/*
 * 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.hdfs;

import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import org.apache.commons.vfs2.FileSystem;
import org.apache.commons.vfs2.FileSystemConfigBuilder;
import org.apache.commons.vfs2.FileSystemOptions;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;

Configuration settings for the HdfsFileSystem.
Since:
2.1/**
 * Configuration settings for the HdfsFileSystem.
 *
 * @since 2.1
 */
public final class HdfsFileSystemConfigBuilder extends FileSystemConfigBuilder {

    private static final HdfsFileSystemConfigBuilder BUILDER = new HdfsFileSystemConfigBuilder();
    private static final String KEY_CONFIG_NAMES = "configNames";
    private static final String KEY_CONFIG_PATHS = "configPaths";
    private static final String KEY_CONFIG_URLS = "configURLs";
    private static final String KEY_CONFIG_STREAM = "configStream";
    private static final String KEY_CONFIG_CONF = "configConf";

    private HdfsFileSystemConfigBuilder() {
        super("hdfs.");
    }

    
Returns:
HdfsFileSystemConfigBuilder instance/**
     * @return HdfsFileSystemConfigBuilder instance
     */
    public static HdfsFileSystemConfigBuilder getInstance() {
        return BUILDER;
    }

    
Returns:
HDFSFileSystem/**
     * @return HDFSFileSystem
     */
    @Override
    protected Class<? extends FileSystem> getConfigClass() {
        return HdfsFileSystem.class;
    }

    
Get names of alternate configuration resources.
Params:
opts – The FileSystemOptions.
See Also:
setConfigName(FileSystemOptions, String)
Returns:
resource name list of alternate configurations or null./**
     * Get names of alternate configuration resources.
     *
     * @return resource name list of alternate configurations or {@code null}.
     * @param opts The FileSystemOptions.
     * @see #setConfigName(FileSystemOptions, String)
     */
    public String[] getConfigNames(final FileSystemOptions opts) {
        final String names = this.getString(opts, KEY_CONFIG_NAMES);
        return names == null || names.isEmpty() ? null : names.split(",");
    }

    
Sets the name of configuration resource to be loaded after the defaults.
 Specifies the name of a config resource to override any specific HDFS settings. The property will be passed on to org.apache.hadoop.conf.Configuration#addResource(String) after the URL was set as the default name with: Configuration#set(FileSystem.FS_DEFAULT_NAME_KEY, url). 
 One use for this is to set a different value for the dfs.client.use.datanode.hostname property in order to access HDFS files stored in an AWS installation (from outside their firewall). There are other possible uses too. 

This method may be called multiple times and all the specified resources will be loaded in the order they were
specified.

 Note also, that if a list of names is provided, separated by commas (","), that this will work the same as calling this method a number of times with just one name each. 
Params:
opts – The FileSystemOptions to modify.
name – resource name of additional configuration or null to unset all the values set so far.
See Also:
getConfigNames/**
     * Sets the name of configuration resource to be loaded after the defaults.
     * <p>
     * Specifies the name of a config resource to override any specific HDFS settings. The property will be passed on to
     * {@code org.apache.hadoop.conf.Configuration#addResource(String)} after the URL was set as the default name with:
     * {@code Configuration#set(FileSystem.FS_DEFAULT_NAME_KEY, url)}.
     * </p>
     * <p>
     * One use for this is to set a different value for the {@code dfs.client.use.datanode.hostname} property in order
     * to access HDFS files stored in an AWS installation (from outside their firewall). There are other possible uses
     * too.
     * </p>
     * <p>
     * This method may be called multiple times and all the specified resources will be loaded in the order they were
     * specified.
     * </p>
     * <p>
     * Note also, that if a list of names is provided, separated by commas ({@code ","}), that this will work the same
     * as calling this method a number of times with just one name each.
     * </p>
     *
     * @param opts The FileSystemOptions to modify.
     * @param name resource name of additional configuration or {@code null} to unset all the values set so far.
     * @see #getConfigNames
     */
    public void setConfigName(final FileSystemOptions opts, final String name) {
        if (name == null || name.isEmpty()) {
            this.setParam(opts, KEY_CONFIG_NAMES, null);
        } else {
            final String previousNames = this.getString(opts, KEY_CONFIG_NAMES);
            if (previousNames == null || previousNames.isEmpty()) {
                this.setParam(opts, KEY_CONFIG_NAMES, name);
            } else {
                this.setParam(opts, KEY_CONFIG_NAMES, previousNames + "," + name);
            }
        }
    }

    
Get paths of alternate configuration file system files.
Params:
opts – The FileSystemOptions.
See Also:
setConfigPath(FileSystemOptions, Path)
Returns:
list of full paths of alternate configuration files or null./**
     * Get paths of alternate configuration file system files.
     *
     * @return list of full paths of alternate configuration files or {@code null}.
     * @param opts The FileSystemOptions.
     * @see #setConfigPath(FileSystemOptions, Path)
     */
    public Path[] getConfigPaths(final FileSystemOptions opts) {
        final String pathNames = this.getString(opts, KEY_CONFIG_PATHS);
        if (pathNames == null || pathNames.isEmpty()) {
            return null;
        }
        final String[] paths = pathNames.split(",");
        final Path[] realPaths = new Path[paths.length];
        for (int i = 0; i < paths.length; i++) {
            realPaths[i] = new Path(paths[i]);
        }
        return realPaths;
    }

