// ==UserScript==
// @name        Smaller bot comments
// @version     6
// @description Changes bot comments into one-liners.
// @downloadURL https://phabricator.wikimedia.org/paste/raw/11638/
// @match       https://phabricator.wikimedia.org/*
// @grant       none
// ==/UserScript==

const uselessMessage = "Your browser timezone setting differs from the timezone setting in your profile, click to reconcile.";
const gitlabUrl = "https://gitlab.wikimedia.org/repos/"
const olderHidden = document.getElementsByClassName("phui-timeline-older-transactions-are-hidden");

// This MutationObserver is used to monitor the removal of the
// "Show Older Changes" banner which will get removed from DOM after
// all oder changes have been added already.
function handleMutation(mutationsList, observer) {
  mutationsList.forEach(mutation => {
    mutation.removedNodes.forEach(node => {
      // Check if the removed node is the show-older-block
      if (node.getAttribute('data-sigil') === 'show-older-block') {
        main();
      }
    });
  });
}

function getCleanTitle(me) {
  // Remove the text node: "added a comment."
  title = me.querySelector(".phui-timeline-title")
  title.childNodes.forEach(n => {
    if (n.nodeType == 3) {
      n.remove()
    }
  });
  return title
}

function handleGerritbot(me) {
  content = me.querySelectorAll(".phabricator-remarkup p")
  if (content[0].textContent.includes(gitlabUrl)) {
    // gerritbot seems to have handled gitlab changes in the past
    return handleCodeReviewBot(me)
  } else {
    // Comments from gerrit changes
    lastIDX = content.length - 1
    link = content[lastIDX].children[0]
    text = []
    content.forEach(function(e, i){
      if (i < lastIDX) {
        text = text.concat(e.textContent.split('\n'))
      }
    })
    textContent = text[0].trim()
    textTooltip = text[1].trim()

    changeId = textContent.match(/^Change #?(\d+)/)[1]
    newText = textContent.replace(/^Change #?\d+ (.*):$/, '$1')
    link.text = changeId
    // Add repo name and commit message as title for the changeId link
    link.setAttribute('title', textTooltip)

    title = getCleanTitle(me)
    title.append(": Change ", link, " ", newText)
    return true
  }
}

function handleCodeReviewBot(me) {
  content = me.querySelectorAll(".phabricator-remarkup p")

  // Comments from gitlab changes
  link = content[0].querySelector(".remarkup-link")
  actionLine = content[0].textContent.replace(link.href, "").trim().split(" ")
  action = actionLine.pop()
  user = actionLine.join(" ")

  // Remove the gitlab base URL from link rext
  link.text = link.href.replace(gitlabUrl, "")
  // Add the commit message as title for the link
  link.setAttribute('title', content[1].textContent)

  title = getCleanTitle(me)
  title.append(": MR ", link, " ", action, " by ", user)

  return true
 }


function handleStashbot(me) {
  content = me.querySelector(".phabricator-remarkup p")

  salSpan = content.querySelector("span")
  ircChannel = salSpan.textContent.match(/.*\((#\S+)\)/)[1]
  salURL = salSpan.querySelector("a").href
  salSpan.remove()

  salLink = document.createElement("a")
  salLink.setAttribute("href", salURL)
  salLink.setAttribute("target", "_blank")
  salLink.text = ircChannel

  title = getCleanTitle(me)
  title.append(" ", salLink, ": ")

  // remove the timestamp from text node
  content.childNodes.forEach(n => {
    if (n.nodeType == 3) {
      n.textContent = n.textContent.trimLeft().replace(/\[[\d-TZ:]+\] /, '')
    }
  })
  title.append(...content.childNodes)

  return true
}

function main() {
  const majorEvents = document.querySelectorAll(".phui-timeline-major-event")
  majorEvents.forEach(me => {
    let modified = false

    if (me.querySelector(".phui-handle").text == 'gerritbot') {
      modified = handleGerritbot(me)
    }

    if (me.querySelector(".phui-handle").text == 'Stashbot') {
      modified = handleStashbot(me)
    }

    if (me.querySelector(".phui-handle").text == 'CodeReviewBot') {
      modified = handleCodeReviewBot(me)
    }

    if (modified) {
      // remove the "quote" menu on the right
      me.querySelector(".phui-timeline-menu").remove()
      // remove the original comment content
      me.querySelector(".phui-timeline-core-content").remove()
      // make this event minor (one-liner)
      me.classList.replace("phui-timeline-major-event", "phui-timeline-minor-event")
    }
  });
}

// Remove irrelevant stuff from page title
// ⚓ T307943
document.title = document.title.replace(/⚓ T\d+ /, "");
// Run the main function
main();

// Register observers to watch for loading of older events
// which might happen on click or when a anchor to an older
// event is in the URL.
if (olderHidden.length > 0) {
  const observer = new MutationObserver(handleMutation);
  const observerConfig = { childList: true };
  for (let ohb of olderHidden) {
    observer.observe(ohb.parentNode, observerConfig);
  }
}