Enhance lesson editor: prev/next nav + richer toolbar

- page.tsx: fetch sibling lessons, pass prevLesson/nextLesson props
- LessonEditor: ChevronLeft/Right nav buttons with lesson title tooltip
- Toolbar: added Underline, Strikethrough, inline Code, H1, Horizontal rule,
  Link dialog (prompt), labeled buttons for better discoverability
- Install @tiptap/extension-underline

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

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

@@ -12,19 +12,30 @@ interface Props {
 export default async function LessonEditorPage({ params }: Props) {
   const { courseId, moduleId, lessonId } = await params;
 
-  const lesson = await prisma.lesson.findUnique({
-    where: { id: lessonId },
-    include: {
-      files: { orderBy: { createdAt: "asc" } },
-      homework: true,
-      module: {
-        include: { course: { select: { title: true, slug: true } } },
+  const [lesson, siblings] = await Promise.all([
+    prisma.lesson.findUnique({
+      where: { id: lessonId },
+      include: {
+        files: { orderBy: { createdAt: "asc" } },
+        homework: true,
+        module: {
+          include: { course: { select: { title: true, slug: true } } },
+        },
       },
-    },
-  });
+    }),
+    prisma.lesson.findMany({
+      where: { moduleId },
+      orderBy: { order: "asc" },
+      select: { id: true, title: true },
+    }),
+  ]);
 
   if (!lesson || lesson.moduleId !== moduleId) notFound();
 
+  const idx = siblings.findIndex((l) => l.id === lessonId);
+  const prevLesson = idx > 0 ? siblings[idx - 1] : null;
+  const nextLesson = idx < siblings.length - 1 ? siblings[idx + 1] : null;
+
   return (
     <div className="p-8 max-w-4xl">
       <nav className="text-xs mb-6 uppercase tracking-widest" style={{ color: "var(--muted-foreground)" }}>
@@ -50,6 +61,8 @@ export default async function LessonEditorPage({ params }: Props) {
           courseId={courseId}
           moduleId={moduleId}
           courseSlug={lesson.module.course.slug}
+          prevLesson={prevLesson}
+          nextLesson={nextLesson}
         />
       </div>
 

src/components/admin/lesson-editor.tsx

@@ -5,8 +5,10 @@ import { useEditor, EditorContent } from "@tiptap/react";
 import StarterKit from "@tiptap/starter-kit";
 import Image from "@tiptap/extension-image";
 import Link from "@tiptap/extension-link";
+import Underline from "@tiptap/extension-underline";
 import Placeholder from "@tiptap/extension-placeholder";
-import { Save, Eye, FileUp } from "lucide-react";
+import { Save, Eye, FileUp, ChevronLeft, ChevronRight } from "lucide-react";
+import { useRouter } from "next/navigation";
 import { saveLesson } from "@/app/admin/courses/[courseId]/modules/[moduleId]/lessons/[lessonId]/actions";
 
 interface LessonData {
@@ -17,17 +19,27 @@ interface LessonData {
   published: boolean;
 }
 
+interface SiblingLesson {
+  id: string;
+  title: string;
+}
+
 export function LessonEditor({
   lesson,
   courseId,
   moduleId,
   courseSlug,
+  prevLesson,
+  nextLesson,
 }: {
   lesson: LessonData;
   courseId: string;
   moduleId: string;
   courseSlug: string;
+  prevLesson?: SiblingLesson | null;
+  nextLesson?: SiblingLesson | null;
 }) {
+  const router = useRouter();
   const [title, setTitle] = useState(lesson.title);
   const [kinescopeId, setKinescopeId] = useState(lesson.kinescopeId);
   const [published, setPublished] = useState(lesson.published);
@@ -50,6 +62,7 @@ export function LessonEditor({
   const editor = useEditor({
     extensions: [
       StarterKit,
+      Underline,
       Image.configure({ inline: false }),
       Link.configure({ openOnClick: false }),
       Placeholder.configure({ placeholder: "Начните писать текст урока..." }),
@@ -108,6 +121,18 @@ export function LessonEditor({
     input.click();
   }, [editor]);
 
+  const addLink = useCallback(() => {
+    if (!editor) return;
+    const prev = editor.getAttributes("link").href as string | undefined;
+    const url = window.prompt("Ссылка:", prev ?? "https://");
+    if (url === null) return;
+    if (url === "") {
+      editor.chain().focus().unsetLink().run();
+    } else {
+      editor.chain().focus().setLink({ href: url, target: "_blank" }).run();
+    }
+  }, [editor]);
+
   function handleSave() {
     if (!editor) return;
     startTransition(async () => {
@@ -122,44 +147,74 @@ export function LessonEditor({
     });
   }
 
