subject-two/entry/src/main/ets/utils/FileUtils.ets

import common from "@ohos.app.ability.common"
import Want from "@ohos.app.ability.Want"
import fileAccess from "@ohos.file.fileAccess"
import fs from '@ohos.file.fs'
import abilityAccessCtrl, { Permissions } from "@ohos.abilityAccessCtrl"
import promptAction from "@ohos.promptAction"

const LOG_TAG = '[file utils]'


export default class FileUtils {
  private context: common.UIAbilityContext
  private wantInfos: Want[]
  private fileAccessHelper: fileAccess.FileAccessHelper
  private absolutePath = '/mnt/hmdfs/100/account/device_view/local/files/duolun'
  public destFile: string
  public filePathFdObj: Record<string, fs.File> = {}

  constructor(context: common.UIAbilityContext) {
    this.context = context
    this.requestPermission();
    fs.mkdir(this.absolutePath)
  }

  private async requestPermission() {
    let permissions: Array<Permissions> = [
      'ohos.permission.READ_MEDIA',
      'ohos.permission.WRITE_MEDIA'
    ];
    this.wantInfos = await fileAccess.getFileAccessAbilityInfo();
    let atManager: abilityAccessCtrl.AtManager = abilityAccessCtrl.createAtManager()
    atManager.requestPermissionsFromUser(this.context, permissions, async (code, result) => {
      const permissionRequest = result.authResults[0]
      if (permissionRequest == -1) {
        promptAction.showToast({
          message: "请先授权",
          duration: 3000,
        })
        return
      }
    })
  }

  async initFolder(folderPath: string): Promise<string> {
    const folderList = folderPath.split('/').filter(folderName => folderName !== '');
    let path = this.absolutePath
    folderList.forEach(folderName => {
      path += `/${folderName}`;
      try {
        const isExit = fs.accessSync(path);
        if (!isExit) {
          fs.mkdirSync(path)
        }
      } catch (e) {
        console.info('初始化文件夹失败', path)
        promptAction.showToast({
          message: `初始化文件夹失败` + folderPath + JSON.stringify(e),
          duration: 4000,
        })
      }
    })
    return path
  }

  async addFile(filePath: string, content: string) {
    try {
      //文件存在先删除
      if (fs.accessSync(filePath)) {
        fs.unlinkSync(filePath);
      }
      let file = fs.openSync(filePath, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);
      //追加写入文件
      fs.writeSync(file.fd, content)
      fs.closeSync(file)
      console.error(LOG_TAG, '写入文件成功')
      return true
    } catch (e) {
      promptAction.showToast({
        message: `addFile文件失败` + filePath + JSON.stringify(e),
        duration: 4000,
      })
      console.error(LOG_TAG, '写入失败', JSON.stringify(e))
    }
  }

  async editFile(filePath: string, content: string, fd?: number) {
    const thisFile: fs.File = this.filePathFdObj[filePath];
    try {
      if (thisFile) {
        fs.writeSync(thisFile.fd, content + '\n')
        return fd;
      } else {
        let file = fs.openSync(filePath, fs.OpenMode.READ_WRITE | fs.OpenMode.APPEND | fs.OpenMode.CREATE);
        fs.writeSync(file.fd, content + '\n')
        this.filePathFdObj[filePath] = file
        return file.fd
      }
    } catch (e) {
      promptAction.showToast({
        message: `editFile文件失败` + filePath + JSON.stringify(e),
        duration: 4000,
      })
      console.error(LOG_TAG, JSON.stringify(e))
    }
  }

  async readFile(filePath: string): Promise<string> {
    try {
      const str = await fs.readText(filePath);
      return str
    } catch (e) {
      promptAction.showToast({
        message: `读取文件失败` + filePath + JSON.stringify(e),
        duration: 4000,
      })
      console.log('readFile文件失败' + filePath + JSON.stringify(e))
      return ''
    }
  }
}