    
Sets the full path of configuration file to be loaded after the defaults.
 Specifies the path of a local file system config file to override any specific HDFS settings. The property will be passed on to org.apache.hadoop.conf.Configuration#addResource(Path) after the URL was set as the default name with: Configuration#set(FileSystem.FS_DEFAULT_NAME_KEY, url). 
 One use for this is to set a different value for the dfs.client.use.datanode.hostname property in order to access HDFS files stored in an AWS installation (from outside their firewall). There are other possible uses too. 

This method may be called multiple times and all the specified resources will be loaded in the order they were
specified.
Params:
opts – The FileSystemOptions to modify.
path – full path of additional configuration file (local file system) or null to unset all the path values set so far./**
     * Sets the full path of configuration file to be loaded after the defaults.
     * <p>
     * Specifies the path of a local file system config file to override any specific HDFS settings. The property will
     * be passed on to {@code org.apache.hadoop.conf.Configuration#addResource(Path)} after the URL was set as the
     * default name with: {@code Configuration#set(FileSystem.FS_DEFAULT_NAME_KEY, url)}.
     * <p>
     * One use for this is to set a different value for the {@code dfs.client.use.datanode.hostname} property in order
     * to access HDFS files stored in an AWS installation (from outside their firewall). There are other possible uses
     * too.
     * <p>
     * This method may be called multiple times and all the specified resources will be loaded in the order they were
     * specified.
     *
     * @param opts The FileSystemOptions to modify.
     * @param path full path of additional configuration file (local file system) or {@code null} to unset all the path
     *            values set so far.
     */
    public void setConfigPath(final FileSystemOptions opts, final Path path) {
        if (path == null) {
            this.setParam(opts, KEY_CONFIG_PATHS, null);
        } else {
            final String previousPathNames = this.getString(opts, KEY_CONFIG_PATHS);
            if (previousPathNames == null || previousPathNames.isEmpty()) {
                this.setParam(opts, KEY_CONFIG_PATHS, path.toString());
            } else {
                this.setParam(opts, KEY_CONFIG_PATHS, previousPathNames + "," + path.toString());
            }
        }
    }

    
Get URLs of alternate configurations.
Params:
opts – The FileSystemOptions.
See Also:
setConfigURL(FileSystemOptions, URL)
Returns:
list of alternate configuration URLs or null./**
     * Get URLs of alternate configurations.
     *
     * @return list of alternate configuration URLs or {@code null}.
     * @param opts The FileSystemOptions.
     * @see #setConfigURL(FileSystemOptions, URL)
     */
    public URL[] getConfigURLs(final FileSystemOptions opts) {
        try {
            final String urlNames = this.getString(opts, KEY_CONFIG_URLS);
            if (urlNames == null || urlNames.isEmpty()) {
                return null;
            }
            final String[] urls = urlNames.split(",");
            final URL[] realURLs = new URL[urls.length];
            for (int i = 0; i < urls.length; i++) {
                realURLs[i] = new URL(urls[i]);
            }
            return realURLs;
        } catch (final MalformedURLException mue) {
            // This should never happen because we save it in the proper form
        }
        return null;
    }

    
Sets the URL of configuration file to be loaded after the defaults.
 Specifies the URL of a config file to override any specific HDFS settings. The property will be passed on to org.apache.hadoop.conf.Configuration#addResource(URL) after the URL was set as the default name with: Configuration#set(FileSystem.FS_DEFAULT_NAME_KEY, url). 
 One use for this is to set a different value for the dfs.client.use.datanode.hostname property in order to access HDFS files stored in an AWS installation (from outside their firewall). There are other possible uses too. 

This method may be called multiple times and all the specified resources will be loaded in the order they were
specified.
Params:
opts – The FileSystemOptions to modify.
url – URL of additional configuration file or null to unset all the URL values set so far./**
     * Sets the URL of configuration file to be loaded after the defaults.
     * <p>
     * Specifies the URL of a config file to override any specific HDFS settings. The property will be passed on to
     * {@code org.apache.hadoop.conf.Configuration#addResource(URL)} after the URL was set as the default name with:
     * {@code Configuration#set(FileSystem.FS_DEFAULT_NAME_KEY, url)}.
     * <p>
     * One use for this is to set a different value for the {@code dfs.client.use.datanode.hostname} property in order
     * to access HDFS files stored in an AWS installation (from outside their firewall). There are other possible uses
     * too.
     * <p>
     * This method may be called multiple times and all the specified resources will be loaded in the order they were
     * specified.
     *
     * @param opts The FileSystemOptions to modify.
     * @param url URL of additional configuration file or {@code null} to unset all the URL values set so far.
     */
    public void setConfigURL(final FileSystemOptions opts, final URL url) {
        if (url == null) {
            this.setParam(opts, KEY_CONFIG_URLS, null);
        } else {
            final String previousURLNames = this.getString(opts, KEY_CONFIG_URLS);
            if (previousURLNames == null || previousURLNames.isEmpty()) {
                this.setParam(opts, KEY_CONFIG_URLS, url.toString());
            } else {
                this.setParam(opts, KEY_CONFIG_URLS, previousURLNames + "," + url.toString());
            }
        }
    }

