ObjectModelParser.java

/*
** Module   : ObjectModelParser.java
** Abstract : Implementation of the Progress.Json.Objectmodel.ObjectModelParser builtin class.
**
** Copyright (c) 2018-2023, Golden Code Development Corporation.
**
** -#- -I- --Date-- ---------------------------------------Description---------------------------------------
** 001 OM  20181218 First version.
** 002 GES 20190308 Added a basic implementation.
** 003 CA  20190423 Added LegacyResource annotation.
** 004 HC  20190701 Implemented most of the legacy methods.
** 005 CA  20191024 Added method support levels and updated the class support level.
** 006 ME  20210115 Fix (some of) the error handling to match the 4GL side.
** 007 CA  20210221 Fixed 'qualified', 'extent' and 'returns' annotations at the legacy signature.
**     OM  20210329 FIX-CODEPAGE is emitted as static method call to accomodate dereferenciation cases.
**     CA  20210709 JSON parse must use a pristine byte stream and use the reader to decode it.
**     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.
**     ME  20220427 Simplify error messages for json parser errors, use character offset instead of binary.
**     VVT 20221003 CommonHandle.getResourceType() method renamed to resourceType() to prevent conflicts
**                  with namesakes in DMO. See #6694.
**     CA  20221024 parse(memptr) must interpret the memptr bytes as UTF-8.
** 008 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
**     publicity purposes without written authorization.
**
**   2. No Misrepresentation of Affiliation.
**
**     You may not represent yourself as Golden Code Development Corporation or FWD.
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**     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.
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**     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
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*/

package com.goldencode.p2j.oo.json.objectmodel;

import java.io.*;

import com.fasterxml.jackson.core.JsonParseException;
import com.goldencode.p2j.util.*;
import com.goldencode.p2j.util.BlockManager.Action;
import com.goldencode.p2j.util.BlockManager.Condition;
import com.goldencode.p2j.oo.json.*;

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

/**
 * Implementation of the Progress.Json.Objectmodel.ObjectModelParser builtin class.
 */
@LegacyResource(resource = "Progress.Json.Objectmodel.ObjectModelParser")
@LegacyResourceSupport(supportLvl = CVT_LVL_FULL|RT_LVL_FULL)
public class ObjectModelParser
extends com.goldencode.p2j.oo.json.JsonParser
{
   /**
    * Default external procedure method which exists to ensure that any
    * long lived resources can be initialized properly.
    */
   @LegacySignature(type = Type.EXECUTE)
   public void __json_objectmodel_ObjectModelParser_execute__()
   {
      onBlockLevel(Condition.ERROR, Action.THROW);
   }

   /**
    * Method to duplicate the default constructor.
    */
   @LegacySignature(type = Type.CONSTRUCTOR)
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL|RT_LVL_FULL)
   public void __json_objectmodel_ObjectModelParser_constructor__()
   {
      internalProcedure(this, "__json_objectmodel_ObjectModelParser_constructor__", new Block((Body) () -> 
      {
         __json_JsonParser_constructor__();
      }));
   }

   /**
    * Reads the JSON content from the given source, parses it and returns the top level
    * construct.
    *
    * @param    _str
    *           The stream handle source from which to read.
    *
    * @return   The top level JSON construct.
    */
   @LegacySignature(returns = "OBJECT", type = Type.METHOD, name = "Parse", qualified = "Progress.Json.ObjectModel.JsonConstruct", parameters = 
   {
      @LegacyParameter(name = "str", type = "HANDLE", mode = "INPUT")
   })
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL|RT_LVL_FULL)
   public object<? extends JsonConstruct> parse(final handle _str)
   {
      handle str = TypeFactory.initInput(_str);
      object<? extends JsonConstruct> res = TypeFactory.object(JsonConstruct.class);
      
