// simple event stacking.
// i don't like Mochikit's one.

function attachToElementEvent(elem, event_name, func) {
    // catch IE (grumble)
    if (elem.attachEvent) {
        elem.attachEvent('on'+event_name, func);
    } else {
        elem.addEventListener(event_name, func, false);
    }
}

function removeFromElementEvent(elem, event_name, func) {
    // catch IE (grumble)
    if (elem.detachEvent) {
        elem.detachEvent('on'+event_name, func);
    } else {
        elem.removeEventListener(event_name, func, false);
    }
}

// quick and dirty helper - find the nearest parent item matching tagName. 
// FIXME steal the klass or tagName logic from MochiK.
function breadcrumbFind(elem, tagName) {
    var stopTag = 'BODY';
    var currentTag = elem.tagName;
    var currentElem = elem;
    while ((currentTag != stopTag) && (currentTag != tagName)) {
        currentElem = currentElem.parentNode;
        currentTag = currentElem.tagName;
    }
    if (currentTag == tagName) { 
        return currentElem; 
    } else {
        return null;
    }
}

var autoIndexCriteria = Array();

// initiate the criteria creation process.
function addNewCriteria(add_button) {
    var parent_row = breadcrumbFind(add_button, 'TR');
    simpleLog('DEBUG','addNewCriteria found parent row: '+parent_row);
    var select_source = parent_row.getElementsByTagName('select');
    if (select_source.length == 0) {
        simpleLog('ERROR','addNewCriteria found no criteria specification source.: '+parent_row);
    } else {
        var select = select_source[0];
    }
    var notify_source = parent_row.getElementsByTagName('p');    
    if (notify_source.length == 0) {
        simpleLog('ERROR','addNewCriteria found no message storage in row: '+parent_row);
    } else {
        var notify_message = notify_source[0];
    }


    // make this one identifiable.
    autoIndexCriteria.push(0);
    var critId = autoIndexCriteria.length;

    // ok, warn the user that we're loading the item.
    replaceChildNodes(notify_message, 'loading...');
    var newCriteriaText = scrapeText(select.options[select.selectedIndex])+' '; // FIXME insert the "input" here.
    replaceChildNodes(select.parentNode, newCriteriaText, INPUT({'type':'hidden', 'name':'boolean_search['+critId+'][\'type\']','value':select.value}));           // works thanks to DOM co-ercion.
    createAdditionalCriteriaOption();
    var removeButton = INPUT({'type':'button', 'value':'Remove'});
    attachToElementEvent(removeButton, 'click', partial(removeCriteria, removeButton));
    add_button.parentNode.replaceChild(removeButton, add_button);

    
    // fetch.
    var dest_cell = notify_message.parentNode;
    var targeturl='ajaxBooleanSearch.php?action=getNewCriteria&type='+select.value+'&critId='+critId;
    simpleLog('DEBUG','addNewCriteria initiating request to: '+targeturl);
    
    var deferred = doSimpleXMLHttpRequest(targeturl); 
    deferred.addCallbacks(partial(do_addNewCriteria, dest_cell, critId), handleAjaxError);
}


// FIXME multi-select items using PHP array[] syntax won't work.  we'd need to:
//          - check for the presence of [ or ].  if so, use everything before [ as
//            the key, and append everything after [.
// actually replace the contents of the specified td with the responseText.
function do_addNewCriteria(destination_cell, crit_id, req) { 
    simpleLog('DEBUG','replacing content of cell with: \n'+req.responseText);
    destination_cell.innerHTML = req.responseText; 
    // whatever was passed in almost certainly has the wrong name, but that's what
    // will be expected in the backend.  
    // wrap it so we don't get clashes.

    var inputs = destination_cell.getElementsByTagName('INPUT');
    var selects = destination_cell.getElementsByTagName('SELECT');

    for (var i=0; i<inputs.length; i++) {
        var obj = inputs[i];
        obj.name = "boolean_search["+crit_id+"]['data']['"+obj.name+"']";
    }
    for (var i=0; i<selects.length; i++) {
        var obj = selects[i];
        obj.name = "boolean_search["+crit_id+"]['data']['"+obj.name+"']";
    }
    simpleLog('DEBUG','criteria addition complete.');
}
function handleAjaxError(err) {
    simpleLog('ERROR','ajax error: '+err);
}


function removeCriteria(removeButton) {
    var parent_row = breadcrumbFind(removeButton, 'TR');
    if (parent_row == null) {
        simpleLog('ERROR','removeCriteria found no effective parent row.');
    } else {
        parent_row.parentNode.removeChild(parent_row);
    }
    simpleLog('DEBUG','criteria removed.');
}

function createAdditionalCriteriaOption() {
    var tbody = getSearchContainer();
    if (tbody == null) {
        simpleLog('ERROR','createAdditionalCriteriaOption: No criteria table found.');
        return null;        
    }
    
    // now we need to instantiate the selection stuff.
    // to do this we find a hidden div in the page which contains the container types...
    var master_div = getElement('search-criteria-container');
    if (master_div == null) {
        simpleLog('ERROR','createAdditionalCriteriaOption: No criteria types identified within the request.');
        return null;        
    }    
    
    // clone, and append.
    var clonedObject = master_div.getElementsByTagName('select')[0].cloneNode(true);
    var select_entry = TD(null, clonedObject);
    var notification_entry = TD(null, createDOM('P',{'class':'helpText'},'first select a type of query'));
    var add_button = INPUT({'type':'button', 'value':'Add'});
    attachToElementEvent(add_button, 'click', partial(addNewCriteria, add_button));
    var add_entry = TD(null, add_button);
    tbody.appendChild(TR(null, select_entry, notification_entry, add_entry));
}

function getSearchContainer() {
    var container = getElement('advanced-search-form');
    if (container == null) {
        simpleLog('ERROR','No criteria table found.');
        return null;
    } else {
        var innerContainer = container.getElementsByTagName('TBODY');
    }

    if (innerContainer.length == 0) {
        simpleLog('ERROR','No criteria tbody found.');
        return null;
    } else {
        var container = innerContainer[0];
        delete innerContainer;
    }
    return container;
}