/**
 * @param {Record<string, unknown>} st
 * @param {string} displayPath
 * @param {string} fmt
 */
function statApplyFormat(st, displayPath, fmt) {
  let out = ''
  for (let i = 0; i < fmt.length; i++) {
    if (fmt[i] === '%' && i + 1 < fmt.length) {
      const c = fmt[++i]
      if (c === 'n') out += displayPath.split('/').pop() || displayPath
      else if (c === 'N') out += displayPath
      else if (c === 's') out += String(st.size ?? 0)
      else if (c === 'Y')
        out += String(
          Math.floor(
            (typeof st.mtimeMs === 'number' ? st.mtimeMs : Date.now()) / 1000
          )
        )
      else if (c === 'A') out += bareFormatModeString(st.mode, st.type)
      else if (c === 'U') out += String(st.user ?? '')
      else if (c === 'G') out += String(st.group ?? '')
      else if (c === 'u') out += String(st.uid ?? 0)
      else if (c === 'g') out += String(st.gid ?? 0)
      else if (c === 'F') {
        const ty = st.type
        if (ty === 'directory') out += 'directory'
        else if (ty === 'symlink') out += 'symbolic link'
        else out += 'regular file'
      } else if (c === '%') out += '%'
      else out += '%' + c
    } else {
      out += fmt[i]
    }
  }
  return out
}

async function run(ctx, argv) {
  /** @type {string | null} */
  let formatStr = null
  /** @type {string[]} */
  const paths = []
  for (let i = 1; i < argv.length; i++) {
    const a = argv[i]
    if (a === '-c' && argv[i + 1]) {
      formatStr = argv[++i]
      continue
    }
    if (a.startsWith('--format=')) {
      formatStr = a.slice('--format='.length)
      continue
    }
    if (a === '--format' && argv[i + 1]) {
      formatStr = argv[++i]
      continue
    }
    if (a.startsWith('-')) {
      ctx.console.error('stat: unsupported option ' + a)
      ctx.exitCode = 1
      return
    }
    paths.push(a)
  }
  if (!paths.length) {
    ctx.console.error('usage: stat [-c FORMAT | --format=FORMAT] FILE...')
    ctx.exitCode = 1
    return
  }
  for (const p of paths) {
    try {
      const st = await ctx.vfs.stat(p)
      if (!st) {
        ctx.console.error('stat: ' + p + ': No such file')
        ctx.exitCode = 1
        continue
      }
      if (formatStr != null) {
        ctx.console.log(statApplyFormat(st, p, formatStr))
        continue
      }
      const modeStr = bareFormatModeString(st.mode, st.type)
      ctx.console.log(
        'File: ' +
          p +
          '\n' +
          'Size: ' +
          (st.size || 0) +
          '\n' +
          'Type: ' +
          st.type +
          '\n' +
          'Mode: ' +
          modeStr +
          '\n' +
          'Uid: ' +
          (st.uid ?? 0) +
          ' Gid: ' +
          (st.gid ?? 0)
      )
    } catch (e) {
      ctx.console.error('stat: ' + p + ': ' + ((e && e.message) || e))
      ctx.exitCode = 1
    }
  }
}