      return function(this, "Parse", object.class, new Block((Body) () -> 
      {
         // TODO: wrap that to WEB-CONTEXT handle when available, only accepted input value
         if (str == null || str.isUnknown() || !LegacyResource.PSEUDO_WIDGET.equals(str.unwrapType().resourceType().getValue()))
         {
            undoThrow(JsonError.newInstance(ErrorManager.getInvalidParameterError("source", this,
                     "Parse", "Must be a WEB-CONTEXT handle."), 16071));
         }

         try (Reader reader = new InputStreamReader(new InputStreamWrapper((Stream) str.getResource())))
         {
            res.assign(JsonBackend.instance().parse(reader));
            reader.close();
         }
         catch (Exception exc) 
         {
            handleError(exc);
         }
         
         returnNormal(res);
      }));
   }
   
   /**
    * Reads the JSON content from the given source, parses it and returns the top level construct.
    *
    * @param    _source
    *           The longchar source from which to read.
    *
    * @return   The top level JSON construct.
    */
   @LegacySignature(returns = "OBJECT", type = Type.METHOD, name = "Parse", qualified = "Progress.Json.ObjectModel.JsonConstruct", parameters = {
            @LegacyParameter(name = "source", type = "LONGCHAR", mode = "INPUT") })
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
   public object<? extends JsonConstruct> parse(final longchar _source)
   {
      longchar source = TypeFactory.initInput(_source);
      object<? extends JsonConstruct> res = TypeFactory.object(JsonConstruct.class);
      
      return function(this, "Parse", object.class, new Block((Body) () -> {
         // only if unknown or empty space, spaces only are (attempted to be) parsed
         if (source.isUnknown() || source.getValue().isEmpty())
         {
            undoThrow(JsonError.newInstance(ErrorManager.getInvalidParameterError("source", this,
                     "Parse", "Can not be UNKNOWN (?) or empty string."), 16055));
         }
         
         String cp = source._getCodePage();
         cp = (cp != null) ? cp.toLowerCase() : I18nOps._getCPInternal().toLowerCase();
         
         if (!cp.startsWith("utf"))
         {
            undoThrow(JsonError.newInstance(
                  ErrorManager.getInvalidParameterError("encoding",
                                                        this,
                                                        "Parse",
                                                        "'" + cp + "' is not a valid UTF encoding."),
                  16063));
         }
         
         if (!cp.equals("utf-8")) 
         {
            // create a new longchar and make sure it will use utf-8 CP before copying the content
            longchar utf8Source = new longchar();
            utf8Source.fixCodePage("utf-8");
            utf8Source.assign(source.getValue());
            returnNormal(parse(utf8Source));
         }
         else
         {
            try
            {
               res.assign(JsonBackend.instance().parse(source.getValue()));
            }
            catch (Exception exc) 
            {
               handleError(exc);
            }
            
            returnNormal(res);
         }
      }));
   }
   
   /**
    * Reads the JSON content from the given source, parses it and returns the top level
    * construct.
    *
    * @param    _source
    *           The memptr source from which to read.
    *
    * @return   The top level JSON construct.
    */
   @LegacySignature(returns = "OBJECT", type = Type.METHOD, name = "Parse", qualified = "Progress.Json.ObjectModel.JsonConstruct", parameters = 
   {
      @LegacyParameter(name = "source", type = "MEMPTR", mode = "INPUT")
   })
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL|RT_LVL_FULL)
   public object<? extends JsonConstruct> parse(final memptr _source)
   {
      memptr source = TypeFactory.initInput(_source);
      object<? extends JsonConstruct> res = TypeFactory.object(JsonConstruct.class);
      
      return function(this, "Parse", object.class, new Block((Body) () -> 
      {
         if (source == null || source.isUnknown() || source.isUninitialized())
         {
            undoThrow(JsonError.newInstance(ErrorManager.getInvalidParameterError("source", this,
                     "Parse", "Can not be UNKNOWN (?) or empty string."), 16055));
         }
         
