feat: 盲盒想法输入增加 AI 灵感推荐

输入框下方展示灵感建议标签，点击即填入，降低创作门槛：
- 房间有 ≥2 条想法时调用 DeepSeek 生成贴合调性的推荐
- 想法不足或 AI 失败时 fallback 到 18 条静态灵感随机选 4 条
- 提交新想法后自动刷新推荐，支持手动换一批

src/app/api/blindbox/suggest/route.ts

@@ -0,0 +1,35 @@
+import { NextResponse } from "next/server";
+import { prisma } from "@/lib/prisma";
+import { requireMembership } from "@/lib/blindbox";
+import { apiHandler, ApiError, requireUserId } from "@/lib/api";
+import { suggestIdeas } from "@/lib/ai";
+
+export const GET = apiHandler(async (req) => {
+  const { searchParams } = new URL(req.url);
+  const roomId = searchParams.get("roomId");
+  const userId = searchParams.get("userId");
+
+  requireUserId(userId);
+  if (!roomId) throw new ApiError("roomId 不能为空");
+
+  await requireMembership(roomId, userId!);
+
+  const recentIdeas = await prisma.blindBoxIdea.findMany({
+    where: { roomId, status: "in_pool" },
+    orderBy: { createdAt: "desc" },
+    take: 10,
+    select: { content: true },
+  });
+
+  if (recentIdeas.length < 2) {
+    return NextResponse.json({ suggestions: [], source: "none" });
+  }
+
+  const suggestions = await suggestIdeas(recentIdeas.map((i) => i.content));
+
+  if (suggestions.length === 0) {
+    return NextResponse.json({ suggestions: [], source: "none" });
+  }
+
+  return NextResponse.json({ suggestions, source: "ai" });
+});

src/app/blindbox/[code]/page.tsx

@@ -20,6 +20,8 @@ import {
   Sparkles,
   ClipboardCheck,
   ChevronRight,
+  Lightbulb,
+  Shuffle,
 } from "lucide-react";
 import confetti from "canvas-confetti";
 import { getCachedProfile, isRegistered } from "@/lib/userId";
@@ -49,6 +51,32 @@ interface RoomInfo {
 
 type Phase = "pool" | "shaking" | "reveal" | "time_select" | "planning" | "plan_reveal";
 
+const IDEA_INSPIRATIONS = [
+  "去城市最高楼看日落",
+  "挑战一人做一道菜",
+  "找一家从没去过的店",
+  "逛一个从没去过的街区",
+  "去公园野餐",
+  "看一场午夜电影",
+  "在家做一顿异国料理",
+  "骑车去郊外探险",
+  "去二手市场淘宝",
+  "去博物馆逛半天",
+  "试一项没玩过的运动",
+  "随机坐公交到终点站",
+  "一起画画或做手工",
+  "找个天台看星星",
+  "去一家评分最低的餐厅",
+  "穿最好看的衣服去拍照",
+  "交换手机玩一个小时",
+  "一起去做志愿者",
+];
+
+function pickRandom<T>(arr: T[], n: number): T[] {
+  const shuffled = [...arr].sort(() => Math.random() - 0.5);
+  return shuffled.slice(0, n);
+}
+
 export default function BlindboxRoomPage() {
   const { code } = useParams<{ code: string }>();
   const router = useRouter();
@@ -61,6 +89,9 @@ export default function BlindboxRoomPage() {
 
   const [input, setInput] = useState("");
   const [submitting, setSubmitting] = useState(false);
+  const [suggestions, setSuggestions] = useState(() => pickRandom(IDEA_INSPIRATIONS, 4));
+  const [suggestionsLoading, setSuggestionsLoading] = useState(false);
+  const [suggestionsSource, setSuggestionsSource] = useState<"static" | "ai">("static");
   const [poolCount, setPoolCount] = useState(0);
   const [myIdeas, setMyIdeas] = useState<MyIdea[]>([]);
   const [drawnHistory, setDrawnHistory] = useState<DrawnIdea[]>([]);
@@ -146,6 +177,35 @@ export default function BlindboxRoomPage() {
     } catch { /* ignore */ }
   }, [room]);
 
