/*

 * 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

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package jdk.javadoc.internal.doclets.toolkit.util;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.OutputStream;

import java.io.UnsupportedEncodingException;

import java.io.Writer;

import javax.tools.JavaFileManager.Location;

import javax.tools.StandardLocation;

/**

 * Abstraction for handling files, which may be specified directly

 * (e.g. via a path on the command line) or relative to a Location.

 *

 *  <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 DocFile {

    /** Create a DocFile for a directory. */

        return DocFileFactory.getFactory(configuration).createFileForDirectory(file);

    }

    /** Create a DocFile for a file that will be opened for reading. */

        return DocFileFactory.getFactory(configuration).createFileForInput(file);

    }

    /** Create a DocFile for a file that will be opened for writing. */

        return DocFileFactory.getFactory(configuration).createFileForOutput(path);

    }

    /**

     * The location for this file. Maybe null if the file was created without

     * a location or path.

     */

    protected final Location location;

    /**

     * The path relative to the (output) location. Maybe null if the file was

     * created without a location or path.

     */

    protected final DocPath path;

    /**

     * List the directories and files found in subdirectories along the

     * elements of the given location.

     * @param configuration the doclet configuration

     * @param location currently, only {@link StandardLocation#SOURCE_PATH} is supported.

     * @param path the subdirectory of the directories of the location for which to

     *  list files

     */

        return DocFileFactory.getFactory(configuration).list(location, path);

    }

    /** Create a DocFile without a location or path */

    protected DocFile() {

        this.location = null;

        this.path = null;

    }

    /** Create a DocFile for a given location and relative path. */

    protected DocFile(Location location, DocPath path) {

        this.location = location;

        this.path = path;

    }

    /**

     * Open an input stream for the file.

     *

     * @return an open input stream for the file

     * @throws DocFileIOException if there is a problem opening the stream

     */

    public abstract InputStream openInputStream() throws DocFileIOException;

    /**

     * Open an output stream for the file.

     * The file must have been created with a location of

     * {@link DocumentationTool.Location#DOCUMENTATION_OUTPUT}

     * and a corresponding relative path.

     *

     * @return an open output stream for the file

     * @throws DocFileIOException if there is a problem opening the stream

     * @throws UnsupportedEncodingException if the configured encoding is not supported

     */

    public abstract OutputStream openOutputStream() throws DocFileIOException, UnsupportedEncodingException;

    /**

     * Open an writer for the file, using the encoding (if any) given in the

     * doclet configuration.

     * The file must have been created with a location of

     * {@link DocumentationTool.Location#DOCUMENTATION_OUTPUT} and a corresponding relative path.

     *

     * @return an open output stream for the file

     * @throws DocFileIOException if there is a problem opening the stream

     * @throws UnsupportedEncodingException if the configured encoding is not supported

     */

    public abstract Writer openWriter() throws DocFileIOException, UnsupportedEncodingException;

    /**

     * Copy the contents of another file directly to this file.

     *

     * @param fromFile the file to be copied

     * @throws DocFileIOException if there is a problem file copying the file

     */

    public void copyFile(DocFile fromFile) throws DocFileIOException {

        try (OutputStream output = openOutputStream()) {

            try (InputStream input = fromFile.openInputStream()) {

                byte[] bytearr = new byte[1024];

                int len;

                while ((len = read(fromFile, input, bytearr)) != -1) {

                    write(this, output, bytearr, len);

                }

            } catch (IOException e) {

                throw new DocFileIOException(fromFile, DocFileIOException.Mode.READ, e);

            }

        } catch (IOException e) {

            throw new DocFileIOException(this, DocFileIOException.Mode.WRITE, e);

        }

    }

    /**

     * Copy the contents of a resource file to this file.

     *

     * @param resource the path of the resource, relative to the package of this class

     * @param overwrite whether or not to overwrite the file if it already exists

     * @param replaceNewLine if false, the file is copied as a binary file;

     *     if true, the file is written line by line, using the platform line

     *     separator

     *

     * @throws DocFileIOException if there is a problem while writing the copy

     * @throws ResourceIOException if there is a problem while reading the resource

     */

    public void copyResource(DocPath resource, boolean overwrite, boolean replaceNewLine)

                throws DocFileIOException, ResourceIOException {

        if (exists() && !overwrite)

            return;

        try {

            if (in == null)

                return;

            try {

                if (replaceNewLine) {

                    try (BufferedReader reader = new BufferedReader(new InputStreamReader(in))) {

                        try (Writer writer = openWriter()) {

                            String line;

                            while ((line = readResourceLine(resource, reader)) != null) {

                                write(this, writer, line);

                                write(this, writer, DocletConstants.NL);

                            }

                        } catch (IOException e) {

                            throw new DocFileIOException(this, DocFileIOException.Mode.WRITE, e);

                        }

                    }

                } else {

                    try (OutputStream out = openOutputStream()) {

                        byte[] buf = new byte[2048];

                        int n;

