/*
 * Copyright (c) 2009 Tom Coote (http://www.tomcoote.co.uk)
 * This is licensed under GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

/*jslint  eqeqeq: true, browser: true */
/*global jQuery */
 
/**
 * Turn a text box into an auto suggest box which search's and 
 * displays results specified in a JSON string
 * 
 *
 * @name jsonSuggest
 * @type jQuery
 * @param searchData :	[required] Can be one of three things; a JSON string which specified the search data, an object that is representative of a parsed JSON string or a function which returns either of these two things.
 *					expected object format example; (either as raw object or JSON string)
 					[
						{
							id: 1,
							text: 'Thomas',
							image: 'img/avator1.jpg',	// optional
							extra: 'www.thomas.com'	// optional
						},
						{
							id: 2,
							text: 'Frederic',
							image: 'img/avator2.jpg',	// optional
							extra: 'www.freddy.com'	// optional
						},
						{
							id: 2,
							text: 'James',
							image: 'img/avator2.jpg',	// optional
							extra: 'www.james.com'	// optional
						}
					]
 * @param Object settings;	[optional]
 *			minCharacters :	[default 1] Number of characters that the input should accept before running a search.
 *			maxResults:	[default undefined] If set then no more results than this number will be found.
 *			wildCard :		[default ''] A character to be used as a match all wildcard when searching. Leaving empty will mean results are matched inside
 *						strings but if a wildCard is present then results are matched from the beginning of strings.
 *			caseSensitive :	[defautl false] True if the filter search's are to be case sensitive.
 *			notCharacter :	[default !] The character to use at the start of any search text to specify that the results should NOT contain the following text.
 *			maxHeight :	[default 350] This is the maximum height that the results box can reach before scroll bars are shown instead of getting taller.	
 *			highlightMatches: [default true] This will add strong tags around the text that matches the search text in each result.
 *			onSelect : 		[default undefined] Function that gets called once a result has been selected, gets passed in the object version of the result as specified in the json string
 *			ajaxResults : 	[default false] If this is set to true then you must specify a function as the searchData construction parameter. This is because when this
 *						settings is true then results are retrieved from an external function each time they are needed instead of being retrieved from the data given on 
 * 						contruction. The searchData function must return a JSON string of resulting objects or the object which represents the JSON string. The function is
 *						passed the following paramenters;
 *						1. The search text typed into the input box
 *						2. The current wildCard setting
 *						3. The current caseSensitive setting
 *						4. The current notCharacter setting 
 *			width:		[default undefined] If set this will become the width of the results box else the box will be the same width as the input
 * @author Tom Coote (www.tomcoote.co.uk)
 * @version 1.2.4
 */

(function($){

    $.fn.jsonSuggest = function(searchData, settings) {
        var defaults = {
            minCharacters: 1,
            maxResults: undefined,
            wildCard: "",
            caseSensitive: false,
            notCharacter: "!",
            maxHeight: 350,
            highlightMatches: true,
            onSelect: undefined,
            ajaxResults: false,
            width: undefined
        };
        settings = $.extend(defaults, settings);
	
        return this.each(function() {
			
            function regexEscape(txt, omit) {
                var specials = ['/', '.', '*', '+', '?', '|',
                '(', ')', '[', ']', '{', '}', '\\'];
				
                if (omit) {
                    for (var i=0; i < specials.length; i++) {
                        if (specials[i] === omit) {
                            specials.splice(i,1);
                        }
                    }
                }
				
                var escapePatt = new RegExp('(\\' + specials.join('|\\') + ')', 'g');
                return txt.replace(escapePatt, '\\$1');
            }
			
            var obj = $(this),
            wildCardPatt = new RegExp(regexEscape(settings.wildCard || ''),'g'),
            results = $('<div />'),
            currentSelection, pageX, pageY;
			
