fix(meds): mount the natural-language overlay on /medications/new

The wizard's "✨ Beschreiben" button now opens the extractor on the
production route. The overlay merges its result onto the wizard
payload; one-shot prefills clear timesOfDay so the user has to pick
the dose time explicitly.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/app/medications/new/page.tsx

@@ -1,21 +1,39 @@
 "use client";
 
 /**
- * v1.5.0 — `/medications/new` — host route for the seven-step
- * `CreationWizard`. Keeps the page chrome minimal: a back-link to the
- * medications index sits above the card, and the wizard owns the
- * rest of the page (header, body, footer).
+ * v1.5.0 — `/medications/new` — host route for the medication-create
+ * wizard. Keeps the page chrome minimal: a back-link to the medications
+ * index sits above the card, and the wizard owns the rest of the page
+ * (header, body, footer).
  *
- * The NL-extraction overlay lands on this surface in a follow-up
- * commit; the wizard accepts `onNaturalLanguagePrefill` and surfaces
- * a `✨ Describe it` button on step 1 so the overlay can wire in
- * without further changes here.
+ * Mounts the `NaturalLanguageExtractor` overlay so the wizard's
+ * "✨ Describe it" button has somewhere to land. The wizard hands us
+ * an `apply(partial)` callback; the page opens the overlay, lets the
+ * extractor call our `onPrefill`, then merges the result onto the
+ * wizard payload through that callback.
  */
 
+import { useCallback, useRef, useState } from "react";
 import Link from "next/link";
 import { ChevronLeft } from "lucide-react";
 
-import { CreationWizard } from "@/components/medications/scheduling/CreationWizard";
+import {
+  CreationWizard,
+  type WizardPayload,
+} from "@/components/medications/scheduling/CreationWizard";
+import {
+  NaturalLanguageExtractor,
+  type WizardPayload as ExtractorPayload,
+} from "@/components/medications/scheduling/NaturalLanguageExtractor";
+import {
+  encodeCadence,
+} from "@/components/medications/scheduling/CadencePicker";
+import {
+  DEFAULT_SUB_CONTROLS,
+  type CadenceSubControls,
+  type WeekdayToken,
+} from "@/components/medications/scheduling/types";
+import { isoStringToDate } from "@/components/medications/scheduling/CourseWindowRow";
 import { useTranslations } from "@/lib/i18n/context";
 
 /**
@@ -27,7 +45,37 @@ import { useTranslations } from "@/lib/i18n/context";
 const PAGE_NS = "medications.create.wizard.page";
 
