/* -----------------------------------------------------------------------------
 * STARTUP
 */

/* TODO: Check setup variables */
/* TODO: Loading indicator */

var categoryCurrent = null;
var categoryArea = document.getElementById("headers");
var xmlData = null;
var gdoc = null;
var gwindow = null;

function init()
{
    /* Set by frame.html */
    if(!window._frameLoaded)
    {
        window.setTimeout("init();", 100);
        return;
    }

    setupFrame();
    loadXml(makeEndpointURI(), loadedGraphData);
}

init();

function loadedGraphData(doc)
{
    if(!doc)
    {
        displayError("Couldn't load graph data from server", categoryArea);
        return;
    }

    xmlData = doc;

    displayCategories();
    displayCurrentPage();
}


/* -----------------------------------------------------------------------------
 * GRAPHS
 */

function getFrameDocument()
{
    var frame = document.getElementById("main-frame");
    /* COMPAT: IE and Mozilla access the content of frames differently */
    return frame.contentDocument ? frame.contentDocument : frame.contentWindow.document;
}

function setupFrame()
{
    gdoc = getFrameDocument();
    var frame = document.getElementById("main-frame");
    /* COMPAT: IE and Mozilla access the content of frames differently */
    gwindow = frame.contentDocument ? frame.contentDocument.defaultView : frame.contentWindow;
}

function displayCurrentPage()
{
    var area = gdoc.getElementById("graphs");
    var img;

    /* Hide all images not from this category */
    var i, images = area.getElementsByTagName("img");
    for(i = 0; i < images.length; i++)
    {
        img = images.item(i);
        var vis = (img._category == categoryCurrent);

        img.style.display = vis ? "inline" : "none";

        if(vis != img._visible)
        {
            /* The graph needs reloading if now turning visible */
            img._visible = vis;
            if(vis)
                reloadGraph(img, false);
            else
                img._loading = false;
        }
    }

    var graphs = findCategoryGraphs(categoryCurrent);
    if(!graphs)
    {
        displayError("Graph data isn't loaded from server", area);
        return;
    }

    var tend = nowTime();
    var tbeg = tend - 86400; /* One day by default */

    for(i = 0; i < graphs.length; i++)
    {
        var child = graphs[i];

        var name = child.getAttribute("name");
        if(!name || !name.length)
            continue;

        /* Make sure we don't already have this graph */
        var id = "graph-" + categoryCurrent + "-" + name;
        img = gdoc.getElementById(id);
        if(img != null)
            continue;

        var interval = child.getAttribute("interval");
        if(!interval || isNaN(interval) || interval <= 0)
            interval = 0;
        interval = Number(interval);

        img = gdoc.createElement("img");

        var title = child.getAttribute("title");
        if(title && title.length)
        {
            img.setAttribute("title", child.getAttribute("title"));
            img.setAttribute("alt", child.getAttribute("title"));
        }
        else
            img.setAttribute("alt", "Graph");

        img.className = "graph";
        img.id = id;
        img.style.cursor = "crosshair";

        area.appendChild(img);

        img._category = categoryCurrent;
        img._name = name;
        img._tbeg = tbeg;
        img._tend = tend;
        img._tinterval = interval;
        img._visible = true;
        img._loading = false;

        reloadGraph(img, false);

        img.onmousedown = function(evt)
            { actionGotoCancel(); return zoomGraphStart(evt || gwindow.event); }
        img.onmouseover = function(evt)
            { return actionsDisplay(gwindow.event ? gwindow.event : evt); }

        /* Setup for an auto scroll */
        if(interval)
        {
            /* Bump up auto scroll interval to 5 seconds */
            var interval = img._tinterval < 5 ? 5 : img._tinterval;
            window.setInterval(autoScroll, interval * 1000, img);
        }
    }
}

function reloadGraph(img, force)
{
    img._last = nowTime();

    if(!img._visible)
        return;

    /* TODO: Move these into settings */
    /* TODO: We should encode colons properly */
    var GRAPH_COLOR_BACK = ":252424";
    var GRAPH_COLOR_FONT = ":E7E1CC";
    var GRAPH_WIDTH = 450;
    var GRAPH_HEIGHT = 120

    var uri = makeEndpointURI() + "/graph?category=" + img._category + "&name=" + img._name;

    /* Add date options */
    uri += "&start=" + img._tbeg + "&end=" + img._tend;

