/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.vfs2.provider.local;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.file.Files;
import java.nio.file.StandardOpenOption;

import org.apache.commons.vfs2.FileObject;
import org.apache.commons.vfs2.FileSystemException;
import org.apache.commons.vfs2.FileType;
import org.apache.commons.vfs2.RandomAccessContent;
import org.apache.commons.vfs2.provider.AbstractFileName;
import org.apache.commons.vfs2.provider.AbstractFileObject;
import org.apache.commons.vfs2.provider.UriParser;
import org.apache.commons.vfs2.util.FileObjectUtils;
import org.apache.commons.vfs2.util.RandomAccessMode;

/**
 * A file object implementation which uses direct file access.
 */
public class LocalFile extends AbstractFileObject<LocalFileSystem> {

    private final String rootFile;

    private File file;

    /**
     * Creates a non-root file.
     *
     * @param fileSystem the file system this file belongs to.
     * @param rootFile the root file for the file system.
     * @param name the file name on this file system.
     * @throws FileSystemException if an error occurs.
     */
    protected LocalFile(final LocalFileSystem fileSystem, final String rootFile, final AbstractFileName name)
            throws FileSystemException {
        super(name, fileSystem);
        this.rootFile = rootFile;
    }

    /**
     * Attaches this file object to its file resource.
     */
    @Override
    protected void doAttach() throws Exception {
        if (file == null) {
            // Remove the "file:///"
            // LocalFileName localFileName = (LocalFileName) getName();
            final String fileName = rootFile + getName().getPathDecoded();
            // fileName = UriParser.decode(fileName);
            file = new File(fileName);
        }
    }

    /**
     * Creates this folder.
     */
    @Override
    protected void doCreateFolder() throws Exception {
        if (!file.mkdirs()) {
            throw new FileSystemException("vfs.provider.local/create-folder.error", file);
        }
    }

    /**
     * Deletes this file, and all children.
     */
    @Override
    protected void doDelete() throws Exception {
        if (!file.delete()) {
            throw new FileSystemException("vfs.provider.local/delete-file.error", file);
        }
    }

    /**
     * Returns the size of the file content (in bytes).
     */
    @Override
    protected long doGetContentSize() throws Exception {
        return file.length();
    }

    /**
     * Creates an input stream to read the content from.
     */
    @Override
    protected InputStream doGetInputStream(final int bufferSize) throws Exception {
        return new FileInputStream(file);
    }

    /**
     * Gets the last modified time of this file.
     */
    @Override
    protected long doGetLastModifiedTime() throws FileSystemException {
        // Workaround OpenJDK 8 and 9 bug JDK-8177809
        // https://bugs.openjdk.java.net/browse/JDK-8177809
        try {
            return Files.getLastModifiedTime(file.toPath()).toMillis();
        } catch (final IOException e) {
            throw new FileSystemException(file.toString(), e);
        }
    }

    /**
     * Creates an output stream to write the file content to.
     */
    @Override
    protected OutputStream doGetOutputStream(final boolean bAppend) throws Exception {
        return Files.newOutputStream(file.toPath(),  bAppend ? StandardOpenOption.APPEND : StandardOpenOption.CREATE);
    }

    @Override
    protected RandomAccessContent doGetRandomAccessContent(final RandomAccessMode mode) throws Exception {
        return new LocalFileRandomAccessContent(file, mode);
    }

    /**
     * Returns the file's type.
     */
    @Override
    protected FileType doGetType() throws Exception {
        if (!file.exists()) {
            return FileType.IMAGINARY;
        }

        if (file.isDirectory()) {
            return FileType.FOLDER;
        }

        // In doubt, treat an existing file as file
        // if (file.isFile())
        // {
        return FileType.FILE;
        // }

        // throw new FileSystemException("vfs.provider.local/get-type.error", file);
    }

    /**
     * Determines if this file is hidden.
     */
    @Override
    protected boolean doIsExecutable() {
        return file.canExecute();
    }

    /**
     * Determines if this file is hidden.
     */
    @Override
    protected boolean doIsHidden() {
        return file.isHidden();
    }

    /**
     * Determines if this file can be read.
     */
    @Override
    protected boolean doIsReadable() throws FileSystemException {
        return file.canRead();
    }

    @Override
    protected boolean doIsSameFile(final FileObject destFile) throws FileSystemException {
        if (!FileObjectUtils.isInstanceOf(destFile, LocalFile.class)) {
            return false;
        }

        final LocalFile destLocalFile = (LocalFile) FileObjectUtils.getAbstractFileObject(destFile);
        if (!exists() || !destLocalFile.exists()) {
            return false;
        }

        try {
            return file.getCanonicalPath().equals(destLocalFile.file.getCanonicalPath());
        } catch (final IOException e) {
            throw new FileSystemException(e);
        }
    }

    /**
     * Determines if this file is a symbolic link.
     * @since 2.4
     */
    @Override
    protected boolean doIsSymbolicLink() throws FileSystemException {
        return Files.isSymbolicLink(file.toPath());
    }

    /**
     * Determines if this file can be written to.
     */
    @Override
    protected boolean doIsWriteable() throws FileSystemException {
        return file.canWrite();
    }

    /**
     * Returns the children of the file.
     */
    @Override
    protected String[] doListChildren() throws Exception {
        return UriParser.encode(file.list());
    }

    /**
     * rename this file
     */
    @Override
    protected void doRename(final FileObject newFile) throws Exception {
        final LocalFile newLocalFile = (LocalFile) FileObjectUtils.getAbstractFileObject(newFile);

        if (!file.renameTo(newLocalFile.getLocalFile())) {
            throw new FileSystemException("vfs.provider.local/rename-file.error", file.toString(), newFile.toString());
        }
    }

    @Override
    protected boolean doSetExecutable(final boolean executable, final boolean ownerOnly) throws Exception {
        return file.setExecutable(executable, ownerOnly);
    }

    /**
     * Sets the last modified time of this file.
     *
     * @since 2.0
     */
    @Override
    protected boolean doSetLastModifiedTime(final long modtime) throws FileSystemException {
        return file.setLastModified(modtime);
    }

    @Override
    protected boolean doSetReadable(final boolean readable, final boolean ownerOnly) throws Exception {
        return file.setReadable(readable, ownerOnly);
    }

    @Override
    protected boolean doSetWritable(final boolean writable, final boolean ownerOnly) throws Exception {
        return file.setWritable(writable, ownerOnly);
    }

    /**
     * Returns the local file that this file object represents.
     *
     * @return the local file that this file object represents.
     */
    protected File getLocalFile() {
        return file;
    }

    /**
     * Returns the URI of the file.
     *
     * @return The URI of the file.
     */
    @Override
    public String toString() {
        try {
            // VFS-325: URI may contain percent-encoded values as part of file name, so decode
            // those characters before returning
            return UriParser.decode(getName().getURI());
        } catch (final FileSystemException e) {
            return getName().getURI();
        }
    }
}