/**
 * Class to receive grammar checking service notification
 * 
 * This implementation handles the status icon in the lower-right corner of the host element.
 */
class BesStatusIconEventSink {
  /**
   * Called when grammar checking service is registered
   *
   * @param {BesService} service Grammar checking service
   */
  register(service) {
    this.statusDiv = document.createElement('div')
    this.statusDiv.classList.add('bes-status-div')
    this.statusIcon = document.createElement('div')
    this.statusIcon.classList.add('bes-status-icon')
    this.statusDiv.appendChild(this.statusIcon)
    this.setStatusDivPosition(service)
    service.textElement.parentNode.insertBefore(
      this.statusDiv,
      service.textElement.nextSibling
    )
  }

  /**
   * Called when grammar checking service is unregistered
   *
   * @param {BesService} service Grammar checking service
   */
  unregister(service) {
    this.statusDiv.remove()
    this.statusIcon.remove()
  }

  /**
   * Called to report repositioning
   *
   * @param {BesService} service Grammar checking service
   */
  reposition(service) {
    this.setStatusDivPosition(service)
  }

  /**
   * Called to report resizing
   *
   * @param {BesService} service Grammar checking service
   */
  resize(service) {
    this.setStatusDivPosition(service)
  }

  /**
   * Repositions status DIV element.
   *
   * @param {BesService} service Grammar checking service
   */
  setStatusDivPosition(service) {
    const rect = service.textElement.getBoundingClientRect()
    const scrollbarWidth =
      service.textElement.offsetWidth - service.textElement.clientWidth
    this.statusDiv.style.left = `${rect.right - 40 - scrollbarWidth + window.scrollX}px`
    const scrollbarHeight =
      service.textElement.offsetHeight - service.textElement.clientHeight
    this.statusDiv.style.top = `${rect.bottom - 30 - scrollbarHeight + window.scrollY}px`
  }

  /**
   * Called to report grammar proofing started
   *
   * @param {BesService} service Grammar checking service
   */
  startProofing(service) {
    this.updateStatusIcon('bes-status-loading', 'Besana preverja pravopis.')
  }

  /**
   * Called to report grammar-checking failed (as 500 Internal server error, timeout, etc.)
   *
   * @param {BesService} service Grammar checking service
   * @param {Response} response HTTP response
   */
  failedProofing(service, response) {
    this.updateStatusIcon(
      'bes-status-error',
      `Pri preverjanju pravopisa je prišlo do napake ${response.status} ${response.statusText}.`
    )
  }

  /**
   * Called to report grammar-checking run is ended
   *
   * @param {BesService} service Grammar checking service
   */
  endProofing(service) {
    if (service.proofingError) {
      this.updateStatusIcon(
        'bes-status-error',
        `Pri obdelavi odgovora pravopisnega strežnika je prišlo do napake: ${service.proofingError}`
      )
    } else if (service.proofingMatches > 0)
      this.updateStatusIcon(
        'bes-status-mistakes',
        `Število napak: ${service.proofingMatches}`
      )
    else this.updateStatusIcon('bes-status-success', 'V besedilu ni napak.')
  }

  /**
   * Sets status icon style and title.
   *
   * @param {String} status CSS class name to set status icon to
   * @param {String} title Title of the status icon
   */
  updateStatusIcon(status, title) {
    const statuses = [
      'bes-status-loading',
      'bes-status-success',
      'bes-status-mistakes',
      'bes-status-error'
    ]
    statuses.forEach(statusClass => {
      this.statusIcon.classList.remove(statusClass)
    })
    this.statusIcon.classList.add(status)
    this.statusDiv.title = title
  }
}

class BesCKStatusIconEventSink extends BesStatusIconEventSink {
  /**
   * Repositions status DIV element.
   *
   * @param {BesService} service Grammar checking service
   */
  setStatusDivPosition(service) {
    this.statusDiv.style.right = `10px`
    this.statusDiv.style.bottom = `10px`
  }
}