import test from 'brittle'
import { readFile } from 'node:fs/promises'
import { createContext, runInContext } from 'node:vm'
import { dirname, join } from 'node:path'
import { fileURLToPath } from 'node:url'

const __dirname = dirname(fileURLToPath(import.meta.url))
const helpersPath = join(__dirname, '../lib/baretop/baretop-ui-helpers.js')
const composePath = join(__dirname, '../lib/baretop/baretop-compose.js')

test('stress synthetic snapshots do not crash compose loop', async (t) => {
  const helpers = await readFile(helpersPath, 'utf8')
  const compose = await readFile(composePath, 'utf8')
  const ctx = createContext({})
  runInContext(helpers + '\n' + compose, ctx)

  let prevLines = null
  for (let i = 0; i < 120; i++) {
    const huge = Array.from({ length: 1600 }, (_, k) => ({
      pid: k + 1,
      ppid: k % 17,
      name: 'proc-' + k,
      state: k % 2 ? 'run' : 'sleep',
      cpuPct: (k * 7 + i) % 100,
      rssBytes: (k + 1) * 4096
    }))
    const rows = ctx.bareTopSortProcessRows(huge, 'cpu', false, { sortWallMs: 1000 })
    const frame = ['stress-' + i, 'rows=' + rows.length]
    for (const r of rows.slice(0, 500)) {
      frame.push(
        String(r.pid) +
          ' ' +
          String(r.name) +
          ' cpu=' +
          String(r.cpuPct) +
          ' rss=' +
          String(r.rssBytes)
      )
    }
    const em = ctx.bareTopEmitFrame({}, { write() {} }, frame.join('\r\n'), {
      prevLines,
      rows: 46,
      cols: 140,
      incrementalFrameDiff: true,
      useLineHash: true,
      fullscreenPanel: false,
      cup: (r, c) => `\x1b[${r};${c}H`
    })
    prevLines = em.nextLines
    t.ok(Array.isArray(prevLines))
  }
})