# ProgRestService.java

    /*
    ** Module   : ProgRestService.java
    ** Abstract : Implementation of a REST service invocation via an external program.
    **
    ** Copyright (c) 2019-2022, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- ---------------------------------------Description----------------------------------------
    ** 001 CA  20190614 First version.
    ** 002 CA  20190628 Proper SINGLETON and SINGLE-RUN implementation; misc improvements.
    ** 003 CA  20200427 Use InvokeConfig APIs to perform the remote request.
    **     CA  20200514 Refactoring to allow common code for SOAP services support.
    ** 004 CA  20210226 Pass the argument modes to the invocation, as the Agent will not pre-process the args
    **                  otherwise.
    **     CA  20211214 For State-free appservers, the agents can be bound to remote persistent procedures; this
    **                  binding must be made using the agent's ID, as a client can invoke multiple remote
    **                  persistent procedures, and using the procedure's ID for this binding can lead to
    **                  collisions, as the pair (connection ID, procedure ID) is not guaranteed to be unique for
    **                  a connection.
    **     CA  20220120 Mutable state must be thread-local.
    **     CA  20220405 Added authentication and authorization for web requests.  When this is enabled, the target
    **                  API call will be executed under the authenticated FWD context, and not the agent's context.
    */

    /*
    ** 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.lang.reflect.*;
    import java.util.*;

    import com.goldencode.p2j.util.*;
    import com.goldencode.p2j.util.Parameter;

    /**
     * Implementation to invoke REST services mapped to OO methods.
     * <p>
     * Allows both PERSISTENT and DELETE mode, in use by SOAP services.
     */
    public class ProgRestService
    extends RestService
    {
       /**
        * The external program resource ID (for persistent procedures as the result, and for internal entries as
        * input).
        */
       protected ThreadLocal<String> resourceId = new ThreadLocal<>();

       /** The target program name. */
       protected final String pname;

       /** The agent ID where the remote procedure was created. */
       protected ThreadLocal<Integer> agentId = new ThreadLocal<>();

       /**
        * Initialize with the details for an external program invocation.
        *
        * @param    ls
        *           The annotation at the Java class (defining the resource).
        * @param    pname
        *           The program name.
        * @param    m
        *           The target method for this service.
        * @param    key
        *           The service key.
        * @param    timeout
        *           The invocation timeout.
        */
       public ProgRestService(LegacyService   ls,
                              String          pname,
                              Method          m,
                              ServiceKey      key,
                              int             timeout)
       {
          super(ls, m.getAnnotation(LegacySignature.class), key, timeout);

          this.pname = pname;
       }

       /**
        * Get the {@link Parameter}s as they are defined at the external program.
        *
        * @return   See above.
        */
       protected List<Parameter> getParameters()
       {
          return SourceNameMapper.getParameters(pname, null, null, false);
       }

       /**
        * Set the external program resource ID to be used by this service.
        *
        * @param    resourceId
        *           The {@link #resourceId}.
        * @param    agentId
        *           The {@link #agentId}.
        */
       public void setResourceId(String resourceId, int agentId)
       {
          this.resourceId.set(resourceId);
          this.agentId.set(agentId);
       }

       /**
        * Reset the last invoke configuration.
        */
       @Override
       public void reset()
       {
          super.reset();

          this.resourceId.set(null);
          this.agentId.set(null);
       }

       /**
        * Invoke this service.
        *
        * @param    helper
        *           The appserver helper used to execute the requests.
        * @param    token
        *           When not null, it represents the token of a FWD context created for an authenticated and
        *           authorized web service call.  The API call will be performed in that context.
        * @param    args
        *           The arguments.
        *
        * @return   The returned value.
        */
       @Override
       public Object invoke(AppServerHelper helper, String token, Object[] args)
       {
          String executionMode = getExecutionMode();
          if (executionMode.equalsIgnoreCase(LegacyWebServiceHandler.EXTERNAL))
          {
             String modes = resolveModes();

             InvokeConfig cfg = new InvokeConfig(new character(pname));
             cfg.setArguments(args)
                .setModes(modes)
                .setRequestId(nextRequestId())
                .setWebServiceToken(token);

             this.cfg.set(cfg);

             // invoke it
             return helper.invoke(timeout, null, cfg);
          }
          else if (executionMode.equalsIgnoreCase(LegacyWebServiceHandler.PERSISTENT))
          {
             String modes = resolveModes();

             InvokeConfig cfg = new InvokeConfig(new character(pname));
             cfg.setPersistent(true)
                .setProcedureHandle(new handle())
                .setArguments(args)
                .setModes(modes)
                .setRequestId(nextRequestId())
                .setWebServiceToken(token);

             this.cfg.set(cfg);

             // invoke it
             return helper.invoke(timeout, null, cfg);
          }
          else if (executionMode.equalsIgnoreCase(LegacyWebServiceHandler.DELETE))
          {
             helper.deleteProcedure(resourceId.get(), agentId.get(), token);
          }
          else
          {
             // TODO: not good mode - throw? error? something else?
          }

          return null;
       }
     }