/** 
 * This script lets you use a custom summary with the rollback feature
 * by adding a "sum" link wherever a rollback link appears. When you
 * click "sum" you are prompted for a custom summary, and the script
 * adds an additional summary parameter to the rollback URL submitting it.
 *
 * For usage and extra options, see the talk page.
 */

function addSumLink() {
    var rbnode = [], diffnode, index = {}, gebcn = document.getElementsByClassName
        ? function(a, b, c) { return a ? a.getElementsByClassName(c) : [] }
        : getElementsByClassName;
    if (typeof rollbackLinksDisable == 'object' && rollbackLinksDisable instanceof Array)
        for (var i = 0; i < rollbackLinksDisable.length; i++)
            index[rollbackLinksDisable[i]] = true;
    if (!('user' in index) && mw.config.get("wgCanonicalSpecialPageName") == "Contributions" ||
        !('recent' in index) && mw.config.get("wgCanonicalSpecialPageName") == "Recentchanges" ||
        !('watchlist' in index) && mw.config.get("wgCanonicalSpecialPageName") == "Watchlist")
        rbnode = gebcn(document.getElementById("bodyContent"), "span", "mw-rollback-link");
    else if (!('history' in index) && mw.config.get("wgAction") == "history")
        rbnode = gebcn(document.getElementById("pagehistory"), "span", "mw-rollback-link");
    else if (!('diff' in index) && (diffnode = document.getElementById("mw-diff-ntitle2")))
        rbnode = gebcn(diffnode, "span", "mw-rollback-link");
    for (var i = 0, len = rbnode.length; i < len; i++)
        addRollbackSummaryLink(rbnode[i]);
}

function confirmRollback() {
    var url = this.href;
    var user = url.match(/[?&]from=([^&]*)/);
    if (!user) return;
    user = decodeURIComponent(user[1].replace(/\+/g, " "));
    var summary = prompt("Enter a summary to use for rollback.\n\nLeave blank to use the default. $user will be replaced with \"" + user + "\".",
                         rollbackSummaryDefault);
    if (summary == undefined)
        return false;
    else if (summary == "")
        return true;
    this.href += "&summary=" + encodeURIComponent(summary.replace(/\$user/g, user));
    return true;
}

function addRollbackSummaryLink(rbnode) {
    var rblink = rbnode.getElementsByTagName("a")[0];
    var alink = rblink.cloneNode(true);
    alink.className = ""; //don't confuse other scripts
    alink.firstChild.nodeValue = "sum";
    alink.onclick = confirmRollback;
    rbnode.insertBefore(alink, rblink.nextSibling);
    rbnode.insertBefore(document.createTextNode(" | "), alink);
}
if (typeof rollbackLinksDisable == 'undefined')
    rollbackLinksDisable = [];
if (typeof rollbackSummaryDefault == 'undefined')
    rollbackSummaryDefault = "";

$(addSumLink);