                        while ((n = readResource(resource, in, buf)) > 0) {

                            write(this, out, buf, n);

                        }

                    } catch (IOException e) {

                        throw new DocFileIOException(this, DocFileIOException.Mode.WRITE, e);

                    }

                }

            } finally {

                in.close();

            }

        } catch (IOException e) {

            throw new ResourceIOException(resource, e);

        }

    }

    /** Return true if the file can be read. */

    public abstract boolean canRead();

    /** Return true if the file can be written. */

    public abstract boolean canWrite();

    /** Return true if the file exists. */

    public abstract boolean exists();

    /** Return the base name (last component) of the file name. */

    public abstract String getName();

    /** Return the file system path for this file. */

    public abstract String getPath();

    /** Return true if file has an absolute path name. */

    public abstract boolean isAbsolute();

    /** Return true if file identifies a directory. */

    public abstract boolean isDirectory();

    /** Return true if file identifies a file. */

    public abstract boolean isFile();

    /** Return true if this file is the same as another. */

    public abstract boolean isSameFile(DocFile other);

    /** If the file is a directory, list its contents.

     *

     * @return the contents of the directory

     * @throws DocFileIOException if there is a problem while listing the directory

     */

    public abstract Iterable<DocFile> list() throws DocFileIOException;

    /** Create the file as a directory, including any parent directories. */

    public abstract boolean mkdirs();

    /**

     * Derive a new file by resolving a relative path against this file.

     * The new file will inherit the configuration and location of this file

     * If this file has a path set, the new file will have a corresponding

     * new path.

     */

    public abstract DocFile resolve(DocPath p);

    /**

     * Derive a new file by resolving a relative path against this file.

     * The new file will inherit the configuration and location of this file

     * If this file has a path set, the new file will have a corresponding

     * new path.

     */

    public abstract DocFile resolve(String p);

    /**

     * Resolve a relative file against the given output location.

     * @param locn Currently, only

     * {@link DocumentationTool.Location#DOCUMENTATION_OUTPUT} is supported.

     */

    public abstract DocFile resolveAgainst(Location locn);

    /**

     * Reads from an input stream opened from a given file into a given buffer.

     * If an IOException occurs, it is wrapped in a DocFileIOException.

     *

     * @param inFile the file for the stream

     * @param input the stream

     * @param buf the buffer

     * @return the number of bytes read, or -1 if at end of file

     * @throws DocFileIOException if an exception occurred while reading the stream

     */

    private static int read(DocFile inFile, InputStream input, byte[] buf) throws DocFileIOException {

        try {

            return input.read(buf);

        } catch (IOException e) {

            throw new DocFileIOException(inFile, DocFileIOException.Mode.READ, e);

        }

    }

    /**

     * Writes to an output stream for a given file from a given buffer.

     * If an IOException occurs, it is wrapped in a DocFileIOException.

     *

     * @param outFile the file for the stream

     * @param out the stream

     * @param buf the buffer

     * @throws DocFileIOException if an exception occurred while writing the stream

     */

    private static void write(DocFile outFile, OutputStream out, byte[] buf, int len) throws DocFileIOException {

        try {

            out.write(buf, 0, len);

        } catch (IOException e) {

            throw new DocFileIOException(outFile, DocFileIOException.Mode.WRITE, e);

        }

    }

    /**

     * Writes text to an output stream for a given file from a given buffer.

     * If an IOException occurs, it is wrapped in a DocFileIOException.

     *

     * @param outFile the file for the stream

     * @param out the stream

     * @param text the text to be written

     * @throws DocFileIOException if an exception occurred while writing the stream

     */

    private static void write(DocFile outFile, Writer out, String text) throws DocFileIOException {

        try {

            out.write(text);

        } catch (IOException e) {

            throw new DocFileIOException(outFile, DocFileIOException.Mode.WRITE, e);

        }

    }

    /**

     * Reads from an input stream opened from a given resource into a given buffer.

     * If an IOException occurs, it is wrapped in a ResourceIOException.

     *

     * @param resource the resource for the stream

     * @param in the stream

     * @param buf the buffer

     * @return the number of bytes read, or -1 if at end of file

     * @throws ResourceIOException if an exception occurred while reading the stream

     */

    private static int readResource(DocPath resource, InputStream in, byte[] buf) throws ResourceIOException {

        try {

            return in.read(buf);

        } catch (IOException e) {

            throw new ResourceIOException(resource, e);

        }

    }

    /**

     * Reads a line of characters from an input stream opened from a given resource.

     * If an IOException occurs, it is wrapped in a ResourceIOException.

     *

     * @param resource the resource for the stream

     * @param in the stream

     * @return the line of text, or {@code null} if at end of stream

     * @throws ResourceIOException if an exception occurred while reading the stream

     */

    private static String readResourceLine(DocPath docPath, BufferedReader in) throws ResourceIOException {

        try {

            return in.readLine();

        } catch (IOException e) {

            throw new ResourceIOException(docPath, e);

        }

    }

}