// ==UserScript==
// @name         Lovely Forks
// @namespace    musically-ut
// @version      2.7.0
// @description  Show notable forks of GitHub projects.
// @homepage     https://github.com/musically-ut/lovely-forks
// @icon         https://github.com/musically-ut/lovely-forks/raw/master/userscript/icon.png
// @author       musically-ut
// @match        *://github.com/*
// @grant        GM_addStyle
// @run-at       document-end
// ==/UserScript==
/* WARNING: This usescript was created from a legacy version of Lovely Forks
* which does not support user preferences setting and maintains code in pre-ES6
* JavaScript format which ought to be supported by most browsers out there.
* If you are using Firefox or Chrome, it is best to use the respective
* extension/addon for your browser for a better experience.
*/
'use strict';
/*jshint browser: true, es5: true, sub:true */
var script_css = `/* placeholder */
.repohead-details-container .public:after {
display: block;
visibility: hidden;
content: ".";
font-size: 12px;
line-height: 12px;
}
/* remove placeholder */
.repohead-details-container .has-lovely-forks.public:after {
display: none;
}
/* smoother integration, show hierarchy */
.lovely-forks-addon {
animation: fade-in 0.2s;
padding-left: 1em;
}
.lovely-fork-style {
font-size: 12px;
}
@keyframes fade-in {
from {
opacity: 0;
}
}
`;
GM_addStyle(script_css);
var _logName = 'lovely-forks:';
var DEBUG = false;
var text;
var svgNS = 'http://www.w3.org/2000/svg';
function createIconSVG(type) {
var svg = document.createElementNS(svgNS, 'svg');
svg.setAttributeNS(null, 'height', 12);
svg.setAttributeNS(null, 'width', 10.5);
svg.setAttributeNS(null, 'viewBox', '0 0 14 16');
svg.style['vertical-align'] = 'bottom';
svg.style['fill'] = 'currentColor';
svg.classList.add('opticon', 'opticon-' + type);
var title = document.createElementNS(svgNS, 'title');
var iconPath = document.createElementNS(svgNS, 'path');
switch(type) {
case 'star':
title.appendChild(document.createTextNode('Number of stars'));
iconPath.setAttributeNS(null, 'd', 'M14 6l-4.9-0.64L7 1 4.9 5.36 0 6l3.6 3.26L2.67 14l4.33-2.33 4.33 2.33L10.4 9.26 14 6z');
break;
case 'flame':
title.appendChild(document.createTextNode('Fork may be more recent than upstream.'));
iconPath.setAttributeNS(null, 'd',  'M5.05 0.31c0.81 2.17 0.41 3.38-0.52 4.31-0.98 1.05-2.55 1.83-3.63 3.36-1.45 2.05-1.7 6.53 3.53 7.7-2.2-1.16-2.67-4.52-0.3-6.61-0.61 2.03 0.53 3.33 1.94 2.86 1.39-0.47 2.3 0.53 2.27 1.67-0.02 0.78-0.31 1.44-1.13 1.81 3.42-0.59 4.78-3.42 4.78-5.56 0-2.84-2.53-3.22-1.25-5.61-1.52 0.13-2.03 1.13-1.89 2.75 0.09 1.08-1.02 1.8-1.86 1.33-0.67-0.41-0.66-1.19-0.06-1.78 1.25-1.23 1.75-4.09-1.88-6.22l-0.02-0.02z');
iconPath.setAttributeNS(null, 'fill', '#d26911');
break;
}
iconPath.appendChild(title);
svg.appendChild(iconPath);
return svg;
}
function emptyElem(elem) {
elem.textContent = ''; // How jQuery does it
}
function mbStrToMs(dateStr) {
return dateStr !== null ? Date.parse(dateStr) : null;
}
function isExpired(timeMs) {
var currentTime = new Date();
// The time of expiry of data is set to be an hour ago
var expiryTimeMs = currentTime.valueOf() - 1000 * 60 * 60;
return timeMs < expiryTimeMs;
}
function makeSelfDataKey(user, repo) {
return 'lovely-forks@self:' + user + '/' + repo;
}
function makeRemoteDataKey(user, repo) {
return 'lovely-forks@remote:' + user + '/' + repo;
}
var reDateKey = new RegExp('^lovely-forks@date:(.*)/(.*)$');
function makeTimeKey(user, repo) {
return 'lovely-forks@date:' + user + '/' + repo;
}
function parseTimeKey(key) {
var match = reDateKey.exec(key);
if (match !== null) {
return [match[1], match[2]];
} else {
return null;
}
}
function getForksElement() {
// Verify that the element exists and it's still valid
// otherwise, create it
if (document.body.contains(text)) {
return text;
}
// If the layout of the page changes, we'll have to change this location.
