// 把 public/werewolf 下的牌图压到每张 <= 200KB（原地覆盖）。
// 策略：最长边限 900px，mozjpeg 质量从高到低递减，直到达标。
// 已经 <= 目标的文件跳过，避免重复编码反复掉质量。
// 运行: npm run compress:images
import sharp from 'sharp'
import { readdir, stat, writeFile } from 'node:fs/promises'
import { fileURLToPath } from 'node:url'
import { dirname, resolve, join } from 'node:path'

const here = dirname(fileURLToPath(import.meta.url))
const root = resolve(here, '../public/werewolf')

const TARGET = 200 * 1024
const MAX_EDGE = 900
const QUALITIES = [82, 76, 70, 64, 58, 52, 46]

async function listJpgs(dir) {
  const out = []
  for (const name of await readdir(dir, { withFileTypes: true })) {
    const p = join(dir, name.name)
    if (name.isDirectory()) out.push(...(await listJpgs(p)))
    else if (/\.jpe?g$/i.test(name.name)) out.push(p)
  }
  return out
}

async function compress(file) {
  const before = (await stat(file)).size
  if (before <= TARGET) return { file, skipped: true, before }
  let chosen = null
  for (const quality of QUALITIES) {
    const buf = await sharp(file)
      .rotate() // 按 EXIF 摆正
      .resize({ width: MAX_EDGE, height: MAX_EDGE, fit: 'inside', withoutEnlargement: true })
      .jpeg({ quality, mozjpeg: true })
      .toBuffer()
    chosen = { buf, quality }
    if (buf.length <= TARGET) break
  }
  await writeFile(file, chosen.buf)
  return { file, before, after: chosen.buf.length, quality: chosen.quality }
}

const files = await listJpgs(root)
let totalBefore = 0
let totalAfter = 0
for (const f of files) {
  const r = await compress(f)
  const rel = f.slice(root.length + 1)
  if (r.skipped) {
    totalBefore += r.before
    totalAfter += r.before
    console.log(`skip  ${rel}  (${(r.before / 1024) | 0}K)`)
  } else {
    totalBefore += r.before
    totalAfter += r.after
    console.log(`ok    ${rel}  ${(r.before / 1024) | 0}K -> ${(r.after / 1024) | 0}K  q${r.quality}`)
  }
}
console.log(`\n${files.length} files: ${(totalBefore / 1024 / 1024).toFixed(1)}MB -> ${(totalAfter / 1024 / 1024).toFixed(1)}MB`)