import { randomUUID } from 'crypto'
import { mkdir } from 'fs/promises'
import path from 'path'
import { downloadS3ObjectToFile } from '@/lib/s3'
import { resolveStoredUploadPath } from '@/lib/upload-paths'
import { buildPublicDisplayUrl, buildWhiteBackgroundPublicDisplayPathFromAssetPath } from '@/lib/public-display'
import { existsSync } from 'fs'

const MATERIAL_FILE_FIELDS = [
  'previewUrl', 'zipFilePath', 'zipFileName', 'videoSourceUrl',
  'videoPreview540Url', 'videoPreviewClipUrl', 'videoCoverUrl',
] as const

/** 将已公开的存储对象改为受素材访问权限保护的独立文件。 */
export async function prepareOperationsGMaterialFiles(
  material: Record<string, any>,
  assets: Array<{ id: string; fileUrl: string }>,
  skus: Array<{ id: string; filePath: string; previewUrl: string | null }> = [],
) {
  const replacements = new Map<string, string>()
  const copyUrl = async (url: string) => {
    if (!/^https?:\/\//i.test(url)) return url
    const existing = replacements.get(url)
    if (existing) return existing
    const fileName = `${randomUUID()}${path.posix.extname(new URL(url).pathname)}`
    const storedPath = path.posix.join('uploads', 'materials', material.id, 'protected-display', fileName)
    const destination = resolveStoredUploadPath(storedPath)
    await mkdir(path.dirname(destination), { recursive: true })
    await downloadS3ObjectToFile(url, destination)
    replacements.set(url, storedPath)
    return storedPath
  }
  const materialFiles: Record<string, string | string[]> = {}
  for (const field of MATERIAL_FILE_FIELDS) {
    if (material[field]) materialFiles[field] = await copyUrl(material[field])
  }
  if (Array.isArray(material.displayImages)) {
    materialFiles.displayImages = []
    for (const url of material.displayImages) materialFiles.displayImages.push(await copyUrl(url))
  }
  const assetFiles = []
  for (const asset of assets) {
    const fileUrl = await copyUrl(asset.fileUrl)
    if (fileUrl !== asset.fileUrl) assetFiles.push({ id: asset.id, fileUrl })
    const previewPath = buildWhiteBackgroundPublicDisplayPathFromAssetPath(asset.fileUrl)
    const publicPreview = previewPath && /\.webp$/i.test(previewPath) ? buildPublicDisplayUrl(previewPath) : null
    if (previewPath && publicPreview) {
      const storedPath = path.posix.join('uploads', 'materials', material.id, 'protected-display', previewPath)
      const destination = resolveStoredUploadPath(storedPath)
      if (!existsSync(destination)) {
        await mkdir(path.dirname(destination), { recursive: true })
        await downloadS3ObjectToFile(publicPreview, destination)
      }
      replacements.set(publicPreview, storedPath)
    }
  }
  const skuFiles = []
  for (const sku of skus) {
    const filePath = await copyUrl(sku.filePath)
    const previewUrl = sku.previewUrl ? await copyUrl(sku.previewUrl) : sku.previewUrl
    if (filePath !== sku.filePath || previewUrl !== sku.previewUrl) skuFiles.push({ id: sku.id, filePath, previewUrl })
  }
  return { materialFiles, assetFiles, skuFiles, publicUrls: Array.from(replacements.keys()) }
}