# ExportFieldExpansion.java

    /*
    ** Module   : ExportFieldExpansion.java
    ** Abstract : Expansion for EXPORT array with dynamic indices.
    **
    ** Copyright (c) 2017, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- ----------------------------------Description---------------------------------
    ** 001 CA  20170827 Created initial version.
    **     HC  20170830 Modified conversion of EXPORT to expand extent fields dynamically. This
    **                  should prevent the Java source file to get out of control for large extents.
    */
    /*
    ** This program is free software: you can redistribute it and/or modify
    ** it under the terms of the GNU Affero General Public License as
    ** published by the Free Software Foundation, either version 3 of the
    ** License, or (at your option) any later version.
    **
    ** This program is distributed in the hope that it will be useful,
    ** but WITHOUT ANY WARRANTY; without even the implied warranty of
    ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    ** GNU Affero General Public License for more details.
    **
    ** You may find a copy of the GNU Affero GPL version 3 at the following
    ** location: https://www.gnu.org/licenses/agpl-3.0.en.html
    **
    ** Additional terms under GNU Affero GPL version 3 section 7:
    **
    **   Under Section 7 of the GNU Affero GPL version 3, the following additional
    **   terms apply to the works covered under the License.  These additional terms
    **   are non-permissive additional terms allowed under Section 7 of the GNU
    **   Affero GPL version 3 and may not be removed by you.
    **
    **   0. Attribution Requirement.
    **
    **     You must preserve all legal notices or author attributions in the covered
    **     work or Appropriate Legal Notices displayed by works containing the covered
    **     work.  You may not remove from the covered work any author or developer
    **     credit already included within the covered work.
    **
    **   1. No License To Use Trademarks.
    **
    **     This license does not grant any license or rights to use the trademarks
    **     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
    **     of Golden Code Development Corporation. You are not authorized to use the
    **     name Golden Code, FWD, or the names of any author or contributor, for
    **     publicity purposes without written authorization.
    **
    **   2. No Misrepresentation of Affiliation.
    **
    **     You may not represent yourself as Golden Code Development Corporation or FWD.
    **
    **     You may not represent yourself for publicity purposes as associated with
    **     Golden Code Development Corporation, FWD, or any author or contributor to
    **     the covered work, without written authorization.
    **
    **   3. No Misrepresentation of Source or Origin.
    **
    **     You may not represent the covered work as solely your work.  All modified
    **     versions of the covered work must be marked in a reasonable way to make it
    **     clear that the modified work is not originating from Golden Code Development
    **     Corporation or FWD.  All modified versions must contain the notices of
    **     attribution required in this license.
    */

    package com.goldencode.p2j.util;

    import com.goldencode.p2j.persist.*;

    import java.util.*;

    /**
     * TODO: finish this implementation
     * TODO: table extent field support?
     */
    public class ExportFieldExpansion
    implements ExtentExpansion
    {
       private BaseDataType[] arr;

       private final integer start = new integer();

       private final integer end = new integer();

       private final character format = new character();

       /** Buffer fields to be expanded */
       private FieldReference[] fieldRefs;

       public ExportFieldExpansion(BaseDataType[] arr)
       {
          this.arr = arr;
          this.start.assign(0);
          this.end.assign(arr.length - 1);
       }

       public ExportFieldExpansion(BaseDataType[] arr, NumberType start, long end)
       {
          this.arr = arr;
          this.start.assign(start);
          this.end.assign(end);
       }

       public ExportFieldExpansion(BaseDataType[] arr, long start, long end)
       {
          this.arr = arr;
          this.start.assign(start);
          this.end.assign(end);
       }

       public ExportFieldExpansion(BaseDataType[] arr, NumberType start, long end, String format)
       {
          this.arr = arr;
          this.start.assign(start);
          this.end.assign(end);
          this.format.assign(format);
       }

       public ExportFieldExpansion(BaseDataType[] arr, long start, long end, String format)
       {
          this.arr = arr;
          this.start.assign(start);
          this.end.assign(end);
          this.format.assign(format);
       }

       /**
        * Constructs export-field expansion on top of buffer fields.
        *
        * @param   fieldRefs
        *          Buffer fields, must not be <code>null</code>.
        */
       public ExportFieldExpansion(FieldReference... fieldRefs)
       {
          if (fieldRefs == null)
          {
             throw new IllegalArgumentException();
          }

          this.fieldRefs = fieldRefs;
       }

       public FieldEntry[] expand()
       {
          // TODO: deduplicate this method implementation with ImportFieldExpansion

          // TODO: validate

          FieldEntry[] fields;

          if (fieldRefs != null)
          {
             ArrayList<FieldEntry> entries = new ArrayList<>();
             for (FieldReference ref : fieldRefs)
             {
                Integer extent = ref.getExtent();
                if (extent == null)
                {
                   entries.add(new ExportField(ref));
                }
                else
                {
                   for (int i = 0; i < extent; i++)
                   {
                      entries.add(new ExportField(new FieldReference(ref, i)));
                   }
                }
             }

             fields = entries.toArray(new FieldEntry[0]);
          }
          else
          {
             int istart = start.intValue();
             int iend = end.intValue();

             fields = new PutField[iend - istart + 1];

             for (int i = istart; i <= iend; i++)
             {
                int idx = i;
                // TODO: validate
                fields[i - istart] = new PutField(() -> arr[idx]);
             }
          }

          return fields;
       }
    }