/*
 * @file Manages all advanced search form logic.
 */

var searchGroups = $("div#search-groups");

/*
 * Load all advanced search form libraries.
 */
function loadInputFieldWidgets(){
    $(".search-group input#date-last-modified").datepicker();
    $(".search-group input#date-created").datepicker();
    $(".search-group input#autocomplete").autocomplete({
        source: function(request, response){
            var matcher = new RegExp(
                $.ui.autocomplete.escapeRegex(request.term), "i");
            response($.grep(AUTOCOMPLETE_LANGUAGES, function(item){
                return matcher.test(item);
            }));
        }
    });
};
loadInputFieldWidgets();

/*
 * Set all advanced search form button callbacks.
 */
(function setSearchFormCallbacks(){
    // Create a new search group, and update the `#sidebar` checklist.
    $("button#add-group").click(function(){
        $("div#sidebar input[type=checkbox]").prop("checked", false);

        searchGroups.children("#selected").removeAttr("id");
        var searchGroup = $("<div/>", {
            class : "search-group",
            id : "selected"
        });
        searchGroups.append(
            searchGroup.append(createSearchGroupInput("language", "languages")));
        loadInputFieldWidgets();
        $("div#sidebar input[type=checkbox]#language").prop("checked", true);

        searchGroups[0].scrollTop = searchGroups[0].scrollHeight;
    });

    // Remove the currently selected group if it's not the only one, and mark
    // one of its siblings as selected.
    $("button#remove-group").click(function(){
        var currentGroup = $("div.search-group#selected");

        if($("div.search-group").length == 1)
            return;
        else {
            var nextGroup = currentGroup.prev();
            if(nextGroup.size() == 0)
                nextGroup = currentGroup.next();
        }
        currentGroup.remove();
        nextGroup.click();
    });

    // Select a search group, and update the `#sidebar` checklist accordingly.
    $(document).on("click", "div.search-group", function(){
        searchGroups.children("#selected").removeAttr("id");
        $(this).attr("id", "selected");
        $("div#sidebar input[type=checkbox]").prop("checked", false);
        $(this).find("input[type=text]").each(function(){
            var checkBoxSelector = "div#sidebar input[type=checkbox]";
            $(checkBoxSelector + "#" + $(this).attr("class").split(" ")[0]).
                    prop("checked", true);
        })
    });

    // Toggle the presence of an input field.
    $("div#sidebar input[type=checkbox]").click(function(){
        var fieldId = $(this).prop("id");
        if($(this).is(":checked")){
            $("div.search-group#selected").append(
                    $.parseHTML(createSearchGroupInput(
                            fieldId, $(this).next("label").children("div").
                            text())));
            loadInputFieldWidgets();
            if(fieldId.slice(0, 4) == "date")
                $(".search-group#selected ." + fieldId).datepicker();
        }
        else {
            if($(".search-group#selected").children("div").length > 1)
                $(".search-group#selected #" + fieldId).remove()
            else
                $(this).prop("checked", true);
        }
        searchGroups[0].scrollTop = searchGroups[0].scrollHeight;
    });

    $("div#advanced-search button#submit").click(function(){
        $("div#advanced-search").hide();
        advancedSearchButton.removeClass("clicked");
        assembleQuery();
        queryServer();
    })

    var previousAdvancedQuery = "";
    var searchBar = $("form#search-bar input[name=query]");

    window.setInterval(function(){
        var currentQuery = assembleQuery();
        if(currentQuery != previousAdvancedQuery){
            previousAdvancedQuery = currentQuery;
            searchBar.val(assembleQuery());
        }
    }, 1e3 / 15);
}());

/*
 * Return an HTML string representing a new input field div in a search group.
 *
 * @param fieldId The id of the input field div, and its child elements.
 * @param name The name to display next to the input field.
 */
function createSearchGroupInput(fieldId, name){
    var fieldHTML = [
        "<div id='" + fieldId + "'>",
            "<div class='name'>" + name + "</div>",
            "<input class='" + fieldId + "' name='" + fieldId + "'type='text'>",
            "<input type='checkbox' name='regex'>",
            "<span class='regex'>Regex</span>",
        "</div>"
    ]

    if(fieldId == "language")
        fieldHTML[2] = [
            "<input id='autocomplete' class='language'",
            "name='language' type='text'>"
        ].join(" ");

    return fieldHTML.join("");
}

/*
 * Create a query from advanced-search groups.
 */
function assembleQuery(){
    var groups = searchGroups.children(".search-group");
    var groupQueries = [];

    for(var group = 0; group < groups.length; group++){
        var inputFields = groups[group].querySelectorAll("input[type=text]");
        var regexCheckbox = groups[group].querySelectorAll("input[name=regex]");
        var groupQuery = [];

        for(var field = 0; field < inputFields.length; field++)
            if(inputFields[field].value.length > 0)
                groupQuery.push(genFieldQueryString(
                        inputFields[field], regexCheckbox[field].checked));

        if(groupQuery.length > 0)
            groupQueries.push(groupQuery.join(" AND "));
    }

    return groupQueries.join(" OR ");
}

/*
 * Generate a processed query string for an input field's value.
 *
 * @param field (DOM element) An `input[type=text]` element.
 * @param hasRegex (boolean) Whether or not the field's value has regex.
 *
 * @return The processed query.
 */
function genFieldQueryString(field, hasRegex){
    var terms = field.value.replace(/\\/g, "\\\\").replace(/\"/g, "\\\"");
    var query = field.getAttribute("name") + ":" + (hasRegex?"re:":"") + terms;
    return '"' + query + '"';
}