import { NextResponse } from 'next/server';
import { cookies } from 'next/headers';
import {
  buildGoogleAuthUrl,
  createOAuthState,
  isGoogleOAuthConfigured,
} from '@/infrastructure/auth/google-oauth';
import {
  getOAuthReturnCookieName,
  sanitizeOAuthReturnPath,
} from '@/infrastructure/auth/oauth-return';

export const dynamic = 'force-dynamic';

const OAUTH_STATE_COOKIE = 'shahi_google_oauth_state';

export async function GET(request: Request) {
  if (!isGoogleOAuthConfigured()) {
    return NextResponse.redirect(new URL('/login?tab=customer&error=google_not_configured', getOrigin()));
  }

  const url = new URL(request.url);
  const returnTo = sanitizeOAuthReturnPath(url.searchParams.get('returnTo'));

  const state = createOAuthState();
  const cookieStore = await cookies();
  cookieStore.set(OAUTH_STATE_COOKIE, state, {
    httpOnly: true,
    secure: process.env.NODE_ENV === 'production',
    sameSite: 'lax',
    path: '/',
    maxAge: 600,
  });
  cookieStore.set(getOAuthReturnCookieName(), returnTo, {
    httpOnly: true,
    secure: process.env.NODE_ENV === 'production',
    sameSite: 'lax',
    path: '/',
    maxAge: 600,
  });

  return NextResponse.redirect(buildGoogleAuthUrl(state));
}

function getOrigin(): string {
  return process.env.NEXT_PUBLIC_SITE_URL ?? 'http://localhost:3000';
}