cassandra-trunk/tools/stress/src/org/apache/cassandra/stress/settings/SettingsMisc.java
package org.apache.cassandra.stress.settings;
/*
 * 
 * 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.
 * 
 */


import java.io.IOException;
import java.io.PrintStream;
import java.io.Serializable;
import java.net.URL;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import com.google.common.base.Charsets;
import com.google.common.io.Resources;

import org.apache.cassandra.stress.generate.Distribution;

class SettingsMisc implements Serializable
{

    static boolean maybeDoSpecial(Map<String, String[]> clArgs)
    {
        if (maybePrintHelp(clArgs))
            return true;
        if (maybePrintDistribution(clArgs))
            return true;
        if (maybePrintVersion(clArgs))
            return true;
        return false;
    }

    private static final class PrintDistribution extends GroupedOptions
    {
        final OptionDistribution dist = new OptionDistribution("dist=", null, "A mathematical distribution");

        @Override
        public List<? extends Option> options()
        {
            return Arrays.asList(dist);
        }
    }


    private static boolean maybePrintDistribution(Map<String, String[]> clArgs)
    {
        final String[] args = clArgs.get("print");
        if (args == null)
            return false;
        final PrintDistribution dist = new PrintDistribution();
        if (null == GroupedOptions.select(args, dist))
        {
            printHelpPrinter().run();
            System.out.println("Invalid print options provided, see output for valid options");
            System.exit(1);
        }
        printDistribution(dist.dist.get().get());
        return true;
    }

    private static void printDistribution(Distribution dist)
    {
        PrintStream out = System.out;
        out.println("% of samples    Range       % of total");
        String format = "%-16.1f%-12d%12.1f";
        double rangemax = dist.inverseCumProb(1d) / 100d;
        for (double d : new double[]{ 0.1d, 0.2d, 0.3d, 0.4d, 0.5d, 0.6d, 0.7d, 0.8d, 0.9d, 0.95d, 0.99d, 1d })
        {
            double sampleperc = d * 100;
            long max = dist.inverseCumProb(d);
            double rangeperc = max / rangemax;
            out.println(String.format(format, sampleperc, max, rangeperc));
        }
    }

    private static boolean maybePrintHelp(Map<String, String[]> clArgs)
    {
        if (!clArgs.containsKey("-?") && !clArgs.containsKey("help"))
            return false;
        String[] params = clArgs.remove("-?");
        if (params == null)
            params = clArgs.remove("help");
        if (params.length == 0)
        {
            if (!clArgs.isEmpty())
            {
                if (clArgs.size() == 1)
                {
                    String p = clArgs.keySet().iterator().next();
                    if (clArgs.get(p).length == 0)
                        params = new String[]{ p };
                }
            }
            else
            {
                printHelp();
                return true;
            }
        }
        if (params.length == 1)
        {
            printHelp(params[0]);
            return true;
        }
        throw new IllegalArgumentException("Invalid command/option provided to help");
    }

    private static boolean maybePrintVersion(Map<String, String[]> clArgs)
    {
        if (clArgs.containsKey("version"))
        {
            try
            {
                URL url = Resources.getResource("org/apache/cassandra/config/version.properties");
                System.out.println(parseVersionFile(Resources.toString(url, Charsets.UTF_8)));
            }
            catch (IOException e)
            {
                e.printStackTrace(System.err);
            }
            return true;
        }
        return false;
    }

    static String parseVersionFile(String versionFileContents)
    {
        Matcher matcher = Pattern.compile(".*?CassandraVersion=(.*?)$").matcher(versionFileContents);
        if (matcher.find())
        {
            return "Version: " + matcher.group(1);
        }
        else
        {
            return "Unable to find version information";
        }
    }

    public static void printHelp()
    {
        System.out.println("Usage:      cassandra-stress <command> [options]");
        System.out.println("Help usage: cassandra-stress help <command>");
        System.out.println();
        System.out.println("---Commands---");
        for (Command cmd : Command.values())
        {
            System.out.println(String.format("%-20s : %s", cmd.toString().toLowerCase(), cmd.description));
        }
        System.out.println();
        System.out.println("---Options---");
        for (CliOption cmd : CliOption.values())
        {
            System.out.println(String.format("-%-20s : %s", cmd.toString().toLowerCase(), cmd.description));
        }
    }

    public static void printHelp(String command)
    {
        Command cmd = Command.get(command);
        if (cmd != null)
        {
            cmd.printHelp();
            return;
        }
        CliOption opt = CliOption.get(command);
        if (opt != null)
        {
            opt.printHelp();
            return;
        }
        printHelp();
        throw new IllegalArgumentException("Invalid command or option provided to command help");
    }

    static Runnable helpHelpPrinter()
    {
        return () -> {
            System.out.println("Usage: ./bin/cassandra-stress help <command|option>");
            System.out.println("Commands:");
            for (Command cmd : Command.values())
                System.out.println("    " + cmd.names.toString().replaceAll("\\[|\\]", ""));
            System.out.println("Options:");
            for (CliOption op : CliOption.values())
                System.out.println("    -" + op.toString().toLowerCase() + (op.extraName != null ? ", " + op.extraName : ""));
        };
    }

    static Runnable printHelpPrinter()
    {
        return () -> GroupedOptions.printOptions(System.out, "print", new GroupedOptions()
        {
            @Override
            public List<? extends Option> options()
            {
                return Arrays.asList(new OptionDistribution("dist=", null, "A mathematical distribution"));
            }
        });
    }
}