+  function navigateTo(lessonId: string) {
+    router.push(`/admin/courses/${courseId}/modules/${moduleId}/lessons/${lessonId}`);
+  }
+
   return (
     <div className="space-y-5">
       {/* Header controls */}
-      <div className="flex items-center justify-between">
-        <button
-          type="button"
-          role="switch"
-          aria-checked={published}
-          onClick={() => setPublished(!published)}
-          className="flex items-center gap-2 text-sm"
-        >
-          <span
-            className="relative inline-block w-10 h-6 transition-colors"
-            style={{
-              background: published ? "var(--accent)" : "var(--border)",
-              border: "2px solid var(--foreground)",
-            }}
+      <div className="flex items-center justify-between gap-2 flex-wrap">
+        {/* Left: published toggle + prev/next */}
+        <div className="flex items-center gap-3">
+          <button
+            type="button"
+            role="switch"
+            aria-checked={published}
+            onClick={() => setPublished(!published)}
+            className="flex items-center gap-2 text-sm"
           >
             <span
-              className="absolute top-0.5 w-4 h-4 transition-transform"
+              className="relative inline-block w-10 h-6 transition-colors"
               style={{
-                background: "var(--foreground)",
-                left: "2px",
-                transform: published ? "translateX(16px)" : "translateX(0)",
+                background: published ? "var(--accent)" : "var(--border)",
+                border: "2px solid var(--foreground)",
               }}
-            />
-          </span>
-          <span style={{ color: published ? "var(--foreground)" : "var(--muted-foreground)" }}>
-            {published ? "Опубликован" : "Черновик"}
-          </span>
-        </button>
+            >
+              <span
+                className="absolute top-0.5 w-4 h-4 transition-transform"
+                style={{
+                  background: "var(--foreground)",
+                  left: "2px",
+                  transform: published ? "translateX(16px)" : "translateX(0)",
+                }}
+              />
+            </span>
+            <span style={{ color: published ? "var(--foreground)" : "var(--muted-foreground)" }}>
+              {published ? "Опубликован" : "Черновик"}
+            </span>
+          </button>
 
+          {/* Prev / Next navigation */}
+          <div className="flex items-center gap-1">
+            <button
+              type="button"
+              onClick={() => prevLesson && navigateTo(prevLesson.id)}
+              disabled={!prevLesson}
+              title={prevLesson ? `← ${prevLesson.title}` : "Первый урок в модуле"}
+              className="btn-aubade flex items-center gap-1 px-2 py-2 text-sm disabled:opacity-30"
+            >
+              <ChevronLeft size={14} />
+            </button>
+            <button
+              type="button"
+              onClick={() => nextLesson && navigateTo(nextLesson.id)}
+              disabled={!nextLesson}
+              title={nextLesson ? `${nextLesson.title} →` : "Последний урок в модуле"}
+              className="btn-aubade flex items-center gap-1 px-2 py-2 text-sm disabled:opacity-30"
+            >
+              <ChevronRight size={14} />
+            </button>
+          </div>
+        </div>
+
+        {/* Right: Import / Preview / Save */}
         <div className="flex items-center gap-2">
           <button
             type="button"
             onClick={importMd}
             disabled={importing || pending}
-            className="btn-aubade flex items-center gap-1.5 px-4 py-2 text-sm"
+            className="btn-aubade flex items-center gap-1.5 px-3 py-2 text-sm"
             title="Импортировать из .md файла Obsidian"
             style={{ opacity: importing || pending ? 0.6 : 1 }}
           >
@@ -170,7 +225,7 @@ export function LessonEditor({
             href={`/courses/${courseSlug}/lessons/${lesson.id}`}
             target="_blank"
             rel="noopener noreferrer"
-            className="btn-aubade flex items-center gap-1.5 px-4 py-2 text-sm"
+            className="btn-aubade flex items-center gap-1.5 px-3 py-2 text-sm"
             title="Просмотр как студент"
           >
             <Eye size={14} />
@@ -180,7 +235,7 @@ export function LessonEditor({
             type="button"
             onClick={handleSave}
             disabled={pending || uploading}
-            className="btn-aubade btn-aubade-accent flex items-center gap-1.5 px-4 py-2 text-sm"
+            className="btn-aubade btn-aubade-accent flex items-center gap-1.5 px-3 py-2 text-sm"
             style={{ opacity: pending || uploading ? 0.6 : 1 }}
             title="Сохранить урок"
           >
@@ -233,23 +288,43 @@ export function LessonEditor({
 
