/*
    * 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.PascalDistribution;
  import picocli.CommandLine.ArgGroup;
  import picocli.CommandLine.Command;
  import picocli.CommandLine.Option;
  
  /**
   * Command for the {@link PascalDistribution}.
   */
  @Command(name = "pascal",
           aliases = {"negativebinomial", "nbin"},
           description = "Pascal distribution.",
           subcommands = {
               PascalCommand.Check.class,
               PascalCommand.PMF.class,
               PascalCommand.LPMF.class,
               PascalCommand.CDF.class,
               PascalCommand.SF.class,
               PascalCommand.ICDF.class,
               PascalCommand.ISF.class,
           })
  class PascalCommand 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 trials. */
              @Option(names = {"-r", "--number-of-successes"},
                      arity = "1..*",
                      split = ",",
                      description = {"number of successes (default: ${DEFAULT-VALUE})."})
              private int[] r = {1, 2, 3, 4, 5, 10, 20, 40};
  
              /** The distribution p. */
              @Option(names = {"-p", "--probability"},
                      arity = "1..*",
                      split = ",",
                      description = {"probability of success (default: ${DEFAULT-VALUE})."})
              // mean = (r * (1 - p)) / p = (r / p) - r
              // p = r / (mean + r)
              // Compute for a mean=10
              private double[] p = {1.0 / 11, 2.0 / 12, 3.0 / 13, 4.0 / 14, 5.0 / 15, 10.0 / 20, 20.0 / 30, 40.0 / 50};
          }
  
          /** Extend the options to set the default values for this distribution. */
          static final class Options extends DiscreteDistributionOptions {
              /** Set defaults. */
              private Options() {
                  min = 0;
                  max = 25;
              }
          }
  
          @Override
          protected List<Distribution<DiscreteDistribution>> getDistributions() {
              int[] r = params.r;
              double[] p = params.p;
              final int n = DistributionUtils.validateLengths(r.length, p.length);
  
              r = DistributionUtils.expandToLength(r, n);
              p = DistributionUtils.expandToLength(p, n);
  
              // Create distributions
              final ArrayList<Distribution<DiscreteDistribution>> list = new ArrayList<>();
              for (int i = 0; i < n; i++) {
                  final DiscreteDistribution d = PascalDistribution.of(r[i], p[i]);
                  list.add(new Distribution<>(d, "r=" + r[i] + ",p=" + p[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 = "Pascal distribution verification checks.")
     static class Check extends ProbabilityCommand {}
 
     /** PMF command. */
     @Command(name = "pmf",
              aliases = {"pdf"},
              description = "Pascal distribution PMF.")
     static class PMF extends ProbabilityCommand {}
 
     /** LPMF command. */
     @Command(name = "lpmf",
              aliases = {"lpdf"},
              description = "Pascal distribution natural logarithm of the PMF.")
     static class LPMF extends ProbabilityCommand {}
 
     /** CDF command. */
     @Command(name = "cdf",
              description = "Pascal distribution CDF.")
     static class CDF extends ProbabilityCommand {}
 
     /** SF command. */
     @Command(name = "sf",
              description = "Pascal distribution survival probability.")
     static class SF extends ProbabilityCommand {}
 
     /** ICDF command. */
     @Command(name = "icdf",
              description = "Pascal distribution inverse CDF.")
     static class ICDF extends InverseProbabilityCommand {}
 
     /** ISF command. */
     @Command(name = "isf",
              description = "Pascal distribution inverse SF.")
     static class ISF extends InverseProbabilityCommand {}
 }