//
// ==UserScript==
// @name          Perlmonks AJAX Vote
// @namespace     http://www.perlmonks.org/?node_id=398318
// @description   Allow background voting via AJAX
// @include       http://www.perlmonks.*
// @include       http://perlmonks.*
// @exclude       http://www.perlmonks.*/?node=Fullpage%20Chat
// @exclude       http://perlmonks.*/?node=Fullpage%20Chat
// ==/UserScript==

function postRequest (url, params, onLoad) {
    var xmlHttpReq = new XMLHttpRequest();
    xmlHttpReq.open('POST', url, true);
    xmlHttpReq.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    xmlHttpReq.onreadystatechange = function() {
            if (xmlHttpReq.readyState == 4) {
                onLoad(xmlHttpReq.responseText);
            };
    };
    xmlHttpReq.send(params);

}

function _cast_vote(node_id, voteString, vc, vote) {
 document.getElementById('pm_'+voteString).innerHTML='<b>Casting Vote...</b>';
 postRequest('/?', 'displaytype=xml&vc='+vc+'&op=vote&.cgifields='+voteString+'&'+voteString+'='+vote,
    function () {
        document.getElementById('pm_'+voteString).innerHTML = 'Retrieving Node Reputation...';
        postRequest('/?', 'displaytype=xml&node_id=' + node_id,
            function (retHTML) {
                var parser=new DOMParser();
                var doc=parser.parseFromString(retHTML,'text/xml');
                var x=doc.getElementsByTagName('field');
                for(i=0;i<x.length;i++) {
                    var item=x.item(i);
                    if (item.attributes.getNamedItem('name').value == 'reputation') {
                        document.getElementById('pm_'+voteString).innerHTML = 'Reputation: ' + item.childNodes[0].nodeValue;
                    }
                };
            });
    });
};

function getNode_byPath (path) {
    var temp = document.evaluate(path, document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null);
    if (temp) {
        return temp.singleNodeValue;
    } else {
        return null;
    }
}

function getNodes_byPath(path,context) {
    var nodes = document.evaluate(path,context, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
    var ret = [];
    for (var i = 0; i < nodes.snapshotLength; i++) {
        ret.push(nodes.snapshotItem(i));
    }
    return ret;
}

function remove_byPath (path, context) {
    var nodes = getNodes_byPath(path, context);
    for (i in nodes) {
        nodes[i].parentNode.removeChild(nodes[i]);
    }
}

function cast_vote (node_id, voteString, vc, vote) {
    return function () { _cast_vote(node_id, voteString, vc, vote); };
}

function _refresh_votes () {
    postRequest('/?', 'node_id=16046',
        function (retHTML) {
        var parser=new DOMParser();
        var doc=parser.parseFromString(retHTML,'text/xml');
        var x=doc.getElementsByTagName('XP');
        for(i=0;i<x.length;i++) {
                var item=x.item(i);
                var xpNodelet = getNode_byPath("//tr[@id='nodelet_body_row_XP_Nodelet']/td");
                if (xpNodelet)
                     xpNodelet.innerHTML = "You have " + item.attributes.getNamedItem('votesleft').value + ' votes left today.';
                };
        });       
}

function refresh_votes () {
    return function () { _refresh_votes() }
}


var xpNodelet = getNode_byPath("//tr[@id='nodelet_head_row_XP_Nodelet']/th");
if (xpNodelet) 
        var refresh = document.createElement('a');
        refresh.setAttribute("href",'javascript:void(0);');
        refresh.removeAttribute("onclick"); 
        refresh.addEventListener("click", refresh_votes(), true);
        refresh.innerHTML = " @";
        xpNodelet.appendChild(refresh);
}

var inputNode = getNode_byPath("//input[@name='op' and @value='vote']");
if (inputNode) {
    var formNode = inputNode.parentNode;

    var vc;
    var inputVC = getNode_byPath("//input[@name='vc']", formNode);
    if (inputVC) {
        vc = inputVC.value;
    }

    var votinginputs = getNodes_byPath("//label/input[@type='radio']", formNode);
    for (var i in votinginputs) { 
        var thisInput = votinginputs[i];
        if (thisInput.value == 0) {
            var voteString = thisInput.name;
            var node_id    = voteString.substring(6);

            var voting_both = document.createElement("div");
            voting_both.class      = 'reputation';
            voting_both.id         = "pm_" + voteString;

            var up_vote = document.createElement('a');
            up_vote.setAttribute("href",'javascript:void(0);');
            up_vote.removeAttribute("onclick"); 
            up_vote.addEventListener("click", cast_vote(node_id, voteString, vc, 1), true);
            up_vote.innerHTML = "++";
            voting_both.appendChild(up_vote);

            var spacer = document.createElement("span");
            spacer.innerHTML = "&nbsp;";
            voting_both.appendChild(spacer);
            
            var down_vote = document.createElement('a');
            down_vote.setAttribute("href",'javascript:void(0);');
            down_vote.removeAttribute("onclick"); 
            down_vote.addEventListener("click", cast_vote(node_id, voteString, vc, -1), true);
            down_vote.innerHTML = "--";
            voting_both.appendChild(down_vote);
            
            thisInput.parentNode.insertBefore(voting_both, thisInput);
        }
        thisInput.parentNode.removeChild(thisInput);
        
    }
    
    // remove the original voting labels
    remove_byPath("//div[@class='vote']//tt", formNode);
    
    // delete the submit button
    remove_byPath("//input[@name='sexisgreat']", document);    
}