            // When an item has been selected then update the input box,
            // hide the results again and if set, call the onSelect function
            function selectResultItem(item) {
                // obj.val(item.text);
                $(results).html('').hide();
				
                if (typeof settings.onSelect === 'function') {
                    settings.onSelect(item);
                }
            }

            // Used to get rid of the hover class on all result item elements in the
            // current set of results and add it only to the given element. We also
            // need to set the current selection to the given element here.
            function setHoverClass(el) {
                $('div.resultItem', results).removeClass('hover');
                $(el).addClass('hover');
				
                currentSelection = el;
            }
			
            // Build the results HTML based on an array of objects that matched
            // the search criteria, highlight the matches if feature is turned on in
            // the settings.
            function buildResults(resultObjects, sFilterTxt) {
                sFilterTxt = "(" + sFilterTxt + ")";
			
                var bOddRow = true, i, iFound = 0,
                filterPatt = settings.caseSensitive ? new RegExp(sFilterTxt, "g") : new RegExp(sFilterTxt, "ig");
					
                $(results).html('').hide();
				
                for (i = 0; i < resultObjects.length; i += 1) {
                    var item = $('<div />'),
                    text = resultObjects[i].text;
						
                    if (settings.highlightMatches === true) {
                        text = text.replace(filterPatt, "<strong>$1</strong>");
                    }
					
                    $(item).append('<p class="text">' + text + '</p>');
					
                    if (typeof resultObjects[i].extra === 'string') {
                        $(item).append('<p class="extra">' + resultObjects[i].extra + '</p>');
                    }
					
                    if (typeof resultObjects[i].image === 'string') {
                        $(item).prepend('<img src="' + resultObjects[i].image + '" />').
                        append('<br style="clear:both;" />');
                    }
					
                    $(item).addClass('resultItem').
                    addClass((bOddRow) ? 'odd' : 'even').
                    click(function(n) {
                        return function() {
                            selectResultItem(resultObjects[n]);
                        };
                    }(i)).
                    mouseover(function(el) {
                        return function() {
                            setHoverClass(el);
                        };
                    }(item));
					
                    $(results).append(item);
					
                    bOddRow = !bOddRow;
					
                    iFound += 1;
                    if (typeof settings.maxResults === 'number' && iFound >= settings.maxResults) {
                        break;
                    }
                }
				
                if ($('div', results).length > 0) {
                    currentSelection = undefined;
                    $(results).show().css('height', 'auto');
					
                    if ($(results).height() > settings.maxHeight) {
                        $(results).css({
                            'overflow': 'auto',
                            'height': settings.maxHeight + 'px'
                            });
                    }
                }
            }
			
            // Prepare the search string based on the settings for this plugin,
            // run it against each item in the searchData and display any
            // results on the page allowing selection by the user.
            function runSuggest(e) {
                if (this.value.length < settings.minCharacters) {
                    $(results).html('').hide();
                    return false;
                }
				
                var resultObjects = [],
                sFilterTxt = (!settings.wildCard) ? regexEscape(this.value) : regexEscape(this.value, settings.wildCard).replace(wildCardPatt, '.*'),
                bMatch = true,
                filterPatt, i;
						
                if (settings.notCharacter && sFilterTxt.indexOf(settings.notCharacter) === 0) {
                    sFilterTxt = sFilterTxt.substr(settings.notCharacter.length,sFilterTxt.length);
                    if (sFilterTxt.length > 0) {
                        bMatch = false;
                    }
                }
                sFilterTxt = sFilterTxt || '.*';
                sFilterTxt = settings.wildCard ? '^' + sFilterTxt : sFilterTxt;
                filterPatt = settings.caseSensitive ? new RegExp(sFilterTxt) : new RegExp(sFilterTxt,"i");
				
