const fs = require('fs');
const path = require('path');
const {handle} = require("./handle_cjs");
async function mvFile(file, targetPath, newFileName, maxRename = 10 , renameTotal = 0){
  try {
    // 判断路径是否存在,不存在则创建
    let err, exists;
    [err] = await handle(fs.promises.mkdir(targetPath, {recursive: true}));
    if (err) {
      return [err, null];
    }
    // 拼接新的文件路径
    let newFilePath = path.join(targetPath, newFileName);
    let ext = null;
    let name = null;
    let newName = '';
    // 判断文件是否存在
    [err, exists] = await handle(fs.existsSync(newFilePath));
    if (err) {
      return [err, null];
    }
    // 如果文件存在,则重命名在最后加上 _n n为数字
    if (exists) {
      renameTotal++;// 1
      if (renameTotal >= maxRename) {
        return [{message: `重命名次数超过最大值`}, null];
      }
      ext = path.extname(newFileName);
      name = path.basename(newFileName, ext)
      newName = `${name}_${renameTotal}${ext}`;
      newFilePath = path.join(targetPath, newName);
      [err, exists] = await handle(fs.existsSync(newFilePath));
      if (err) {
        return [err, null];
      }
      if(exists){
        return await mvFile(file, targetPath, newFileName, maxRename, renameTotal);
      }
    }
    // console.log(file);
    // 移动文件
    [err] = await handle(fs.promises.rename(file.filepath, newFilePath));
    if (err) {
      return [err, null];
    }
    return [null, newName || newFileName];
  } catch (e) {
    return [e, null];
  }

}

async function rmFile(filePath){
  // 判断是否为文件夹
  let err, stats ,res;
  [err, stats] = await handle(fs.promises.stat(filePath));
  if(err){
    return [err,null];
  }
  if(stats.isDirectory()){
    return [{message:`${filePath} 为文件夹`},null];
  }
  // 删除文件
  [err,res] = await handle(fs.promises.unlink(filePath));
  if(err){
    return [err,null];
  }
  return [null,res];
}

module.exports = {
  mvFile,
  rmFile
}