优化前端，修改返回逻辑，添加视频实时背景，音量倍速持久化

app/api/aweme/around/route.ts

@@ -0,0 +1,77 @@
+import { NextRequest, NextResponse } from "next/server";
+import { prisma } from "@/lib/prisma";
+
+// GET /api/aweme/around?awemeId=xxxx
+// Response: { prev?: { type: 'video'|'image', aweme_id: string, created_at: string }, next?: { ... } }
+export async function GET(req: NextRequest) {
+  const { searchParams } = new URL(req.url);
+  const awemeId = searchParams.get("awemeId");
+  if (!awemeId) {
+    return NextResponse.json({ error: "missing awemeId" }, { status: 400 });
+  }
+
+  // Find current item timestamp from either table
+  const [video, post] = await Promise.all([
+    prisma.video.findUnique({ where: { aweme_id: awemeId }, select: { aweme_id: true, created_at: true } }),
+    prisma.imagePost.findUnique({ where: { aweme_id: awemeId }, select: { aweme_id: true, created_at: true } }),
+  ]);
+
+  const current = video ?? post;
+  if (!current) {
+    return NextResponse.json({ error: "aweme not found" }, { status: 404 });
+  }
+
+  const createdAt = current.created_at as unknown as Date;
+
+  // Newer than current (prev in a desc-ordered feed): pick the nearest newer by created_at
+  const [newerVideo, newerPost] = await Promise.all([
+    prisma.video.findFirst({
+      where: { created_at: { gt: createdAt } },
+      orderBy: { created_at: "asc" },
+      select: { aweme_id: true, created_at: true },
+    }),
+    prisma.imagePost.findFirst({
+      where: { created_at: { gt: createdAt } },
+      orderBy: { created_at: "asc" },
+      select: { aweme_id: true, created_at: true },
+    }),
+  ]);
+
+  // Older than current (next in a desc-ordered feed): pick the nearest older by created_at
+  const [olderVideo, olderPost] = await Promise.all([
+    prisma.video.findFirst({
+      where: { created_at: { lt: createdAt } },
+      orderBy: { created_at: "desc" },
+      select: { aweme_id: true, created_at: true },
+    }),
+    prisma.imagePost.findFirst({
+      where: { created_at: { lt: createdAt } },
+      orderBy: { created_at: "desc" },
+      select: { aweme_id: true, created_at: true },
+    }),
+  ]);
+
+  const pickPrev = (() => {
+    const cands: { type: "video" | "image"; aweme_id: string; created_at: Date }[] = [];
+    if (newerVideo) cands.push({ type: "video", aweme_id: newerVideo.aweme_id, created_at: newerVideo.created_at as unknown as Date });
+    if (newerPost) cands.push({ type: "image", aweme_id: newerPost.aweme_id, created_at: newerPost.created_at as unknown as Date });
+    if (cands.length === 0) return undefined;
+    // nearest newer -> minimal created_at
+    cands.sort((a, b) => +a.created_at - +b.created_at);
+    const h = cands[0];
+    return { type: h.type, aweme_id: h.aweme_id, created_at: h.created_at.toISOString() };
+  })();
+
+  const pickNext = (() => {
+    const cands: { type: "video" | "image"; aweme_id: string; created_at: Date }[] = [];
+    if (olderVideo) cands.push({ type: "video", aweme_id: olderVideo.aweme_id, created_at: olderVideo.created_at as unknown as Date });
+    if (olderPost) cands.push({ type: "image", aweme_id: olderPost.aweme_id, created_at: olderPost.created_at as unknown as Date });
+    if (cands.length === 0) return undefined;
+    // nearest older -> maximal created_at among older
+    cands.sort((a, b) => +b.created_at - +a.created_at);
+    const h = cands[0];
+    return { type: h.type, aweme_id: h.aweme_id, created_at: h.created_at.toISOString() };
+  })();
+
+  return NextResponse.json({ prev: pickPrev ?? null, next: pickNext ?? null });
+}