import multer from 'multer';
import fs from 'node:fs';
import path from 'node:path';
import { callNodeListener } from 'h3';
import {
  RELATIVE_ASSETS_DIR,
  POST_MEDIA_PUBLIC_PREFIX,
  ALLOWED_MIME_TYPES,
  MAX_FILE_SIZE,
  MAX_FILE_COUNT,
} from '#server/constants/upload';
import { getContextUser } from '#server/utils/context';

interface IFile {
  name: string;
  url: string;
  mimeType: string;
  size: number;
}

export default defineWrappedResponseHandler({ auth: 'required' }, async (event) => {
  const user = getContextUser(event)!;

  const uploadDir = path.resolve(RELATIVE_ASSETS_DIR);

  if (!fs.existsSync(uploadDir)) {
    fs.mkdirSync(uploadDir, { recursive: true });
  }

  const storage = multer.diskStorage({
    destination: uploadDir,
    filename: (_req, file, cb) => {
      const uniqueSuffix = Date.now() + '-' + Math.round(Math.random() * 1e9);
      const ext = path.extname(file.originalname).toLowerCase();
      const baseName = path.basename(file.originalname, ext).replace(/[^a-z0-9]/gi, '-');
      cb(null, `${uniqueSuffix}-${baseName}${ext}`);
    },
  });

  const upload = multer({
    storage,
    limits: { fileSize: MAX_FILE_SIZE },
    fileFilter: (_req, file, cb) => {
      if ((ALLOWED_MIME_TYPES as readonly string[]).includes(file.mimetype)) {
        cb(null, true);
      } else {
        cb(new Error('只支持 PNG/JPG/WebP 格式图片'));
      }
    },
  });

  await callNodeListener(
    // @ts-expect-error Nuxt 类型兼容
    upload.array('file', MAX_FILE_COUNT),
    event.node.req,
    event.node.res,
  );

  // @ts-expect-error
  const uploadedFiles = event.node.req.files || [];

  const result: IFile[] = uploadedFiles.map((file: any) => ({
    name: file.originalname,
    url: `${POST_MEDIA_PUBLIC_PREFIX}${file.filename}`,
    mimeType: file.mimetype,
    size: file.size,
  }));

  return result;
});