/*
    * 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.statistics.examples.distribution;
  
  import java.util.ArrayList;
  import java.util.List;
  import org.apache.commons.statistics.distribution.DiscreteDistribution;
  import org.apache.commons.statistics.distribution.ZipfDistribution;
  import picocli.CommandLine.ArgGroup;
  import picocli.CommandLine.Command;
  import picocli.CommandLine.Option;
  
  /**
   * Command for the {@link ZipfDistribution}.
   */
  @Command(name = "zipf",
           description = "Zipf distribution.",
           subcommands = {
               ZipfCommand.Check.class,
               ZipfCommand.PMF.class,
               ZipfCommand.LPMF.class,
               ZipfCommand.CDF.class,
               ZipfCommand.SF.class,
               ZipfCommand.ICDF.class,
               ZipfCommand.ISF.class,
           })
  class ZipfCommand extends AbstractDistributionCommand {
  
      /** Base command for the distribution that defines the parameters. */
      private abstract static class BaseCommand extends AbstractDiscreteDistributionCommand {
          /** Distribution parameters. */
          @ArgGroup(validate = false, heading = "Distribution parameters:%n", order = 1)
          private Params params = new Params();
  
          /** Parameters class. */
          static class Params {
              /** The distribution number of elements. */
              @Option(names = {"-n", "--number-of-elements"},
                      arity = "1..*",
                      split = ",",
                      description = {"number of elements (default: ${DEFAULT-VALUE})."})
              private int[] n = {10};
  
              /** The distribution exponent. */
              @Option(names = {"-e", "--exponent"},
                      arity = "1..*",
                      split = ",",
                      description = {"exponent (default: ${DEFAULT-VALUE})."})
              private double[] e = {1, 2, 3, 4};
          }
  
          /** Extend the options to set the default values for this distribution. */
          static final class Options extends DiscreteDistributionOptions {
              /** Set defaults. */
              private Options() {
                  min = 1;
                  max = 10;
              }
          }
  
          @Override
          protected List<Distribution<DiscreteDistribution>> getDistributions() {
              int[] n = params.n;
              double[] e = params.e;
              final int max = DistributionUtils.validateLengths(n.length, e.length);
  
              n = DistributionUtils.expandToLength(n, max);
              e = DistributionUtils.expandToLength(e, max);
  
              // Create distributions
              final ArrayList<Distribution<DiscreteDistribution>> list = new ArrayList<>();
              for (int i = 0; i < max; i++) {
                  final DiscreteDistribution d = ZipfDistribution.of(n[i], e[i]);
                  list.add(new Distribution<>(d, "n=" + n[i] + ",p=" + e[i]));
              }
              return list;
          }
      }
  
      /** Base command for the distribution that defines the parameters. */
      private abstract static class ProbabilityCommand extends BaseCommand {
          /** The distribution options. */
          @ArgGroup(validate = false, heading = "Evaluation options:%n", order = 2)
          private Options distributionOptions = new Options();
  
         @Override
         protected DistributionOptions getDistributionOptions() {
             return distributionOptions;
         }
     }
 
     /** Base command for the distribution that defines the parameters for inverse probability functions. */
     private abstract static class InverseProbabilityCommand extends BaseCommand {
         /** The distribution options. */
         @ArgGroup(validate = false, heading = "Evaluation options:%n", order = 2)
         private InverseDiscreteDistributionOptions distributionOptions = new InverseDiscreteDistributionOptions();
 
         @Override
         protected DistributionOptions getDistributionOptions() {
             return distributionOptions;
         }
     }
 
     /** Verification checks command. */
     @Command(name = "check",
              hidden = true,
              description = "Zipf distribution verification checks.")
     static class Check extends ProbabilityCommand {}
 
     /** PMF command. */
     @Command(name = "pmf",
              aliases = {"pdf"},
              description = "Zipf distribution PMF.")
     static class PMF extends ProbabilityCommand {}
 
     /** LPMF command. */
     @Command(name = "lpmf",
              aliases = {"lpdf"},
              description = "Zipf distribution natural logarithm of the PMF.")
     static class LPMF extends ProbabilityCommand {}
 
     /** CDF command. */
     @Command(name = "cdf",
              description = "Zipf distribution CDF.")
     static class CDF extends ProbabilityCommand {}
 
     /** SF command. */
     @Command(name = "sf",
              description = "Zipf distribution survival probability.")
     static class SF extends ProbabilityCommand {}
 
     /** ICDF command. */
     @Command(name = "icdf",
              description = "Zipf distribution inverse CDF.")
     static class ICDF extends InverseProbabilityCommand {}
 
     /** ISF command. */
     @Command(name = "isf",
              description = "Zipf distribution inverse SF.")
     static class ISF extends InverseProbabilityCommand {}
 }