# ResponseArguments.java

    /*
    ** Module   : ResponseArguments.java
    ** Abstract : APIs to manage the response arguments in the HTTP servlet response.
    **
    ** Copyright (c) 2019-2022, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- ---------------------------------------Description----------------------------------------
    ** 001 CA  20190614 First version.
    ** 002 CA  20190628 Added TABLE output support.
    ** 003 CA  20190812 Added a TODO related to DECIMAL serialization.
    ** 004 CA  20200420 Fixes for DATASET, TABLE and error serialization.
    **     CA  20200514 Refactoring to allow common code for SOAP services support.
    **     CA  20200528 Added APIs for REST extent arguments (not implemented yet).
    ** 005 CA  20210304 Fixed an issue with INPUT-OUTPUT DATASET arguments.
    ** 006 CA  20211112 Refactored to allow transfer of the DATASET or TABLE via XML, for SOAP.
    **     CA  20220329 Added support for REST services written directly in Java.
    ** 007 AL2 20250325 Created reset abstract method to let SOAP requests hook on this event.
    */

    /*
    ** 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.rest;

    import java.io.*;
    import java.math.*;

    import javax.servlet.http.*;
    import javax.xml.bind.*;

    import com.goldencode.p2j.oo.lang.*;
    import com.goldencode.p2j.persist.*;
    import com.goldencode.p2j.util.*;

    /**
     * Helper class to serialize the return value and OUTPUT arguments for a REST or SOAP call.
     */
    public abstract class ResponseArguments
    {
       /** The actual serializer to use for interpreting and writing the arguments. */
       protected ThreadLocal<ArgumentsSerializer> serializer = new ThreadLocal<>();

       /**
        * Serialize the error, to be included in the response.
        *
        * @param    err
        *           The error.
        *
        * @return   The serialized version of the error.
        */
       public abstract String writeError(LegacyError err);

       /**
        * Serialize this argument's value, considering the target format.
        *
        * @param    stream
        *           The response stream.
        * @param    target
        *           The argument's encoded target.
        * @param    sval
        *           The argument's string-converted value.
        * @param    val
        *           The argument's value.
        * @param    response
        *           The HTTP response.
        */
       protected abstract void writeArgumentInt(OutputStream        stream,
                                                String              target,
                                                String              sval,
                                                Object              val,
                                                HttpServletResponse response)
       throws IOException;

       /**
        * Flush the arguments to the response stream (i.e. HTTP body).
        *
        * @param    stream
        *           The stream to write the parameters.
        * @param    response
        *           The servlet response.
        */
       protected abstract void flushArguments(OutputStream stream, HttpServletResponse response)
       throws IOException;

       /**
        * Serialize the specified table.
        *
        * @param    target
        *           The target OUTPUT parameter.
        * @param    val
        *           The table result set, as received from the remote side.
        *
        * @return   The serialized version of this table.
        */
       protected abstract Object writeTable(String target, TableWrapper val);

       /**
        * Serialize the specified dataset.
        *
        * @param    target
        *           The target OUTPUT parameter.
        * @param    val
        *           The dataset, as received from the remote side.
        *
        * @return   The serialized version of this dataset.
        */
       protected abstract Object writeDataSet(String target, DataSetContainer val);

       /**
        * Determine if unknown values must be ignored.
        *
        * @return    See above.
        */
       protected abstract boolean ignoreUnknown();

       /**
        * Serialize the specified dataset.
        *
        * @param    target
        *           The target OUTPUT parameter.
        * @param    val
        *           The dataset, as received from the remote side.
        *
        * @return   The serialized version of this dataset.
        */
       protected Object writeDataSet(String target, DatasetWrapper val)
       {
          return writeDataSet(target, val.getResource());
       }

       /**
        * Serialize this argument's values, considering the target format.
        *
        * @param    stream
        *           The response stream.
        * @param    target
        *           The argument's encoded target.
        * @param    val
        *           The argument's value.
        * @param    response
        *           The HTTP response.
        */
       protected abstract void writeExtentArgument(OutputStream        stream,
                                                   String              target,
                                                   Object              val,
                                                   HttpServletResponse response)
       throws IOException;

