LegacyIterator.java

/*
** Module   : LegacyIterator.java
** Abstract : Implementation of the builtin class.
**
** Copyright (c) 2019-2023, Golden Code Development Corporation.
**
** -#- -I- --Date-- ---------------------------------------Description----------------------------------------
** 001 ME  20200514 First version, stubs taken by converting the skeleton using FWD.
** 002 ME  20201016 Change it to work with the collection image at the time of instantiation. 
**                  No protection against collection modification initial image is needed, 
**                  accommodate other 4GL oddities. 
** 003 CA  20210113 Renamed Iiterator.next to Iiterator.next_, to follow NameConverter's rules.
** 004 CA  20210221 Fixed 'qualified', 'extent' and 'returns' annotations at the legacy
**                  signature.
**     CA  20220120 Do not used TypeFactory.object when the OO reference must not be tracked or registered.
**                  Do not use TypeFactory.object for internal usages, use ObjectVar if the reference must 
**                  be tracked.
**                  All TypeFactory.object variable definitions must be done outside of the top-level block.
** 005 CA  20231113 The 'execute' method must be annotated with LegacySignature Type.Execute, and also can be
**                  dropped if is a no-op.
*/

/*
** 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
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** 
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**     You may not represent yourself as Golden Code Development Corporation or FWD.
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*/
package com.goldencode.p2j.oo.core.collections;

import com.goldencode.p2j.util.*;
import com.goldencode.p2j.util.BlockManager.Action;
import com.goldencode.p2j.util.BlockManager.Condition;
import com.goldencode.p2j.oo.core.collections.Iiterator;
import com.goldencode.p2j.oo.lang.*;
import com.goldencode.p2j.persist.P2JQuery;
import com.goldencode.p2j.persist.QueryWrapper;
import com.goldencode.p2j.persist.RecordBuffer;

import static com.goldencode.p2j.report.ReportConstants.CVT_LVL_FULL;
import static com.goldencode.p2j.report.ReportConstants.RT_LVL_FULL;
import static com.goldencode.p2j.util.BlockManager.*;
import static com.goldencode.p2j.util.InternalEntry.Type;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;

/**
 * Business logic (converted to Java from the 4GL source code
 * in OpenEdge/Core/Collections/Iterator.cls).
 */
@LegacyResource(resource = "OpenEdge.Core.Collections.Iterator")
@LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
public class LegacyIterator extends BaseObject implements Iiterator
{
   @LegacySignature(type = Type.PROPERTY, name = "OwnerCollection")
   private object<? extends Icollection> ownerCollection = TypeFactory.object(Icollection.class);

   @LegacySignature(type = Type.PROPERTY, name = "QueryHandle")
   private handle queryHandle = TypeFactory.handle();

   @LegacySignature(type = Type.PROPERTY, name = "BufferHandle")
   private handle bufferHandle = TypeFactory.handle();

   @LegacySignature(type = Type.PROPERTY, name = "ObjectFieldHandle")
   private handle objectFieldHandle = TypeFactory.handle();

   private Collection objectsCollection;
   private boolean emptyCollection;
   
   private Iterator<object<? extends _BaseObject_>> iterator;
   private object<? extends _BaseObject_> next;

   @LegacySignature(type = Type.EXECUTE)
   public void __core_collections_LegacyIterator_execute__()
   {
      onBlockLevel(Condition.ERROR, Action.THROW);
   }

   @LegacySignature(returns = "OBJECT", qualified = "OpenEdge.Core.Collections.ICollection", type = Type.GETTER, name = "OwnerCollection")
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
   protected object<? extends Icollection> getOwnerCollection()
   {
      return function(LegacyIterator.class, this, "OwnerCollection", object.class,
               new Block((Body) () ->
               {
                  returnNormal(ownerCollection);
               }));
   }

   @LegacySignature(type = Type.SETTER, name = "OwnerCollection", parameters = {
            @LegacyParameter(qualified = "OpenEdge.Core.Collections.ICollection", name = "var", type = "OBJECT", mode = "INPUT") })
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
   protected void setOwnerCollection(final object<? extends Icollection> _var)
   {
      object<? extends Icollection> var = TypeFactory.initInput(_var);

      internalProcedure(LegacyIterator.class, this, "OwnerCollection", new Block((Body) () ->
      {
         ownerCollection.assign(var);
      }));
   }

   @LegacySignature(returns = "HANDLE", type = Type.GETTER, name = "QueryHandle")
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
   protected handle getQueryHandle()
   {
      return function(LegacyIterator.class, this, "QueryHandle", handle.class,
               new Block((Body) () ->
               {
                  returnNormal(queryHandle);
               }));
   }

   @LegacySignature(type = Type.SETTER, name = "QueryHandle", parameters = {
            @LegacyParameter(name = "var", type = "HANDLE", mode = "INPUT") })
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
   protected void setQueryHandle(final handle _var)
   {
      handle var = TypeFactory.initInput(_var);

      internalProcedure(LegacyIterator.class, this, "QueryHandle", new Block((Body) () ->
      {
         queryHandle.assign(var);
      }));
   }

