import assert from 'node:assert/strict'
import { mkdtemp, rm, writeFile } from 'node:fs/promises'
import { connect } from 'node:net'
import { tmpdir } from 'node:os'
import { join } from 'node:path'
import { after, before, test } from 'node:test'

import { createWebServer } from './server.mjs'
import { SessionRenewalPendingError } from './server/oauth.mjs'

let base
let root
let server

before(async () => {
  root = await mkdtemp(join(tmpdir(), 'remora-web-server-'))
  await writeFile(join(root, 'index.html'), '<main>Remora</main>')
  await writeFile(join(root, 'application.js'), 'application()')
  await writeFile(join(root, 'application.js.br'), 'compressed')
  const config = {
    root,
    publicOrigin: 'http://127.0.0.1',
  }
  const created = createWebServer(config, {
    store: { ready: true },
    oauth: { route: async () => false },
    proxy: {
      route: async () => false,
      upgrade: async () => false,
    },
  })
  server = created.server
  await new Promise((resolve) => server.listen(0, '127.0.0.1', resolve))
  const address = server.address()
  if (typeof address !== 'object' || address === null)
    throw new Error('server address unavailable')
  base = `http://127.0.0.1:${address.port}`
})

after(async () => {
  server.closeIdleConnections()
  server.closeAllConnections()
  await new Promise((resolve, reject) =>
    server.close((error) => (error ? reject(error) : resolve())),
  )
  await rm(root, { recursive: true })
})

test('serves health, metrics, runtime configuration, and security headers', async () => {
  const ready = await fetch(`${base}/health/ready`)
  assert.equal(ready.status, 200)
  assert.deepEqual(await ready.json(), { status: 'ready' })
  assert.equal(ready.headers.get('x-content-type-options'), 'nosniff')
  assert.equal(ready.headers.get('x-frame-options'), 'DENY')
  assert.match(
    ready.headers.get('content-security-policy'),
    /connect-src 'self'/,
  )

  const metrics = await fetch(`${base}/metrics`)
  assert.match(await metrics.text(), /remora_web_requests_total/)

  const runtime = await fetch(`${base}/runtime-config.js`)
  const script = await runtime.text()
  assert.match(script, /"apiUrl":"\/bff\/api\/"/)
  assert.doesNotMatch(script, /oidc|client|secret/i)
  assert.equal(runtime.headers.get('cache-control'), 'no-store')
})

test('serves immutable precompressed assets and correct HEAD responses', async () => {
  const asset = await fetch(`${base}/application.js`, {
    headers: { 'Accept-Encoding': 'br' },
  })
  assert.equal(asset.status, 200)
  assert.equal(asset.headers.get('content-encoding'), 'br')
  assert.equal(asset.headers.get('vary'), 'Accept-Encoding')
  assert.match(asset.headers.get('cache-control'), /immutable/)

  const head = await fetch(`${base}/application.js`, { method: 'HEAD' })
  assert.equal(head.status, 200)
  assert.equal(await head.text(), '')
  assert.equal(
    head.headers.get('content-type'),
    'text/javascript; charset=utf-8',
  )
})

test('limits the SPA fallback to extensionless HTML navigation', async () => {
  const navigation = await fetch(`${base}/jobs/current`, {
    headers: { Accept: 'text/html' },
  })
  assert.equal(navigation.status, 200)
  assert.equal(await navigation.text(), '<main>Remora</main>')

  const data = await fetch(`${base}/jobs/current`, {
    headers: { Accept: 'application/json' },
  })
  assert.equal(data.status, 404)
  const missingAsset = await fetch(`${base}/missing.js`, {
    headers: { Accept: 'text/html' },
  })
  assert.equal(missingAsset.status, 404)
  const traversal = await fetch(`${base}/%2e%2e/package.json`, {
    headers: { Accept: 'text/html' },
  })
  assert.equal(traversal.status, 404)
})

test('graceful shutdown drains active requests and closes dependencies', async () => {
  const requestStarted = deferred()
  const requestReleased = deferred()
  let storeClosed = false
  let proxyClosed = false
  const created = createWebServer(
    {
      root,
      publicOrigin: 'http://127.0.0.1',
    },
    {
      store: {
        ready: true,
        close: async () => {
          storeClosed = true
        },
      },
      oauth: { route: async () => false },
      proxy: {
        route: async (_request, response, url) => {
          if (url.pathname !== '/bff/api/blocked') return false
          requestStarted.resolve()
          await requestReleased.promise
          response.writeHead(204)
          response.end()
          return true
        },
        upgrade: async () => false,
        close: () => {
          proxyClosed = true
        },
      },
      shutdownTimeoutMilliseconds: 1_000,
    },
  )
  await new Promise((resolve) => created.server.listen(0, '127.0.0.1', resolve))
  const address = created.server.address()
  const request = fetch(`http://127.0.0.1:${address.port}/bff/api/blocked`)
  await requestStarted.promise

  let stopped = false
  const stopping = created.shutdown().then(() => {
    stopped = true
  })
  await new Promise((resolve) => setTimeout(resolve, 10))
  assert.equal(stopped, false)
  assert.equal(proxyClosed, true)
  requestReleased.resolve()

  assert.equal((await request).status, 204)
  await stopping
  assert.equal(storeClosed, true)
})

test('preserves the session cookie while renewal is pending', async () => {
  const created = createWebServer(
    {
      root,
      publicOrigin: 'http://127.0.0.1',
    },
    {
      store: { ready: true },
      oauth: {
        route: async () => {
          throw new SessionRenewalPendingError()
        },
      },
      proxy: {
        route: async () => false,
        upgrade: async () => false,
      },
    },
  )
  await new Promise((resolve) => created.server.listen(0, '127.0.0.1', resolve))
  const address = created.server.address()

  const response = await fetch(`http://127.0.0.1:${address.port}/auth/session`)

  assert.equal(response.status, 503)
  assert.equal(response.headers.get('set-cookie'), null)
  await created.shutdown()
})

test('returns transient unavailability for a pending WebSocket renewal', async () => {
  const created = createWebServer(
    {
      root,
      publicOrigin: 'http://127.0.0.1',
    },
    {
      store: { ready: true },
      oauth: { route: async () => false },
      proxy: {
        route: async () => false,
        upgrade: async () => {
          throw new SessionRenewalPendingError()
        },
      },
    },
  )
  await new Promise((resolve) => created.server.listen(0, '127.0.0.1', resolve))
  const address = created.server.address()
  const response = await new Promise((resolve, reject) => {
    const socket = connect(address.port, '127.0.0.1')
    let received = ''
    socket.setEncoding('utf8')
    socket.once('connect', () => {
      socket.write(
        'GET /bff/events HTTP/1.1\r\nHost: 127.0.0.1\r\nConnection: Upgrade\r\nUpgrade: websocket\r\n\r\n',
      )
    })
    socket.on('data', (chunk) => {
      received += chunk
    })
    socket.once('end', () => resolve(received))
    socket.once('error', reject)
  })

  assert.match(response, /^HTTP\/1\.1 503 Service Unavailable\r\n/)
  await created.shutdown()
})

function deferred() {
  let resolve
  const promise = new Promise((complete) => {
    resolve = complete
  })
  return { promise, resolve }
}