 export default function NewMedicationPage() {
-  const { t } = useTranslations();
+  const { t, locale } = useTranslations();
+  const [nlOpen, setNlOpen] = useState(false);
+  // Holds the wizard-supplied apply callback across renders. The wizard
+  // invokes `onNaturalLanguagePrefill(apply)` on every "✨ Describe it"
+  // click; we stash the function in a ref so the overlay's `onPrefill`
+  // can invoke it when the extraction returns a result.
+  const applyRef = useRef<((partial: Partial<WizardPayload>) => void) | null>(
+    null,
+  );
+
+  const handleNaturalLanguagePrefill = useCallback(
+    (apply: (partial: Partial<WizardPayload>) => void) => {
+      applyRef.current = apply;
+      setNlOpen(true);
+    },
+    [],
+  );
+
+  const handlePrefill = useCallback(
+    (partial: Partial<ExtractorPayload>) => {
+      const apply = applyRef.current;
+      if (!apply) return;
+      apply(extractorToWizardPartial(partial));
+    },
+    [],
+  );
+
+  const handleClose = useCallback(() => {
+    setNlOpen(false);
+  }, []);
+
   return (
     <div className="mx-auto max-w-2xl space-y-4">
       <Link
@@ -38,7 +86,124 @@ export default function NewMedicationPage() {
         <ChevronLeft className="h-4 w-4" aria-hidden="true" />
         {t(`${PAGE_NS}.backToList`)}
       </Link>
-      <CreationWizard />
+      <CreationWizard onNaturalLanguagePrefill={handleNaturalLanguagePrefill} />
+      <NaturalLanguageExtractor
+        open={nlOpen}
+        onClose={handleClose}
+        onPrefill={handlePrefill}
+        locale={locale}
+      />
     </div>
   );
 }
+
+/**
+ * Map the extractor's flat result shape onto the wizard's payload
+ * shape. Two cross-shape concerns the adapter handles:
+ *
+ *   - the extractor returns `dose` as a combined string ("5 mg") while
+ *     the wizard splits the amount + unit into separate inputs, so we
+ *     parse the leading number off `dose` and drop the unit token onto
+ *     `doseUnit` when the extractor didn't already pin one.
+ *   - the extractor's `cadenceKind` + weekday / interval / day fields
+ *     are normalised into a `CadenceValue` + `CadenceSubControls` pair
+ *     so the wizard's picker hydrates cleanly when the user lands on
+ *     Step 3.
+ *
+ * When `oneShot: true` is returned, the adapter also drops the
+ * extractor-supplied `timesOfDay` so the wizard's Step 5 forces the
+ * user to pick the dose time explicitly — the extractor never asked
+ * for it and the wizard's "08:00" default would otherwise stick.
+ */
+function extractorToWizardPartial(
+  result: Partial<ExtractorPayload>,
+): Partial<WizardPayload> {
+  const out: Partial<WizardPayload> = {};
+
+  if (typeof result.name === "string") out.name = result.name;
+
+  if (typeof result.dose === "string") {
+    const parsed = parseDoseExpression(result.dose);
+    out.doseAmount = parsed.amount;
+    if (parsed.unit && !result.doseUnit) {
+      out.doseUnit = parsed.unit;
+    }
+  }
+  if (typeof result.doseUnit === "string") {
+    out.doseUnit = result.doseUnit;
+  }
+
+  // Cadence resolution. One-shot wins; otherwise hydrate the picker
+  // off the extractor's cadenceKind + companion fields.
+  if (result.oneShot === true) {
+    out.mode = "oneShot";
+    out.subControls = subControlsFromExtractor(result);
+    out.cadence = encodeCadence("oneShot", out.subControls);
+    // Force an explicit pick on Step 5 — the wizard's default 08:00
+    // shouldn't ride along for a one-shot prefill that never named
+    // a time.
+    out.timesOfDay = [];
+  } else if (result.cadenceKind) {
+    out.mode = "recurring";
+    out.subControls = subControlsFromExtractor(result);
+    out.cadence = encodeCadence(result.cadenceKind, out.subControls);
+  }
+
+  // If the caller specified times, honour them — except when oneShot
+  // already cleared the array above.
+  if (
+    out.timesOfDay === undefined &&
+    Array.isArray(result.timesOfDay) &&
+    result.timesOfDay.length > 0
+  ) {
+    out.timesOfDay = [...result.timesOfDay];
+  }
+
+  if (typeof result.startsOn === "string") {
+    out.startsOn = isoStringToDate(result.startsOn);
+  }
+  if (typeof result.endsOn === "string") {
+    out.endsOn = isoStringToDate(result.endsOn);
+  }
+  // One-shot pins endsOn to startsOn (Step 5's date handler does this
+  // for the interactive path; pre-fill mirrors the contract).
+  if (result.oneShot === true && out.startsOn) {
+    out.endsOn = out.startsOn;
+  }
+
+  return out;
+}
+
+function subControlsFromExtractor(
+  result: Partial<ExtractorPayload>,
+): CadenceSubControls {
+  const base: CadenceSubControls = { ...DEFAULT_SUB_CONTROLS };
+  if (Array.isArray(result.weekdays) && result.weekdays.length > 0) {
+    base.weekdays = result.weekdays.filter((w): w is WeekdayToken =>
+      ["MO", "TU", "WE", "TH", "FR", "SA", "SU"].includes(w),
+    );
+  }
+  if (typeof result.intervalWeeks === "number") {
+    base.intervalWeeks = result.intervalWeeks;
+  }
+  if (typeof result.intervalMonths === "number") {
+    base.intervalMonths = result.intervalMonths;
+  }
+  if (typeof result.dayOfMonth === "number") {
+    base.dayOfMonth = result.dayOfMonth;
+  }
+  if (typeof result.rollingIntervalDays === "number") {
+    base.rollingDays = result.rollingIntervalDays;
+  }
+  return base;
+}
+
+const DOSE_EXPR_RE = /^\s*(\d+(?:[.,]\d+)?)\s*(.*)$/;
+
+function parseDoseExpression(input: string): { amount: string; unit: string } {
+  const match = DOSE_EXPR_RE.exec(input.trim());
+  if (!match) return { amount: "", unit: input.trim() };
+  const amount = match[1] ?? "";
+  const unit = (match[2] ?? "").trim();
+  return { amount, unit };
+}