   @LegacySignature(returns = "HANDLE", type = Type.GETTER, name = "BufferHandle")
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
   protected handle getBufferHandle()
   {
      return function(LegacyIterator.class, this, "BufferHandle", handle.class,
               new Block((Body) () ->
               {
                  returnNormal(bufferHandle);
               }));
   }

   @LegacySignature(type = Type.SETTER, name = "BufferHandle", parameters = {
            @LegacyParameter(name = "var", type = "HANDLE", mode = "INPUT") })
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
   protected void setBufferHandle(final handle _var)
   {
      handle var = TypeFactory.initInput(_var);

      internalProcedure(LegacyIterator.class, this, "BufferHandle", new Block((Body) () ->
      {
         bufferHandle.assign(var);
      }));
   }

   @LegacySignature(returns = "HANDLE", type = Type.GETTER, name = "ObjectFieldHandle")
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
   protected handle getObjectFieldHandle()
   {
      return function(LegacyIterator.class, this, "ObjectFieldHandle", handle.class,
               new Block((Body) () ->
               {
                  returnNormal(objectFieldHandle);
               }));
   }

   @LegacySignature(type = Type.SETTER, name = "ObjectFieldHandle", parameters = {
            @LegacyParameter(name = "var", type = "HANDLE", mode = "INPUT") })
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
   protected void setObjectFieldHandle(final handle _var)
   {
      handle var = TypeFactory.initInput(_var);

      internalProcedure(LegacyIterator.class, this, "ObjectFieldHandle", new Block((Body) () ->
      {
         objectFieldHandle.assign(var);
      }));
   }

   @LegacySignature(type = Type.CONSTRUCTOR, parameters = {
            @LegacyParameter(name = "p1", type = "OBJECT", qualified = "openedge.core.collections.icollection", mode = "INPUT"),
            @LegacyParameter(name = "p2", type = "HANDLE", mode = "INPUT"),
            @LegacyParameter(name = "p3", type = "CHARACTER", mode = "INPUT") })
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
   public void __core_collections_LegacyIterator_constructor__(
            final object<? extends Icollection> _p1, final handle _p2, final character _p3)
   {
      internalProcedure(LegacyIterator.class, this,
               "__core_collections_LegacyIterator_constructor__", new Block((Body) () ->
               {
                  __core_collections_LegacyIterator_constructor__(_p1, _p2, _p3,
                           new character(""), new character(""));
               }));
   }

   @LegacySignature(type = Type.CONSTRUCTOR, parameters = {
            @LegacyParameter(name = "p1", type = "OBJECT", qualified = "openedge.core.collections.icollection", mode = "INPUT"),
            @LegacyParameter(name = "p2", type = "HANDLE", mode = "INPUT"),
            @LegacyParameter(name = "p3", type = "CHARACTER", mode = "INPUT"),
            @LegacyParameter(name = "p4", type = "CHARACTER", mode = "INPUT") })
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
   public void __core_collections_LegacyIterator_constructor__(
            final object<? extends Icollection> _p1, final handle _p2, final character _p3,
            final character _p4)
   {
      internalProcedure(LegacyIterator.class, this,
               "__core_collections_LegacyIterator_constructor__", new Block((Body) () ->
               {
                  __core_collections_LegacyIterator_constructor__(_p1, _p2, _p3, _p4,
                           new character(""));
               }));
   }

   @LegacySignature(type = Type.CONSTRUCTOR, parameters = {
            @LegacyParameter(name = "p1", type = "OBJECT", qualified = "openedge.core.collections.icollection", mode = "INPUT"),
            @LegacyParameter(name = "p2", type = "HANDLE", mode = "INPUT"),
            @LegacyParameter(name = "p3", type = "CHARACTER", mode = "INPUT"),
            @LegacyParameter(name = "p4", type = "CHARACTER", mode = "INPUT"),
            @LegacyParameter(name = "p5", type = "CHARACTER", mode = "INPUT") })
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
   public void __core_collections_LegacyIterator_constructor__(
            final object<? extends Icollection> _p1, final handle _p2, final character _p3,
            final character _p4, final character _p5)
   {
      object<? extends Icollection> oCol = TypeFactory.initInput(_p1);
      handle phTT = TypeFactory.initInput(_p2);
      character valField = TypeFactory.initInput(_p3);
      character sortField = TypeFactory.initInput(_p4);
      character whereString = TypeFactory.initInput(_p5);

      internalProcedure(LegacyIterator.class, this,
               "__core_collections_LegacyIterator_constructor__", new Block((Body) () ->
               {
                  __lang_BaseObject_constructor__();
                  ownerCollection.assign(oCol);

