import { NextResponse } from "next/server";

/**
 * GET /api/auth/tiktok
 * Redirects to TikTok OAuth authorization page.
 * Visit this URL once to start the OAuth flow and get your refresh token.
 */
export async function GET() {
  const clientKey = process.env.TIKTOK_CLIENT_KEY;
  const redirectUri = `${process.env.BASE_URL}/api/auth/tiktok/callback`;

  if (!clientKey) {
    return NextResponse.json(
      { error: "TIKTOK_CLIENT_KEY not set in environment" },
      { status: 500 }
    );
  }

  const csrfState = Math.random().toString(36).substring(2);

  const params = new URLSearchParams({
    client_key: clientKey,
    scope: "user.info.basic,user.info.profile,user.info.stats",
    response_type: "code",
    redirect_uri: redirectUri,
    state: csrfState,
  });

  const authUrl = `https://www.tiktok.com/v2/auth/authorize/?${params.toString()}`;

  return NextResponse.redirect(authUrl);
}