var(--text-on-dark-soft);
+  transition: color var(--dur-fast) var(--ease);
+}
+.difflist__item > summary:hover { color: var(--wv-starlight); }
+.difflist__item[open] > summary { margin-bottom: 8px; }
+.difflist__handle { font-family: ui-monospace, "SF Mono", Menlo, monospace; font-size: 12.5px; }
 .diffchange {
   font-family: ui-monospace, "SF Mono", Menlo, monospace;
   font-size: 12.5px;
   line-height: 1.6;
   color: var(--text-on-dark-soft);
 }
+.diffchange--head { color: var(--text-on-dark-mute); margin-top: 6px; }
 .diffchange__glyph--add { color: var(--st-add); }
 .diffchange__glyph--del { color: var(--st-error); }
 
+/* ── kind chip (preview record summaries, Task 13) ──────────────────────────── */
+.kindchip {
+  display: inline-block;
+  font-family: var(--wv-font-display);
+  font-weight: var(--weight-medium);
+  font-size: 11px;
+  letter-spacing: .06em;
+  text-transform: uppercase;
+  line-height: 1;
+  padding: 3px 9px 2px;
+  border-radius: var(--radius-pill);
+  border: 1px solid var(--border-strong);
+  color: var(--text-on-dark-mute);
+}
+.kindchip--add { color: var(--st-add); border-color: var(--st-add); }
+.kindchip--update { color: var(--st-update); border-color: var(--st-update); }
+.kindchip--error { color: var(--st-error); border-color: var(--st-error); }
+
+/* preview layout rhythm: tiles + errortable sit between header and difflist */
+.products .tiles { margin: 24px 0 18px; }
+.products .errortable { margin: 0 0 18px; }
+
 /* ── sticky confirm/cancel footer (preview, Task 13) ────────────────────────── */
 .sticky-footer {
   position: sticky;