/*
    * 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.ContinuousDistribution;
  import org.apache.commons.statistics.distribution.TrapezoidalDistribution;
  import picocli.CommandLine.ArgGroup;
  import picocli.CommandLine.Command;
  import picocli.CommandLine.Option;
  
  /**
   * Command for the {@link TrapezoidalDistribution}.
   */
  @Command(name = "trapezoidal",
           aliases = {"trap"},
           description = "Trapezoidal distribution.",
           subcommands = {
               TrapezoidalCommand.Check.class,
               TrapezoidalCommand.PDF.class,
               TrapezoidalCommand.LPDF.class,
               TrapezoidalCommand.CDF.class,
               TrapezoidalCommand.SF.class,
               TrapezoidalCommand.ICDF.class,
               TrapezoidalCommand.ISF.class,
           })
  class TrapezoidalCommand extends AbstractDistributionCommand {
  
      /** Base command for the distribution that defines the parameters. */
      private abstract static class BaseCommand extends AbstractContinuousDistributionCommand {
          /** Distribution parameters. */
          @ArgGroup(validate = false, heading = "Distribution parameters:%n", order = 1)
          private Params params = new Params();
  
          /** Parameters class. */
          static class Params {
              /** The distribution lower limit. */
              @Option(names = {"-a", "--lower"},
                      paramLabel = "a",
                      arity = "1..*",
                      split = ",",
                      description = {"lower bound (default: ${DEFAULT-VALUE})."})
              private double[] lower = {-4, 0, 0};
  
              /** The start of the density constant region. */
              @Option(names = {"-b", "--shape1"},
                      paramLabel = "b",
                      arity = "1..*",
                      split = ",",
                      description = {"constant start (default: ${DEFAULT-VALUE})."})
              private double[] start = {-1.5, 0, 1};
  
              /** The end of the density constant region. */
              @Option(names = {"-c", "--shape2"},
                      paramLabel = "c",
                      arity = "1..*",
                      split = ",",
                      description = {"constant end (default: ${DEFAULT-VALUE})."})
              private double[] end = {2.5, 2, 3};
  
              /** The distribution upper limit. */
              @Option(names = {"-d", "--upper"},
                      paramLabel = "d",
                      arity = "1..*",
                      split = ",",
                      description = {"upper bound (default: ${DEFAULT-VALUE})."})
              private double[] upper = {4, 3, 3};
          }
  
          /** Extend the options to set the default values for this distribution. */
          static final class Options extends ContinuousDistributionOptions {
              /** Set defaults. */
              private Options() {
                  min = -5;
                  max = 5;
              }
          }
  
          @Override
          protected List<Distribution<ContinuousDistribution>> getDistributions() {
              double[] a = params.lower;
              double[] b = params.start;
              double[] c = params.end;
              double[] d = params.upper;
             final int n = DistributionUtils.validateLengths(a.length, b.length, c.length, d.length);
 
             a = DistributionUtils.expandToLength(a, n);
             b = DistributionUtils.expandToLength(b, n);
             c = DistributionUtils.expandToLength(c, n);
             d = DistributionUtils.expandToLength(d, n);
 
             // Create distributions
             final ArrayList<Distribution<ContinuousDistribution>> list = new ArrayList<>();
             for (int i = 0; i < n; i++) {
                 final ContinuousDistribution dist = TrapezoidalDistribution.of(a[i], b[i], c[i], d[i]);
                 list.add(new Distribution<>(dist, "a=" + a[i] + ",b=" + b[i] + ",c=" + c[i] + ",d=" + d[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 InverseContinuousDistributionOptions distributionOptions = new InverseContinuousDistributionOptions();
 
         @Override
         protected DistributionOptions getDistributionOptions() {
             return distributionOptions;
         }
     }
 
     /** Verification checks command. */
     @Command(name = "check",
              hidden = true,
              description = "Trapezoidal distribution verification checks.")
     static class Check extends ProbabilityCommand {}
 
     /** PDF command. */
     @Command(name = "pdf",
              description = "Trapezoidal distribution PDF.")
     static class PDF extends ProbabilityCommand {}
 
     /** LPDF command. */
     @Command(name = "lpdf",
              description = "Trapezoidal distribution natural logarithm of the PDF.")
     static class LPDF extends ProbabilityCommand {}
 
     /** CDF command. */
     @Command(name = "cdf",
              description = "Trapezoidal distribution CDF.")
     static class CDF extends ProbabilityCommand {}
 
     /** SF command. */
     @Command(name = "sf",
              description = "Trapezoidal distribution survival probability.")
     static class SF extends ProbabilityCommand {}
 
     /** ICDF command. */
     @Command(name = "icdf",
              description = "Trapezoidal distribution inverse CDF.")
     static class ICDF extends InverseProbabilityCommand {}
 
     /** ISF command. */
     @Command(name = "isf",
              description = "Trapezoidal distribution inverse SF.")
     static class ISF extends InverseProbabilityCommand {}
 }