    
Get alternate configuration input stream.
Params:
opts – The FileSystemOptions.
See Also:
setConfigInputStream(FileSystemOptions, InputStream)
Returns:
alternate configuration input stream or null./**
     * Get alternate configuration input stream.
     *
     * @return alternate configuration input stream or {@code null}.
     * @param opts The FileSystemOptions.
     * @see #setConfigInputStream(FileSystemOptions, InputStream)
     */
    public InputStream getConfigInputStream(final FileSystemOptions opts) {
        return (InputStream) this.getParam(opts, KEY_CONFIG_STREAM);
    }

    
Sets the input stream of configuration file to be loaded after the defaults.
 Specifies an input stream connected to a config file to override any specific HDFS settings. The property will be passed on to org.apache.hadoop.conf.Configuration#addResource(InputStream) after the URL was set as the default name with: Configuration#set(FileSystem.FS_DEFAULT_NAME_KEY, url). 
 One use for this is to set a different value for the dfs.client.use.datanode.hostname property in order to access HDFS files stored in an AWS installation (from outside their firewall). There are other possible uses too. 
Params:
opts – The FileSystemOptions to modify.
inputStream – input stream of additional configuration file or null to unset the configuration input stream previously set up./**
     * Sets the input stream of configuration file to be loaded after the defaults.
     * <p>
     * Specifies an input stream connected to a config file to override any specific HDFS settings. The property will be
     * passed on to {@code org.apache.hadoop.conf.Configuration#addResource(InputStream)} after the URL was set as the
     * default name with: {@code Configuration#set(FileSystem.FS_DEFAULT_NAME_KEY, url)}.
     * <p>
     * One use for this is to set a different value for the {@code dfs.client.use.datanode.hostname} property in order
     * to access HDFS files stored in an AWS installation (from outside their firewall). There are other possible uses
     * too.
     *
     * @param opts The FileSystemOptions to modify.
     * @param inputStream input stream of additional configuration file or {@code null} to unset the configuration input
     *            stream previously set up.
     */
    public void setConfigInputStream(final FileSystemOptions opts, final InputStream inputStream) {
        this.setParam(opts, KEY_CONFIG_STREAM, inputStream);
    }

    
Get alternate configuration object.
Params:
opts – The FileSystemOptions.
See Also:
setConfigConfiguration(FileSystemOptions, Configuration)
Returns:
alternate configuration object or null./**
     * Get alternate configuration object.
     *
     * @return alternate configuration object or {@code null}.
     * @param opts The FileSystemOptions.
     * @see #setConfigConfiguration(FileSystemOptions, Configuration)
     */
    public Configuration getConfigConfiguration(final FileSystemOptions opts) {
        return (Configuration) this.getParam(opts, KEY_CONFIG_CONF);
    }

    
Sets the configuration object to be loaded after the defaults.
 Specifies an already initialized configuration object to override any specific HDFS settings. The property will be passed on to org.apache.hadoop.conf.Configuration#addResource(Configuration) after the URL was set as the default name with: Configuration#set(FileSystem.FS_DEFAULT_NAME_KEY, url). 
 One use for this is to set a different value for the dfs.client.use.datanode.hostname property in order to access HDFS files stored in an AWS installation (from outside their firewall). There are other possible uses too. 
Params:
opts – The FileSystemOptions to modify.
configuration – additional configuration object or null to unset any configuration object previously set./**
     * Sets the configuration object to be loaded after the defaults.
     * <p>
     * Specifies an already initialized configuration object to override any specific HDFS settings. The property will
     * be passed on to {@code org.apache.hadoop.conf.Configuration#addResource(Configuration)} after the URL was set as
     * the default name with: {@code Configuration#set(FileSystem.FS_DEFAULT_NAME_KEY, url)}.
     * <p>
     * One use for this is to set a different value for the {@code dfs.client.use.datanode.hostname} property in order
     * to access HDFS files stored in an AWS installation (from outside their firewall). There are other possible uses
     * too.
     *
     * @param opts The FileSystemOptions to modify.
     * @param configuration additional configuration object or {@code null} to unset any configuration object previously
     *            set.
     */
    public void setConfigConfiguration(final FileSystemOptions opts, final Configuration configuration) {
        this.setParam(opts, KEY_CONFIG_CONF, configuration);
    }

}