         {/* Toolbar */}
         <div
-          className="flex flex-wrap gap-1 p-2"
+          className="flex flex-wrap gap-0.5 p-2"
           style={{ border: "2px solid var(--border)", borderBottom: "1px solid var(--border)", background: "var(--color-surface)" }}
         >
-          <ToolBtn onClick={() => editor?.chain().focus().toggleBold().run()} active={editor?.isActive("bold")}>Ж</ToolBtn>
+          {/* Text style */}
+          <ToolBtn onClick={() => editor?.chain().focus().toggleBold().run()} active={editor?.isActive("bold")}><strong>Ж</strong></ToolBtn>
           <ToolBtn onClick={() => editor?.chain().focus().toggleItalic().run()} active={editor?.isActive("italic")}><em>К</em></ToolBtn>
+          <ToolBtn onClick={() => editor?.chain().focus().toggleUnderline().run()} active={editor?.isActive("underline")}><span style={{ textDecoration: "underline" }}>Ч</span></ToolBtn>
+          <ToolBtn onClick={() => editor?.chain().focus().toggleStrike().run()} active={editor?.isActive("strike")}><span style={{ textDecoration: "line-through" }}>З</span></ToolBtn>
+          <ToolBtn onClick={() => editor?.chain().focus().toggleCode().run()} active={editor?.isActive("code")}>`code`</ToolBtn>
+
+          <Sep />
+
+          {/* Headings */}
+          <ToolBtn onClick={() => editor?.chain().focus().toggleHeading({ level: 1 }).run()} active={editor?.isActive("heading", { level: 1 })}>H1</ToolBtn>
           <ToolBtn onClick={() => editor?.chain().focus().toggleHeading({ level: 2 }).run()} active={editor?.isActive("heading", { level: 2 })}>H2</ToolBtn>
           <ToolBtn onClick={() => editor?.chain().focus().toggleHeading({ level: 3 }).run()} active={editor?.isActive("heading", { level: 3 })}>H3</ToolBtn>
-          <div className="w-px mx-1" style={{ background: "var(--border)" }} />
+
+          <Sep />
+
+          {/* Lists & blocks */}
           <ToolBtn onClick={() => editor?.chain().focus().toggleBulletList().run()} active={editor?.isActive("bulletList")}>• Список</ToolBtn>
           <ToolBtn onClick={() => editor?.chain().focus().toggleOrderedList().run()} active={editor?.isActive("orderedList")}>1. Список</ToolBtn>
-          <ToolBtn onClick={() => editor?.chain().focus().toggleBlockquote().run()} active={editor?.isActive("blockquote")}>&ldquo;&rdquo;</ToolBtn>
-          <ToolBtn onClick={() => editor?.chain().focus().toggleCodeBlock().run()} active={editor?.isActive("codeBlock")}>{'</>'}</ToolBtn>
-          <div className="w-px mx-1" style={{ background: "var(--border)" }} />
+          <ToolBtn onClick={() => editor?.chain().focus().toggleBlockquote().run()} active={editor?.isActive("blockquote")}>&ldquo;&rdquo; Цитата</ToolBtn>
+          <ToolBtn onClick={() => editor?.chain().focus().toggleCodeBlock().run()} active={editor?.isActive("codeBlock")}>{'</>'} Код</ToolBtn>
+          <ToolBtn onClick={() => editor?.chain().focus().setHorizontalRule().run()}>── Разделитель</ToolBtn>
+
+          <Sep />
+
+          {/* Link & image */}
+          <ToolBtn onClick={addLink} active={editor?.isActive("link")}>🔗 Ссылка</ToolBtn>
           <ToolBtn onClick={uploadImage} disabled={uploading}>{uploading ? "Загрузка..." : "🖼 Фото"}</ToolBtn>
-          <div className="w-px mx-1" style={{ background: "var(--border)" }} />
-          <ToolBtn onClick={() => editor?.chain().focus().undo().run()}>↩</ToolBtn>
-          <ToolBtn onClick={() => editor?.chain().focus().redo().run()}>↪</ToolBtn>
+
+          <Sep />
+
+          {/* History */}
+          <ToolBtn onClick={() => editor?.chain().focus().undo().run()}>↩ Отменить</ToolBtn>
+          <ToolBtn onClick={() => editor?.chain().focus().redo().run()}>↪ Повторить</ToolBtn>
         </div>
 
         {/* Editor content */}
@@ -261,6 +336,10 @@ export function LessonEditor({
   );
 }
 
+function Sep() {
+  return <div className="w-px mx-1 self-stretch" style={{ background: "var(--border)" }} />;
+}
+
 function ToolBtn({
   onClick,
   active,