+  const fetchSuggestions = useCallback(async () => {
+    const p = getCachedProfile();
+    if (!room || !p) return;
+    setSuggestionsLoading(true);
+    try {
+      const res = await fetch(`/api/blindbox/suggest?roomId=${room.id}&userId=${p.id}`);
+      if (res.ok) {
+        const data = await res.json();
+        if (data.suggestions?.length > 0) {
+          setSuggestions(data.suggestions);
+          setSuggestionsSource("ai");
+          setSuggestionsLoading(false);
+          return;
+        }
+      }
+    } catch { /* ignore */ }
+    setSuggestions(pickRandom(IDEA_INSPIRATIONS, 4));
+    setSuggestionsSource("static");
+    setSuggestionsLoading(false);
+  }, [room]);
+
+  const refreshSuggestions = useCallback(() => {
+    if (suggestionsSource === "ai") {
+      fetchSuggestions();
+    } else {
+      setSuggestions(pickRandom(IDEA_INSPIRATIONS, 4));
+    }
+  }, [suggestionsSource, fetchSuggestions]);
+
   const fetchAcceptedPlan = useCallback(async () => {
     const p = getCachedProfile();
     if (!room || !p) return;
@@ -167,8 +227,9 @@ export default function BlindboxRoomPage() {
     if (isMember && room) {
       fetchIdeas();
       fetchAcceptedPlan();
+      fetchSuggestions();
     }
-  }, [isMember, room, fetchIdeas, fetchAcceptedPlan]);
+  }, [isMember, room, fetchIdeas, fetchAcceptedPlan, fetchSuggestions]);
 
   // Check for expired contracts on load
   useEffect(() => {
@@ -340,6 +401,7 @@ export default function BlindboxRoomPage() {
         rotate: [0, -3, 3, 0],
         transition: { duration: 0.5 },
       });
+      fetchSuggestions();
     } catch (e) {
       setError(e instanceof Error ? e.message : "提交失败");
     } finally {
@@ -710,6 +772,41 @@ export default function BlindboxRoomPage() {
                   </button>
                 </div>
 
+                {!input && (
+                  <div className="flex w-full flex-wrap items-center gap-1.5">
+                    {suggestionsSource === "ai" ? (
+                      <Sparkles size={13} className="mr-0.5 shrink-0 text-purple-400/80" />
+                    ) : (
+                      <Lightbulb size={13} className="mr-0.5 shrink-0 text-amber-500/80" />
+                    )}
+                    {suggestionsLoading ? (
+                      <>
+                        {[1, 2, 3].map((i) => (
+                          <div key={i} className="h-6 w-20 animate-pulse rounded-full bg-surface/60 ring-1 ring-border/40" />
+                        ))}
+                      </>
+                    ) : (
+                      suggestions.map((s) => (
+                        <button
+                          key={s}
+                          onClick={() => { setInput(s); inputRef.current?.focus(); }}
+                          className="rounded-full bg-surface/80 px-2.5 py-1 text-xs text-secondary ring-1 ring-border/60 transition-all hover:bg-purple-600/10 hover:text-purple-400 hover:ring-purple-600/30 active:scale-95"
+                        >
+                          {s}
+                        </button>
+                      ))
+                    )}
+                    <button
+                      onClick={refreshSuggestions}
+                      disabled={suggestionsLoading}
+                      aria-label="换一批灵感"
+                      className="ml-auto flex h-6 w-6 items-center justify-center rounded-full text-muted transition-colors hover:bg-surface hover:text-secondary disabled:opacity-30"
+                    >
+                      {suggestionsLoading ? <Loader2 size={12} className="animate-spin" /> : <Shuffle size={12} />}
+                    </button>
+                  </div>
+                )}
+
                 <div className="flex w-full gap-2">
                   <motion.button
                     onClick={handleDraw}

src/lib/ai.ts

@@ -113,6 +113,44 @@ export async function tagIdea(content: string): Promise<IdeaTags | null> {
   }
 }
 
+const SUGGEST_SYSTEM_PROMPT = `你是一个脑洞大开的周末活动灵感助手。根据用户房间里已有的活动想法，推荐 4 个风格相近但不重复的新想法。
+
+要求：
+- 贴合已有想法的整体调性（如果偏文艺就推文艺的，偏冒险就推冒险的）
+- 适当加入一些意想不到的创意，激发灵感
+- 每条想法 5-15 个字，口语化、有画面感
+- 不要与已有想法重复或过于相似
+
+只返回 JSON：{ "suggestions": ["想法1", "想法2", "想法3", "想法4"] }`;
+
+export async function suggestIdeas(existingIdeas: string[]): Promise<string[]> {
+  try {
+    const client = getClient();
+    const response = await client.chat.completions.create({
+      model: "deepseek-chat",
+      messages: [
+        { role: "system", content: SUGGEST_SYSTEM_PROMPT },
+        { role: "user", content: `已有想法：\n${existingIdeas.map((s, i) => `${i + 1}. ${s}`).join("\n")}` },
+      ],
+      response_format: { type: "json_object" },
+      max_tokens: 200,
+      temperature: 0.9,
+    });
+
+    const text = response.choices[0]?.message?.content;
+    if (!text) return [];
+
+    const parsed = JSON.parse(text);
+    if (!Array.isArray(parsed.suggestions)) return [];
+
+    return parsed.suggestions
+      .filter((s: unknown) => typeof s === "string" && s.length > 0)
+      .slice(0, 4);
+  } catch {
+    return [];
+  }
+}
+
 export async function generateSchedule(
   ctx: ScheduleContext,
 ): Promise<{ items: PlanItem[]; summary: string } | null> {