                // Get the results from the correct place. If settings.ajaxResults then results are retrieved from
                // an external function each time they are needed else they are retrieved from the data
                // given on contruction.
                if (settings.ajaxResults === true) {
                    resultObjects = searchData(this.value, 	settings.wildCard,
                        settings.caseSensitive,
                        settings.notCharacter);
															
                    if (typeof resultObjects === 'string') {
                        resultObjects = JSON.parse(resultObjects);
                    }
                }
                else {
                    // Look for the required match against each single search data item. When the not
                    // character is used we are looking for a false match.
                    for (i = 0; i < searchData.length; i += 1) {
                        if (filterPatt.test(searchData[i].text) === bMatch) {
                            resultObjects.push(searchData[i]);
                        }
                    }
                }
				
                buildResults(resultObjects, sFilterTxt);
            }
			
            // To call specific actions based on the keys pressed in the input
            // box. Special keys are up, down and return. All other keys
            // act as normal.
            function keyListener(e) {
                switch (e.keyCode) {
                    case 13: // return key
                        $(currentSelection).trigger('click');
					
                        return false;
                    case 40: // down key
                        if (typeof currentSelection === 'undefined') {
                            currentSelection = $('div.resultItem:first', results).get(0);
                        }
                        else {
                            currentSelection = $(currentSelection).next().get(0);
                        }
						
                        setHoverClass(currentSelection);
                        if (currentSelection) {
                            $(results).scrollTop(currentSelection.offsetTop);
                        }
						
                        return false;
                    case 38: // up key
                        if (typeof currentSelection === 'undefined') {
                            currentSelection = $('div.resultItem:last', results).get(0);
                        }
                        else {
                            currentSelection = $(currentSelection).prev().get(0);
                        }
						
                        setHoverClass(currentSelection);
                        if (currentSelection) {
                            $(results).scrollTop(currentSelection.offsetTop);
                        }
						
                        return false;
                    default:
                        runSuggest.apply(this, [e]);
                }
            }
			
            // Prepare the input box to show suggest results by adding in the events
            // that will initiate the search and placing the element on the page
            // that will show the results.
            $(results).addClass('jsonSuggestResults').
            css({
                'top': (obj.position().top + obj.height() + 5) + 'px',
                'left': obj.position().left + 'px',
                'width': settings.width || ((obj.width() + 5) + 'px')
            }).hide();
				
            obj.after(results).
            keyup(keyListener).
            blur(function(e) {
                // We need to make sure we don't hide the result set
                // if the input blur event is called because of clicking on
                // a result item.
                var resPos = $(results).offset();
                resPos.bottom = resPos.top + $(results).height();
                resPos.right = resPos.left + $(results).width();
					
                if (pageY < resPos.top || pageY > resPos.bottom || pageX < resPos.left || pageX > resPos.right) {
                    $(results).hide();
                }
            }).
            focus(function(e) {
                $(results).css({
                    'top': (obj.position().top + obj.height() + 5) + 'px',
                    'left': obj.position().left + 'px'
                });
				
                if ($('div', results).length > 0) {
                    $(results).show();
                }
            }).
            attr('autocomplete', 'off');
            $().mousemove(function(e) {
                pageX = e.pageX;
                pageY = e.pageY;
            });
			
            // Opera doesn't seem to assign a keyCode for the down
            // key on the keyup event. why?
            if ($.browser.opera) {
                obj.keydown(function(e) {
                    if (e.keyCode === 40) { // up key
                        return keyListener(e);
                    }
                });
            }
			
            // Escape the not character if present so that it doesn't act in the regular expression
            settings.notCharacter = regexEscape(settings.notCharacter || '');
			
            // We need to get the javascript array type data from the searchData setting.
            // Setting can either be a string, already an array or a function that returns one
            // of those things. We only get this data if it isn't being provided using ajax on
            // each search
            if (!settings.ajaxResults) {
                if (typeof searchData === 'function') {
                    searchData = searchData();
                }
                if (typeof searchData === 'string') {
                    searchData = JSON.parse(searchData);
                }
            }
        });
    };

})(jQuery);