/*global
  $
  jQuery

jQuery at-username
Autocomplete usernames when typing @
*/

// case insensitive sort

(function ($) {

    var xhrUsernamesList = [];

    var caseInsensitiveSort = function (a, b) {
        var ret = 0;
        a = a.username.toLowerCase();
        b = b.username.toLowerCase();
        if (a > b) { ret = 1; }
        if (a < b) { ret = -1; }
        return ret;
    };

    // get usernames (settings.usernameClass) from a container element, removing duplicates
    // returns an array of strings, sorted alphabetically (case insensitive)

    var getUsernameList = function (container, usernameSelector, url) {
        var users = [];

        // get XHR usernames

        if (xhrUsernamesList.length > 0) {
            for (var i = 0; i < xhrUsernamesList.length; i++) {
                if (xhrUsernamesList[i].url === url) {
                    users = users.concat(xhrUsernamesList[i].usernames);
                    break;
                }
            }
        }

        var origUsers = users;
        var skip = false;

        // search usernames
        if (container) {
            var users_links = container.find(usernameSelector);

            for (var i = 0; i < users_links.length; i++) {

                skip = false;

                //Make sure user doesn't already exist
                for (var j = 0; j < origUsers.length; j++) {
                    if (users_links.eq(i).text() == origUsers[j].username) {
                        skip = true;
                        continue;
                    }
                }

                if (!skip) {
                    var curr_user = new Object();
                    curr_user.username = users_links.eq(i).text();
                    curr_user.photourl = users_links.eq(i).attr("gmr_photo_url");

                    var duplicate = false;

                    for (var j = 0; j < users.length; j++) {
                        if (curr_user === users[j]) {
                            duplicate = true;
                        }
                    }

                    if (!duplicate) {
                        users.push(curr_user);
                    }
                }
            }
        }

        return users.sort(caseInsensitiveSort);
    };

    // search usernames
    // takes a list of usernames and a search term; returns a new list of usernames matching the search term

    var searchUsernameList = function (usernames, search_term) {
        var results = [];

        for (var i = 0; i < usernames.length; i++) {
            var username = usernames[i].username.toLowerCase();
            search_term = search_term.toLowerCase();

            if (username.substring(0, search_term.length) == search_term) {
                results.push(usernames[i]);
            }

            //var result = username.search(search_term);
            //if (result >= 0) { // no match returns -1
            //    results.push(usernames[i]);
            //}
        }

        return results;
    };


    //modified CK

    function getTypingText(areaId) {
        var txtarea = document.getElementById(areaId);

        var scrollPos = txtarea.scrollTop;
        var strPos = 0;

        var br = ((txtarea.selectionStart || txtarea.selectionStart == '0') ?
		"ff" : (document.selection ? "ie" : false));
        if (br == "ie") {

            if (document.selection) {
                // The current selection
                var range = document.selection.createRange();
                // We'll use this as a 'dummy'
                var stored_range = range.duplicate();
                // Select all text
                stored_range.moveToElementText(txtarea);
                // Now move 'dummy' end point to end point of original range
                stored_range.setEndPoint('EndToEnd', range);

                // Now we can calculate start and end points
                strPos = stored_range.text.length - range.text.length;
            }
        }
        else if (br == "ff") strPos = txtarea.selectionStart;

        var front = (txtarea.value).substring(0, strPos);

        return front.substring(front.lastIndexOf('@') + 1, strPos);
    }

    function insertAtCaret(areaId, text) {
        var txtarea = document.getElementById(areaId);

        var scrollPos = txtarea.scrollTop;
        var strPos = 0;

        var br = ((txtarea.selectionStart || txtarea.selectionStart == '0') ?
		"ff" : (document.selection ? "ie" : false));
        if (br == "ie") {

            if (document.selection) {
                // The current selection
                var range = document.selection.createRange();
                // We'll use this as a 'dummy'
                var stored_range = range.duplicate();
                // Select all text
                stored_range.moveToElementText(txtarea);
                // Now move 'dummy' end point to end point of original range
                stored_range.setEndPoint('EndToEnd', range);

                // Now we can calculate start and end points
                strPos = stored_range.text.length - range.text.length;
            }


        }
        else if (br == "ff") strPos = txtarea.selectionStart;

        var front = (txtarea.value).substring(0, strPos);
        var back = (txtarea.value).substring(strPos, txtarea.value.length);

        front = front.substring(0, front.lastIndexOf('@') + 1);

        txtarea.value = front + text + back;
        strPos = strPos + text.length;

        if (br == "ie") {
            txtarea.focus();
            var range = txtarea.createTextRange();
            range.collapse(true);
            range.moveEnd('character', (front + text).length);
            range.moveStart('character', (front + text).length);
            range.select();


        }
        else if (br == "ff") {
            txtarea.selectionStart = (front + text).length;
            txtarea.selectionEnd = (front + text).length;
            txtarea.focus();
        }
        txtarea.scrollTop = scrollPos;
    }


    // create username autocomplete dropdown
    // takes an array of usernames and creates a username automcompletion HTML element
    // only returns first numResults results

    var createUsernameAutocomplete = function (textarea, container, users, numResults) {
        var username_list = $('<ul id="at-username-autocomplete"></ul>');

        username_list.css({
            top: textarea.offset().top + textarea.outerHeight() - 1,
            left: textarea.offset().left
        });

        for (var i = 0; i < users.length; i++) {
            if (i === numResults) {
                break;
            }
            username_list.append($('<li><div style="float: left;"><img src="' + users[i].photourl + '"></div><div style="float: left; padding: 8px 0 0 5px;"><b>' + users[i].username + '</b></div><div class="clr"></div></li>'));
        }

        username_list.find('li:first-child').addClass('active');

        username_list.find('li').click(function () {

            //modified CK
            insertAtCaret(textarea.attr('id'), $(this).text() + " ");

