Add Create form with subject input and status polling

src/app/create/CreateForm.tsx

@@ -0,0 +1,131 @@
+"use client";
+import { useEffect, useRef, useState } from "react";
+import Link from "next/link";
+
+type Phase = "idle" | "submitting" | "generating" | "review" | "ready" | "failed";
+
+export default function CreateForm({ level: initialLevel, enabled }: { level: string; enabled: boolean }) {
+  const [level, setLevel] = useState(initialLevel);
+  const [subject, setSubject] = useState("");
+  const [phase, setPhase] = useState<Phase>("idle");
+  const [msg, setMsg] = useState("");
+  const [slug, setSlug] = useState("");
+  const poll = useRef<ReturnType<typeof setInterval> | undefined>(undefined);
+
+  useEffect(() => () => clearInterval(poll.current), []);
+
+  async function start(e: React.FormEvent) {
+    e.preventDefault();
+    setMsg("");
+    setSlug("");
+    setPhase("submitting");
+    try {
+      const res = await fetch("/api/create", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({ level, subject }),
+      });
+      const data = await res.json();
+      if (!res.ok) {
+        setPhase("failed");
+        setMsg(data.error || "Something went wrong.");
+        return;
+      }
+      if (data.status === "needs_review") {
+        setPhase("review");
+        return;
+      }
+      setSlug(data.slug);
+      setPhase("generating");
+      watch(data.id, data.slug);
+    } catch {
+      setPhase("failed");
+      setMsg("Couldn't reach the server.");
+    }
+  }
+
+  function watch(id: number, baseSlug: string) {
+    clearInterval(poll.current);
+    poll.current = setInterval(async () => {
+      try {
+        const r = await fetch(`/api/create/${id}`);
+        const d = await r.json();
+        if (d.status === "ready") {
+          clearInterval(poll.current);
+          setSlug(baseSlug);
+          setPhase("ready");
+        } else if (d.status === "failed" || d.status === "blocked") {
+          clearInterval(poll.current);
+          setPhase("failed");
+          setMsg(d.error || "The drawing couldn't be made. Try a different subject.");
+        }
+      } catch {
+        /* keep polling */
+      }
+    }, 2500);
+  }
+
+  if (!enabled) {
+    return (
+      <div className="card" style={{ marginTop: 16 }}>
+        <p className="muted" style={{ margin: 0 }}>
+          The Create feature isn&apos;t turned on for this DrawIt instance yet. Ask your administrator to configure a
+          drawing server (ComfyUI).
+        </p>
+      </div>
+    );
+  }
+
+  const busy = phase === "submitting" || phase === "generating";
+
+  return (
+    <div style={{ marginTop: 16, maxWidth: 560 }}>
+      <form onSubmit={start} className="card" style={{ display: "grid", gap: 12 }}>
+        <label className="field">
+          <span style={{ fontWeight: 700 }}>What do you want to draw?</span>
+          <input
+            value={subject}
+            onChange={(e) => setSubject(e.target.value)}
+            placeholder="e.g. Zebra"
+            maxLength={30}
+            disabled={busy}
+            required
+          />
+        </label>
+        <label className="field">
+          <span style={{ fontWeight: 700 }}>Level</span>
+          <select value={level} onChange={(e) => setLevel(e.target.value)} disabled={busy}>
+            <option value="early-beginner">Early Beginner</option>
+            <option value="beginner">Beginner</option>
+          </select>
+        </label>
+        <button className="btn big" type="submit" disabled={busy || subject.trim().length < 2}>
+          {busy ? "Drawing…" : "✨ Make my lesson"}
+        </button>
+      </form>
+
+      {phase === "generating" && (
+        <div className="card" style={{ marginTop: 12, textAlign: "center" }}>
+          <p style={{ margin: 0 }}>🎨 Drawing your {subject || "picture"}… this can take a little while.</p>
+          <p className="muted" style={{ marginTop: 6, fontSize: "0.9rem" }}>You can stay on this page.</p>
+        </div>
+      )}
+      {phase === "review" && (
+        <div className="card" style={{ marginTop: 12 }}>
+          <p style={{ margin: 0 }}>📨 Thanks! &quot;{subject}&quot; was sent to a grown-up to approve. Check back soon.</p>
+        </div>
+      )}
+      {phase === "ready" && (
+        <div className="card" style={{ marginTop: 12, textAlign: "center" }}>
+          <p style={{ marginTop: 0 }}>🎉 Your lesson is ready!</p>
+          <Link className="btn big" href={`/learn/${level}/${slug}-trace`}>Start drawing</Link>
+        </div>
+      )}
+      {phase === "failed" && (
+        <div className="notice" style={{ marginTop: 12 }}>
+          <p style={{ margin: 0 }}>{msg || "Something went wrong. Try a different subject."}</p>
+        </div>
+      )}
+    </div>
+  );
+}