// We should make sure that we do not accidentally cause errors here.
var repoName = document.querySelector('strong[itemprop="name"]').parentNode;
if (repoName) {
try {
text = document.createElement('span');
text.classList.add('lovely-fork-style', 'lovely-forks-addon');
repoName.appendChild(text);
return text;
} catch (e) {
console.error(_logName,
'Error appending data to DOM',
e);
}
} else {
console.warn(_logName,
'Looks like the layout of the GitHub page has changed.');
}
}
function clearLocalStorage() {
var keysToUnset = [];
/* Remove all items which have expired. */
for(var ii = 0; ii < localStorage.length; ii++) {
var key = localStorage.key(ii);
var mbUserRepo = parseTimeKey(key);
if (mbUserRepo !== null) {
var timeMs = mbStrToMs(localStorage.getItem(key));
if (timeMs) {
if (isExpired(timeMs)) {
var user = mbUserRepo[0],
repo = mbUserRepo[1];
keysToUnset.push(makeRemoteDataKey(user, repo));
keysToUnset.push(makeSelfDataKey(user, repo));
keysToUnset.push(makeTimeKey(user, repo));
}
} else {
console.warn(_logName,
'Unable to parse time: ',
localStorage.getItem(key));
}
}
}
keysToUnset.forEach(function (key) {
if (DEBUG) {
console.log(_logName,
'Removing key: ', key);
}
localStorage.removeItem(key);
});
}
function safeUpdateDOM(action, actionName) {
// Get the stored version or create it if it doesn't exist
var text = getForksElement();
// We should make sure that we do not accidentally cause errors here.
if (text) {
try {
emptyElem(text);
action(text);
} catch (e) {
console.error(_logName,
'Error appending data to DOM', e,
'during action', actionName);
}
} else {
console.warn(_logName,
'Unable to find the lovely-forks loading indicator',
'during action', actionName);
}
}
function showDetails(fullName, url, numStars, remoteIsNewer) {
return function (text) {
var forkA = document.createElement('a');
forkA.href = url;
forkA.appendChild(document.createTextNode(fullName));
text.appendChild(document.createTextNode('also forked to '));
text.appendChild(forkA);
text.appendChild(document.createTextNode(' '));
text.appendChild(createIconSVG('star'));
text.appendChild(document.createTextNode('' + numStars + ' '));
if (remoteIsNewer) {
text.appendChild(createIconSVG('flame'));
}
text.parentNode.classList.add('has-lovely-forks');
};
}
function makeRemoteDataURL(user, repo) {
return 'https://api.github.com/repos/' +
user + '/' + repo + '/forks?sort=stargazers';
}
function makeCommitDiffURL(user, repo, remoteUser, default_branch) {
return 'https://api.github.com/repos/' +
user + '/' + repo + '/compare/' +
user + ':' + default_branch + '...' +
remoteUser + ':' + default_branch;
}
// From: http://crocodillon.com/blog/always-catch-localstorage-security-and-quota-exceeded-errors
function isQuotaExceeded(e) {
var quotaExceeded = false;
if (e) {
if (e.code) {
switch (e.code) {
case 22:
quotaExceeded = true;
break;
case 1014:
// Firefox
if (e.name === 'NS_ERROR_DOM_QUOTA_REACHED') {
quotaExceeded = true;
}
break;
}
}
}
return quotaExceeded;
}
function processWithData(user, repo, remoteDataStr, selfDataStr, isFreshData) {
try {
/* Parse fork data */
/* Can either be just one data element,
* or could be the list of all forks. */
var allForksData = JSON.parse(remoteDataStr);
var mostStarredFork = allForksData[0];
var forkUrl = mostStarredFork['html_url'],
fullName = mostStarredFork['full_name'];
/* Parse self data */
/* This could either be the commit-diff data (v2)
* or `all_commits` data (v1). */
/* selfData can also be null, if the commit difference API r###lted in
* an error. */
var selfData = JSON.parse(selfDataStr),
selfDataToSave = selfData,
remoteIsNewer = false;
if (selfData !== null) {
if (selfData.hasOwnProperty('ahead_by')) {
// New version
var diffData = selfData;
remoteIsNewer = (diffData['ahead_by'] - diffData['behind_by']) > 0;
} else {
// Old version
var allCommits = selfData;
var remoteUpdateTimeMs = mbStrToMs(mostStarredFork['pushed_at']);
if (!allCommits || allCommits.length < 1) {
if (DEBUG) {
console.log(_logName,
'Repository does not have any commits.');
}
return;
}
var latestCommit = allCommits[0]['commit'];
var committer = latestCommit['committer'];
if (!committer) {
if (DEBUG) {
console.error(_logName,
'Could not find the latest committer.');
}
return;
}
var selfUpdateTimeMs = mbStrToMs(committer['date']);
remoteIsNewer = remoteUpdateTimeMs > selfUpdateTimeMs;
selfDataToSave = [allCommits[0]];
}
} else {
remoteIsNewer = false;
}
/* Cache data, if necessary */
if (isFreshData) {
var currentTimeMs = (new Date()).toString();
if (DEBUG) {
console.log(_logName, 'Saving data');
}
try {
clearLocalStorage();
localStorage.setItem(makeTimeKey(user, repo), currentTimeMs);
// Only the most starred fork is relevant
var relevantRemoteDataStr = JSON.stringify([mostStarredFork]);
localStorage.setItem(makeRemoteDataKey(user, repo),
relevantRemoteDataStr);
// Only the latest commit is relevant
var relevantSelfDataStr = JSON.stringify(selfDataToSave);
localStorage.setItem(makeSelfDataKey(user, repo),
relevantSelfDataStr);
} catch(e) {
if (isQuotaExceeded(e)) {
console.warn(_logName, 'localStorage quota full.');
} else {
throw e;
}
}
}
// Now if the repository doesn't have any notable forks, so not
// touch the DOM.
