// Autocompleter.Base handles all the autocompletion functionality
// that's independent of the data source for autocompletion. This
// includes drawing the autocompletion menu, observing keyboard
// and mouse events, and similar.
//
// Specific autocompleters need to provide, at the very least,
// a getUpdatedChoices function that will be invoked every time
// the text inside the monitored textbox changes. This method
// should get the text for which to provide autocompletion by
// invoking this.getEntry(), NOT by directly accessing
// this.element.value. This is to allow incremental tokenized
// autocompletion. Specific auto-completion logic (AJAX, etc)
// belongs in getUpdatedChoices.
//
// Tokenized incremental autocompletion is enabled automatically
// when an autocompleter is instantiated with the 'tokens' option
// in the options parameter, e.g.:
// new Ajax.Autocompleter('id','upd', '/url/', { tokens: ',' });
// will incrementally autocomplete with a comma as the token.
// Additionally, ',' in the above example can be replaced with
// a token array, e.g. { tokens: new Array (',', '\n') } which
// enables autocompletion on multiple tokens. This is most
// useful when one of the tokens is \n (a newline), as it
// allows smart autocompletion after linebreaks.
var Autocompleter = {}
Autocompleter.Base = function()
{
};
Autocompleter.Base.prototype = {
    base_initialize: function(element, update, options)
    {
        this.element = $(element);
        this.update = $(update);
        this.has_focus = false;
        this.changed = false;
        this.active = false;
        this.index = 0;
        this.entry_count = 0;
        if (this.setOptions)
            this.setOptions(options);
        else
            this.options = options || {};
        this.options.tokens = this.options.tokens || new Array();
        this.options.frequency = this.options.frequency || 0.4;
        this.options.min_chars = this.options.min_chars || 1;
        this.options.onShow = this.options.onShow ||
                              function(element, update)
                              {
                                  if (!update.style.position || update.style.position == 'absolute')
                                  {
                                      update.style.position = 'absolute';
                                      var offsets = Position.cumulativeOffset(element);
                                      update.style.left = offsets[0] + 'px';
                                      update.style.top = (offsets[1] + element.offsetHeight) + 'px';
                                      update.style.width = element.offsetWidth + 'px';
                                  }
                                  new Effect.Appear(update, {duration:0.15});
                              };
        this.options.onHide = this.options.onHide ||
                              function(element, update)
                              {
                                  new Effect.Fade(update, {duration:0.15})
                              };
        if (this.options.indicator)
            this.indicator = $(this.options.indicator);
        if (typeof(this.options.tokens) == 'string')
            this.options.tokens = new Array(this.options.tokens);
        this.observer = null;
        Element.hide(this.update);
        Event.observe(this.element, "blur", this.onBlur.bindAsEventListener(this));
        Event.observe(this.element, "keypress", this.onKeyPress.bindAsEventListener(this));
    },
    show: function()
    {
        if (this.update.style.display == 'none') this.options.onShow(this.element, this.update);
        if (!this.iefix && (navigator.appVersion.indexOf('MSIE') > 0) && this.update.style.position == 'absolute')
        {
            new Insertion.After(this.update,
                    '<iframe id="' + this.update.id + '_iefix" ' +
                    'style="display:none;filter:progid:DXImageTransform.Microsoft.Alpha(opacity=0);" ' +
                    'src="javascript:false;" frameborder="0" scrolling="no"></iframe>');
            this.iefix = $(this.update.id + '_iefix');
        }
        if (this.iefix)
        {
            Position.clone(this.update, this.iefix);
            this.iefix.style.zIndex = 1;
            this.update.style.zIndex = 2;
            Element.show(this.iefix);
        }
    },
    hide: function()
    {
        if (this.update.style.display == '') this.options.onHide(this.element, this.update);
        if (this.iefix) Element.hide(this.iefix);
    },
    startIndicator: function()
    {
        if (this.indicator) Element.show(this.indicator);
    },
    stopIndicator: function()
    {
        if (this.indicator) Element.hide(this.indicator);
    },
    onKeyPress: function(event)
    {
        if (this.active)
            switch (event.keyCode)
                    {
                case Event.KEY_TAB:
                case Event.KEY_RETURN:
                    this.select_entry();
                    Event.stop(event);
                case Event.KEY_ESC:
                    this.hide();
                    this.active = false;
                    return;
                case Event.KEY_LEFT:
                case Event.KEY_RIGHT:
                    return;
                case Event.KEY_UP:
                    this.mark_previous();
                    this.render();
                    if (navigator.appVersion.indexOf('AppleWebKit') > 0) Event.stop(event);
                    return;
                case Event.KEY_DOWN:
                    this.mark_next();
                    this.render();
                    if (navigator.appVersion.indexOf('AppleWebKit') > 0) Event.stop(event);
                    return;
            }
        else
            if (event.keyCode == Event.KEY_TAB || event.keyCode == Event.KEY_RETURN)
                return;
        this.changed = true;
        this.has_focus = true;
        if (this.observer) clearTimeout(this.observer);
        this.observer =
        setTimeout(this.onObserverEvent.bind(this), this.options.frequency * 1000);
    },
    onHover: function(event)
    {
        var element = Event.findElement(event, 'LI');
        if (this.index != element.autocompleteIndex)
        {
            this.index = element.autocompleteIndex;
            this.render();
        }
        Event.stop(event);
    },
    onClick: function(event)
    {
        var element = Event.findElement(event, 'LI');
        this.index = element.autocompleteIndex;
        this.select_entry();
        Event.stop(event);
    },
    onBlur: function(event)
    {
        // needed to make click events working
        setTimeout(this.hide.bind(this), 250);
        this.has_focus = false;
        this.active = false;
    },
    render: function()
    {
        if (this.entry_count > 0)
        {
            for (var i = 0; i < this.entry_count; i++)
            {
                this.index == i ?
