Add quiz feature: student UI, admin editor, lesson page integration

- QuizSection component: shows questions as text inputs, read-only after submission
- QuizEditor component: admin CRUD for quiz questions with type selector
- saveQuiz/deleteQuiz server actions for admin
- submitQuizAttempt server action: idempotent, auto-marks lesson complete
- Student lesson page: renders QuizSection, updates complete button logic
- Admin lesson page: renders QuizEditor below homework section

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/(student)/courses/[slug]/lessons/[lessonId]/page.tsx

@@ -7,6 +7,7 @@ import { KinescopePlayer } from "@/components/player/kinescope-player";
 import { LessonContent } from "@/components/student/lesson-content";
 import { LessonCompleteButton } from "@/components/student/lesson-complete-button";
 import { HomeworkSection } from "@/components/student/homework-section";
+import { QuizSection } from "@/components/student/quiz-section";
 import { LessonComments } from "@/components/student/lesson-comments";
 import { FileFormatBadge } from "@/components/shared/file-format-badge";
 
@@ -26,6 +27,9 @@ export default async function LessonPage({ params }: Props) {
       include: {
         files: { orderBy: { createdAt: "asc" } },
         homework: true,
+        quiz: {
+          include: { questions: { orderBy: { order: "asc" } } },
+        },
         module: {
           include: {
             course: {
@@ -71,6 +75,12 @@ export default async function LessonPage({ params }: Props) {
       })
     : null;
 
+  const quizAttempt = lesson?.quiz && session && !isAdmin
+    ? await prisma.quizAttempt.findFirst({
+        where: { quizId: lesson.quiz.id, userId: session.user.id },
+      })
+    : null;
+
   if (!lesson || lesson.module.course.slug !== slug) notFound();
 
   const isCompleted = !!progress;
@@ -163,6 +173,21 @@ export default async function LessonPage({ params }: Props) {
         </div>
       )}
 
+      {/* Quiz */}
+      {lesson.quiz && !isAdmin && (
+        <div className="mb-8">
+          <p className="text-xs font-bold uppercase tracking-widest mb-3" style={{ color: "var(--muted-foreground)" }}>
+            Тест
+          </p>
+          <QuizSection
+            quiz={lesson.quiz}
+            attempt={quizAttempt ? { answers: quizAttempt.answers as Record<string, string> } : null}
+            slug={slug}
+            lessonId={lessonId}
+          />
+        </div>
+      )}
+
       {/* Complete button + Prev/Next navigation */}
       <div
         className="flex items-center justify-between pt-6 mt-6"
@@ -179,10 +204,10 @@ export default async function LessonPage({ params }: Props) {
           <div />
         )}
 
-        {!isAdmin && !lesson.homework && (
+        {!isAdmin && !lesson.homework && !lesson.quiz && (
           <LessonCompleteButton lessonId={lessonId} slug={slug} isCompleted={isCompleted} />
         )}
-        {!isAdmin && lesson.homework && isCompleted && (
+        {!isAdmin && (lesson.homework || lesson.quiz) && isCompleted && (
           <LessonCompleteButton lessonId={lessonId} slug={slug} isCompleted={true} readOnly={true} />
         )}
 

src/app/admin/courses/[courseId]/modules/[moduleId]/lessons/[lessonId]/page.tsx

@@ -4,6 +4,7 @@ import Link from "next/link";
 import { LessonEditor } from "@/components/admin/lesson-editor";
 import { LessonFilesManager } from "@/components/admin/lesson-files-manager";
 import { HomeworkEditor } from "@/components/admin/homework-editor";
+import { QuizEditor } from "@/components/admin/quiz-editor";
 
 interface Props {
   params: Promise<{ courseId: string; moduleId: string; lessonId: string }>;
@@ -18,6 +19,9 @@ export default async function LessonEditorPage({ params }: Props) {
       include: {
         files: { orderBy: { createdAt: "asc" } },
         homework: true,
+        quiz: {
+          include: { questions: { orderBy: { order: "asc" } } },
+        },
         module: {
           include: { course: { select: { title: true, slug: true } } },
         },
@@ -40,10 +44,12 @@ export default async function LessonEditorPage({ params }: Props) {
   const plain = JSON.parse(JSON.stringify({
     files: lesson.files,
     homework: lesson.homework,
+    quiz: lesson.quiz,
     siblings,
   })) as {
     files: typeof lesson.files;
     homework: typeof lesson.homework;
+    quiz: typeof lesson.quiz;
     siblings: typeof siblings;
   };
 
