Reddit - Hide mod threads

// ==UserScript==
// @name            Reddit - Modmail hide threads
// @namespace       http://userscripts.org
// @author          gavin19
// @description     Add context to links that don't have any
// @match           http://*.reddit.com/message/moderator
// @match           https://*.reddit.com/message/moderator
// @include         http://*.reddit.com/message/moderator
// @include         https://*.reddit.com/message/moderator
// @match           http://*.reddit.com/message/moderator*
// @match           https://*.reddit.com/message/moderator*
// @include         http://*.reddit.com/message/moderator*
// @include         https://*.reddit.com/message/moderator*
// @match           http://*.reddit.com/message/moderator/*
// @match           https://*.reddit.com/message/moderator/*
// @include         http://*.reddit.com/message/moderator/*
// @include         https://*.reddit.com/message/moderator/*
// @version         1.0
// ==/UserScript==
(function () {
    var hideModThreads = {
        opts: {
            hideInvites: false /** Hide 'moderator invited' mails by default **/
        },
        checkThreads: function ( threads ) {
            var i, curr, nodes, j, lenj, content,
                mailThreads = threads || document.querySelectorAll( '.message-parent' ),
                hiddenModmail = JSON.parse( localStorage.getItem( 'hiddenModmail' ) ) || [];
            for ( i = 0, len = mailThreads.length; i < len; i += 1 ) {
                if ( hideModThreads.opts.hideInvites ) {
                    content = mailThreads[i].querySelector('.subject');
                    if ( content && ( content.innerHTML.match( 'moderator invited' ) || ( content.innerHTML.match( 'moderator added' )  ) ) ) {
                        hideModThreads.click( mailThreads[i] );
                        mailThreads[i].setAttribute( 'style', 'display:none;' );
                    }
                }
                curr = mailThreads[i].getAttribute( 'data-fullname' );
                if ( hiddenModmail.indexOf( curr ) !== -1 ) {
                    nodes = mailThreads[i].querySelectorAll( '.subject ~ *' );
                    for ( j = 0, lenj = nodes.length; j < lenj; j += 1) {
                        nodes[j].setAttribute( 'style', 'display:none' );
                    }
                    hideModThreads.addLinks( 'show', curr );
                    mailThreads[i].classList.add( 'reduced' );
                } else {
                    hideModThreads.addLinks( 'hide', curr );
                }
            }
            this.checkNewMails();
        },
        checkNewMails: function () {
            var i, len, newMail,
                reduced = document.querySelectorAll( '.reduced' );
            for ( i = 0, len = reduced.length; i < len; i += 1 ) {
                newMail = reduced[i].querySelector( '.new' );
                if ( newMail ) {
                    reduced[i].parentNode.parentNode.parentNode.classList.add( 'flag' );
                }
            }
        },
        click: function ( ele ) {
            var cEvt = document.createEvent( 'MouseEvents' );
            cEvt.initMouseEvent( 'click', false, true, window, 0, 1, 1, 1, 1, false, false, false, false, 0, null );
            ele.dispatchEvent( cEvt );
            return false;
        },
        addHandler: function () {
            var i, len,
                id = this.parentNode.parentNode.getAttribute( 'data-fullname' ),
                node = this.parentNode.parentNode.querySelectorAll( '.subject ~ *' ),
                hiddenModmail = JSON.parse( localStorage.getItem( 'hiddenModmail' ) ) || [];
            if ( this.textContent.match( 'show' ) ) {
                hiddenModmail.splice( hiddenModmail.indexOf( id ), 1 );
                localStorage.setItem( 'hiddenModmail', JSON.stringify( hiddenModmail ) );
                for ( i = 0, len = node.length; i < len; i += 1) {
                    node[i].setAttribute( 'style', 'display:block' );
                }
                this.parentNode.parentNode.classList.remove( 'reduced' );
                this.textContent = ' hide thread';
            } else {
                hiddenModmail.push( id );
                localStorage.setItem( 'hiddenModmail', JSON.stringify( hiddenModmail ) );
                for ( i = 0, len = node.length; i < len; i += 1 ) {
                    node[i].setAttribute( 'style', 'display:none' );
                }
                this.parentNode.parentNode.classList.add( 'reduced' );
                this.textContent = ' show thread';
            }
        },
        addLinks: function ( state, thread ) {
            var link = document.createElement( 'a' ),
                subj = '.id-' + thread,
                target;
            link.href = 'javascript:;';
            link.textContent = ' ' + state + ' thread';
            link.className += 'threadToggle';
            target = document.querySelector( subj );
            target.querySelector( '.subject' ).appendChild( link );
            link.addEventListener( 'click', hideModThreads.addHandler, false );
        },
        addStyle: function () {
            var sheet = '' + '\
            .threadToggle {\
                font-size:smaller;\
                color:#369!important;\
            }\
            .flag::before {\
                content:\'!\';\
                font-weight:bolder;\
                color:#f00;\
            }\
            .reduced {\
                margin:0 10px 0 5px;\
            }';
            style = document.createElement( 'style' );
            style.type = 'text/css';
            style.textContent = sheet;
            document.querySelector( 'head' ).appendChild( style );
        },
        init: function () {
            var t;
            document.body.addEventListener( 'DOMNodeInserted', function ( e ) {
                t = e.target;
                if ( t.localName === 'div' && t.id && t.id.indexOf( 'siteTable' ) !== -1 ) {
                    hideModThreads.checkThreads( t.querySelectorAll( '.message-parent' ) );
                }
            }, true );
            hideModThreads.addStyle();
            hideModThreads.checkThreads();
        }
    };
    if ( document.body && document.querySelector( '.messages-page' ) && window.localStorage ) {
        setTimeout(function () {
            hideModThreads.init();
        }, 100);
    }
}());