/*
 *
 * Copyright (c) 2006 The Apache Software Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
package org.apache.qpid.tasks;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Task;

import java.util.HashSet;
import java.util.Set;

/**
 * BaseTask -- an abstract base task for blaze specific tasks.
 **/

public abstract class BaseTask extends Task {

    private static Set EMPTY = new HashSet();
    {
        EMPTY.add(0);
        EMPTY.add("");
    }

    public static class Validator {

        private String name;
        private Object value;

        private  Validator(String name, Object value) {
            this.name = name;
            this.value = value;
        }

        public Validator required() {
            if (value == null) {
                error("value is required");
            }
            return this;
        }

        public Validator nonempty() {
            if (EMPTY.contains(value)) {
                error("value is empty");
            }
            return this;
        }

        private void error(String msg) {
            throw new BuildException(name + ": " + msg);
        }
    }

    public Validator validate(String name, Object value) {
        return new Validator(name, value);
    }

}
