import fs from 'fs'
import path from 'path'
import { fileURLToPath } from 'url'
import pngToIco from 'png-to-ico'
import { Resvg } from '@resvg/resvg-js'

const __filename = fileURLToPath(import.meta.url)
const __dirname = path.dirname(__filename)

const root = path.resolve(__dirname, '..')
const buildDir = path.join(root, 'build')
const srcSvg = path.join(buildDir, 'app-icon.svg')
const outPng = path.join(buildDir, 'icon.png')
const outIco = path.join(buildDir, 'icon.ico')

if (!fs.existsSync(srcSvg)) {
  console.error(`[gen:icons] missing ${srcSvg}`)
  process.exit(1)
}

fs.mkdirSync(buildDir, { recursive: true })

const svgBuf = fs.readFileSync(srcSvg)
const svg = svgBuf.toString('utf8')

function renderSvgToPngBuffer(svgInputUtf8, size) {
  const resvg = new Resvg(svgInputUtf8, {
    fitTo: { mode: 'width', value: size },
    background: 'rgba(0,0,0,0)',
  })
  const img = resvg.render()
  return img.asPng()
}

// 生成一张 256x256 的 PNG（也可供托盘/文档等使用）
fs.writeFileSync(outPng, renderSvgToPngBuffer(svg, 256))

// Windows .ico：包含多尺寸位图更稳（任务栏/快捷方式/高 DPI）
const sizes = [16, 24, 32, 48, 64, 128, 256]
const pngBuffers = sizes.map((s) => renderSvgToPngBuffer(svg, s))

const ico = await pngToIco(pngBuffers)
fs.writeFileSync(outIco, ico)

console.log(`[gen:icons] wrote ${path.relative(root, outIco)} and ${path.relative(root, outPng)}`)