import { test } from '@japa/runner'
import net from 'node:net'
import env from '#start/env'
import coordinatorConfig from '#config/coordinator'
import pool from '#services/nntp_pool'
import type { NntpShare } from '#services/nntp_shares'

/** A tiny NNTP server that only logs in, counting the connections open. */
function server(): Promise<{ port: number; open: () => number; close: () => void }> {
  return new Promise((resolve) => {
    let open = 0
    const srv = net.createServer((sock) => {
      open++
      sock.on('close', () => open--)
      sock.write('200 welcome\r\n')
      sock.on('data', (chunk) => {
        for (const line of chunk.toString().split('\r\n')) {
          if (line.startsWith('AUTHINFO USER')) sock.write('381 more\r\n')
          else if (line.startsWith('AUTHINFO PASS')) sock.write('281 ok\r\n')
          else if (line === 'XFEATURE COMPRESS GZIP') sock.write('290 Feature Enabled\r\n')
          else if (line === 'QUIT') sock.end('205 bye\r\n')
        }
      })
    })
    srv.listen(0, '127.0.0.1', () =>
      resolve({
        port: (srv.address() as net.AddressInfo).port,
        open: () => open,
        close: () => srv.close(),
      })
    )
  })
}

const sleep = (ms: number) => new Promise((r) => setTimeout(r, ms))
const share = { sync: async () => 4 } as unknown as NntpShare

test.group('nntp / pool', () => {
  test('a connection free for nntpIdleCloseMs closes on the next sync; one used since stays', async ({
    assert,
    cleanup,
  }) => {
    const { port, open, close } = await server()
    const idleCloseMs = coordinatorConfig.nntpIdleCloseMs
    env.set('NNTP_HOST', '127.0.0.1')
    env.set('NNTP_PORT', port)
    env.set('NNTP_SECURE', false)
    coordinatorConfig.nntpIdleCloseMs = 100
    cleanup(async () => {
      coordinatorConfig.nntpIdleCloseMs = idleCloseMs
      await pool.close()
      close()
    })
    await pool.share(share)
    // Two at once: two connections.
    await Promise.all([pool.use(() => sleep(20)), pool.use(() => sleep(20))])
    assert.equal(open(), 2)
    await sleep(150)
    // One used again: the other has been free for longer than 100 ms.
    await pool.use(async () => {})
    await pool.share(share)
    await sleep(50)
    assert.equal(open(), 1)
    await sleep(150)
    await pool.share(share)
    await sleep(50)
    assert.equal(open(), 0)
  })
})