/*global $, selectAllOptions, moveOptions */

function toggle_filter(field) {
    var remove, to_toggle;
    label = $('label_' + field);
    to_toggle = label.up().siblings();
    if (label.visible()) {
        to_toggle.invoke('show');
        $('rm_' + field).hide();
    } else {
        to_toggle.invoke('hide');
    }
}

function make_select_accept_multiple_values(select) {
    select.multiple = true;
    select.size = 4;
}

function make_select_accept_single_value(select) {
    select.multiple = false;
    select.size = 1;
}

function toggle_multi_select(select) {
    if (select.multiple === true) {
        make_select_accept_single_value(select);
    } else {
        make_select_accept_multiple_values(select);
    }
}

function change_argument_visibility(field, arg_nr) {
    var params, i;
    params = [$(field + '_arg_1'), $(field + '_arg_2')];

    for (i = 0; i < 2; i++) {
        if (params[i] !== null) {
            if (arg_nr >= (i + 1) || arg_nr <= (-1 - i) ) {
                params[i].show();
            }
            else {
                params[i].hide();
            }
        }
    }
}

function operator_changed(field, select) {
    var option_tag, arity;
    option_tag = select.options[select.selectedIndex];
    arity = parseInt(option_tag.getAttribute("data-arity"));
    change_argument_visibility(field, arity);
}

function display_category(tr_field) {
    var label = $(tr_field.getAttribute("data-label"));
    if (label !== null) {
        label.show();
    }
}

function hide_category(tr_field) {
    var label = $(tr_field.getAttribute("data-label"));
    if (label !== null) {
        label.hide();
    }
}

function register_remove_hover(field) {
    table = $('tr_' +  field);
    Event.observe(table, 'mouseover', function(event) { set_remove_button_visibility(field, true) });
    Event.observe(table, 'mouseout', function(event) { set_remove_button_visibility(field, false) });
}


function set_remove_button_visibility(field, value) {
    remove = $('rm_' + field);
    if (remove !== null) {
        if (value == true) {
            remove.show();
        } else {
            remove.hide();
        }
    }
}

function show_filter(field) {
    show_filter_callback(field, function(){;});
}

function show_filter_callback(field, callback_func) {
    var field_el = $('tr_' +  field);
    register_remove_hover(field);
    if (field_el !== null) {
        load_available_values_for_filter(field, callback_func);
        // the following command might be included into the callback_function (which is called after the ajax request) later
        field_el.show();
        toggle_filter(field);
        $('rm_' + field).value = field;
        operator_changed(field, $("operators_" + field));
        display_category(field_el);
    }
}

function hide_filter(field) {
    var field_el = $('tr_' +  field);
    if (field_el !== null) {
        $('rm_' + field).value = "";
        field_el.hide();
        toggle_filter(field);
        operator_changed(field, $("operators_" + field));
        if (!occupied_category(field_el)) {
            hide_category(field_el);
        }
    }
}

function occupied_category(tr_field) {
    var i, hit = false, data_label = tr_field.getAttribute("data-label");
    filters = document.getElementsByClassName('filter');
    for (i = 0; i < filters.length; i++) {
        if (filters[i].visible() && filters[i].getAttribute("data-label") == data_label) {
            return hit = true;
        }
    }
    return hit;
}

function disable_select_option(select, field) {
    for (var i = 0; i < select.options.length; i++) {
        if (select.options[i].value == field) {
            select.options[i].disabled = true;
            break;
        }
    }
}

function enable_select_option(select, field) {
    for (var i = 0; i < select.options.length; i++) {
        if (select.options[i].value == field) {
            select.options[i].disabled = false;
            break;
        }
    }
}

function add_filter(select) {
    var field;
    field = select.value;
    show_filter(field);
    select.selectedIndex = 0;
    disable_select_option(select, field);
}

function remove_filter(field) {
    hide_filter(field);
    enable_select_option($("add_filter_select"), field);
}

function show_group_by(group_by, target) {
    var source, group_option, i;
    source = $("group_by_container");
    group_option = null;
    // find group_by option-tag in target select-box
    for (i = 0; i < source.options.length; i++) {
        if (source.options[i].value == group_by) {
            group_option = source.options[i];
            source.options[i] = null;
            break;
        }
    }
    // die if the appropriate option-tag can not be found
    if (group_option === null) {
        return;
    }
    // move the option-tag to the taget select-box while keepings its data
    target.options[target.length] = group_option;
}

function select_operator(field, operator) {
    var select, i;
    select = $("operators_" + field);
    for (i = 0; i < select.options.length; i++) {
        if (select.options[i].value == operator) {
            select.selectedIndex = i;
            break;
        }
    }
    operator_changed(field, select);
}