@@ -86,12 +92,20 @@ export default async function LessonEditorPage({ params }: Props) {
       </div>
 
       {/* Homework section */}
-      <div className="card-aubade p-6">
+      <div className="card-aubade p-6 mb-6">
         <p className="text-xs font-bold uppercase tracking-widest mb-4" style={{ color: "var(--muted-foreground)" }}>
           Домашнее задание
         </p>
         <HomeworkEditor lessonId={lessonId} initial={plain.homework} />
       </div>
+
+      {/* Quiz section */}
+      <div className="card-aubade p-6">
+        <p className="text-xs font-bold uppercase tracking-widest mb-4" style={{ color: "var(--muted-foreground)" }}>
+          Тест
+        </p>
+        <QuizEditor lessonId={lessonId} initial={plain.quiz} />
+      </div>
     </div>
   );
 }

src/components/admin/quiz-editor.tsx

@@ -0,0 +1,176 @@
+"use client";
+
+import { useState, useTransition } from "react";
+import { saveQuiz, deleteQuiz } from "@/lib/actions/quiz-actions";
+
+type QType = "TEXT" | "SINGLE" | "MULTIPLE";
+
+interface Question {
+  id?: string;
+  text: string;
+  type: QType;
+  order: number;
+}
+
+interface Props {
+  lessonId: string;
+  initial: { id: string; questions: Question[] } | null;
+}
+
+const TYPE_LABELS: Record<QType, string> = {
+  TEXT: "Текстовый ответ",
+  SINGLE: "Один вариант",
+  MULTIPLE: "Несколько вариантов",
+};
+
+export function QuizEditor({ lessonId, initial }: Props) {
+  const [questions, setQuestions] = useState<Question[]>(
+    initial?.questions ?? []
+  );
+  const [saved, setSaved] = useState(false);
+  const [pending, startTransition] = useTransition();
+
+  const inputStyle = {
+    border: "2px solid var(--border)",
+    background: "var(--background)",
+    outline: "none",
+    width: "100%",
+    padding: "0.5rem 0.75rem",
+    fontSize: "0.875rem",
+    fontFamily: "inherit",
+  };
+
+  function addQuestion() {
+    setQuestions((prev) => [
+      ...prev,
+      { text: "", type: "TEXT", order: prev.length },
+    ]);
+  }
+
+  function updateQuestion(idx: number, patch: Partial<Question>) {
+    setQuestions((prev) =>
+      prev.map((q, i) => (i === idx ? { ...q, ...patch } : q))
+    );
+  }
+
+  function removeQuestion(idx: number) {
+    setQuestions((prev) =>
+      prev.filter((_, i) => i !== idx).map((q, i) => ({ ...q, order: i }))
+    );
+  }
+
+  function handleSave() {
+    if (questions.length === 0) return;
+    startTransition(async () => {
+      await saveQuiz(
+        lessonId,
+        questions.map((q, i) => ({ text: q.text.trim(), type: q.type, order: i }))
+      );
+      setSaved(true);
+      setTimeout(() => setSaved(false), 2000);
+    });
+  }
+
+  function handleDelete() {
+    if (!confirm("Удалить квиз и все ответы студентов?")) return;
+    startTransition(async () => {
+      await deleteQuiz(lessonId);
+      setQuestions([]);
+    });
+  }
+
+  return (
+    <div className="space-y-4">
+      {questions.length === 0 && (
+        <p className="text-sm" style={{ color: "var(--muted-foreground)" }}>
+          Вопросов нет
+        </p>
+      )}
+
+      {questions.map((q, idx) => (
+        <div
+          key={idx}
+          className="space-y-2 px-4 py-3"
+          style={{ border: "2px solid var(--border)" }}
+        >
+          <div className="flex items-center justify-between gap-2">
+            <span
+              className="text-xs font-bold uppercase tracking-widest"
+              style={{ color: "var(--muted-foreground)" }}
+            >
+              Вопрос {idx + 1}
+            </span>
+            <button
+              onClick={() => removeQuestion(idx)}
+              className="text-xs"
+              style={{ color: "oklch(0.577 0.245 27.325)" }}
+            >
+              Удалить
+            </button>
+          </div>
+          <input
+            value={q.text}
+            onChange={(e) => updateQuestion(idx, { text: e.target.value })}
+            style={{ ...inputStyle, minHeight: "unset" }}
+            placeholder="Текст вопроса..."
+            onFocus={(e) => (e.currentTarget.style.borderColor = "var(--foreground)")}
+            onBlur={(e) => (e.currentTarget.style.borderColor = "var(--border)")}
+          />
+          <div className="flex gap-2">
+            {(["TEXT", "SINGLE", "MULTIPLE"] as QType[]).map((t) => (
+              <button
+                key={t}
+                onClick={() => updateQuestion(idx, { type: t })}
+                className="text-xs px-2 py-1"
+                style={{
+                  border: `2px solid ${q.type === t ? "var(--foreground)" : "var(--border)"}`,
+                  background: q.type === t ? "var(--foreground)" : "transparent",
+                  color: q.type === t ? "var(--background)" : "var(--foreground)",
+                }}
+              >
+                {TYPE_LABELS[t]}
+              </button>
+            ))}
+          </div>
+        </div>
+      ))}
+
+      <div className="flex items-center gap-2 flex-wrap">
+        <button onClick={addQuestion} className="btn-aubade text-xs px-3 py-1.5">
+          + Добавить вопрос
+        </button>
+        <button
+          onClick={handleSave}
+          disabled={pending || questions.length === 0 || questions.some((q) => !q.text.trim())}
+          className="btn-aubade btn-aubade-accent text-xs px-4 py-1.5"
+          style={{
+            opacity:
+              pending || questions.length === 0 || questions.some((q) => !q.text.trim())
+                ? 0.6
+                : 1,
+          }}
+        >
+          {pending ? "Сохранение..." : "Сохранить квиз"}
+        </button>
+        {initial && (
+          <button
+            onClick={handleDelete}
+            disabled={pending}
+            className="text-xs px-3 py-1.5"
+            style={{ color: "oklch(0.577 0.245 27.325)" }}
+          >
+            Удалить квиз
+          </button>
+        )}
+        {saved && (
+          <span
+            className="text-xs self-center"
+            style={{ color: "var(--muted-foreground)" }}
+          >
+            ✓ Сохранено
+          </span>
+        )}
+      </div>
+    </div>
+  );
+}

