import { mkdir, writeFile, copyFile, stat } from 'fs/promises'
import path from 'path'
import { resolveStoredUploadPath } from '@/lib/upload-paths'

function protectedDisplayPath(materialId: string, fileName: string) {
  return path.posix.join('uploads', 'materials', materialId, 'protected-display', fileName.replace(/\\/g, '/'))
}

export async function saveProtectedMaterialDisplay(
  materialId: string,
  fileName: string,
  buffer: Buffer,
): Promise<string> {
  const storedPath = protectedDisplayPath(materialId, fileName)
  const destination = resolveStoredUploadPath(storedPath)
  await mkdir(path.dirname(destination), { recursive: true })
  await writeFile(destination, buffer)
  return storedPath
}

export async function saveProtectedMaterialDisplayFile(
  materialId: string,
  fileName: string,
  source: string,
  expectedSize?: number,
): Promise<string> {
  const storedPath = protectedDisplayPath(materialId, fileName)
  const destination = resolveStoredUploadPath(storedPath)
  await mkdir(path.dirname(destination), { recursive: true })
  await copyFile(source, destination)
  if (expectedSize != null && (await stat(destination)).size !== expectedSize) {
    throw new Error('专属素材文件复制不完整')
  }
  return storedPath
}