# HttpClient.java

    /*
    ** Module   : HttpClient.java
    ** Abstract : Implementation of the builtin class.
    **
    ** Copyright (c) 2019-2023, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- ---------------------------------------Description----------------------------------------
    ** 001 IAS 20190923 First version.
    ** 002 IAS 20191108 Added HTTP Redirect support.
    ** 003 ME  20200410 Added setter method for logger.
    ** 004 MP  20200602 Added static method instance and static constructor
    ** 005 MP  20200611 Added missing methods as stub.
    ** 006 ME  20201103 Added default logger, cookies state management.
    **         20210128 Update assert messages, add user agent and retry support.
    **     CA  20210221 Fixed parameters at the LegacySignature annotation.
    ** 007 CA  20210221 Fixed 'qualified', 'extent' and 'returns' annotations at the legacy signature.
    ** 008 ME  20210524 Added support for retries, destroy library and fix variable scope on execute.
    **     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.
    **     CA  20220923 Variable definitions (including associated with parameters) must be done always outside of
    **                  the BlockManager API
    ** 009 CA  20230817 Removed ObjectOps.register, as this registration is handled by runtime.
    ** 010 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.
    **
    **     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.oo.net.http;

    import static com.goldencode.p2j.util.BlockManager.externalProcedure;
    import static com.goldencode.p2j.report.ReportConstants.*;
    import static com.goldencode.p2j.util.BlockManager.function;
    import static com.goldencode.p2j.util.BlockManager.internalProcedure;
    import static com.goldencode.p2j.util.BlockManager.onBlockLevel;
    import static com.goldencode.p2j.util.BlockManager.returnNormal;
    import com.goldencode.p2j.oo.core.*;
    import com.goldencode.p2j.oo.logging.*;
    import com.goldencode.p2j.oo.net.http.filter.writer.*;
    import com.goldencode.p2j.ui.LogicalTerminal;
    import com.goldencode.p2j.util.*;
    import com.goldencode.p2j.util.BlockManager.Action;
    import com.goldencode.p2j.util.BlockManager.Condition;
    import com.goldencode.p2j.util.InternalEntry.*;

    /**
     *
     * Public HttpClient. All client code should be written against this class.
     *
     */
    @LegacyResource(resource = "OpenEdge.Net.HTTP.HttpClient")
    @LegacyResourceSupport(supportLvl = CVT_LVL_FULL|RT_LVL_PARTIAL)
    public class HttpClient
    extends com.goldencode.p2j.oo.lang.BaseObject
    implements IhttpClient, ISupportInitialize, ISupportLogging
    {
       protected static final String ICLIENTLIBRARY = "openedge.net.http.ihttpclientlibrary";

       /** Client name. */
       @LegacySignature(type = Type.PROPERTY, name = "ClientName")
       private final character clientName = UndoableFactory.character();

       /** Client version. */
       @LegacySignature(type = Type.PROPERTY, name = "ClientVersion")
       private final character clientVersion = UndoableFactory.character();

       /** Client options. */
       @LegacySignature(type = Type.PROPERTY, name = "Options")
       private final object<? extends ClientOptions> options =
             UndoableFactory.object(ClientOptions.class);

       /** Client library. */
       private final object<? extends IHttpClientLibrary> library =
             UndoableFactory.object(IHttpClientLibrary.class);

       /** Logger **/
       @LegacySignature(type = Type.PROPERTY, name = "Logger")
       private final object<? extends IlogWriter> logger = TypeFactory.object(IlogWriter.class);

       /**
        * Destroy.
        */
       @LegacySignature(type = Type.METHOD, name = "Destroy")
       @LegacyResourceSupport(supportLvl = CVT_LVL_FULL|RT_LVL_FULL)
       @Override
       public void destroy()
       {
          internalProcedure(HttpClient.class, this, "Destroy", new Block((Body) () ->
          {
             if (ObjectOps.typeOf(library, ISupportInitialize.class).booleanValue())
                ObjectOps.cast(library, ISupportInitialize.class).ref().destroy();
          }));
       }

       /**
        * Initialize
        */
       @LegacySignature(type = Type.METHOD, name = "Initialize")
       @LegacyResourceSupport(supportLvl = CVT_LVL_FULL|RT_LVL_FULL)
       public void initialize()
       {
          internalProcedure(HttpClient.class, this, "Initialize", new Block((Body) () ->
          {
             // no-op (oe12.2)
          }));
       }

