/**
 * Copyright (c) 2011, The University of Southampton and the individual contributors.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 *   *  Redistributions of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 *
 *   *  Redistributions in binary form must reproduce the above copyright notice,
 *      this list of conditions and the following disclaimer in the documentation
 *      and/or other materials provided with the distribution.
 *
 *   *  Neither the name of the University of Southampton nor the names of its
 *      contributors may be used to endorse or promote products derived from this
 *      software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.openimaj.hadoop.tools.downloader;

import java.io.IOException;
import java.net.URI;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapreduce.lib.map.MultithreadedMapper;
import org.kohsuke.args4j.CmdLineException;
import org.kohsuke.args4j.CmdLineParser;
import org.kohsuke.args4j.Option;
import org.kohsuke.args4j.ProxyOptionHandler;
import org.openimaj.hadoop.sequencefile.SequenceFileUtility;
import org.openimaj.hadoop.tools.downloader.InputMode.Parser;

/**
 * Command-line options for the downloader tool
 *
 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
 */
public class HadoopDownloaderOptions {
        private String[] args;

        @Option(name = "--input", aliases = "-i", required = true, usage = "Input file or URL.", metaVar = "STRING")
        private String input;

        @Option(name = "--output", aliases = "-o", required = true, usage = "Output file or URL.", metaVar = "STRING")
        private String output;

        @Option(
                        name = "--remove",
                        aliases = "-rm",
                        required = false,
                        usage = "Remove the existing output location if it exists.",
                        metaVar = "BOOLEAN")
        private boolean replace = false;

        @Option(
                        name = "--num-reducers",
                        aliases = "-nr",
                        required = false,
                        usage = "Number of reducers. Controls the number of sequencefile parts created.")
        private int nreducers = 0;

        @Option(
                        name = "--num-threads",
                        aliases = "-nt",
                        required = false,
                        usage = "Number of mapper threads. If > 1, then a multithreaded mapper will be used.")
        private int nThreads = 1;

        @Option(
                        name = "--input-mode",
                        aliases = "-m",
                        required = false,
                        usage = "How should the URLs be processed to be downloaded.",
                        handler = ProxyOptionHandler.class)
        private InputMode inputMode = InputMode.PLAIN;
        private Parser inputModeOp;

        @Option(
                        name = "--sleep",
                        aliases = "-s",
                        required = false,
                        usage = "Time in milliseconds to sleep after downloading a file.",
                        metaVar = "LONG")
        private long sleep = 0;

        @Option(name = "--follow-redirects", aliases = "-f", usage = "Follow URL redirections", required = false)
        private boolean followRedirects = false;

        @Option(name = "--log-failures", aliases = "-l", usage = "Log failed records to a file", required = false)
        private boolean writeFailures = false;

        /**
         * Construct with the given arguments
         *
         * @param args
         *            the arguments
         */
        public HadoopDownloaderOptions(String[] args) {
                this.args = args;
        }

        /**
         * Prepare the options
         *
         * @param initial
         *            true if initial setup is being performed; false if inside the
         *            mapper
         */
        public void prepare(boolean initial) {
                final CmdLineParser parser = new CmdLineParser(this);
                try {
                        parser.parseArgument(args);
                        this.validate(initial);
                } catch (final CmdLineException e) {
                        System.err.println(e.getMessage());
                        System.err.println("Usage: hadoop -jar HadoopImageDownloader [options...] [files...]");
                        parser.printUsage(System.err);

                        System.exit(1);
                }
        }

        private void validate(boolean initial) {
                if (replace && initial) {
                        try {
                                final URI outuri = SequenceFileUtility.convertToURI(output);

                                final FileSystem fs = SequenceFileUtility.getFileSystem(outuri, new Configuration());

                                fs.delete(new Path(outuri.toString()), true);
                        } catch (final IOException e) {

                        }
                }
        }

        /**
         * Get the input file(s) containing the URLs
         *
         * @return the input paths
         * @throws IOException
         */
        public Path[] getInputPaths() throws IOException {
                return SequenceFileUtility.getFilePaths(input, "part");
        }

        /**
         * @return the output file location
         */
        public Path getOutputPath() {
                return new Path(SequenceFileUtility.convertToURI(output).toString());
        }

        /**
         * @return the number of reducers
         */
        public int getNumberOfReducers() {
                return this.nreducers;
        }

        /**
         * @return the {@link Parser} corresponding to the selected mode.
         */
        public Parser getInputParser() {
                return inputModeOp;
        }

        /**
         * @return the time in milliseconds to sleep after downloading a file
         */
        public long getSleep() {
                return sleep;
        }

        /**
         * @return true if redirects should be followed; false otherwise
         */
        public boolean followRedirects() {
                return followRedirects;
        }

        /**
         * @return true if failed records should be logged to a file
         */
        public boolean writeFailures() {
                return writeFailures;
        }

        /**
         * Get the number of threads to use in the mapper. If >1 a
         * {@link MultithreadedMapper} will be used.
         *
         * @return number of threads to use
         */
        public int getNumberOfThreads() {
                return nThreads;
        }
}