/*
 * Copyright (c) 2020, 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
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 */

package com.sun.tools.doclint;

import java.util.ServiceLoader;

import com.sun.source.util.JavacTask;
import com.sun.source.util.Plugin;

The base class for the DocLint service used by javac.
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.
/**
 * The base class for the DocLint service used by javac.
 *
 * <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>
 */
public abstract class DocLint implements Plugin {
    public static final String XMSGS_OPTION = "-Xmsgs";
    public static final String XMSGS_CUSTOM_PREFIX = "-Xmsgs:";
    public static final String XHTML_VERSION_PREFIX = "-XhtmlVersion:";
    public static final String XCHECK_PACKAGE = "-XcheckPackage:";

    private static ServiceLoader.Provider<DocLint> docLintProvider;

    public abstract boolean isValidOption(String opt);

    public static synchronized DocLint newDocLint() {
        if (docLintProvider == null) {
            docLintProvider = ServiceLoader.load(DocLint.class, ClassLoader.getSystemClassLoader()).stream()
                    .filter(p_ -> p_.get().getName().equals("doclint"))
                    .findFirst()
                    .orElse(new ServiceLoader.Provider<>() {
                        @Override
                        public Class<? extends DocLint> type() {
                            return NoDocLint.class;
                        }

                        @Override
                        public DocLint get() {
                            return new NoDocLint();
                        }
                    });
        }
        return docLintProvider.get();
    }

    private static class NoDocLint extends DocLint {
        @Override
        public String getName() {
            return "doclint-not-available";
        }

        @Override
        public void init(JavacTask task, String... args) {
            throw new IllegalStateException("doclint not available");
        }

        @Override
        public boolean isValidOption(String s) {
            // passively accept all "plausible" options
            return s.equals(XMSGS_OPTION)
                    || s.startsWith(XMSGS_CUSTOM_PREFIX)
                    || s.startsWith(XHTML_VERSION_PREFIX)
                    || s.startsWith(XCHECK_PACKAGE);
        }
    }
}