SourceData.java

/*
** Module   : SourceData.java
** Abstract : Describes an external source from which data is read into a buffer.
**
** Copyright (c) 2017-2023, Golden Code Development Corporation.
**
** -#- -I- --Date-- ---------------------------------------Description---------------------------------------
** 001 ECF 20170820 Created initial version.
** 002 ECF 20171008 Implemented file as an output resource.
** 003 ECF 20190120 Added implementation for c'tor which accepts longchar.
** 004 OM  20190327 Renamed to SourceData to avoid conflicts with DataSet source.
** 005 CA  20200503 Added c'tor to read data from a JsonObject instance (stubbed).
** 006 OM  20201120 Implementing Closeable interface. Lazily open the file stream.
**     OM  20210120 Added full type support, including validation and error handling.
**     OM  20210825 Added support methods for READ-JSON methods.
** 007 IAS 20230325 Changed type of 15357/13184 message from Error to Warning. 
** 008 CA  20230907 Added support for X-Document source.  X-Noderef is not yet supported.
** 009 SP  20240606 Error 4065 must not set ERROR-STATUS:ERROR flag.
*/

/*
** 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.
**
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**     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.
**
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**     name Golden Code, FWD, or the names of any author or contributor, for
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**     attribution required in this license.
*/

package com.goldencode.p2j.persist;

import com.goldencode.p2j.persist.serial.*;
import com.goldencode.p2j.util.*;
import com.goldencode.p2j.xml.*;

import java.io.*;
import java.util.*;

/**
 * Object which describes an external source from which data is read into a temp-table buffer or dataset
 * member buffer.
 */
public class SourceData
implements Serializator
{
   /** Normalized input stream */
   private InputStream stream = null;
   
   /** The file name if such source was created. */
   private String fileName = null;
   
   /**
    * Constant used to identify the calls from READ-XML method. Also used to store the supported stream types
    * for this method.
    */
   public static final String SD_READ_XML = "READ-XML";
   
   /**
    * Constant used to identify the calls from READ-XMLSCHEMA method. Also used to store the supported stream
    * types for this method.
    */
   public static final String SD_READ_XMLSCHEMA = "READ-XMLSCHEMA";
   
   /**
    * Constant used to identify the calls from READ-JSON method. Also used to store the supported stream types
    * for this method.
    */
   public static final String SD_READ_JSON = "READ-JSON";
   
   /* The initialization of static member data. */
   private static final Map<String, Integer> supportedStreams = new HashMap<>();
   static
   {
      supportedStreams.put(SD_READ_XML, SER_FILE | SER_MEMPTR | SER_HANDLE | SER_LONGCHAR);
      supportedStreams.put(SD_READ_XMLSCHEMA, SER_FILE | SER_MEMPTR | SER_HANDLE | SER_LONGCHAR);
      supportedStreams.put(SD_READ_JSON,
                           SER_FILE | SER_MEMPTR | SER_HANDLE | SER_LONGCHAR | SER_JSON_ARRAY | SER_JSON_OBJECT);
   }
   
   /** Local copy of the stream type configured in constructor. */
   private final String origType;
   
   /** Local reference to stream (or stream name), as configured in constructor. */
   private final BaseDataType origSrc;
   
   /**
    * The constructor saves the configured parameters but does not process them in any way. The validation
    * will be executed later, when the calling method is in progress.
    * 
    * @param   type
    *          The source stream type.
    * @param   source
    *          The reference to resource or the file name.
    */
   public SourceData(character type, BaseDataType source)
   {
      this((type == null) ? null : type.toJavaType(), source);
   }
   
   /**
    * The constructor saves the configured parameters but does not process them in any way. The validation
    * will be executed later, when the calling method is in progress.
    * 
    * @param   type
    *          The source stream type.
    * @param   source
    *          The reference to resource or the file name.
    */
   public SourceData(String type, BaseDataType source)
   {
      origType = type;
      origSrc = source;
   }
   
