// ==UserScript==
// @name        4chan Page 10 Notifier
// @namespace   moe.rita.4chanPage10Notifier
// @match       https://boards.4chan.org/*/thread/*
// @run-at      document-end
// @grant       none
// @version     1.2.2
// @author      Kody
// @description Notify when the thread gets to page 10.
// @icon        https://www.google.com/s2/favicons?domain=4chan.org
// @downloadURL https://gist.rita.moe/kody/c3cd33a8d923423c9045ad738ec302ba/raw/HEAD/4chan-page-notifier.user.js
// ==/UserScript==

(function () {
  'use strict'

  let pageCountEl
  const lastPage = 10
  let notified = false

  const pageNotify = () => {
    // Extract the current page number from the text
    // but be careful that it might be 10(x)
    const currPage = parseInt(pageCountEl.innerText.split('(')[0]?.trim(), 10)
    console.log('Current page:', currPage)

    // Check if it's a valid number and greater than 0
    if (isNaN(currPage) || currPage < 1) {
      console.warn('Invalid page number:', currPage)
      return
    }

    // Reset notification state if page is less than 10
    if (currPage < lastPage && notified) {
      notified = false
      return
    }

    // Skip if already notified or current page is less than the last page
    if (currPage < lastPage || notified) {
      return
    }

    // Send a browser notification
    const subject = document.querySelector('.subject')?.innerText || 'Last Page Reached'
    if (window.Notification.permission === 'granted') {
      const notification = new window.Notification(
        subject,
        {
          body: `The thread has reached page ${currPage}.`,
          icon: 'https://www.google.com/s2/favicons?domain=4chan.org',
        }
      )
      notification.onclick = () => {
        window.focus()
        notification.close()
      }

      notified = true
    }
  }

  const setupObserver = () => {
    pageCountEl = document.getElementById('page-count')

    if (pageCountEl) {
      const observer = new window.MutationObserver(pageNotify)
      observer.observe(
        pageCountEl,
        {
          childList: true,
          subtree: true,
          characterData: true,
        }
      )
    } else {
      console.error('Could not find element with ID "page-count"')
    }
  }

  // Wait 3 seconds before setting up the observer
  setTimeout(setupObserver, 3000)
})()