define([], function () {

    'use strict';

    /**
     * Type of the operator which can be used by particular {@link operation/js/api/Condition Condition}.
     *
     * @AbcsAPI stable
     * @version 15.4.5
     * @exports operation/js/api/Operator
     *
     * @see {@link operation/js/api/Condition Condition}
     * @see {@link module:operation/js/api/Conditions Conditions}
     */
    var Operator = function() {
        AbcsLib.throwStaticClassError();
    };

    /**
     * Equals operator.
     *
     * @AbcsAPI stable
     * @version 15.4.5
     * @constant
     * @type {String}
     */
    Operator.EQUALS = 'Equals';

    /**
     * Not equals operator.
     *
     * @AbcsAPI stable
     * @version 15.4.5
     * @constant
     * @type {String}
     */
    Operator.NOT_EQUALS = 'NotEquals';

    /**
     * Starts-with operator.
     *
     * @AbcsAPI stable
     * @version 15.4.5
     * @constant
     * @type {String}
     */
    Operator.STARTS_WITH = 'StartsWith';

    /**
     * Ends-with operator.
     *
     * @AbcsAPI stable
     * @version 15.4.5
     * @constant
     * @type {String}
     */
    Operator.ENDS_WITH = 'EndsWith';

    /**
     * Contains operator.
     *
     * @AbcsAPI stable
     * @version 15.4.5
     * @constant
     * @type {String}
     */
    Operator.CONTAINS = 'Contains';

    /**
     * Does not contain operator.
     *
     * @AbcsAPI stable
     * @version 15.4.5
     * @constant
     * @type {String}
     */
    Operator.NOT_CONTAINS = 'NotContains';

    /**
     */
    Operator.LESS = 'Less';

    /**
     */
    Operator.LESS_OR_EQUAL = 'LessOrEqual';

    /**
     */
    Operator.MORE = 'More';

    /**
     */
    Operator.MORE_OR_EQUAL = 'MoreOrEqual';

    /**
     */
    Operator.IS_EMPTY = 'IsEmpty';

    /**
     */
    Operator.IS_NOT_EMPTY = 'IsNotEmpty';

    /**
     * Array of all possible query operators.
     *
     *
     * @returns {string[]} all possible query operators
     */
    Operator.getAll = function() {
        return [
            Operator.EQUALS,
            Operator.CONTAINS,
            Operator.NOT_EQUALS,
            Operator.NOT_CONTAINS,
            Operator.LESS,
            Operator.LESS_OR_EQUAL,
            Operator.MORE,
            Operator.MORE_OR_EQUAL,
            Operator.STARTS_WITH,
            Operator.ENDS_WITH,
            Operator.IS_EMPTY,
            Operator.IS_NOT_EMPTY
        ];
    };

    return Operator;
});