var D = MochiKit.DOM;

function submitCommentForm(form) {
    var container = form.containerDiv;
    var selElem = container.selectedElement;
    if (selElem) {
        unshowCommented(selElem);
    }
    var postBody = formQueryString(form);
    var action = form.getAttribute('action');
    action += '?_=t';
    d = doSimplePost(action, postBody);
    d.addCallbacks(function (data) {
        if (data.responseText == 'XXX') {
            unshowForm(container, selElem);
            return;
        }
        deselectElement(selElem);
        if (container.editingComment) {
            if (container.editingComment.parentNode) {
                D.removeElement(container.editingComment);
            }
            container.editingComment = null;
        }
        if (data.responseText == '__DELETE__') {
            unshowForm(container);
            return;
        }
        container.innerHTML = data.responseText;
    }, function (error) {
        container.innerHTML = error.req.responseText;
        D.addElementClass(container, 'commentary-error');
    });
    return false;
}

function submitFormInPlace(button) {
    var form = button.form;
    var postBody = formQueryString(form, ['inplace'], ['t']);
    var action = form.getAttribute('action');
    action += '?_=t';
    /* Start with a throb... */
    var effect = new Effect.Highlight(
        form.containerDiv,
        {startcolor: '#ffff88', endcolor: '#ff8888',
         restorecolor: '#ffff88', duration: 1000});
    d = doSimplePost(action, postBody);
    d.addCallbacks(function (data) {
        effect.cancel();
        /* Finish with green... */
        new Effect.Highlight(
            form.containerDiv,
        {startcolor: '#88ff88', endcolor: '#ffff88',
         restorecolor: '#ffff88'});
        if (form.elements.position_id) {
            var old = form.elements.position_id;
            old.setAttribute('name', 'comment_id');
            form.elements.comment_id = old;
            old.value = data.responseText;
            form.setAttribute('action', commentary_edit_uri);
        }
        return false;
    }, function (error) {
        var container = form.containerDiv;
        var errorContainer = D.DIV({'class': 'commentary-error'});
        errorContainer.innerHTML = error.req.responseText;
        container.appendChild(errorContainer);
    });
    return false;
}

function createCommentForm(position_id, inline) {
    var form, position, page, username, email;
    form = $('commentary-form').cloneNode(true);
    form.id = null;
    fixupForm(form);
    var formDiv = setupCommentForm(form, inline);
    position = form.elements.position_id;
    page = form.elements.page;
    position.value = position_id;
    page.value = commentary_this_page;
    return formDiv;
}

function setupCommentForm(form, inline) {
    var divClass = 'commentary-comment';
    if (inline) {
        divClass += ' commentary-inline';
    }
    var formDiv = D.DIV({'class': divClass, 'comment-meta': '1'});
    formDiv.appendChild(form);
    form.containerDiv = formDiv;
    formDiv.form = form;
    username = form.elements.username;
    email = form.elements.email;
    defaultLabel(username, 'Your name', 'username');
    defaultLabel(email, 'Your email', 'email');
    return formDiv;
}

function cancelSubmitForm(button) {
    var container = button.form.containerDiv;
    _cancelSubmitForm(container);
}

function _cancelSubmitForm(container) {
    var selElem = container.selectedElement;
    if (selElem) {
        for (var i=0; i<_elementsCommentedOn.length; i++) {
            if (_elementsCommentedOn[i]
                && _elementsCommentedOn[i].element == selElem) {
                _elementsCommentedOn[i] = null;
            }
        }
        unshowCommented(container.selectedElement);
        D.removeElementClass(
            selElem, 'commentary-selected-element');
    }
    unshowForm(container, selElem);
    return false;
}

_elementsCommentedOn = [];