                Element.addClassName(this.get_entry(i), "selected") :
                Element.removeClassName(this.get_entry(i), "selected");
            }
            if (this.has_focus)
            {
                if (this.get_current_entry().scrollIntoView)
                    this.get_current_entry().scrollIntoView(false);
                this.show();
                this.active = true;
            }
        }
        else this.hide();
    },
    mark_previous: function()
    {
        if (this.index > 0) this.index--
        else this.index = this.entry_count - 1;
    },
    mark_next: function()
    {
        if (this.index < this.entry_count - 1) this.index++
        else this.index = 0;
    },
    get_entry: function(index)
    {
        return this.update.firstChild.childNodes[index];
    },
    get_current_entry: function()
    {
        return this.get_entry(this.index);
    },
    select_entry: function()
    {
        this.active = false;
        value = Element.collectTextNodesIgnoreClass(this.get_current_entry(), 'informal').unescapeHTML();
        this.updateElement(value);
        this.element.focus();
    },
    updateElement: function(value)
    {
        var last_token_pos = this.findLastToken();
        if (last_token_pos != -1)
        {
            var new_value = this.element.value.substr(0, last_token_pos + 1);
            var whitespace = this.element.value.substr(last_token_pos + 1).match(/^\s+/);
            if (whitespace)
                new_value += whitespace[0];
            this.element.value = new_value + value;
        }
        else
        {
            this.element.value = value;
        }
    },
    updateChoices: function(choices)
    {
        if (!this.changed && this.has_focus)
        {
            this.update.innerHTML = choices;
            Element.cleanWhitespace(this.update);
            Element.cleanWhitespace(this.update.firstChild);
            if (this.update.firstChild && this.update.firstChild.childNodes)
            {
                this.entry_count =
                this.update.firstChild.childNodes.length;
                for (var i = 0; i < this.entry_count; i++)
                {
                    entry = this.get_entry(i);
                    entry.autocompleteIndex = i;
                    this.addObservers(entry);
                }
            }
            else
            {
                this.entry_count = 0;
            }
            this.stopIndicator();
            this.index = 0;
            this.render();
        }
    },
    addObservers: function(element)
    {
        Event.observe(element, "mouseover", this.onHover.bindAsEventListener(this));
        Event.observe(element, "click", this.onClick.bindAsEventListener(this));
    },
    onObserverEvent: function()
    {
        this.changed = false;
        if (this.getEntry().length >= this.options.min_chars)
        {
            this.startIndicator();
            this.getUpdatedChoices();
        }
        else
        {
            this.active = false;
            this.hide();
        }
    },
    getEntry: function()
    {
        var token_pos = this.findLastToken();
        var ret;
        if (token_pos != -1)
            ret = this.element.value.substr(token_pos + 1).replace(/^\s+/, '').replace(/\s+$/, '');
        else
            ret = this.element.value;
        return /\n/.test(ret) ? '' : ret;
    },
    findLastToken: function()
    {
        var last_token_pos = -1;
        for (var i = 0; i < this.options.tokens.length; i++)
        {
            var this_token_pos = this.element.value.lastIndexOf(this.options.tokens[i]);
            if (this_token_pos > last_token_pos)
                last_token_pos = this_token_pos;
        }
        return last_token_pos;
    }
}
AJS.Autocompleter = Class.create();
Object.extend(Object.extend(AJS.Autocompleter.prototype, Autocompleter.Base.prototype), {
    initialize: function(element, update, url, options)
    {
        this.base_initialize(element, update, options);
        this.options.asynchronous = true;
        this.options.onComplete = this.onComplete.bind(this)
        this.options.method = 'post';
        this.options.defaultParams = this.options.parameters || null;
        this.url = url;
    },
    getUpdatedChoices: function()
    {
        var entry = encodeURIComponent(this.element.name) + '=' +
                    encodeURIComponent(this.getEntry());
        this.options.parameters = this.options.callback ?
