feat(google): Google Calendar OAuth 연동 기능 구현

src/app/api/google/auth/route.ts

@@ -0,0 +1,13 @@
+import { NextResponse } from "next/server";
+import { buildAuthUrl } from "@/lib/google/auth";
+
+export const dynamic = "force-dynamic";
+
+/**
+ * GET /api/google/auth
+ * Google OAuth 동의 화면으로 리다이렉트한다.
+ */
+export async function GET() {
+  const authUrl = buildAuthUrl();
+  return NextResponse.redirect(authUrl);
+}

src/app/api/google/calendars/route.ts

@@ -0,0 +1,41 @@
+import { NextResponse } from "next/server";
+import { getValidTokens } from "@/lib/google/auth";
+import { listCalendars } from "@/lib/google/calendars";
+
+export const dynamic = "force-dynamic";
+
+/**
+ * GET /api/google/calendars
+ * 연결된 Google 계정의 캘린더 목록을 반환한다.
+ */
+export async function GET() {
+  const tokens = await getValidTokens();
+  if (!tokens) {
+    return NextResponse.json(
+      {
+        error:
+          "Google 계정이 연결되지 않았습니다. /api/google/auth로 인증해주세요.",
+      },
+      { status: 401 },
+    );
+  }
+
+  try {
+    const calendars = await listCalendars(tokens.accessToken);
+    return NextResponse.json({ calendars });
+  } catch (err) {
+    console.error("[google.calendars] 오류:", err);
+
+    if (err instanceof Error && err.message.includes("만료")) {
+      return NextResponse.json(
+        { error: "Google 인증이 만료되었습니다. 다시 연결해주세요." },
+        { status: 401 },
+      );
+    }
+
+    return NextResponse.json(
+      { error: "캘린더 목록 조회 중 오류가 발생했습니다." },
+      { status: 502 },
+    );
+  }
+}

src/app/api/google/callback/route.ts

@@ -0,0 +1,49 @@
+import { NextRequest, NextResponse } from "next/server";
+import {
+  exchangeCodeForTokens,
+  getUserEmail,
+  saveTokensToCookie,
+} from "@/lib/google/auth";
+
+export const dynamic = "force-dynamic";
+
+/**
+ * GET /api/google/callback
+ * Google OAuth 콜백. authorization code를 토큰으로 교환한 뒤 쿠키에 저장한다.
+ */
+export async function GET(req: NextRequest) {
+  const code = req.nextUrl.searchParams.get("code");
+  const error = req.nextUrl.searchParams.get("error");
+
+  if (error) {
+    return NextResponse.json(
+      { error: `Google OAuth 거부: ${error}` },
+      { status: 400 },
+    );
+  }
+
+  if (!code) {
+    return NextResponse.json(
+      { error: "authorization code가 없습니다." },
+      { status: 400 },
+    );
+  }
+
+  try {
+    const tokens = await exchangeCodeForTokens(code);
+    const email = await getUserEmail(tokens.accessToken);
+
+    await saveTokensToCookie(tokens);
+
+    const baseUrl = process.env.NEXT_PUBLIC_BASE_URL ?? "http://localhost:3000";
+    return NextResponse.redirect(
+      `${baseUrl}/api/google/calendars?connected=true&email=${encodeURIComponent(email)}`,
+    );
+  } catch (err) {
+    console.error("[google.callback] 오류:", err);
+    return NextResponse.json(
+      { error: "Google 계정 연결에 실패했습니다." },
+      { status: 500 },
+    );
+  }
+}