    /* And colors */
    uri += "&color=BACK" + GRAPH_COLOR_BACK + "&color=FONT" + GRAPH_COLOR_FONT +
           "&color=SHADEA" + GRAPH_COLOR_BACK + "&color=SHADEB" + GRAPH_COLOR_BACK;

    /* Size */
    uri += "&height=" + GRAPH_HEIGHT + "&width=" + GRAPH_WIDTH;

    if(force || img.getAttribute("src") != uri)
    {
        img._loading = true;
        updateCursors(img);

        /* HACK: The onload event for IMG is called with a strange event target */
        img.onload = new Function("reloadedGraph('" + img.id + "');");
        img.setAttribute("src", uri);
    }
}

function reloadedGraph(id)
{
    var img = getFrameDocument().getElementById(id);
    img._loading = false;
    updateCursors(img);
}

function updateCursors(img)
{
    if(img._actions)
    {
        var i, acts = img._actions.getElementsByTagName("img");
        for(i = 0; i < acts.length; i++)
            acts.item(i).style.cursor = img._loading ? "wait" : "pointer";
    }

    img.style.cursor = img._loading ? "wait" : "crosshair";
}

function autoScroll(img)
{
    /* Don't auto scroll if we have loading issues */
    if(img._loading)
        return;

    /* If we're displaying 'now' somewhere in the graph... */
    var now = nowTime();
    if((img._tend + (img._tinterval * 2)) >= now)
    {
        var diff = now - img._last;

        if(diff > 0)
        {
            /* ... then scroll by X seconds to scroll the graph */
            img._tbeg += diff;
            img._tend += diff;
            reloadGraph(img, false);
        }
    }
}



/* -----------------------------------------------------------------------------
 * ZOOM
 */

function zoomGraphStart(evt)
{
    /* COMPAT: In IE the left button is 1, Mozilla is 0 */
    var lbutton = gwindow.event ? 1 : 0;

    if(evt.button != lbutton)
        return;

    /* COMPAT: Target is handled differently in Internet nastiness */
    var img = evt.target || evt.srcElement;

    if(img.className != "graph")
        return;

    var zoom = gdoc.getElementById("zoom");

    zoom._img = img;
    zoom._zooming = true;
    zoom._from = evt.clientX + gdoc.body.scrollLeft;

    zoom._start = zoom._from - img.offsetLeft;
    zoom._end = zoom._start;

    zoom.style.width = 1;
    zoom.style.left = zoom._from;
    zoom.style.height = img.height;
    zoom.style.top = img.offsetTop;
    zoom.style.display = "block";

    zoom.onmousemove = zoom._img.onmousemove = function(evt)
        { return zoomGraphUpdate(gwindow.event ? gwindow.event : evt); }
    zoom.onmouseup = zoom._img.onmouseup = function(evt)
        { return zoomGraphDone(gwindow.event ? gwindow.event : evt); }
    document.onmouseup = gdoc.onmouseup = function(evt)
        { return zoomGraphDone(gwindow.event ? gwindow.event : evt); }

    cancelEvent(evt);
    return false;
}

function zoomGraphUpdate(evt)
{
    var zoom = gdoc.getElementById("zoom");
    if(!zoom._zooming || !zoom._img)
        return;

    var to = evt.clientX + gdoc.body.scrollLeft;
    var width = to - zoom._from;
    zoom._end = to - zoom._img.offsetLeft;

    if(width == 0)
        width = 1;

    if(width < 0)
    {
        zoom.style.left = to;
        zoom.style.width = -width;
    }
    else
    {
        zoom.style.left = zoom._from;
        zoom.style.width = width;
    }

    zoom.style.height = zoom._img.height;
    zoom.style.top = zoom._img.offsetTop;
    zoom.style.display = "block";

    cancelEvent(evt);
    return false;
}

function zoomGraphDone(evt)
{
    var zoom = gdoc.getElementById("zoom");
    if(!zoom._zooming)
        return;

    /* COMPAT: Target is handled differently in Internet nastiness */
    var targ = evt.target || evt.srcElement;
    if(targ == zoom || targ == zoom._img)
        zoomGraphSelect(zoom);

    zoomGraphCancel(evt);
}

function zoomGraphSelect(zoom)
{
    // Arbitrary values (TODO: Move these to CONFIG)
    var GRAPH_MARGIN_LEFT = 67;
    var GRAPH_MARGIN_RIGHT = 27;

    var left = GRAPH_MARGIN_LEFT;
    var right = zoom._img.width - GRAPH_MARGIN_RIGHT;

    var start = zoom._start > zoom._end ? zoom._end : zoom._start;
    var end = zoom._start > zoom._end ? zoom._start : zoom._end;