//cancelSubmitForm = MochiKit.Logging.catchException(cancelSubmitForm);

function commentOnElement(el) {
    for (var i=0; i<_elementsCommentedOn.length; i++) {
        if (_elementsCommentedOn[i] && 
            el == _elementsCommentedOn[i].element) {
            var formDiv = _elementsCommentedOn[i].formDiv;
            if (formDiv.form.elements.comment.value) {
                highlightCommented(el);
            } else {
                cancelSubmitForm(formDiv);
                _elementsCommentedOn[i] = null;
            }
            return;
        }
    }
    var expr = dumbpath.makeExpression(el);
    var formDiv = createCommentForm(expr);
    formDiv.selectedElement = el;
    showCommented(el);
    D.addElementClass(formDiv, 'commentary-inline');
    showForm(formDiv, el);
    _elementsCommentedOn.push({element: el, formDiv: formDiv});
    try {
        formDiv.form.elements.comment.focus();
    } catch (e) {
        /* We can get an exception here because the visibility of the
           textarea hasn't registered yet. */
    }
}

function fixupForm(form) {
    tags = ['select', 'input', 'textarea', 'button'];
    for (var i=0; i<tags.length; i++) {
        var els = form.getElementsByTagName(tags[i]);
        for (var j=0; j<els.length; j++) {
            if (! form.elements[els[j].name]) {
                /* Only Mozilla really needs this... */
                form.elements[els[j].name] = els[j];
            }
        }
    }
}

function editLink(link, comment_id) {
    var container = findParent(link, 'commentary-comment');
    d = MochiKit.Async.doSimpleXMLHttpRequest(
        commentary_base + '/edit_comment',
        {_: 't', page: commentary_this_page,
         comment_id: comment_id, form: 't', z: Math.random()});
    d.addCallbacks(function(data) {
        var div = D.DIV();
        div.innerHTML = data.responseText;
        var form = div.getElementsByTagName('FORM')[0];
        fixupForm(form);
        var formDiv = setupCommentForm(form, true);
        appendSibling(formDiv, container);
        formDiv.editingComment = container;
        D.removeElement(container);
        form.elements.comment.focus();
    }, function (error) {
        container.innerHTML = error.req.responseText;
        D.addElementClass(container, 'commentary-error');
    });
    return false;
}

/************************************************************
 * Effects
 ************************************************************/

function showCommented(el) {
    el.oldColor = el.style.backgroundColor;
    new Effect.Highlight(el, 
        {startcolor: '#ffffff', endcolor: '#ddddff',
         restorecolor: '#ddddff'});
}

function unshowCommented(el) {
    var endcolor = el.oldColor || '#ffffff';
    new Effect.Highlight(el,
        {duration: 0.5, startcolor: '#ddddff', endcolor: endcolor,
         restorecolor: endcolor});
}

function highlightCommented(el) {
    new Effect.Highlight(el,
        {duration: 0.4, startcolor: '#ff9999', endcolor: '#ddddff',
         restorecolor: '#ddddff'});
}

function showForm(div, container) {
    div.style.display = 'none';
    if (container) {
        container.parentNode.insertBefore(div, container);
    }
    new Effect.Appear(div, 
        {duration: 0.3, afterFinish: function () {
            div.form.elements.comment.focus();}});
}

function unshowForm(div, selectedElement) {
    if (selectedElement) {
        deselectElement(selectedElement);
    }
    var editingComment = div.editingComment;
    if (div.editingComment) {
        appendSibling(div.editingComment, div);
        div.editingComment = null;
        D.removeElement(div);
    } else {
        new Effect.DropOut(div,
            {duration: 0.4,
             afterFinish: function () {
                 D.removeElement(div);
            }});
    }
}

function deselectElement(selectedElement) {
    for (var i=0; i<_elementsCommentedOn.length; i++) {
        if (_elementsCommentedOn[i] &&
            _elementsCommentedOn[i].element == selectedElement) {
            _elementsCommentedOn[i] = null;
        }
    }
}

function isCommentMeta(el) {
    /* Returns true if this element is part of the commenting
       system, which means it (or a parent) has a comment-meta="1"
       or no parent has a comment-meta="0" (the second implies
       that the element is part of the navigation) */
    while (el) {
        var attr = el.getAttribute('comment-meta');
        if (attr == '1') {
            return true;
        } else if (attr == '0') {
            return false;
        }
        el = el.parentNode;
    }
    return true;
}