src/components/student/quiz-section.tsx

@@ -0,0 +1,104 @@
+"use client";
+
+import { useState, useTransition } from "react";
+import { submitQuizAttempt } from "@/lib/actions/student-actions";
+
+interface Question {
+  id: string;
+  text: string;
+  type: "TEXT" | "SINGLE" | "MULTIPLE";
+  order: number;
+}
+
+interface Props {
+  quiz: { id: string; questions: Question[] };
+  attempt: { answers: Record<string, string> } | null;
+  slug: string;
+  lessonId: string;
+}
+
+const inputStyle = {
+  border: "2px solid var(--border)",
+  background: "var(--background)",
+  outline: "none",
+  width: "100%",
+  padding: "0.5rem 0.75rem",
+  fontSize: "0.875rem",
+  fontFamily: "inherit",
+  resize: "vertical" as const,
+  minHeight: "80px",
+};
+
+export function QuizSection({ quiz, attempt, slug, lessonId }: Props) {
+  const [answers, setAnswers] = useState<Record<string, string>>(
+    attempt?.answers ?? {}
+  );
+  const [pending, startTransition] = useTransition();
+
+  const allFilled = quiz.questions.every((q) => answers[q.id]?.trim());
+
+  if (attempt) {
+    return (
+      <div className="space-y-4">
+        <div className="flex items-center gap-2">
+          <span
+            className="text-xs px-2 py-0.5 font-bold uppercase tracking-widest"
+            style={{
+              border: "2px solid var(--foreground)",
+              background: "var(--accent)",
+            }}
+          >
+            Заполнено
+          </span>
+        </div>
+        <div className="space-y-3">
+          {quiz.questions.map((q) => (
+            <div key={q.id} className="space-y-1">
+              <p className="text-sm font-medium">{q.text}</p>
+              <div
+                className="px-4 py-3 text-sm whitespace-pre-wrap opacity-70"
+                style={{ border: "2px solid var(--border)" }}
+              >
+                {attempt.answers[q.id] || "—"}
+              </div>
+            </div>
+          ))}
+        </div>
+      </div>
+    );
+  }
+
+  return (
+    <div className="space-y-4">
+      {quiz.questions.map((q, idx) => (
+        <div key={q.id} className="space-y-1">
+          <p className="text-sm font-medium">
+            {idx + 1}. {q.text}
+          </p>
+          <textarea
+            value={answers[q.id] ?? ""}
+            onChange={(e) =>
+              setAnswers((prev) => ({ ...prev, [q.id]: e.target.value }))
+            }
+            style={inputStyle}
+            placeholder="Ваш ответ..."
+            onFocus={(e) => (e.currentTarget.style.borderColor = "var(--foreground)")}
+            onBlur={(e) => (e.currentTarget.style.borderColor = "var(--border)")}
+          />
+        </div>
+      ))}
+      <button
+        disabled={pending || !allFilled}
+        onClick={() =>
+          startTransition(() =>
+            submitQuizAttempt(quiz.id, lessonId, slug, answers)
+          )
+        }
+        className="btn-aubade btn-aubade-accent text-sm px-5 py-2"
+        style={{ opacity: pending || !allFilled ? 0.6 : 1 }}
+      >
+        {pending ? "Отправка..." : "Отправить"}
+      </button>
+    </div>
+  );
+}

