import { readFile } from 'fs/promises'
import { open } from 'sqlite'
import sqlite3 from 'sqlite3'
import AdmZip from 'adm-zip'

// database structure: https://github.com/ankidroid/Anki-Android/wiki/Database-Structure
// python example: https://github.com/patarapolw/ankisync2
// old js example: https://github.com/nornagon/mkanki/blob/master/index.js

// to create a zip file
// const zip = new AdmZip()
// zip.addLocalFolder('./folder_to_zip')
// zip.writeZip('./output.zip')

class Deck {

  /**
   * 
   * @param info ID of internal deck, or filename or anki export
   * @param process whether or not this is an external anki export to process
   */
  constructor(info, process) {
    // pull out variables
    this.notes = null // this is what is edited; may create multiple cards
    this.media = null // image and audio files attached to cards/notes
  }

  /**
   * Loads an internal deck
   */
  async load(id) {
    // open database
    // open media files
  }

  /**
   * Processes an anki export for internal use. Currently only supports
   * .apkg files. In the future, may support:
   *   colpkg
   *   txt (notes)
   *   txt (cards)
   * 
   * @param filename path of file to process
   */
  async process(filename) {
    return await this.processApkg(filename)
  }

  /**
   * Processes a .apkg file into a database
   * 
   * @param filename name of file to open and process
  */
  async processApkg(filename) {
    // error handling
    if (!filename) throw new Error('Must specify a .apkg filename')

    // setup
    let uuid = crypto.randomUUID()
    let location = `../data/anki/decks/${uuid}/`

    // make the resource folder if it does not exist already
    // let resource = ''
    // if (!fs.existsSync(resource)) fs.mkdirSync(resource, { recursive: true })

    // extract zip
    // https://stuk.github.io/jszip/documentation/howto/read_zip.html#in-nodejs
    let zip = new AdmZip(filename)
    zip.extractAllTo(location, true)

    // extract the notes database
    let db = await open({
      filename: location + 'collection.anki2',
      driver: sqlite3.cached.Database
    })

    let result = await db.get('SELECT sfld FROM notes WHERE id = :n', 1486785585103)

    console.log(result);

    // extract media files
    // ? process/rename media files and update in db?
    // load data into this obj

    // return { notes, media }
  }
}

export default Deck