/*

 * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package com.sun.tools.javadoc.api;

import com.sun.tools.javac.util.ClientCodeException;

import java.util.Locale;

import java.util.concurrent.atomic.AtomicBoolean;

import javax.tools.DocumentationTool.DocumentationTask;

import javax.tools.JavaFileObject;

import com.sun.tools.javac.util.Context;

import com.sun.tools.javadoc.Start;

import java.util.Collections;

/**

 * Provides access to functionality specific to the JDK documentation tool,

 * javadoc.

 *

 * <p><b>This is NOT part of any supported API.

 * If you write code that depends on this, you do so at your own

 * risk.  This code and its internal interfaces are subject to change

 * or deletion without notice.</b></p>

 */

public class JavadocTaskImpl implements DocumentationTask {

    private final AtomicBoolean used = new AtomicBoolean();

    private final Context context;

    private Class<?> docletClass;

    private Iterable<String> options;

    private Iterable<? extends JavaFileObject> fileObjects;

    private Locale locale;

    public JavadocTaskImpl(Context context, Class<?> docletClass,

            Iterable<String> options, Iterable<? extends JavaFileObject> fileObjects) {

        this.context = context;

        this.docletClass = docletClass;

        this.options = (options == null) ? Collections.<String>emptySet()

                : nullCheck(options);

        this.fileObjects = (fileObjects == null) ? Collections.<JavaFileObject>emptySet()

                : nullCheck(fileObjects);

        setLocale(Locale.getDefault());

    }

    public void setLocale(Locale locale) {

        if (used.get())

            throw new IllegalStateException();

        this.locale = locale;

    }

    public Boolean call() {

        if (!used.getAndSet(true)) {

            initContext();

            Start jdoc = new Start(context);

            try {

                return jdoc.begin(docletClass, options, fileObjects);

            } catch (ClientCodeException e) {

                throw new RuntimeException(e.getCause());

            }

        } else {

            throw new IllegalStateException("multiple calls to method 'call'");

        }

    }

    private void initContext() {

        //initialize compiler's default locale

        context.put(Locale.class, locale);

    }

    private static <T> Iterable<T> nullCheck(Iterable<T> items) {

        for (T item: items) {

            if (item == null)

                throw new NullPointerException();

        }

        return items;

    }

}