       /**
        * Constructor.
        *
        * @param _pcClientName client name.
        * @param _pcClientVersion client version.
        * @param _poLibrary client library.
        */
       @LegacySignature(type = Type.CONSTRUCTOR, parameters =
       {
          @LegacyParameter(name = "pcClientName", type = "CHARACTER", mode = "INPUT"),
          @LegacyParameter(name = "pcClientVersion", type = "CHARACTER", mode = "INPUT"),
          @LegacyParameter(name = "poLibrary", type = "object", qualified = ICLIENTLIBRARY, mode = "INPUT")
       })
       @LegacyResourceSupport(supportLvl = CVT_LVL_FULL|RT_LVL_FULL)
       public void __net_http_HttpClient_constructor__(final character _pcClientName,
             final character _pcClientVersion,
             final object<? extends IHttpClientLibrary> _poLibrary)
       {
          character pcClientName = TypeFactory.initInput(_pcClientName);
          character pcClientVersion = TypeFactory.initInput(_pcClientVersion);
          object<? extends IHttpClientLibrary> poLibrary = TypeFactory.initInput(_poLibrary);

          internalProcedure(this, "__net_http_RequestBuilder_constructor__", new Block((Body) () ->
          {
             __lang_BaseObject_constructor__();
             Assert.notNullOrEmpty(_pcClientName, new character("Client name"));
             Assert.notNullOrEmpty(_pcClientVersion, new character("Client version"));
             Assert.notNull(_poLibrary, new character("Http library"));
             this.clientName.assign(pcClientName);
             this.clientVersion.assign(pcClientVersion);
             this.library.assign(poLibrary);
             this.options.assign(ObjectOps.newInstance(ClientOptions.class));
          }));
       }

       @LegacySignature(type = Type.CONSTRUCTOR)
       @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
       public static void __net_http_HttpClient_constructor__static__()
       {
          externalProcedure(HttpClient.class, new Block((Body) () ->
          {
             onBlockLevel(Condition.ERROR, Action.THROW);
          }));
       }

       @LegacySignature(type = Type.DESTRUCTOR)
       @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_STUB)
       public void __net_http_HttpClient_destructor__()
       {
          internalProcedure(HttpClient.class, this, "__net_http_HttpClient_destructor__", new Block());
       }

       /**
        * Execute method.
        */
       @LegacySignature(type = Type.EXECUTE)
       public void __net_http_HttpClient_execute__()
       {
          onBlockLevel(Condition.ERROR, Action.THROW);
       }

       @LegacySignature(type = Type.METHOD, name = "AddUserAgent", parameters = {
                @LegacyParameter(name = "p1", type = "OBJECT", qualified = "openedge.net.http.ihttprequest", mode = "INPUT") })
       @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_STUB)
       protected void addUserAgent(
                final object<? extends com.goldencode.p2j.oo.net.http.IhttpRequest> _p1)
       {
          object<? extends com.goldencode.p2j.oo.net.http.IhttpRequest> p1 = TypeFactory
                   .initInput(_p1);

          internalProcedure(HttpClient.class, this, "AddUserAgent", new Block((Body) () -> {
             p1.ref().setHeader(HttpHeaderBuilder.build(new character("User-Agent")).ref()
                      .value(TextOps.substitute("&1/&2 (&3/&4) OpenEdge/&5", clientName,
                               clientVersion, EnvironmentOps.getOperatingSystem(),
                               EnvironmentOps.getProcessArchitecture(), EnvironmentOps.getVersion()))
                      .ref().getHeader());
          }));
       }

       /**
        * Get logger.
        *
        * @return logger.
        */
       @LegacySignature(returns = "OBJECT", qualified = "OpenEdge.Logging.ILogWriter", type = Type.GETTER, name = "Logger")
       @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_PARTIAL)
       @Override
       public object<? extends IlogWriter> getLogger()
       {
          return function(this, "Logger", object.class, new Block((Body) () ->
          {
             if (!logger._isValid())
                logger.assign(ObjectOps.newInstance(VoidLogger.class));

             returnNormal(logger);
          }));
       }

       /**
        * Set logger.
        *
        * @param _logger The logger instance to be used by the client.
        */
       @LegacySignature(type = Type.SETTER, name = "Logger", parameters =
       {
          @LegacyParameter(name = "logger", type = "OBJECT", mode = "INPUT", qualified = "OpenEdge.Logging.ILogWriter")
       })
       @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
       @Override
       public void setLogger(object<? extends IlogWriter> _logger)
       {
          object<? extends IlogWriter> logger = TypeFactory.initInput(_logger);

          internalProcedure(this, "Logger", new Block((Body) () ->
          {
             this.logger.assign(logger);
          }));