         // empty string does not throw as for character/longchar so parse the string directly
         
         try
         {
            res.assign(JsonBackend.instance().parse(new String(source.getByteArray(), "utf-8")));
         }
         catch (Exception exc) 
         {
            handleError(exc);
         }
         
         returnNormal(res);
      }));
   }

   /**
    * Reads the JSON content from the given source, parses it and returns the top level
    * construct.
    *
    * @param    _source
    *           The character source from which to read.
    *
    * @return   The top level JSON construct.
    */
   @LegacySignature(returns = "OBJECT", type = Type.METHOD, name = "Parse", qualified = "Progress.Json.ObjectModel.JsonConstruct", parameters = 
   {
      @LegacyParameter(name = "source", type = "CHARACTER", mode = "INPUT")
   })
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL|RT_LVL_FULL)
   public object<? extends JsonConstruct> parse(final character _source)
   {
      character source = TypeFactory.initInput(_source);
      object<? extends JsonConstruct> res = TypeFactory.object(JsonConstruct.class);
      
      return function(this, "Parse", object.class, new Block((Body) () -> 
      {
         // only if unknown or empty space, spaces only are (attempted to be) parsed
         if (source == null || source.isUnknown() || source.getValue().isEmpty())
         {
            undoThrow(JsonError.newInstance(ErrorManager.getInvalidParameterError("source", this,
                     "Parse", "Can not be UNKNOWN (?) or empty string."), 16055));
         }
         
         try
         {
            res.assign(JsonBackend.instance().parse(source.toStringMessage()));
         }
         catch (Exception exc) 
         {
            handleError(exc);
         }
         
         returnNormal(res);
      }));
   }

   /**
    * Reads the JSON content from the given source, parses it and returns the top level
    * construct.
    *
    * @param    _fname
    *           The filename from which to read the JSON.
    *
    * @return   The top level JSON construct.
    */
   @LegacySignature(returns = "OBJECT", type = Type.METHOD, name = "ParseFile", qualified = "Progress.Json.ObjectModel.JsonConstruct", parameters = 
   {
      @LegacyParameter(name = "fname", type = "CHARACTER", mode = "INPUT")
   })
   @LegacyResourceSupport(supportLvl = CVT_LVL_FULL|RT_LVL_FULL)
   public object<? extends JsonConstruct> parseFile(final character _fname)
   {
      character fname = TypeFactory.initInput(_fname);
      object<? extends JsonConstruct> res = TypeFactory.object(JsonConstruct.class);

      return function(this, "ParseFile", object.class, new Block((Body) () -> 
      {
         if (TextOps.isEmpty(fname))
         {
            undoThrow(JsonError.newInstance(ErrorManager.getInvalidParameterError("source", this,
                     "ParseFile", "Can not be UNKNOWN (?) or empty string."), 16055));
         }
         
         String filename = fname.toStringMessage();
         Stream stream   = StreamFactory.openFileStream(filename, false, false);
         
         // this reads the client-side file
         try (Reader reader = new InputStreamReader(new InputStreamWrapper(stream)))
         {
            res.assign(JsonBackend.instance().parse(reader));
            reader.close();
         }
         catch (Exception exc) 
         {
            handleError(exc);
         }
         finally {
            stream.close();
         }
         
         returnNormal(res);
      }));
   }
   
   private void handleError (Exception exc) {
      if (exc.getCause() != null && exc.getCause() instanceof CharConversionException)
      {
         // offset seems to always be 1
         undoThrow(JsonParserError.newInstance("Json Parser Error at offset 1: lexical error: invalid char in json text..", 16068));
      } 
      else if (exc instanceof JsonParseException) 
      {
         // TODO: align the message details with 4GL
         undoThrow(JsonParserError.newInstance(String.format("Json Parser Error at offset %d: unknown error", 
                     ((JsonParseException) exc).getLocation().getCharOffset()), 16068));
      }
      else 
      {
         undoThrow(JsonParserError.newInstance("Json Parser Error: unknown error", 16068));
      }
   }
}