                                  this.options.callback(this.element, entry) : entry;
        if (this.options.defaultParams)
            this.options.parameters += '&' + this.options.defaultParams;
        // (Jeremy Higgs: Instead of using AJAX.Request, let's be consistent and use DWR)
        this.options.dwrFunction(this.url, this.getEntry(), this.options.onComplete)
    },
    onComplete: function(response)
    {
        this.updateChoices(response.response);
    }
});
// The local array autocompleter. Used when you'd prefer to
// inject an array of autocompletion options into the page, rather
// than sending out Ajax queries, which can be quite slow sometimes.
//
// The constructor takes four parameters. The first two are, as usual,
// the id of the monitored textbox, and id of the autocompletion menu.
// The third is the array you want to autocomplete from, and the fourth
// is the options block.
//
// Extra local autocompletion options:
// - choices - How many autocompletion choices to offer
//
// - partial_search - If false, the autocompleter will match entered
//                    text only at the beginning of strings in the
//                    autocomplete array. Defaults to true, which will
//                    match text at the beginning of any *word* in the
//                    strings in the autocomplete array. If you want to
//                    search anywhere in the string, additionally set
//                    the option full_search to true (default: off).
//
// - full_search - Search anywhere in autocomplete array strings.
//
// - partial_chars - How many characters to enter before triggering
//                   a partial match (unlike min_chars, which defines
//                   how many characters are required to do any match
//                   at all). Defaults to 2.
//
// - ignore_case - Whether to ignore case when autocompleting.
//                 Defaults to true.
//
// It's possible to pass in a custom function as the 'selector'
// option, if you prefer to write your own autocompletion logic.
// In that case, the other options above will not apply unless
// you support them.
Autocompleter.Local = Class.create();
Autocompleter.Local.prototype = Object.extend(new Autocompleter.Base(), {
    initialize: function(element, update, array, options)
    {
        this.base_initialize(element, update, options);
        this.options.array = array;
    },
    getUpdatedChoices: function()
    {
        this.updateChoices(this.options.selector(this));
    },
    setOptions: function(options)
    {
        this.options = Object.extend({
            choices: 10,
            partial_search: true,
            partial_chars: 2,
            ignore_case: true,
            full_search: false,
            selector: function(instance)
            {
                var ret = new Array();
                // Beginning matches
                var partial = new Array();
                // Inside matches
                var entry = instance.getEntry();
                var count = 0;
                for (var i = 0; i < instance.options.array.length &&
                                ret.length < instance.options.choices; i++)
                {
                    var elem = instance.options.array[i];
                    var found_pos = instance.options.ignore_case ?
                                    elem.toLowerCase().indexOf(entry.toLowerCase()) :
                                    elem.indexOf(entry);
                    while (found_pos != -1)
                    {
                        if (found_pos == 0 && elem.length != entry.length)
                        {
                            ret.push("<li><strong>" + elem.substr(0, entry.length) + "</strong>" +
                                     elem.substr(entry.length) + "</li>");
                            break;
                        }
                        else if (entry.length >= instance.options.partial_chars &&
                                 instance.options.partial_search && found_pos != -1)
                        {
                            if (instance.options.full_search || /\s/.test(elem.substr(found_pos - 1, 1)))
                            {
                                partial.push("<li>" + elem.substr(0, found_pos) + "<strong>" +
                                             elem.substr(found_pos, entry.length) + "</strong>" + elem.substr(
                                        found_pos + entry.length) + "</li>");
                                break;
                            }
                        }
                        found_pos = instance.options.ignore_case ?
                                    elem.toLowerCase().indexOf(entry.toLowerCase(), found_pos + 1) :
                                    elem.indexOf(entry, found_pos + 1);
                    }
                }
                if (partial.length)
                    ret = ret.concat(partial.slice(0, instance.options.choices - ret.length))
                return "<ul>" + ret.join('') + "</ul>";
            }
        }, options || {});
    }
});