import { EventEmitter } from 'events'
import fs from 'fs/promises'

export default class Application extends EventEmitter {
  constructor(util, db, provider, name, opts = {}) {
    super()
    this.util = util
    this.db = db
    this.config = db.config[name]
    this.provider = provider
    this.name = name
    this.updating = false

    Object.assign(this, {
      setInterval: opts.setInterval || setInterval,
    })

    this.db.addApplication(name)
  }

  startAutoupdater() {
    let timer = this.setInterval(() => {
      this.update().then(
        () => {
          this.db.data.core[this.name].updater += 'Automatic update finished successfully. '
        },
        (err) => {
          this.db.data.core[this.name].updater += 'Error while running automatic update: ' + err.message + '. '
        }
      )
    }, (this.config.updateEvery || 180) * 60 * 1000)
    timer.unref()
  }

  updateLog(message) {
    this.db.data.core[this.name].updater += message
    this.db.log.info(message)
  }

  async update() {
    if (this.updating) return

    this.updating = true
    this.db.data.core[this.name].updater = ''

    try {
      this.updateLog(`Checking for latest version at ${new Date().toISOString().replace('T', ' ').split('.')[0]}. `)

      let latest = await this.provider.getLatestVersion()

      this.updateLog(`Found ${latest.version}. `)

      if (this.db.data.core[this.name].latestInstalled === latest.version) {
        this.updateLog('Already up to date, nothing to do. ')
        return
      }

      let target = this.util.getPathFromRoot(`./${this.name}/${latest.version}/file${this.util.getExtension(latest.filename)}`)

      await fs.mkdir(this.util.getPathFromRoot(`./${this.name}/${latest.version}`), { recursive: true })

      this.updateLog(`Downloading ${latest.link} to ${target}. `)
      await this.provider.downloadVersion(latest, target)
    } catch (err) {
      this.updating = false
      return Promise.reject(err)
    }
  }
}