                  // default 4GL temp-table implementation
                  if (phTT.isType(LegacyResource.TEMP_TABLE) || phTT.isType(LegacyResource.BUFFER))
                  {
                     RecordBuffer.create(bufferHandle, phTT);
                     
                     objectFieldHandle.assign(bufferHandle.unwrapBuffer().bufferField(valField));
                     QueryWrapper.createQuery(queryHandle);
                     queryHandle.unwrapBufferCollection().setBuffers(bufferHandle);
                     StringBuffer qryString = new StringBuffer();

                     if (!TextOps.isEmpty(whereString.getValue()))
                        qryString.append(" where " + whereString.getValue());

                     if (!TextOps.isEmpty(sortField.getValue()))
                        qryString.append(" by " + sortField.getValue());
                     else
                        queryHandle.unwrapQuery().changeForwardOnly(true);
                     queryHandle.unwrapQuery()
                              .prepare(String.format("preselect each %s %s no-lock",
                                       bufferHandle.unwrap().name().getValue(), qryString.toString()));

                     queryHandle.unwrapQuery().queryOpen();
                     iterator = null;
                  }
                  else
                  {
                     Object resource = phTT.get();
                     if (resource instanceof Collection) {
                        // keep a reference to the actual objects collections
                        objectsCollection = (Collection) resource;
                        emptyCollection = objectsCollection.isEmpty();
                        // make a copy so the iterator always sees the elements present when created
                        iterator = new ArrayList(objectsCollection).iterator();
                     }
                  }
               }));
   }

   @LegacySignature(returns = "LOGICAL", type = Type.METHOD, name = "HasNext")
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
   public logical hasNext()
   {
      return function(LegacyIterator.class, this, "HasNext", logical.class, new Block((Body) () ->
      {
         if (iterator != null) 
         {
            // 4GL BUG, if collection (temp-table) was empty hasNext returns unknown
            returnNormal(emptyCollection ? new logical() : new logical(iterator.hasNext()));
         }
         else
         {
            P2JQuery qry = queryHandle.unwrapQuery();

            if (qry._isOffEnd())
            {
               boolean ok = qry.forward(1);
               if (!qry.forwardOnly().booleanValue())
                  qry.backward(1);
               returnNormal(ok);
            }
            else if (qry.getNumResults().intValue() == 1 && qry.currentRow().intValue() == 1)
            {
               returnNormal(!bufferHandle.unwrapBuffer().available().booleanValue());
            }
            else
            {
               returnNormal(qry.currentRow().intValue() < qry.getNumResults().intValue());
            }
         }
      }));
   }

   @LegacySignature(returns = "OBJECT", type = Type.METHOD, name = "Next", qualified = "progress.lang.object")
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
   public object<? extends com.goldencode.p2j.oo.lang._BaseObject_> next_()
   {
      object<_BaseObject_> ret = TypeFactory.object(_BaseObject_.class);

      return function(LegacyIterator.class, this, "Next", object.class, new Block((Body) () ->
      {
         if (iterator != null) 
         {
            while (iterator.hasNext()) {
               next = iterator.next();
               
               // check if object still in original collection, if removed skip
               if (objectsCollection.contains(next)) 
               {
                  returnNormal(next);
               } 
               else 
               {
                  next = null;
               }
            }
            
            returnNormal(new object());
         }
         else
         {
            queryHandle.unwrapQuery().next();
            
            if (bufferHandle.unwrapBuffer()._available())
            {
               ret.assign(objectFieldHandle.unwrapBufferField().value());
            }
            
            returnNormal(ret);
         }
      }));
   }

   @LegacySignature(returns = "LOGICAL", type = Type.METHOD, name = "Remove")
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
   public logical remove()
   {
      return function(LegacyIterator.class, this, "Remove", logical.class, new Block((Body) () ->
      {
         if (iterator != null)
         {
            if (next == null) 
            {
               returnNormal(false);
            }
            else 
            {
               iterator.remove();
               // remove the item from parent collection, iterator is working on a copy
               if (ownerCollection._isValid())
                  ownerCollection.ref().remove(next);
               next = null;
               
               returnNormal(true);
            }
         }
         else
         {
            boolean ok = false;
            if (bufferHandle.unwrapBuffer()._available())
            {
               ok = ownerCollection.ref()
                        .remove((object<? extends _BaseObject_>) objectFieldHandle
                                 .unwrapBufferField().value())
                        .booleanValue();
               if (ok)
               {
                  queryHandle.unwrapQuery().deleteResultListEntry();
               }
            }

            returnNormal(ok);
         }
      }));
   }

   @LegacySignature(type = Type.DESTRUCTOR)
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
   public void __core_collections_LegacyIterator_destructor__()
   {
      internalProcedure(LegacyIterator.class, this,
               "__core_collections_LegacyIterator_destructor__", new Block((Body) () ->
               {
                  if (bufferHandle._isValid())
                     HandleOps.delete(bufferHandle);
                  if (queryHandle._isValid())
                     HandleOps.delete(queryHandle);
               }));
   }
}