feat: add the tiktok integration

app/api/tiktok/connect/route.ts

@@ -0,0 +1,34 @@
+import { NextResponse } from "next/server";
+import { auth } from "@/lib/auth";
+import { getTikTokAuthUrl, generateCodeVerifier, generateCodeChallenge } from "@/lib/tiktok";
+import { prisma } from "@/lib/prisma";
+
+export async function GET() {
+    const session = await auth();
+
+    if (!session?.user) {
+        return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
+    }
+
+    const userId = (session.user as { id?: string }).id;
+    if (!userId) {
+        return NextResponse.json({ error: "Session error" }, { status: 401 });
+    }
+
+    const state = crypto.randomUUID();
+    const codeVerifier = generateCodeVerifier();
+    const codeChallenge = await generateCodeChallenge(codeVerifier);
+
+    console.log("[TikTok PKCE] verifier:", codeVerifier);
+    console.log("[TikTok PKCE] challenge:", codeChallenge);
+    console.log("[TikTok PKCE] verifier length:", codeVerifier.length);
+
+    // Stocker state + verifier + userId en DB
+    await prisma.tikTokPKCE.create({
+        data: { state, codeVerifier, userId },
+    });
+
+    const authUrl = getTikTokAuthUrl(state, codeChallenge);
+    console.log("[TikTok PKCE] authUrl:", authUrl);
+    return NextResponse.redirect(authUrl);
+}