/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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.tools.ant.taskdefs.condition;

import java.io.File;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.util.JavaEnvUtils;
import org.apache.tools.ant.util.ReflectWrapper;
import org.apache.tools.ant.util.StringUtils;

/**
 * &lt;hasfreespace&gt;
 * <p>Condition returns true if selected partition
 * has the requested space, false otherwise.</p>
 * @since Ant 1.7
 */
public class HasFreeSpace implements Condition {

    private String partition;
    private String needed;

    /**
     * Evaluate the condition.
     * @return true if there enough free space.
     * @throws BuildException if there is a problem.
     */
    @Override
    public boolean eval() throws BuildException {
        validate();
        try {
            if (JavaEnvUtils.isAtLeastJavaVersion("1.6")) {
                //reflection to avoid bootstrap/build problems
                File fs = new File(partition);
                ReflectWrapper w = new ReflectWrapper(fs);
                long free = w.<Long>invoke("getFreeSpace");
                return free >= StringUtils.parseHumanSizes(needed);
            }
            throw new BuildException(
                "HasFreeSpace condition not supported on Java5 or less.");
        } catch (Exception e) {
            throw new BuildException(e);
        }
    }

    private void validate() throws BuildException {
        if (null == partition) {
            throw new BuildException("Please set the partition attribute.");
        }
        if (null == needed) {
            throw new BuildException("Please set the needed attribute.");
        }
    }

    /**
     * The partition/device to check
     * @return the partition.
     */
    public String getPartition() {
        return partition;
    }

    /**
     * Set the partition name.
     * @param partition the name to use.
     */
    public void setPartition(String partition) {
        this.partition = partition;
    }

    /**
     * The amount of free space required
     * @return the amount required
     */
    public String getNeeded() {
        return needed;
    }

    /**
     * Set the amount of space required.
     * @param needed the amount required.
     */
    public void setNeeded(String needed) {
        this.needed = needed;
    }
}
