// Migrated from https://en.wikipedia.org/wiki/User:Garzfoth/common.js on 2021-05-04

// Notes:
// • Variable naming: I believe I stripped the dollar sign prefixes for readability. IIRC they were only in use as an informal way to denote jQuery variables, and I believe they were being misused for sloppy variable declaration as well...
// • Major changes: Wrapped mw.util.addCSS() inside mw.loader expression

// FROM: https://en.wikipedia.org/wiki/User:Mattflaschen/Compare_link.js
// SINCE: 7/21/2015
/**
 * Convert the "Compare selected versions" button to a link
 * (Based on [[w:en:User:Superm401/Compare_link.js]])
 * @source: http://www.mediawiki.org/wiki/Snippets/Compare_link
 * @rev: 2
 * @see: [[bugzilla:16165]]
 * Copyright 2006-2013 Matthew Flaschen ([[User:Superm401]]), [[User:Helder.wiki]]
 */

function fixCompareSelectedVersionsButton() {
	var histForm = $('#mw-history-compare');
	var diffList = $('#pagehistory');
	var buttons = histForm.find('input.historysubmit');
	
	if (buttons.length === 0) {
		// Only one version, so do nothing
		return;
	}
	
	var buttonText = buttons.remove().first().val();
	
	var compareLink = $('<a></a>', {
		'class': 'compare-link',
		'text': buttonText
	});
	
	histForm.prepend(compareLink).append(compareLink.clone());
	
	var updateCompare = function (){
		var radio = histForm.find('input[type=radio]:checked');
		var genLink = mw.config.get('wgScript') + '?title=' + mw.util.wikiUrlencode(mw.config.get('wgPageName')) + '&diff=' + radio.eq(0).val() + '&oldid=' + radio.eq(1).val();
		$('.compare-link').each(function () {
			$(this).attr('href', genLink);
		});
	};
	
	updateCompare();
	diffList.change(updateCompare);
}

if (mw.config.get('wgAction') === 'history') {
	$.when( mw.loader.using( 'mediawiki.util' ), $.ready ).then( function () {
		mw.util.addCSS('.compare-link { border-radius:5px; color:black; text-decoration:none; border-width:1px 2px 2px 1px; border-style:solid; border-color:#DDDDDD #BBBBBB #BBBBBB #DDDDDD; padding:0.2em 1em; background-color:#EEEEEE; white-space:nowrap; } .compare-link:active{ border-width:0.1em; margin:0.1em; }');
	});
	$(fixCompareSelectedVersionsButton);
}