   /**
    * The constructor saves the configured parameters but does not process them in any way. The validation
    * will be executed later, when the calling method is in progress.
    * 
    * @param   type
    *          The source stream type.
    * @param   source
    *          The file name.
    */
   public SourceData(String type, String source)
   {
      origType = type;
      origSrc = new character(source);
   }
   
   /**
    * Configures the resource stream types for the current usage. The caller passes in its name and the
    * method does the selection. It also does the verification whether the already configured parameters (in
    * the constructor) are valid and eventual raise the error condition.
    * 
    * @param   method
    *          The identifier for the method using the source stream. It is used to get the set of acceptable
    *          stream types to check against them.
    * @param   widgetType
    *          The parent widget. Only used for composing the error messages.
    *
    * @return  {@code true} if the parameters configured in constructor seems correct. This method does not
    *          check the content, only the variable types. If there is not a match with the possible streams
    *          supported by the {@code method}, {@code false} is returned, after eventually raising a specific
    *          error condition.
    */
   public boolean configureSupportedSources(String method, String widgetType)
   {
      boolean isJson = method.contains("JSON");
      if (origType == null)
      {
         ErrorManager.recordOrShowError(5442, method, "character");
         // Invalid datatype for argument to method ''<name>. Expecting ''<name>
         return false;
      }
      
      if (origSrc == null || origSrc.isUnknown())
      {
         ErrorManager.recordOrShowError(4065, false, method, widgetType);
         // **The <attribute> attribute on the <widget id> has invalid arguments. (4065)
         return false;
      }
      
      // [method] must always be one of the supported methods 
      int supportedSources = supportedStreams.get(method);
      
      switch (origType.toUpperCase())
      {
         case TYPE_FILE:
            if ((supportedSources & SER_FILE) != 0)
            {
               if ((origSrc instanceof longchar))
               {
                  // no error, but false
                  return false;
               }
               
               if (!(origSrc instanceof character))
               {
                  ErrorManager.recordOrShowError(4065, false, method, widgetType);
                  // **The <attribute> attribute on the <widget id> has invalid arguments. (4065)
                  return false;
               }
               return true;
            }
            break;
         
         case TYPE_STREAM:
            if ((supportedSources & SER_STREAM) != 0)
            {
               return true;
            }
            break;
         
         case TYPE_STREAM_HANDLE:
            if ((supportedSources & SER_STREAM_HANDLE) != 0)
            {
               return true;
            }
            break;
         
         case TYPE_MEMPTR:
            if ((supportedSources & SER_MEMPTR) != 0)
            {
               if (!(origSrc instanceof memptr))
               {
                  if (isJson)
                  {
                     ErrorManager.recordOrShowError(15362, "", "");
                     // READ-JSON source is not a valid LONGCHAR or MEMPTR. (15362)
                     ErrorManager.recordOrShowError(17956, "", "");
                     // Unable to create reader for READ-JSON (17956)
                  }
                  else
                  {
                     ErrorManager.recordOrShowError(4065, false, method, widgetType);
                     // **The <attribute> attribute on the <widget id> has invalid arguments. (4065)
                  }
                  return false;
               }
               return true;
            }
            break;
         
         case TYPE_HANDLE:
            if (isJson)
            {
               ErrorManager.recordOrShowError(15356, "", "");
               // Handle type not valid as JSON input source. (15356)
            }
            else
            {
               // 1. not unknown
               if (origSrc.isUnknown())
               {
                  ErrorManager.recordOrShowError(4065, false, method, widgetType);
                  // **The <attribute> attribute on the <widget id> has invalid arguments. (4065)
                  return false;
               }
               