    /* If too small selected, then punt */
    if((end - start) <= 1)
        return;

    /* If entire thing selected, then punt */
    if(start < left && end > right)
        return;

    /* If only margins selected, then punt */
    if(!(start < right && end > left))
        return;

    /* Limit it to the right range */
    var range = zoom._img.width - GRAPH_MARGIN_RIGHT - GRAPH_MARGIN_LEFT;
    start = start < left ? 0 : start - left;
    end = end - left > range ? range : end - left;

    /* Compute the ratio pixels:time */
    var ratio = (zoom._img._tend - zoom._img._tbeg) / range;

    var obeg = zoom._img._tbeg;
    var oend = zoom._img._tend;

    zoom._img._tend = Math.floor((end * ratio) + zoom._img._tbeg);
    zoom._img._tbeg = Math.floor((start * ratio) + zoom._img._tbeg);

    reloadGraph(zoom._img, true);
}

function zoomGraphCancel(evt)
{
    var zoom = gdoc.getElementById("zoom");

    if(zoom._zooming) {
        if(zoom._img)
            zoom._img.onmousemove = zoom._img.onmouseup = zoom._img.onmouseleave = null;
        zoom._img = null;
        zoom.onmousemove = zoom.onmouseup = null;
        zoom._zooming = false;
    }

    zoom.style.display = "none";
}

function zoomGraphOut(img)
{
    var factor = Math.floor((img._tend - img._tbeg) / 2.5);
    var now = nowTime();

    /* If near the end we have special behavior */
    if(img._tend >= now - 300 || img._tend <= now)
    {
        img._tbeg -= factor;
        img._tend = now;
    }
    else
    {
        factor = Math.floor(factor / 2);
        img._tbeg -= factor
        img._tend += factor;
    }

    reloadGraph(img, true);
}

function zoomGraphMove(img, dir)
{
    var factor = Math.floor((img._tend - img._tbeg) / 3);
    if(!dir)
        factor = -factor;
    img._tbeg += factor;
    img._tend += factor;
    reloadGraph(img, true);
}

function actionsDisplay(evt)
{
    /* COMPAT: Target is handled differently in Internet nastiness */
    var img = evt.target || evt.srcElement;

    if(img.className != "graph")
        return;

    var actions = gdoc.getElementById("actions");

    /* Disconnect from previous image */
    if(actions._img)
        actions._img._actions = null;

    /* Attach to this image */
    actions._img = img;
    img._actions = actions;
    updateCursors(img);

    actions._display = true;

    actions.style.top = img.offsetTop;
    actions.style.left = img.offsetLeft + (img.width - 16);
    actions.style.display = "block";

    actions.onmouseout = img.onmouseout = function(evt)
            { return actionsHide(gwindow.event ? gwindow.event : evt); }

    /* TODO: We only actually have to do this once */
    var i, acts = actions.getElementsByTagName("img");
    for(i = 0; i < acts.length; i++)
    {
        acts.item(i).onclick = function(evt)
            { return actionRun(gwindow.event ? gwindow.event : evt); }
    }
}

function actionsHide(evt)
{
    var actions = gdoc.getElementById("actions");
    if(!actions._display)
        return;

    var x = evt.clientX + gdoc.body.scrollLeft;
    var y = evt.clientY + gdoc.body.scrollTop;
    var img = actions._img;

    /* See if we're actually still within the image */
    if(x >= img.offsetLeft && x <= img.offsetLeft + img.width &&
       y >= img.offsetTop && y <= img.offsetTop + img.height)
        return;

    actions.style.display = "none";
    img.onmouseout = actions.onmouseout = null;
    img._actions = null;
    actions._img = null;
    actions._display = false;
}

function actionRun(evt)
{
    /* COMPAT: Target is handled differently in Internet nastiness */
    var act = evt.target || evt.srcElement;

    if(act.className != "action")
        return;

    var actions = gdoc.getElementById("actions");
    if(!actions._display)
        return;

    switch(act.getAttribute("id"))
    {
    case "action-zoom":
        zoomGraphOut(actions._img);
        break;
    case "action-next":
        zoomGraphMove(actions._img, true);
        break;
    case "action-prev":
        zoomGraphMove(actions._img, false);
        break;
    case "action-goto":
        actionGoto(actions._img, act);
        break;
    }
}

function actionGoto(img, act)
{
    /* Display the selection thingy */
    var got = gdoc.getElementById("goto");