src/app/api/google/events/create/route.ts

@@ -0,0 +1,83 @@
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+import { getValidTokens } from "@/lib/google/auth";
+import { createEvent } from "@/lib/google/events";
+
+export const dynamic = "force-dynamic";
+
+const CreateEventSchema = z.object({
+  calendarId: z.string().min(1, "calendarId는 필수입니다."),
+  summary: z
+    .string()
+    .min(1, "제목은 1자 이상이어야 합니다.")
+    .max(255, "제목은 255자 이하여야 합니다."),
+  startDateTime: z.string().datetime({
+    offset: true,
+    message: "startDateTime은 ISO 8601 형식이어야 합니다.",
+  }),
+  endDateTime: z.string().datetime({
+    offset: true,
+    message: "endDateTime은 ISO 8601 형식이어야 합니다.",
+  }),
+  location: z.string().max(500).optional(),
+  description: z.string().max(8000).optional(),
+  timeZone: z.string().optional(),
+});
+
+/**
+ * POST /api/google/events/create
+ * Google Calendar에 새 일정을 생성한다.
+ */
+export async function POST(req: NextRequest) {
+  const tokens = await getValidTokens();
+  if (!tokens) {
+    return NextResponse.json(
+      { error: "Google 계정이 연결되지 않았습니다." },
+      { status: 401 },
+    );
+  }
+
+  const body = await req.json().catch(() => null);
+  const parsed = CreateEventSchema.safeParse(body);
+  if (!parsed.success) {
+    return NextResponse.json(
+      { error: parsed.error.issues[0].message },
+      { status: 400 },
+    );
+  }
+
+  const { calendarId, summary, startDateTime, endDateTime, ...rest } =
+    parsed.data;
+
+  if (new Date(startDateTime) >= new Date(endDateTime)) {
+    return NextResponse.json(
+      { error: "endDateTime은 startDateTime보다 나중이어야 합니다." },
+      { status: 400 },
+    );
+  }
+
+  try {
+    const event = await createEvent(tokens.accessToken, calendarId, {
+      summary,
+      startDateTime,
+      endDateTime,
+      ...rest,
+    });
+
+    return NextResponse.json({ event }, { status: 201 });
+  } catch (err) {
+    console.error("[google.events.create] 오류:", err);
+
+    if (err instanceof Error && err.message.includes("만료")) {
+      return NextResponse.json(
+        { error: "Google 인증이 만료되었습니다." },
+        { status: 401 },
+      );
+    }
+
+    return NextResponse.json(
+      { error: "일정 생성 중 오류가 발생했습니다." },
+      { status: 502 },
+    );
+  }
+}

src/app/api/google/events/query/route.ts

@@ -0,0 +1,71 @@
+import { NextRequest, NextResponse } from "next/server";
+import { getValidTokens } from "@/lib/google/auth";
+import { queryEvents } from "@/lib/google/events";
+
+export const dynamic = "force-dynamic";
+
+/**
+ * GET /api/google/events/query?calendarId=...&startDate=...&endDate=...
+ * 특정 캘린더의 기간별 일정을 조회한다.
+ */
+export async function GET(req: NextRequest) {
+  const tokens = await getValidTokens();
+  if (!tokens) {
+    return NextResponse.json(
+      { error: "Google 계정이 연결되지 않았습니다." },
+      { status: 401 },
+    );
+  }
+
+  const calendarId = req.nextUrl.searchParams.get("calendarId");
+  const startDate = req.nextUrl.searchParams.get("startDate");
+  const endDate = req.nextUrl.searchParams.get("endDate");
+
+  if (!calendarId || !startDate || !endDate) {
+    return NextResponse.json(
+      { error: "calendarId, startDate, endDate 파라미터가 필요합니다." },
+      { status: 400 },
+    );
+  }
+
+  const start = new Date(startDate);
+  const end = new Date(endDate);
+
+  if (isNaN(start.getTime()) || isNaN(end.getTime())) {
+    return NextResponse.json(
+      { error: "날짜 형식이 올바르지 않습니다. ISO 8601 형식을 사용하세요." },
+      { status: 400 },
+    );
+  }
+
+  if (start >= end) {
+    return NextResponse.json(
+      { error: "endDate는 startDate보다 나중이어야 합니다." },
+      { status: 400 },
+    );
+  }
+
+  try {
+    const events = await queryEvents(
+      tokens.accessToken,
+      calendarId,
+      start,
+      end,
+    );
+    return NextResponse.json({ events });
+  } catch (err) {
+    console.error("[google.events.query] 오류:", err);
+
+    if (err instanceof Error && err.message.includes("만료")) {
+      return NextResponse.json(
+        { error: "Google 인증이 만료되었습니다." },
+        { status: 401 },
+      );
+    }
+
+    return NextResponse.json(
+      { error: "일정 조회 중 오류가 발생했습니다." },
+      { status: 502 },
+    );
+  }
+}

src/app/layout.tsx

@@ -1,17 +1,15 @@
 import type { Metadata } from "next";
-import localFont from "next/font/local";
+import { Inter, JetBrains_Mono } from "next/font/google";
 import "./globals.css";
 import { cn } from "@/lib/utils";
 
-const geistSans = localFont({
-  src: "./fonts/GeistVF.woff",
+const geistSans = Inter({
+  subsets: ["latin"],
   variable: "--font-geist-sans",
-  weight: "100 900",
 });
-const geistMono = localFont({
-  src: "./fonts/GeistMonoVF.woff",
+const geistMono = JetBrains_Mono({
+  subsets: ["latin"],
   variable: "--font-geist-mono",
-  weight: "100 900",
 });
 
 export const metadata: Metadata = {