       }

       /**
        * Execute HTTP request.
        *
        * @param _poRequest HTTP request.
        *
        * @return HTTP Response.
        */
       @LegacySignature(returns = "OBJECT", type = Type.METHOD, name = "Execute", qualified = IHTTPRESPONSE, parameters = {
                @LegacyParameter(name = "poRequest", type = "OBJECT", qualified = IHTTPREQUEST, mode = "INPUT") })
       @LegacyResourceSupport(supportLvl = CVT_LVL_FULL | RT_LVL_FULL)
       @Override
       public object<? extends IhttpResponse> execute(object<? extends IhttpRequest> _poRequest)
       {
          object<? extends IhttpRequest> poRequest = TypeFactory.initInput(_poRequest);
          object<? extends IhttpResponse> poResponse = TypeFactory.object(IhttpResponse.class);

          return function(this, "execute", object.class, new Block((Body) () ->
          {
             poResponse.assign(ResponseBuilder.build().ref().getResponse());
             execute(poRequest, poResponse);
             returnNormal(poResponse);
          }));
       }

       @LegacySignature(returns = "OBJECT", type = Type.METHOD, name = "Instance", qualified = "openedge.net.http.httpclient")
       @LegacyResourceSupport(supportLvl = CVT_LVL_FULL|RT_LVL_STUB)
       public static object<? extends com.goldencode.p2j.oo.net.http.HttpClient> instance()
       {
          object<? extends HttpClient> httpClient = TypeFactory.object(HttpClient.class);

          return function(HttpClient.class, "Instance", object.class, new Block((Body) () ->
          {
             httpClient.assign(ClientBuilder.build().ref().getClient());

             returnNormal(httpClient);

          }));
       }

       /**
        * Execute HTTP request.
        *
        * @param _poRequest HTTP request.
        * @param _poResponse HTTP Response.
        */
       @LegacySignature(type = Type.METHOD, name = "Execute", parameters =
       {
          @LegacyParameter(name = "poRequest", type = "OBJECT", qualified = IHTTPREQUEST, mode = "INPUT"),
          @LegacyParameter(name = "poResponse", type = "OBJECT", qualified = IHTTPRESPONSE, mode = "INPUT")
       })
       @LegacyResourceSupport(supportLvl = CVT_LVL_FULL|RT_LVL_FULL)
       @Override
       public void execute(object<? extends IhttpRequest> _poRequest,
             object<? extends IhttpResponse> _poResponse)
       {
          object<? extends IhttpRequest> poRequest = TypeFactory.initInput(_poRequest);
          object<? extends IhttpResponse> poResponse = TypeFactory.initInput(_poResponse);
          object<? extends IAuthenticatedRequest> authRequest = TypeFactory.object(IAuthenticatedRequest.class);
          raw reqHash = TypeFactory.raw();

          internalProcedure(this, "execute", new Block((Body) () ->
          {

             Assert.notNull(poRequest, new character("Http request"));
             Assert.notNull(poResponse, new character("Http response"));

             int retries = Math.max(options.ref().getNumRetries().intValue(), 0);
             int retry = 0;
             double retryPause = retries > 0 ? Math.max(options.ref().getPauseBetweenRetry().doubleValue(), 0) : 0;

             if (retries > 0)
                getLogger().ref().debug(TextOps.substitute("Initial request for &1 &2; max retries=&3",
                         poRequest.ref().getMethod(),
                         poRequest.ref().getUri().ref().toLegacyString(),
                         retries));

             do
             {
                if (retry > 0)
                   getLogger().ref().debug(TextOps.substitute("Retry attempt &1 of &2 for &3 &4",
                            retry,
                            retries,
                            poRequest.ref().getMethod(),
                            poRequest.ref().getUri().ref().toLegacyString()));

                addUserAgent(poRequest);

                _addAuthentication(poRequest, authRequest);

                reqHash.assign(poRequest.ref().getContentMd5());

                library.ref().execute(poRequest, poResponse);

                if (processStatusAction(poRequest, poResponse).booleanValue())
                   break;

                if (retries == 0 || (retries > 0 && CompareOps._isEqual(reqHash, poRequest.ref().getContentMd5())))
                {
                   retry++;

                   if (retryPause > 0)
                      LogicalTerminal.pause(retryPause, (String) null);
                }
             }
             while(retry <= retries);
          }));
       }

       private void _addAuthentication(object<? extends IhttpRequest> _poRequest, object<? extends IAuthenticatedRequest> authRequest)
       {
          if (ObjectOps.typeOf(_poRequest, IAdaptable.class).booleanValue())
          {
             authRequest.assign(ObjectOps.cast(_poRequest, IAdaptable.class).ref()
                      .getAdapter(ObjectOps.getLegacyClass(IAuthenticatedRequest.class)));
          }

          if (!authRequest._isValid() && ObjectOps.typeOf(_poRequest, IAuthenticatedRequest.class).booleanValue())
          {
             authRequest.assign(ObjectOps.cast(_poRequest, IAuthenticatedRequest.class));
          }

          if (authRequest._isValid())
             authRequest.ref().addAuthentication();