               // 2. not a handle or the handle's type is not X-Document
               boolean validType = false;
               if (origSrc instanceof handle)
               {
                  WrappedResource res = ((handle) origSrc).getResource();
                  if (res instanceof XDocument)
                  {
                     validType = true;
                  }
                  else if (res instanceof XNodeRef)
                  {
                     // TODO: allow X-Noderef
                     UnimplementedFeature.missing(method + " with X-Noderef target is not supported.");
                     validType = false;
                  }
               }
               
               if (!validType)
               {
                  ErrorManager.recordOrShowError(10515, false, "", "");
                  // Handle type not valid as XML input source. (10515)
                  ErrorManager.recordOrShowError(4065, false, method, widgetType);
                  // **The <attribute> attribute on the <widget id> has invalid arguments. (4065)
                  return false;
               }
               
               return true;
            }
            return false;
         
         case TYPE_LONGCHAR:
            if ((supportedSources & SER_LONGCHAR) != 0)
            {
               if (!(origSrc instanceof longchar))
               {
                  if (isJson)
                  {
                     ErrorManager.recordOrShowError(15362, "", "");
                     // READ-JSON source is not a valid LONGCHAR or MEMPTR. (15362)
                     ErrorManager.recordOrShowError(17956, "", "");
                     // Unable to create reader for READ-JSON (17956)
                  }
                  else
                  {
                     ErrorManager.recordOrShowError(4065, false, method, widgetType);
                     // **The <attribute> attribute on the <widget id> has invalid arguments. (4065)
                     return false;
                  }
                  return false;
               }
               return true;
            }
            break;
         
         case TYPE_JSON_OBJECT:
            if ((supportedSources & SER_JSON_OBJECT) != 0)
            {
               return true;
            }
            break;
         
         case TYPE_JSON_ARRAY:
            if ((supportedSources & SER_JSON_ARRAY) != 0)
            {
               return true;
            }
            break;
      }
      
      ErrorManager.recordOrShowWarning(isJson ? 15357 : 13184, origType);
      // err 13184: Invalid source-type for READ-XML: <argument>.
      // err 15357: Invalid source-type for READ-JSON: <type>.
      return false;
   }
   
   /**
    * Get the input stream representing the source resource from which data will be read. This may be backed
    * by a remote or a local resource.
    *
    * @return  Input stream.
    * 
    * @throws  IOException
    *          if the method encounters issues with the resource.
    */
   @Override
   public InputStream getStream()
   throws IOException
   {
      // if already built, return it again 
      if (stream != null)
      {
         return stream;
      }
      
      switch (origType.toUpperCase())
      {
         case TYPE_FILE:
            if (origSrc instanceof character)
            {
               fileName = ((character) origSrc).toJavaType();
               try
               {
                  stream = new InputStreamWrapper(StreamFactory.openFileStream(fileName, false, false));
               }
               catch (ErrorConditionException ece)
               {
                  throw new FileNotFoundException(fileName);
               }
               return stream;
            }
            return null;
         
         case TYPE_LONGCHAR:
            if (origSrc instanceof longchar)
            {
               longchar source = (longchar) origSrc;
               stream = new ByteArrayInputStream(source.asByteArray(0, source.lengthOf()));
               return stream;
            }
            return null;
         
         case TYPE_MEMPTR:
            if (origSrc instanceof memptr)
            {
               memptr source = (memptr) origSrc;
               stream = new ByteArrayInputStream(source.asByteArray(0, source.lengthOf()));
               return stream;
            }
            return null;
      }
      
      return null;
   }
   
   /**
    * Close the input stream underlying this data source.
    *
    * @throws  IOException
    *          if there is an error closing the stream.
    */
   public void close()
   throws IOException
   {
      if (stream != null)
      {
         stream.close();
      }
   }
   
   /**
    * Obtain the file name of the source, if one was used to create the source.
    *
    * @return  the file name of the source, if one was used to create the source. Otherwise {@code null}.
    */
   public String getFileName()
   {
      return fileName;
   }
   
   /**
    * Obtain the original source.
    * 
    * @return  the original source this object was created for.
    */
   public BaseDataType getSource()
   {
      return origSrc;
   }
   
   /**
    * Obtain the type of source this objects wraps.
    * 
    * @return  the type of source this objects wraps.
    */
   public String getType()
   {
      return origType;
   }
}