import { decThreshold, incThreshold, state } from './state'
import { expand } from './utils'

/**
 * variables
 */

// threshold div
const thresholdDiv = document
  .getElementsByClassName('threshold')
  .item(0) as HTMLDivElement

// threshold nums span
const thresholdDispNums = Array.from(
  thresholdDiv.getElementsByClassName('num')
) as HTMLSpanElement[]

// threshold buttons
const decButton = thresholdDiv
  .getElementsByClassName('dec')
  .item(0) as HTMLButtonElement
const incButton = thresholdDiv
  .getElementsByClassName('inc')
  .item(0) as HTMLButtonElement

// index div
const indexDiv = document.getElementsByClassName('index').item(0) as HTMLDivElement

// index nums span
const indexDispNums = Array.from(
  indexDiv.getElementsByClassName('num')
) as HTMLSpanElement[]

// links div
const linksDiv = document.getElementsByClassName('links').item(0) as HTMLDivElement

// links
const links = Array.from(linksDiv.getElementsByClassName('link')) as HTMLAnchorElement[]

// current link index
const currentLinkIndex = document
  .getElementById('main')!
  .getAttribute('currentMenuItemIndex') as string

// set current link
for (let [index, link] of links.entries()) {
  if (index === parseInt(currentLinkIndex)) {
    link.classList.add('current')
  }
}

/**
 * init
 */

export function initNav() {
  // init threshold text
  updateThresholdText()
  // init index text
  updateIndexText()
  // event listeners
  decButton.addEventListener('click', () => decThreshold())
  incButton.addEventListener('click', () => incThreshold())
}

// helper

export function updateThresholdText(): void {
  const thresholdValue: string = expand(state.get().threshold)
  thresholdDispNums.forEach((e: HTMLSpanElement, i: number) => {
    e.innerText = thresholdValue[i]
  })
}

export function updateIndexText(): void {
  const indexValue: string = expand(state.get().index + 1)
  const indexLength: string = expand(state.get().length)
  indexDispNums.forEach((e: HTMLSpanElement, i: number) => {
    if (i < 4) {
      e.innerText = indexValue[i]
    } else {
      e.innerText = indexLength[i - 4]
    }
  })
}