import type { IncomingMessage, ServerResponse } from 'node:http';

import { createClerkClient } from '@clerk/backend';

import { buildApi } from '../apps/api/src/app.js';

import { TrustEngine } from '../packages/core/src/index.js';

import { HostedRepository } from '../packages/persistence/src/hosted.js';

const databaseUrl = process.env.DATABASE_URL;

const repository = databaseUrl ? new HostedRepository(databaseUrl) : undefined;

const app = buildApi(new TrustEngine(), undefined, repository);

const ready = app.ready();

function clerkRequest(request: IncomingMessage): Request {

  const headers = new Headers();

  for (const [name, value] of Object.entries(request.headers)) {

    if (Array.isArray(value)) for (const item of value) headers.append(name, item);

    else if (value !== undefined) headers.set(name, value);

  }

  const host = request.headers.host ?? 'openclasp.vercel.app';

  return new Request(`https://${host}${request.url ?? '/'}`, { headers });

}

export default async function handler(request: IncomingMessage, response: ServerResponse) {

  const incoming = new URL(request.url ?? '/', 'https://openclasp.local');

  const target = incoming.searchParams.get('path');

  if (target) request.url = target;

  if ((request.url ?? '').startsWith('/v0.1/')) {

    const secretKey = process.env.CLERK_SECRET_KEY;

    const publishableKey = process.env.NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY;

    if (!secretKey || !publishableKey || !request.headers.authorization) {

      response.statusCode = 401;

      response.setHeader('content-type', 'application/json');

      response.end(JSON.stringify({ error: 'authentication_required' }));

      return;

    }

    try {

      const origin = `https://${request.headers.host ?? 'openclasp.vercel.app'}`;

      const authentication = await createClerkClient({

        secretKey,

        publishableKey,

      }).authenticateRequest(clerkRequest(request), {

        acceptsToken: 'session_token',

        authorizedParties: [origin, 'https://openclasp.vercel.app'],

      });

      if (!authentication.isAuthenticated) throw new Error('Invalid session');

      const auth = authentication.toAuth();

      if (!auth.userId) throw new Error('Session has no subject');

      request.headers['x-openclasp-operator'] = auth.userId;

      const user = await createClerkClient({ secretKey, publishableKey }).users.getUser(

        auth.userId,

      );

      request.headers['x-openclasp-email'] = encodeURIComponent(

        user.primaryEmailAddress?.emailAddress ?? '',

      );

      request.headers['x-openclasp-name'] = encodeURIComponent(

        [user.firstName, user.lastName].filter(Boolean).join(' '),

      );

    } catch {

      response.statusCode = 401;

      response.setHeader('content-type', 'application/json');

      response.end(JSON.stringify({ error: 'invalid_session' }));

      return;

    }

  }

  await ready;

  app.server.emit('request', request, response);

}