function restore_select_values(select, values) {
    var i, j;
    if (values.length > 1) {
        make_select_accept_multiple_values(select);
    } else {
        make_select_accept_single_value(select);
    }
    for (i = 0; i < values.length; i++) {
        for (j = 0; j < select.options.length; j++) {
            if (select.options[j].value == values[i]) {
                select.options[j].selected = true;
            }
        }
    }
}

function find_arguments(field) {
    var args = [], arg_count = 0, arg = null;
    arg = $(field + '_arg_' + (arg_count + 1) + '_val');
    while (arg !== null) {
        args[args.length] = arg;
        arg_count++;
        arg = $(field + '_arg_' + (arg_count + 1) + '_val');
    }
    return args;
}

function restore_values(field, values) {
    var op_select, op_arity, args, i;
    op_select = $("operators_" + field);
    op_arity = op_select.options[op_select.selectedIndex].getAttribute("data-arity");
    args = find_arguments(field);
    if (!Object.isArray(values)) {
        values = [values];
    }
    if (op_arity < 0 && !(args[0].type.empty()) && args[0].type.include('select')) {
        restore_select_values(args[0], values);
    } else {
        for (i = 0; i < values.length && i < args.length; i++) {
            args[i].setValue(values[i]);
        }
    }
}

function restore_filter(field, operator, values) {
    select_operator(field, operator);
    disable_select_option($("add_filter_select"), field);
    show_filter_callback(field, function() {
        if (typeof(values) != "undefined") {
            restore_values(field, values);
        }
    });
}

function show_group_by_column(group_by) {
    show_group_by(group_by, $('group_by_columns'));
}

function show_group_by_row(group_by) {
    show_group_by(group_by, $('group_by_rows'));
}

function disable_all_filters() {
    $('filter_table').down().childElements().each(function (e) {
        var field, possible_select;
        e.hide();
        if (e.readAttribute('class') == 'filter') {
            field = e.id.gsub('tr_', '');
            hide_filter(field);
            possible_select = $(field + '_arg_1_val');
            if (possible_select !== null && possible_select.type && possible_select.type.include('select')) {
                make_select_accept_single_value(possible_select);
            }
        }
    });
}

function disable_all_group_bys() {
    var destination;
    destination = $('group_by_container');
    [$('group_by_columns'), $('group_by_rows')].each(function (origin) {
        selectAllOptions(origin);
        moveOptions(origin, destination);
    });
}

function serialize_filter_and_group_by() {
    var ret_str = Form.serialize('query_form');
    var rows = Sortable.serialize('group_rows');
    var columns = Sortable.serialize('group_columns');
    if (rows !== null && rows != "") {
        ret_str += "&" + rows;
    }
    if(columns !== null && columns != "") {
        ret_str += "&" + columns;
    }
    return ret_str;
}

function init_group_bys() {
    var options = {
        tag:'span',
        overlap:'horizontal',
        constraint:'horizontal',
        containment: ['group_columns','group_rows'],
        //only: "group_by",
        dropOnEmpty: true,
        format: /^(.*)$/,
        hoverclass: 'drag_container_accept'
    };
    Sortable.create('group_columns', options);
    Sortable.create('group_rows', options);
}

function load_available_values_for_filter(filter_name, callback_func) {
    var select;
    select = $('' + filter_name + '_arg_1_val');
    if (select.readAttribute('data-loading') == "ajax" && select.childElements().length == 0) {
        new Ajax.Updater({ success: select }, '/cost_reports/available_values', {
            parameters: { filter_name: filter_name },
            insertion: 'bottom',
            evalScripts: false,
            onCreate: function (a,b) {
                $('operators_' + filter_name).disable();
                $('' + filter_name + '_arg_1_val').disable();
            },
            onComplete: function (a,b) {
                $('operators_' + filter_name).enable();
                $('' + filter_name + '_arg_1_val').enable();
                callback_func();
            }
        });
    }
    else {
        callback_func();
    }
}

function defineElementGetter() {
    if (document.getElementsByClassName == undefined) {
        document.getElementsByClassName = function(className)
        {
            var hasClassName = new RegExp("(?:^|\\s)" + className + "(?:$|\\s)");
            var allElements = document.getElementsByTagName("*");
            var results = [];

            var element;
            for (var i = 0; (element = allElements[i]) != null; i++) {
                var elementClass = element.className;
                if (elementClass && elementClass.indexOf(className) != -1 && hasClassName.test(elementClass))
                results.push(element);
            }

            return results;
        }
    }
}

defineElementGetter();