            //textarea.val(textarea.val().substring(0, textarea.data('ac_start') + 1) + $(this).text() + ' ');
            removeUsernameAutocomplete(container);
            return false;
        });
        
        return username_list;
    };

    // remove autocomplete dropdown from container

    var removeUsernameAutocomplete = function (container) {
        $('#at-username-autocomplete').remove();
        //container.find('textarea').removeClass('autocomplete_active').removeData('ac_start').scrollTop(9999); // scrollTop to fix Firefox bug
        return true;
    };

    // the main bit
    $.fn.atUsername = function (userSettings) {
        // settings

        var settings = {
            containerSelector: '#at-username-container',
            usernameSelector: '#username',
            numResults: 5,
            xhrUsernames: null,
            xhrOnFocus: true
        };

        if (userSettings !== undefined) {
            jQuery.extend(settings, userSettings);
        }

        // load in XHR usernames if not already done

        var loaded = false;

        if (settings.xhrUsernames) {

            var fnLoadXhrUsernames = function () {
                for (var i = 0; i < xhrUsernamesList.length; i++) {
                    if (xhrUsernamesList[i].url === settings.xhrUsernames) {
                        loaded = true;
                    }
                }

                if (!loaded) {
                    loaded = true;
                    $.get(settings.xhrUsernames, function (data) {
                        if (data != null && data != '') {
                            var obj = jQuery.parseJSON(data);
                            if (obj.usernames) {
                                xhrUsernamesList.push({
                                    url: settings.xhrUsernames,
                                    usernames: obj.usernames
                                });
                            }
                        }
                    });
                }
            } // fnLoadXhrUsernames()

            jQuery(this).focus(fnLoadXhrUsernames); // bind to textarea
            if (!settings.xhrOnFocus) {
                fnLoadXhrUsernames();
            }
        }

        this.keydown(function (e) {
            var textarea = $(this);
            var textarea_wrapper = textarea.parent();
            var username_list;
            var ddl;

            if (e.which === 16) { // shift
                return;

            } else if (e.which === 50 && e.shiftKey) { // @
                textarea.addClass('autocomplete_active');

                if (!textarea.data('ac_start')) {
                    textarea.data('ac_start', textarea.val().length);
                }

                var users = getUsernameList($(settings.containerSelector), settings.usernameSelector, settings.xhrUsernames);

                if (users.length === 0) {
                    return true;
                }

                username_list = createUsernameAutocomplete(textarea, $(settings.containerSelector), users, settings.numResults);
                ddl = $('#at-username-autocomplete');

                if (ddl.length > 0) {
                    ddl.replaceWith(username_list);
                } else {
                    $('body').append(username_list);
                }

            } else if (e.which === 38 || e.which === 40 || e.which === 13 || e.which === 32) { // up, down, enter, space
                ddl = $('#at-username-autocomplete');

                if (ddl.length === 0) {
                    return;
                }

                var active;

                switch (e.which) {
                    case 38: // up
                        active = ddl.find('li.active');
                        if (active.length > 0) {
                            active.removeClass('active').prev().addClass('active');
                        } else {
                            ddl.find('li:last-child').addClass('active');
                        }
                        return false;

                    case 40: // down
                        active = ddl.find('li.active');
                        if (active.length > 0) {
                            active.removeClass('active').next().addClass('active');
                        } else {
                            ddl.find('li:first-child').addClass('active');
                        }
                        return false;

                    case 13: // enter
                    case 32: // space
                        active = ddl.find('li.active');
                        if (active.length > 0) {

                            //modified CK
                            insertAtCaret(textarea.attr('id'), active.text() + " ");

                            //textarea.val(textarea.val().substring(0, textarea.data('ac_start') + 1) + active.text() + ' ');
                        }
                        removeUsernameAutocomplete(textarea_wrapper);
                        return false;
                }

            } else if (e.which === 27) { // ESC
                removeUsernameAutocomplete(textarea_wrapper);

            } else { // any other key
                if (!textarea.hasClass('autocomplete_active')) {
                    return true;
                }

                var ac_start = textarea.data('ac_start');
                var ac_current = textarea.val().length;

                if (e.which === 8) { // backspace
                    ac_current--;
                }

                if (ac_current <= ac_start) {
                    removeUsernameAutocomplete(textarea_wrapper);
                }

                var search_term = textarea.val().substring(ac_start + 1, ac_current);

                //modified CK
                search_term = getTypingText(textarea.attr('id'));

                if (e.which > 48 && e.which < 90) { // 0-9, a-z
                    search_term += String.fromCharCode(e.which);
                }

                search_term = search_term.toLowerCase();
                var usernames = getUsernameList($(settings.containerSelector), settings.usernameSelector, settings.xhrUsernames);
                var search_results = searchUsernameList(usernames, search_term);
                username_list = createUsernameAutocomplete(textarea, $(settings.containerSelector), search_results, settings.numResults);
                $('#at-username-autocomplete').replaceWith(username_list);
            }

        });
    };

})(jQuery);