// Name: What Occupied Port
// Description: Show which process is using a given port and optionally kill it.
// Author: benhaotang
// GitHub: benhaotang

import '@johnlindquist/kit'

const portStr = await arg({
  placeholder: 'Enter a port number (1-65535)',
  validate: (input: string) => {
    const n = Number(input)
    if (!Number.isInteger(n) || n < 1 || n > 65535) return 'Enter a valid port number between 1 and 65535'
    return true
  },
})
const port = Number(portStr)

let output = ''
let pids = new Set<number>()

const parseLsof = (text: string) => {
  for (const line of text.split('\n').slice(1)) {
    const parts = line.trim().split(/\s+/)
    const pid = Number(parts[1])
    if (Number.isInteger(pid)) pids.add(pid)
  }
}

const parseSs = (text: string) => {
  const re = /pid=(\d+)/g
  let m: RegExpExecArray | null
  while ((m = re.exec(text))) {
    const pid = Number(m[1])
    if (Number.isInteger(pid)) pids.add(pid)
  }
}

const parseNetstat = (text: string) => {
  for (const line of text.split('\n')) {
    const trimmed = line.trim()
    if (!trimmed) continue
    const parts = trimmed.split(/\s+/)
    const last = parts[parts.length - 1]
    const pid = Number(last)
    if (Number.isInteger(pid)) pids.add(pid)
  }
}

try {
  if (isWin) {
    const { stdout } = await exec(`netstat -ano | findstr :${port}`)
    output = stdout || ''
    parseNetstat(output)
  } else if (isMac) {
    try {
      const { stdout } = await exec(`lsof -nP -i TCP:${port} -sTCP:LISTEN`)
      output = stdout || ''
      parseLsof(output)
    } catch {
      output = ''
    }
  } else {
    // Linux
    try {
      const { stdout } = await exec(`lsof -nP -i TCP:${port} -sTCP:LISTEN`)
      output = stdout || ''
      parseLsof(output)
    } catch {
      try {
        const { stdout } = await exec(`ss -ltnp | grep :${port} || true`)
        output = stdout || ''
        parseSs(output)
      } catch {
        output = ''
      }
    }
  }
} catch (err: any) {
  output = err?.all || err?.message || String(err)
}

const summary =
  pids.size > 0
    ? `Found ${pids.size} process(es) using port ${port}.`
    : `No process appears to be listening on port ${port}.`

await div(
  md(`
## Port ${port}

${summary}

### Raw output
\`\`\`
${(output || '(no output)').trim()}
\`\`\`
`)
)

if (pids.size > 0) {
  const pid = await arg<number>(
    {
      placeholder: 'Select a PID to kill (or Esc to cancel)',
    },
    Array.from(pids).map(n => ({
      name: `PID ${n}`,
      description: `Kill process ${n}`,
      value: n,
    }))
  )

  try {
    if (isWin) {
      await exec(`taskkill /PID ${pid} /F`)
    } else {
      await exec(`kill -9 ${pid}`)
    }
    await notify(`Killed PID ${pid} on port ${port}`)
  } catch (err: any) {
    await notify({
      title: 'Failed to kill process',
      body: err?.message || String(err),
    })
  }
}