import { execFile } from 'node:child_process'

export type DockerStatus = 'ready' | 'missing' | 'permission' | 'unavailable' | 'error'

export function classifyDockerError(code: string | number | null | undefined, message: string): DockerStatus {
  if (code === 'ENOENT') return 'missing'
  if (/permission denied|access is denied|EACCES/i.test(message)) return 'permission'
  if (/cannot connect|connection refused|is the docker daemon running/i.test(message)) return 'unavailable'
  return 'error'
}

export function checkDockerStatus(): Promise<{ status: DockerStatus; platform: string }> {
  return new Promise((resolve) => {
    execFile('docker', ['info', '--format', '{{.ServerVersion}}'], {
      timeout: 5000,
      maxBuffer: 256 * 1024,
      env: { ...process.env, LC_ALL: 'C', LANG: 'C' },
    }, (error, stdout, stderr) => {
      resolve({
        status: error
          ? classifyDockerError(error.code, `${error.message}\n${stderr}`)
          : stdout.trim() ? 'ready' : 'error',
        platform: process.platform,
      })
    })
  })
}