       }

       /**
        * Process HttpResponse status code.
        *
        * This basically handle redirects (301, 302, not 307 yet) and authorization required (401).
        *
        * @param poRequest HTTP request.
        * @param poResponse HTTP Response.
        */
       @LegacySignature(returns = "LOGICAL", type = Type.METHOD, name = "ProcessStatusAction", parameters =
       {
          @LegacyParameter(name = "poRequest", type = "OBJECT", qualified = IHTTPREQUEST, mode = "INPUT"),
          @LegacyParameter(name = "poResponse", type = "OBJECT", qualified = IHTTPRESPONSE, mode = "INPUT")
       })
       @LegacyResourceSupport(supportLvl = CVT_LVL_FULL|RT_LVL_FULL)
       protected logical processStatusAction(object<? extends IhttpRequest> poRequest,
             object<? extends IhttpResponse> poResponse)
       {
          object<? extends Cookie> oCookies[][] = new object[][] { TypeFactory.objectExtent(Cookie.class, false) };

          return function(this, "ProcessStatusAction", logical.class, new Block((Body) () ->
          {
             object<? extends IHttpMessageWriter> statusCodeWriter = StatusCodeWriterBuilder.build(poRequest, poResponse);

             if (statusCodeWriter._isValid())
             {
                // maybe there is no point to retry if authorization is required but
                // not an authenticated request, still seems not to be the case in 4GL
                // if (ObjectOps.typeOf(statusCodeWriter, AuthorizationStatusFilter.class).booleanValue() &&
                //         ObjectOps.typeOf(poRequest, AuthenticatedRequest.class).booleanValue())
                //   returnNormal(true);

                // copy session management info from initial response, if any
                _copyCookies(poResponse.ref(), poRequest.ref(), oCookies);

                statusCodeWriter.ref().open();
                statusCodeWriter.ref().write(poResponse);
                statusCodeWriter.ref().close();

                returnNormal(false);
             }

             returnNormal(true);
          }));
       }

       /**
        * Get client name.
        *
        * @return client name.
        */
       @LegacySignature(returns = "CHARACTER", type = Type.GETTER, name = "ClientName")
       @LegacyResourceSupport(supportLvl = CVT_LVL_FULL|RT_LVL_FULL)
       @Override
       public character getClientName()
       {
          return function(this, "ClientName", character.class, new Block((Body) () ->
          {
             returnNormal(this.clientName);
          }));
       }

       /**
        * Get client version.
        * @return client version.
        */
       @LegacySignature(returns = "CHARACTER", type = Type.GETTER, name = "ClientVersion")
       @Override
       @LegacyResourceSupport(supportLvl = CVT_LVL_FULL|RT_LVL_FULL)
       public character getClientVersion()
       {
          return function(this, "ClientVersion", character.class, new Block((Body) () ->
          {
             returnNormal(this.clientVersion);
          }));
       }

       /**
        * Get client options.
        *
        * @return client options.
        */
       @LegacySignature(returns = "OBJECT", qualified = "OpenEdge.Net.HTTP.ClientOptions", type = Type.GETTER, name = "Options")
       @Override
       @LegacyResourceSupport(supportLvl = CVT_LVL_FULL|RT_LVL_FULL)
       public object<? extends ClientOptions> getOptions()
       {
          return function(this, "Options", object.class, new Block((Body) () ->
          {
             returnNormal(this.options);
          }));
       }

       /**
        * Helper method to copy/transfer cookies from one message to another (usually from response to request)
        *
        * @param source the message to copy cookies from
        * @param target the message to copy cookies into
        */
       private void _copyCookies(IhttpMessage source, IhttpMessage target, object<? extends Cookie> oCookies[][])
       {
          if (source != null & target != null)
          {
             source.getCookies(new OutputExtentParameter<object<? extends Cookie>>()
             {

                @Override
                public object<? extends Cookie>[] getVariable()
                {
                   return oCookies[0];
                }

                @Override
                public void setVariable(object<? extends Cookie>[] reference)
                {
                   oCookies[0] = reference;
                }
             });

             // if there are any set those on request
             if (oCookies[0].length > 0)
                target.setCookies(oCookies[0]);
          }
       }
    }