/*
    DummyJob  -  diagnostic job for unit tests

  Copyright (C)         Lumiera.org
    2013,               Hermann Vosseler <Ichthyostega@web.de>

  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License as
  published by the Free Software Foundation; either version 2 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 General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

* *****************************************************/


#include "backend/engine/dummy-job.hpp"

#include "lib/test/test-helper.hpp"
#include "lib/time/timevalue.hpp"
#include "backend/real-clock.hpp"
#include "lib/null-value.hpp"
#include "lib/hash-value.h"
#include "lib/util.hpp"

#include <cstdlib>
#include <unordered_map>
#include <boost/functional/hash.hpp>


namespace backend{
namespace engine {
  
  namespace { // DummyJob implementation details...
    
    using lib::HashVal;
    using lib::NullValue;
    using lib::time::TimeVar;
    using std::unordered_map;
    using util::access_or_default;
    
    
    const int MAX_PARAM_A(1000);   ///< random test values 0...1000
    const int MAX_PARAM_B(10);     ///< random test values -10...+10
    
    
    /**
     * test dummy jobs are backed by this closure.
     * DummyJob invocations are recorded in a hashtable
     * @note as of 9/2013, we use a very simplistic implementation,
     *       causing a consecutive invocation of the same job instance
     *       to overwrite the previous log entry.
     */
    class DummyClosure
      : public JobClosure
      {
        void
        invokeJobOperation (JobParameter parameter)
          {
            invocationLog_[hash_value (parameter)] = Invocation(parameter);
          }
        
        void
        signalFailure (JobParameter,JobFailureReason)
          {
            NOTREACHED ("Job failure is not subject of this test");
          }
        
        JobKind
        getJobKind()  const
          {
            return META_JOB;
          }
        
        bool
        verify (Time nominalJobTime, InvocationInstanceID invoKey)  const
          {
            return Time::NEVER < nominalJobTime
                && 0 <= invoKey.metaInfo.a
                && invoKey.metaInfo.a < MAX_PARAM_A
                && -MAX_PARAM_B <= invoKey.metaInfo.b
                && invoKey.metaInfo.b < MAX_PARAM_B;
          }
        
        size_t
        hashOfInstance(InvocationInstanceID invoKey) const
          {
            return boost::hash_value (invoKey.metaInfo.a);
          }
        
        
        /* === Logging/Reporting of job invocation === */
        
        struct Invocation
          {
            TimeVar nominal;
            TimeVar real;
            int a,b;
            
            Invocation(JobParameter param)
              : nominal(TimeValue(param.nominalTime))
              , real(RealClock::now())
              , a(param.invoKey.metaInfo.a)
              , b(param.invoKey.metaInfo.b)
              { }
            
            Invocation()
              : nominal(Time::NEVER)
              , real(Time::ANYTIME)
              , a(MAX_PARAM_A), b(0)
              { }
          };
        
        /** recording DummyJob invocations */
        unordered_map<HashVal,Invocation> invocationLog_;
        
        
      public:
        Invocation const&
        queryInvocation (JobParameter param)  const
          {
            return access_or_default (invocationLog_, hash_value(param)
                                     ,NullValue<Invocation>::get());
          }
      };
    
    
    
    /** actual instance of the test dummy job operation */
    DummyClosure dummyClosure;
    
  }// (End)Implementation details
  
  
  
  
  
  
  
  
  Job
  DummyJob::build()
  {
    InvocationInstanceID invoKey;
    invoKey.metaInfo.a = rand() % MAX_PARAM_A;
    invoKey.metaInfo.b = rand() % (2*MAX_PARAM_B)  - MAX_PARAM_B;
    
    Time nominalTime = lib::test::randTime();
    
    return Job(dummyClosure, invoKey, nominalTime);
  }
  
  
  Job
  DummyJob::build (Time nominalTime, int additionalKey)
  {
    InvocationInstanceID invoKey;
    invoKey.metaInfo.a = additionalKey;
    invoKey.metaInfo.b = rand() % (2*MAX_PARAM_B)  - MAX_PARAM_B;
    
    return Job(dummyClosure, invoKey, nominalTime);
  }
  
  
  bool
  DummyJob::was_invoked (Job const& job)
  {
    REQUIRE (job.usesClosure (dummyClosure));
    
    return Time::NEVER != dummyClosure.queryInvocation(job.parameter).nominal;
  }
  
  
  Time
  DummyJob::invocationTime (Job const& job)
  {
    REQUIRE (job.usesClosure (dummyClosure));
    
    return dummyClosure.queryInvocation(job.parameter).real;
  }
  
  
}} // namespace backend::engine