/*
 * Copyright (c) 2012, 2016, 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.sjavac.comp;

import java.io.*;
import java.net.URI;
import java.nio.file.NoSuchFileException;

import javax.lang.model.element.Modifier;
import javax.lang.model.element.NestingKind;
import javax.tools.JavaFileObject;

import com.sun.tools.javac.util.DefinedBy;
import com.sun.tools.javac.util.DefinedBy.Api;

The SmartFileObject will return an outputstream that cache the written data
and compare the new content with the old content on disk. Only if they differ,
will the file be updated.
 
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 SmartFileObject will return an outputstream that cache the written data
 * and compare the new content with the old content on disk. Only if they differ,
 * will the file be updated.
 *
 *  <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 class SmartFileObject implements JavaFileObject {

    JavaFileObject file;

    public SmartFileObject(JavaFileObject r) {
        file = r;
    }

    @Override
    public boolean equals(Object other) {
        return file.equals(other);
    }

    @Override
    public int hashCode() {
        return file.hashCode();
    }

    @DefinedBy(Api.COMPILER)
    public Kind getKind() {
        return file.getKind();
    }

    @DefinedBy(Api.COMPILER)
    public boolean isNameCompatible(String simpleName, Kind kind) {
        return file.isNameCompatible(simpleName, kind);
    }

    @DefinedBy(Api.COMPILER)
    public URI toUri() {
        return file.toUri();
    }

    @DefinedBy(Api.COMPILER)
    public String getName() {
        return file.getName();
    }

    @DefinedBy(Api.COMPILER)
    public InputStream openInputStream() throws IOException {
        return file.openInputStream();
    }

    @DefinedBy(Api.COMPILER)
    public OutputStream openOutputStream() throws IOException {
        return file.openOutputStream();
    }

    @DefinedBy(Api.COMPILER)
    public CharSequence getCharContent(boolean ignoreEncodingErrors) throws IOException {
        return file.getCharContent(ignoreEncodingErrors);
    }

    static String lineseparator = System.getProperty("line.separator");

    @DefinedBy(Api.COMPILER)
    public Writer openWriter() throws IOException {
        StringBuilder s = new StringBuilder();
        try (BufferedReader r = new BufferedReader(file.openReader(true))) {
            while (r.ready()) {
                s.append(r.readLine()+lineseparator);
            }
        } catch (FileNotFoundException | NoSuchFileException e) {
            // Perfectly ok.
        }
        return new SmartWriter(file, s.toString(), file.getName());
    }

    @DefinedBy(Api.COMPILER)
    public long getLastModified() {
        return file.getLastModified();
    }

    @DefinedBy(Api.COMPILER)
    public boolean delete() {
        return file.delete();
    }

    @DefinedBy(Api.COMPILER)
    public Modifier getAccessLevel() {
        return file.getAccessLevel();
    }

    @DefinedBy(Api.COMPILER)
    public NestingKind getNestingKind() {
        return file.getNestingKind();
    }

    @DefinedBy(Api.COMPILER)
    public Reader openReader(boolean ignoreEncodingErrors) throws IOException {
        return file.openReader(ignoreEncodingErrors);
    }

}