    /* TODO: Make numbers constants */
    got.style.top = img.offsetTop + 40;
    got.style.left = (img.offsetLeft + img.width) - 160;
    got.style.width = 120;
    got.style.display = "block";

    var sel = gdoc.getElementById("goto-select");
    sel.onchange = actionGotoChange;
    sel._img = img;
    sel.value = null;
    sel.selectedIndex = -1;
}

function actionGotoCancel()
{
    var got = gdoc.getElementById("goto");
    got.style.display = "none";
}

function actionGotoChange()
{
    var sel = gdoc.getElementById("goto-select");
    var img = sel._img;
    sel.onchange = null;
    sel._img = null;

    times = sel.value.split(":");
    img._tbeg = nowTime() - times[0];
    img._tend = nowTime() - times[1];
    reloadGraph(img, true);

    actionGotoCancel();
}

/* -----------------------------------------------------------------------------
 * GROUP CATEGORIES
 */

function findCategoryGraphs(cat)
{
    var i;

    if(!xmlData)
        return null;

    var ret = new Array();
    var graphs = xmlData.getElementsByTagName("graph");
    for(i = 0; i < graphs.length; i++)
    {
        if(graphs.item(i).getAttribute("category") == cat)
            ret.push(graphs.item(i));
    }
    return ret;
}

function changeCategory(evt)
{
    var header = evt.target || evt.srcElement;
    categoryCurrent = header.getAttribute("category");
    displayCurrentPage();
}

function displayCategories()
{
    var cats = new Object();
    var cat, i, name;

    /* Get the template and clean it up a bit */
    var template = document.getElementById("header-template");

    var graphs = xmlData.getElementsByTagName("graph");
    for(i = 0; i < graphs.length; i++)
    {
        cat = graphs.item(i).getAttribute("category");
        if(!cat)
            cat = "Other";
        cats[cat] = true;
    }

    for(name in cats)
    {
        if(!categoryCurrent)
            categoryCurrent = name;

        var el = template.cloneNode(false);
        el.removeAttribute("id");
        el.appendChild(document.createTextNode(name));
        el.setAttribute("category", name);

        el.onclick = function(evt)
            { return changeCategory(evt || window.event); }

        categoryArea.insertBefore(el, template);
    }
}

/* -----------------------------------------------------------------------------
 * HELPERS
 */

function loadXml(uri, callback)
{
    var xmlhttp;
    var xmlHttpChange = function() {
        if(xmlhttp.readyState == 4)
        {
            if(xmlhttp.status == 200)
                callback(xmlhttp.responseXML);
            else
                callback(null);
        }
    }

    /* Mozilla code */
    if(window.XMLHttpRequest)
    {
        xmlhttp = new XMLHttpRequest();
        xmlhttp.onreadystatechange = xmlHttpChange;
        xmlhttp.open("GET", uri, true);
        xmlhttp.send(null);
    }

    /* And now for the Nasty */
    else if (window.ActiveXObject)
    {
        xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
        /* TODO: need to do something when this fails (can it fail?) */
        if(xmlhttp)
        {
            xmlhttp.onreadystatechange = xmlHttpChange;
            xmlhttp.open("GET", uri, true);
            xmlhttp.send()
        }
    }
}

function displayError(message, place)
{
    var el = document.createElement("span");
    el.className = "error";
    var text = document.createTextNode(message);
    el.appendChild(text);

    if(place)
        place.appendChild(el);

    return el;
}

function nowTime()
{
    return Math.floor((new Date()).getTime() / 1000);
}

function debug(msg)
{
   setTimeout(function() { throw new Error("[debug] " + msg); }, 0);
}

function makeEndpointURI()
{
    /* TODO: This should use the scheme of the current URI */
    return "http://" + document.location.host + ENDPOINT;
}

function cancelEvent(evt)
{
    /* COMPAT: Totally different for IE and mozilla */
    if(evt.preventDefault)
        evt.preventDefault();
    if(evt.stopPropagation)
        evt.stopPropagation();
    if("cancelBubble" in evt)
        evt.cancelBubble = true;
    if("returnValue" in evt)
        evt.returnValue = false;
}