src/lib/actions/quiz-actions.ts

@@ -0,0 +1,53 @@
+"use server";
+
+import { prisma } from "@/lib/prisma";
+import { auth } from "@/lib/auth";
+import { headers } from "next/headers";
+import { revalidatePath } from "next/cache";
+
+async function requireAdmin() {
+  const session = await auth.api.getSession({ headers: await headers() });
+  if (!session || session.user.role !== "admin") throw new Error("Forbidden");
+}
+
+export async function saveQuiz(
+  lessonId: string,
+  questions: { text: string; type: "TEXT" | "SINGLE" | "MULTIPLE"; order: number }[]
+) {
+  await requireAdmin();
+
+  const existing = await prisma.quiz.findUnique({ where: { lessonId } });
+
+  if (existing) {
+    await prisma.quizQuestion.deleteMany({ where: { quizId: existing.id } });
+    await prisma.quizQuestion.createMany({
+      data: questions.map((q) => ({
+        quizId: existing.id,
+        text: q.text,
+        type: q.type,
+        order: q.order,
+      })),
+    });
+  } else {
+    await prisma.quiz.create({
+      data: {
+        lessonId,
+        questions: {
+          create: questions.map((q) => ({
+            text: q.text,
+            type: q.type,
+            order: q.order,
+          })),
+        },
+      },
+    });
+  }
+
+  revalidatePath(`/admin`);
+}
+
+export async function deleteQuiz(lessonId: string) {
+  await requireAdmin();
+  await prisma.quiz.delete({ where: { lessonId } });
+  revalidatePath(`/admin`);
+}

src/lib/actions/student-actions.ts

@@ -94,6 +94,43 @@ export async function submitHomework(
   revalidatePath(`/courses/${slug}/lessons/${lessonId}`);
 }
 
+// ── Quiz ──────────────────────────────────────────────────────────────────────
+
+export async function submitQuizAttempt(
+  quizId: string,
+  lessonId: string,
+  slug: string,
+  answers: Record<string, string>
+) {
+  const session = await auth.api.getSession({ headers: await headers() });
+  if (!session) throw new Error("Unauthorized");
+
+  const existing = await prisma.quizAttempt.findFirst({
+    where: { quizId, userId: session.user.id },
+  });
+  if (existing) return;
+
+  await prisma.$transaction(async (tx) => {
+    await tx.quizAttempt.create({
+      data: {
+        userId: session.user.id,
+        quizId,
+        score: 0,
+        answers: answers as object,
+      },
+    });
+    await tx.lessonProgress.upsert({
+      where: { userId_lessonId: { userId: session.user.id, lessonId } },
+      create: { userId: session.user.id, lessonId },
+      update: {},
+    });
+  });
+
+  revalidatePath(`/courses/${slug}/lessons/${lessonId}`);
+  revalidatePath(`/courses/${slug}`);
+  revalidatePath("/dashboard");
+}
+
 // ── Comments ──────────────────────────────────────────────────────────────────
 
 export async function addComment(lessonId: string, slug: string, text: string) {