/************************************************************
 * Setup
 ************************************************************/

document.ondblclick = function (event) {
    if (event) {
        var el = event.target;
    } else {
        event = window.event;
        var el = event.srcElement;
    }
    el = findBlockContainer(el);
    if (! el) {
        return;
    }
    if (isCommentMeta(el)) {
        return;
    }
    commentOnElement(el);
}

/* We only want this class to be hidden when in a Javascript-enabled
   browser:
*/
document.write('<style type="text/css">\n'
               + '.hidden {display: none}\n'
               + '</style>\n');

/*window.onerror = function (desc, page, line, chr) {
    alert(desc+': '+page+'\nline: '+line+', '+chr);
    alert(window.event);
}*/

/************************************************************
 * Generic form handling
 ************************************************************/

function formValues(form) {
    /* Returns an array of [keys, values] from the form.
       Also handles the attributes that defaultLabel puts on
       elements (labelValue and cookieName). */
    var keys = [];
    var values = [];
    for (var i=0; i < form.elements.length; i++) {
        var el = form.elements[i];
        var elType = (el.getAttribute('type') || '').toLowerCase();
        if (elType == 'submit') {
            continue;
        }
        if ((elType == 'radio' || elType == 'checkbox')
            && ! el.checked) {
            continue;
        }
        var value = el.value;
        if (el.labelValue && el.labelValue == el.value) {
            value = '';
        }
        if (el.cookieName && value) {
            createCookie(el.cookieName, value, 180);
        }
        keys.push(el.name);
        values.push(value);
    }
    return [keys, values]
}

function formQueryString(form, /*optional:*/ extraKeys, extraValues) {
    /* Creates a query string from inputs in the given form.  If
       extraKeys and extraValues is given, those values will also
       be included. */
    var fields = formValues(form);
    var keys = fields[0];
    var values = fields[1];
    if (extraKeys) {
        for (var i=0; i<extraKeys.length; i++) {
            keys.push(extraKeys[i]);
            values.push(extraValues[i]);
        }
    }
    return MochiKit.Base.queryString(keys, values);
}

function doSimplePost(action, postBody) {
    /* Do a POST request to the given action, with the URL-encoded
       postBody (typically created with formQueryString).  Returns
       a Deferred. */
    var req = MochiKit.Async.getXMLHttpRequest();
    req.open('POST', action, true);
    req.setRequestHeader(
        'Content-type', 'application/x-www-form-urlencoded');
    return MochiKit.Async.sendXMLHttpRequest(req, postBody);
}

function findParent(node, cond, /* optional */ defaultValue) {
    if (typeof(cond) == 'string') {
        var nodeClass = cond;
        cond = function (node) {
            return D.hasElementClass(node, nodeClass);
        };
    }
    while (node) {
        if (cond(node)) {
            return node;
        }
        node = node.parentNode;
    }
    return defaultValue;
}

var _buttons = ['commentary-hide-comments',
                'commentary-fold-comments',
                'commentary-show-comments'];

function clickButton(buttonId) {
    for (var n=0; n<_buttons.length; n++) {
        if (_buttons[n] == buttonId) {
            D.addElementClass(_buttons[n], 'clicked');
        } else {
            D.removeElementClass(_buttons[n], 'clicked');
        }
    }
}

function hideComments(anchor) {
    clickButton('commentary-hide-comments');
    forAllComments(D.hideElement);
    createCookie('commentary_show', 'hide', 10000);
    return false;
}

function foldComments(anchor) {
    clickButton('commentary-fold-comments');
    forAllComments(function (comment) {
        D.showElement(comment);
        hideClass('commentary-full-comment', comment);
        showClass('commentary-folded', comment);
    });
    createCookie('commentary_show', 'fold', 10000);
    return false;
}

function showComments(anchor) {
    clickButton('commentary-show-comments');
    forAllComments(function (comment) {
        D.showElement(comment);
        showClass('commentary-full-comment', comment);
        hideClass('commentary-folded', comment);
    });
    createCookie('commentary_show', 'show', 10000);
    return false;
}

