// bankai inspect — what did the build produce, and how big is it on the
// wire? Reads the manifest + dist and prints raw/gzip/brotli sizes.

import { readFile, readdir, stat } from 'node:fs/promises'
import { join, resolve, relative } from 'node:path'

export default async function inspect ({ outDir = 'dist' }) {
  outDir = resolve(outDir)
  const meta = JSON.parse(await readFile(join(outDir, 'bankai.json'), 'utf8'))

  const rows = []
  await walk(outDir, rows, outDir)
  rows.sort((a, b) => b.raw - a.raw)

  console.log(`\nbankai build — ${meta.title} (${meta.builtAt})\n`)
  console.log('  ' + 'file'.padEnd(44) + 'raw'.padStart(10) + 'gzip'.padStart(10) + 'brotli'.padStart(10))
  let totals = { raw: 0, gz: 0, br: 0 }
  for (const row of rows) {
    totals.raw += row.raw
    totals.gz += row.gz || 0
    totals.br += row.br || 0
    console.log('  ' + row.file.padEnd(44) + kb(row.raw) + kb(row.gz) + kb(row.br))
  }
  console.log('  ' + 'total'.padEnd(44) + kb(totals.raw) + kb(totals.gz) + kb(totals.br) + '\n')
  return rows
}

async function walk (dir, rows, root) {
  for (const name of await readdir(dir)) {
    if (name === '.vite') continue
    const path = join(dir, name)
    const info = await stat(path)
    if (info.isDirectory()) {
      await walk(path, rows, root)
      continue
    }
    if (name.endsWith('.br') || name.endsWith('.gz')) continue
    const row = { file: relative(root, path), raw: info.size, gz: null, br: null }
    row.gz = await sizeOf(path + '.gz')
    row.br = await sizeOf(path + '.br')
    rows.push(row)
  }
}

async function sizeOf (path) {
  try {
    return (await stat(path)).size
  } catch (e) {
    return null
  }
}

function kb (bytes) {
  if (bytes === null) return '—'.padStart(10)
  return (bytes < 1024 ? bytes + ' B' : (bytes / 1024).toFixed(1) + ' kB').padStart(10)
}