import sharp from 'sharp'
import { readdir, stat, rename, unlink } from 'fs/promises'
import { join, extname } from 'path'

const IMAGE_DIR = 'src/assets/images'
const IMAGE_EXTENSIONS = ['.png', '.jpg', '.jpeg']

// 计算文件大小（KB）
function formatSize(bytes) {
  return (bytes / 1024).toFixed(2) + ' KB'
}

// 压缩单个图片
async function compressImage(fileName) {
  const ext = extname(fileName).toLowerCase()
  const inputPath = join(IMAGE_DIR, fileName)
  const tempPath = join(IMAGE_DIR, 'temp_' + fileName)

  try {
    const inputStats = await stat(inputPath)
    const inputSize = inputStats.size

    let pipeline = sharp(inputPath)

    // 根据图片类型设置压缩参数
    if (ext === '.png') {
      pipeline = pipeline.png({
        compressionLevel: 9,
        palette: true,
        quality: 80
      })
    } else if (ext === '.jpg' || ext === '.jpeg') {
      pipeline = pipeline.jpeg({
        quality: 80,
        mozjpeg: true
      })
    }

    // 执行压缩到临时文件
    await pipeline.toFile(tempPath)

    // 删除原文件并重命名临时文件
    await unlink(inputPath)
    await rename(tempPath, inputPath)

    const outputStats = await stat(inputPath)
    const outputSize = outputStats.size

    const savings = ((inputSize - outputSize) / inputSize * 100).toFixed(1)

    console.log(`✅ ${fileName}`)
    console.log(`   原始：${formatSize(inputSize)} → 压缩后：${formatSize(outputSize)} (节省 ${savings}%)`)

    return { inputSize, outputSize, savings }
  } catch (error) {
    console.error(`❌ 压缩失败 ${fileName}:`, error.message)
    // 清理临时文件（如果存在）
    try {
      await unlink(tempPath)
    } catch (e) {
      // 忽略
    }
    return null
  }
}

// 主函数
async function main() {
  console.log('🚀 开始压缩图片...\n')

  const files = await readdir(IMAGE_DIR)
  const imageFiles = files.filter(file => 
    IMAGE_EXTENSIONS.includes(extname(file).toLowerCase())
  )
  
  if (imageFiles.length === 0) {
    console.log('⚠️  未找到需要压缩的图片')
    return
  }

  console.log(`📁 找到 ${imageFiles.length} 张图片\n`)

  let totalInput = 0
  let totalOutput = 0
  let successCount = 0

  for (const file of imageFiles) {
    const result = await compressImage(file)
    if (result) {
      totalInput += result.inputSize
      totalOutput += result.outputSize
      successCount++
      console.log()
    }
  }

  const totalSavings = ((totalInput - totalOutput) / totalInput * 100).toFixed(1)

  console.log('='.repeat(50))
  console.log(`📊 压缩完成！`)
  console.log(`   成功：${successCount}/${imageFiles.length} 张`)
  console.log(`   原始总大小：${formatSize(totalInput)}`)
  console.log(`   压缩后总大小：${formatSize(totalOutput)}`)
  console.log(`   总计节省：${totalSavings}% (${formatSize(totalInput - totalOutput)})`)
  console.log('='.repeat(50))
}

// 运行
main().catch(console.error)