import { execFileSync } from 'node:child_process';
import { mkdirSync, rmSync } from 'node:fs';
import path from 'node:path';
import type { AddressInfo } from 'node:net';
import { createServer, type RequestListener } from 'node:http';

const ROOT = path.resolve(import.meta.dirname, '../..');

/**
 * Point Prisma at a throwaway SQLite file and apply migrations to it.
 * Must run before anything imports `src/store/db.ts`, because PrismaClient
 * reads DATABASE_URL when it is constructed.
 */
export function prepareTestDatabase(name: string): string {
  const dir = path.join(ROOT, 'data');
  mkdirSync(dir, { recursive: true });
  const file = path.join(dir, `${name}.db`);
  rmSync(file, { force: true });
  rmSync(`${file}-journal`, { force: true });

  const url = `file:${file}`;
  process.env.DATABASE_URL = url;

  execFileSync('npx', ['prisma', 'migrate', 'deploy'], {
    cwd: ROOT,
    env: { ...process.env, DATABASE_URL: url },
    stdio: 'pipe',
  });

  return url;
}

export interface RunningServer {
  baseUrl: string;
  close: () => Promise<void>;
}

export async function startServer(app: RequestListener): Promise<RunningServer> {
  const server = createServer(app);
  await new Promise<void>((resolve) => server.listen(0, '127.0.0.1', resolve));
  const { port } = server.address() as AddressInfo;
  return {
    baseUrl: `http://127.0.0.1:${port}`,
    close: () =>
      new Promise<void>((resolve, reject) =>
        server.close((err) => (err ? reject(err) : resolve())),
      ),
  };
}