import { spawnSync } from 'node:child_process'
import { existsSync } from 'node:fs'
import { extname } from 'node:path'

const CHECK_EXTENSIONS = new Set([
  '.ts',
  '.tsx',
  '.js',
  '.jsx',
  '.mjs',
  '.cjs',
  '.vue',
])
const CHECK_EXCLUDED_ROOTS = ['dist/', 'node_modules/']

function run(command, args) {
  const result = spawnSync(command, args, {
    shell: process.platform === 'win32' && command === 'pnpm',
    stdio: 'inherit',
  })

  if (result.error) {
    console.error(result.error.message)
    process.exit(1)
  }

  if (result.status !== 0) {
    process.exit(result.status ?? 1)
  }
}

function output(command, args) {
  const result = spawnSync(command, args, {
    encoding: 'utf8',
    shell: false,
  })

  if (result.error) {
    console.error(result.error.message)
    process.exit(1)
  }

  if (result.status !== 0) {
    process.exit(result.status ?? 1)
  }

  return result.stdout
}

function getPnpmCommand() {
  return 'pnpm'
}

function getStagedFiles() {
  return output('git', [
    'diff',
    '--cached',
    '--name-only',
    '--diff-filter=ACMR',
    '-z',
  ])
    .split('\0')
    .map((file) => file.replaceAll('\\', '/'))
    .filter(Boolean)
}

const files = getStagedFiles().filter((file) => {
  if (!existsSync(file)) return false
  if (CHECK_EXCLUDED_ROOTS.some((root) => file.startsWith(root))) return false

  return CHECK_EXTENSIONS.has(extname(file))
})

if (files.length === 0) {
  console.info('[husky] no staged files need eslint.')
  process.exit(0)
}

run(getPnpmCommand(), [
  'exec',
  'eslint',
  '--cache',
  '--cache-location',
  'node_modules/.cache/husky-eslint/',
  ...files,
])