feat: add the tiktok integration

app/api/auth/callback/tiktok/route.ts

@@ -0,0 +1,59 @@
+import { NextRequest, NextResponse } from "next/server";
+import { exchangeCodeForTokens } from "@/lib/tiktok";
+import { prisma } from "@/lib/prisma";
+
+export async function GET(request: NextRequest) {
+    const { searchParams } = new URL(request.url);
+    const code = searchParams.get("code");
+    const state = searchParams.get("state");
+    const error = searchParams.get("error");
+
+    if (error || !code || !state) {
+        return NextResponse.redirect(new URL("/tiktok?error=access_denied", request.url));
+    }
+
+    try {
+        // Récupérer verifier + userId depuis la DB via le state
+        const pkceRecord = await prisma.tikTokPKCE.findUnique({ where: { state } });
+        if (!pkceRecord) {
+            return NextResponse.redirect(new URL("/tiktok?error=missing_verifier", request.url));
+        }
+
+        // Supprimer le record PKCE (usage unique)
+        await prisma.tikTokPKCE.delete({ where: { state } });
+
+        const { userId, codeVerifier } = pkceRecord;
+
+        const tokens = await exchangeCodeForTokens(code, codeVerifier);
+        const expiresAt = new Date(Date.now() + tokens.expires_in * 1000);
+
+        await prisma.tikTokToken.upsert({
+            where: { userId },
+            create: {
+                userId,
+                openId: tokens.open_id,
+                accessToken: tokens.access_token,
+                refreshToken: tokens.refresh_token,
+                expiresAt,
+            },
+            update: {
+                openId: tokens.open_id,
+                accessToken: tokens.access_token,
+                refreshToken: tokens.refresh_token,
+                expiresAt,
+            },
+        });
+
+        const existing = await prisma.trackedAccount.findFirst({ where: { userId, platform: "tiktok" } });
+        if (!existing) {
+            await prisma.trackedAccount.create({
+                data: { userId, platform: "tiktok", username: tokens.open_id, accountId: tokens.open_id },
+            });
+        }
+
+        return NextResponse.redirect(new URL("/tiktok?connected=1", request.url));
+    } catch (err) {
+        console.error("[TikTok callback error]", err);
+        return NextResponse.redirect(new URL("/tiktok?error=token_exchange", request.url));
+    }
+}