/*
 *  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.compilers;

import java.io.IOException;
import java.io.File;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.types.Commandline;
import org.apache.tools.ant.taskdefs.condition.Os;
import org.apache.tools.ant.util.JavaEnvUtils;
import org.apache.tools.ant.util.FileUtils;

/**
 * Performs a compile using javac externally.
 *
 * @since Ant 1.4
 */
public class JavacExternal extends DefaultCompilerAdapter {

    /**
     * Performs a compile using the Javac externally.
     * @return true if the compilation succeeded
     * @throws BuildException on error
     */
    public boolean execute() throws BuildException {
        attributes.log("Using external javac compiler", Project.MSG_VERBOSE);

        Commandline cmd = new Commandline();
        cmd.setExecutable(getJavac().getJavacExecutable());
        if (!assumeJava11() && !assumeJava12()) {
            setupModernJavacCommandlineSwitches(cmd);
        } else {
            setupJavacCommandlineSwitches(cmd, true);
        }
        int firstFileName = assumeJava11() ? -1 : cmd.size();
        logAndAddFilesToCompile(cmd);
        //On VMS platform, we need to create a special java options file
        //containing the arguments and classpath for the javac command.
        //The special file is supported by the "-V" switch on the VMS JVM.
        if (Os.isFamily("openvms")) {
            return execOnVMS(cmd, firstFileName);
        }
        return
                executeExternalCompile(cmd.getCommandline(), firstFileName,
                        true)
                == 0;
    }

    /**
     * helper method to execute our command on VMS.
     * @param cmd
     * @param firstFileName
     * @return
     */
    private boolean execOnVMS(Commandline cmd, int firstFileName) {
        File vmsFile = null;
        try {
            vmsFile = JavaEnvUtils.createVmsJavaOptionFile(cmd.getArguments());
            String[] commandLine = {cmd.getExecutable(),
                                    "-V",
                                    vmsFile.getPath()};
            return 0 == executeExternalCompile(commandLine,
                            firstFileName,
                            true);

        } catch (IOException e) {
            throw new BuildException("Failed to create a temporary file for \"-V\" switch");
        } finally {
            FileUtils.delete(vmsFile);
        }
    }

}