       /**
        * Serialize this arguments, considering each target's format.
        *
        * @param    retVal
        *           The return value.
        * @param    args
        *           The arguments.
        * @param    service
        *           The service handler.
        * @param    stream
        *           The HTTP response stream.
        * @param    response
        *           The HTTP response.
        */
       public void writeArguments(Object              retVal,
                                  Object[]            args,
                                  RestService         service,
                                  OutputStream        stream,
                                  HttpServletResponse response)
       throws IOException
       {
          writeArguments(retVal, args, service.ls.parameters(), service.getSerializer(this), stream, response);
       }

       /**
        * Serialize this arguments, considering each target's format.
        *
        * @param    retVal
        *           The return value.
        * @param    args
        *           The arguments.
        * @param    serviceParameters
        *           The legacy service parameters.
        * @param    stream
        *           The HTTP response stream.
        * @param    response
        *           The HTTP response.
        */
       public void writeArguments(Object                   retVal,
                                  Object[]                 args,
                                  LegacyServiceParameter[] serviceParameters,
                                  OutputStream             stream,
                                  HttpServletResponse      response)
       throws IOException
       {
          writeArguments(retVal, args, serviceParameters, new LegacyArgumentsSerializer(this), stream, response);
       }

       /**
        * Serialize this arguments, considering each target's format.
        *
        * @param    retVal
        *           The return value.
        * @param    args
        *           The arguments.
        * @param    serviceParameters
        *           The legacy service parameters.
        * @param    serializer
        *           The serializer to use for interpreting and writing the arguments.
        * @param    stream
        *           The HTTP response stream.
        * @param    response
        *           The HTTP response.
        */
       public void writeArguments(Object                   retVal,
                                  Object[]                 args,
                                  LegacyServiceParameter[] serviceParameters,
                                  ArgumentsSerializer      serializer,
                                  OutputStream             stream,
                                  HttpServletResponse      response)
       throws IOException
       {
          this.serializer.set(serializer);

          for (int i = 0; i < serviceParameters.length; i++)
          {
             LegacyServiceParameter lsp = serviceParameters[i];

             if (lsp.returnValue())
             {
                writeArgument(stream, lsp.target(), retVal, response);
             }
             else if (lsp.output())
             {
                writeArgument(stream, lsp.target(), args[lsp.ordinal() - 1], response);
             }
          }

          flushArguments(stream, response);
       }

       /**
        * Get the string representation of this instance.
        *
        * @param    bdt
        *           The instance.
        *
        * @return   The string representation, using {@link DatatypeConverter}.
        */
       protected String toString(BaseDataType bdt)
       {
          switch (bdt.getClass().getSimpleName())
          {
             case "integer":
                return DatatypeConverter.printInt(((integer) bdt).toJavaIntegerType());

             case "int64":
                return DatatypeConverter.printLong(((int64) bdt).toJavaLongType());

             case "decimal":
                BigDecimal bd = new BigDecimal(((decimal) bdt).toStringExport());
                return DatatypeConverter.printDecimal(bd);

             case "logical":
                return DatatypeConverter.printBoolean(((logical) bdt).booleanValue());

             case "date":
             case "datetime":
             case "datetimetz":
                return date.isoDate((date) bdt).toStringMessage();

             case "blob":
                blob b = (blob) bdt;
                return DatatypeConverter.printBase64Binary(b.asByteArray(0, b.lengthOf()));

             case "clob":
                clob c = (clob) bdt;
                return new String(c.asByteArray(0, c.lengthOf()));

             case "raw":
             case "memptr":
                return DatatypeConverter.printBase64Binary(((BinaryData) bdt).getByteArray());

             default:
                return bdt.toStringMessage();
          }
       }

       /**
        * Serialize this argument's value, considering the target format.
        *
        * @param    stream
        *           The response stream.
        * @param    target
        *           The argument's encoded target.
        * @param    val
        *           The argument's value.
        * @param    response
        *           The HTTP response.
        */
       protected final void writeArgument(OutputStream        stream,
                                          String              target,
                                          Object              val,
                                          HttpServletResponse response)
       throws IOException
       {
          serializer.get().writeArgument(stream, target, val, response);
       }

       /**
        * Reset the state of the response arguments.
        */
       protected abstract void reset();
    }