var starGazers = mostStarredFork['stargazers_count'];
if (!starGazers) {
if (DEBUG) {
console.log(_logName,
'Repo has only zero starred forks.');
}
return;
}
safeUpdateDOM(showDetails(fullName, forkUrl, starGazers,
remoteIsNewer),
'showing details');
} catch (e) {
console.warn(_logName,
'Error while handling response: ',
e);
}
}
function onreadystatechangeFactory(xhr, successFn) {
return function () {
if (xhr.readyState === 4) {
if (xhr.status === 200) {
successFn();
} else if (xhr.status === 403) {
console.warn(_logName,
'Looks like the rate-limit was exceeded.');
} else {
console.warn(_logName,
'GitHub API returned status:', xhr.status);
}
} else {
// Request is still in progress
// Do nothing.
}
};
}
function makeFreshRequest(user, repo) {
var xhrFork = new XMLHttpRequest();
xhrFork.onreadystatechange = onreadystatechangeFactory(
xhrFork,
function () {
var forksDataJson = JSON.parse(xhrFork.responseText);
if (!forksDataJson || forksDataJson.length === 0) {
if (DEBUG) {
console.log(_logName,
'Repository does not have any forks.');
}
return;
}
var mostStarredFork = forksDataJson[0],
forksDataStr = JSON.stringify([mostStarredFork]);
var defaultBranch = mostStarredFork['default_branch'],
remoteUser    = mostStarredFork['owner']['login'];
var xhrDiff = new XMLHttpRequest();
xhrDiff.onreadystatechange = function () {
if (xhrDiff.readyState === 4) {
if (xhrDiff.status === 200) {
var commitDiffJson = JSON.parse(xhrDiff.responseText);
// Dropping the list of commits to conserve space.
commitDiffJson['commits'] = [];
var commitDiffStr = JSON.stringify(commitDiffJson);
processWithData(user, repo, forksDataStr, commitDiffStr, true);
} else {
// In case of any error, ignore recency data.
processWithData(user, repo, forksDataStr, null, true);
}
}
};
xhrDiff.open('GET', makeCommitDiffURL(user, repo, remoteUser, defaultBranch));
xhrDiff.send();
}
);
xhrFork.open('GET', makeRemoteDataURL(user, repo));
xhrFork.send();
}
function getDataFor(user, repo) {
var lfTimeKey       = makeTimeKey(user, repo),
lfRemoteDataKey = makeRemoteDataKey(user, repo),
lfSelfDataKey   = makeSelfDataKey(user, repo);
var ret = { hasData: false };
var savedRemoteDataStr = localStorage.getItem(lfRemoteDataKey);
var savedSelfDataStr   = localStorage.getItem(lfSelfDataKey);
var saveTimeMs         = mbStrToMs(localStorage.getItem(lfTimeKey));
if (saveTimeMs         === null ||
savedRemoteDataStr === null ||
savedSelfDataStr   === null) {
return ret;
}
ret.hasData            = true;
ret.saveTimeMs         = saveTimeMs;
ret.savedRemoteDataStr = savedRemoteDataStr;
ret.savedSelfDataStr   = savedSelfDataStr;
return ret;
}
function runFor(user, repo) {
try {
var cache = getDataFor(user, repo);
if (cache.hasData && !isExpired(cache.saveTimeMs)) {
if (DEBUG) {
console.log(_logName,
'Reusing saved data.');
}
processWithData(user, repo,
cache.savedRemoteDataStr, cache.savedSelfDataStr,
false);
} else {
if (DEBUG) {
console.log(_logName,
'Requesting the data from GitHub API.');
}
makeFreshRequest(user, repo);
}
} catch (e) {
console.error(_logName, 'Could not run for ', user + '/' + repo,
'Exception: ', e);
}
}
/* Script execution */
var pathComponents = window.location.pathname.split('/');
if (pathComponents.length >= 3) {
var user = pathComponents[1], repo = pathComponents[2];
runFor(user, repo);
} else {
if (DEBUG) {
console.log(_logName,
'The URL did not identify a username/repository pair.');
}
}