/*
 * Copyright (c) 2012, 2017, 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 jdk.javadoc.internal.api;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Locale;
import java.util.Objects;
import java.util.concurrent.atomic.AtomicBoolean;

import javax.tools.DocumentationTool.DocumentationTask;
import javax.tools.JavaFileObject;

import com.sun.tools.javac.main.Option;
import com.sun.tools.javac.util.ClientCodeException;
import com.sun.tools.javac.util.Context;
import com.sun.tools.javac.util.Options;
import jdk.javadoc.internal.tool.Start;

Provides access to functionality specific to the JDK documentation tool,
javadoc.
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.
/**
 * 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;
    private List<String> addModules = new ArrayList<>();

    public JavadocTaskImpl(Context context, Class<?> docletClass,
            Iterable<String> options, Iterable<? extends JavaFileObject> fileObjects) {
        this.context = context;
        this.docletClass = docletClass;

        this.options = (options == null) ? Collections.emptySet()
                : nullCheck(options);
        this.fileObjects = (fileObjects == null) ? Collections.emptySet()
                : nullCheck(fileObjects);
        setLocale(Locale.getDefault());
    }

    public void setLocale(Locale locale) {
        if (used.get())
            throw new IllegalStateException();
        this.locale = locale;
    }

    @Override
    public void addModules(Iterable<String> moduleNames) {
        nullCheck(moduleNames);
        if (used.get())
            throw new IllegalStateException();
        for (String name : moduleNames) {
            addModules.add(name);
        }
    }

    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);
        if (!addModules.isEmpty()) {
            String names = String.join(",", addModules);
            Options opts = Options.instance(context);
            String prev = opts.get(Option.ADD_MODULES);
            opts.put(Option.ADD_MODULES, (prev == null) ? names : prev + "," + names);
        }
    }

    private static <T> Iterable<T> nullCheck(Iterable<T> items) {
        for (T item: items) {
            if (item == null)
                throw new NullPointerException();
        }
        return items;
    }
}