function forAllComments(func) {
    var els = document.getElementsByTagName('DIV');
    for (var i=0; i<els.length; i++) {
        if (D.hasElementClass(els[i], 'commentary-inline')) {
            func(els[i]);
        }
    }
}

function unfoldComment(link) {
    var comment = link;
    while (comment) {
        if (D.hasElementClass(comment, 'commentary-inline')) {
            break;
        }
        comment = comment.parentNode;
    }
    showClass('commentary-full-comment', comment);
    hideClass('commentary-folded', comment);
    return false;
}

function hideClass(className, container) {
    els = D.getElementsByTagAndClassName(
        null, className, container);
    for (var i=0; i<els.length; i++) {
        D.hideElement(els[i]);
    }
}

function showClass(className, container) {
    els = D.getElementsByTagAndClassName(
        null, className, container);
    for (var i=0; i<els.length; i++) {
        D.showElement(els[i]);
    }
}

D.addLoadEvent(function () {
    var value = readCookie('commentary_show');
    if (value == 'show') {
        showComments();
    } else if (value == 'hide') {
        hideComments();
    } else if (value == 'fold') {
        foldComments();
    }
});

function helpButton(el) {
    window.open(commentary_base + '/help', '_blank');
    return false;
}

/************************************************************
 * Utility functions
 ************************************************************/

function defaultLabel(el, label, cookieName) {
    /* Setup a input element with the given label (as its value)
       or the value loaded from the given cookie. */
    var cookieValue;
    if (cookieName) {
        el.cookieName = cookieName;
        if (cookieValue = readCookie(cookieName)) {
            el.value = cookieValue;
            return;
        }
    }
    var parent = el.parentNode;
    while (parent) {
        if (parent.tagName == 'FORM') {
            break;
        }
        parent = parent.parentNode;
    }
    el.value = label;
    el.labelValue = label;
    el.onfocus = _focusDefaultLabel;
    D.addElementClass(el, 'commentary-unselected');
}

function _focusDefaultLabel() {
    var el = this;
    D.removeElementClass(el, 'commentary-unselected');
    if (el.value == el.labelValue) {
        el.value = '';
    }
}

function appendSibling(node, sibling) {
    var next = sibling.nextSibling;
    if (next) {
        sibling.parentNode.insertBefore(node, next);
    } else {
        sibling.parentNode.appendChild(node);
    }
}

_blocks = {DIV: true, P: true, 
           PRE: true, CENTER: true, BLOCKQUOTE: true, 
           H1: true, H2: true, H3: true, 
           H4: true, H5: true, H6: true, 
           TD: true, TH: true, 
           FORM: true, FIELDSET: true, 
           DD: true, DL: true, TABLE: true,
           OL: true, UL: true, LI: true};

function findBlockContainer(el) {
    var node = el;
    while (node) {
        if (_blocks[node.tagName]) {
            return node;
        }
        node = node.parentNode;
    }
    throw('No block-level element found for ' + el);
}

function makeId() {
    return 'commentary-' + (commentary_id++);
}

function cancelEvent(event) {
    event.returnValue = false;
    event.cancelBubble = true;
    event.preventDefault && event.preventDefault();
    event.stopPropagation && event.stopPropagation();
    return false;
}

/************************************************************
 * Cookies
 ************************************************************/

/* From: http://www.quirksmode.org/js/cookies.html */

function createCookie(name,value,days)
{
    if (days)
        {
            var date = new Date();
            date.setTime(date.getTime()+(days*24*60*60*1000));
            var expires = "; expires="+date.toGMTString();
        }
    else var expires = "";
    document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name)
{
    var nameEQ = name + "=";
    var ca = document.cookie.split(';');
    for(var i=0;i < ca.length;i++)
        {
            var c = ca[i];
            while (c.charAt(0)==' ') c = c.substring(1,c.length);
            if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
        }
    return null;
}

function eraseCookie(name)
{
    createCookie(name,"",-1);
}