/*
  CyclicWrap(Test)  -  verify cyclically wrapping number domain

   Copyright (C)
     2026,            Hermann Vosseler <Ichthyostega@web.de>

  **Lumiera** 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. See the file COPYING for further details.

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

/** @file util-floordiv-test.cpp
 ** unit test \ref CyclicWrap_test
 */


#include "test/run.hpp"
#include "lib/util-quant.hpp"
#include "lib/util.hpp"
#include "test/diagnostic-output.hpp"//////////////////TODO
//#include "lib/format-cout.hpp"
//#include "lib/format-string.hpp"

using ::Test;
//using util::isnil;
//using util::_Fmt;
using util::isLimited;


namespace util {
namespace test {
  
  
  
  namespace{ // Test helpers...
    
    template<typename NUM>
    constexpr NUM _MAX = std::numeric_limits<NUM>::max();
    
    template<typename NUM>
    constexpr NUM _MIN = std::numeric_limits<NUM>::lowest();
    
  } // (End) Test helpers
  
  
  
  /******************************************************************//**
   * @test Demonstrate and verify a cyclic wrapping numeric domain.
   *     - show the wrapping behaviour with simple numbers
   *     - verify the behaviour pattern for all integer types (signed / unsigned)
   *     - verify the computation works at the very bounds of the domain
   *     - verify the most difficult path with a negative minVal,
   *       and the smallest number in the domain
   * @todo add coverage for floating-point numbers
   * @see util::cyclicWrap
   * @see parameter-scale-test.cpp
   */
  class CyclicWrap_test : public Test
    {
      
      virtual void
      run (Arg)
        {
          simpleDemonstration();
          
          verifyIntegerTypes<int>();
          verifyIntegerTypes<uint>();
          verifyIntegerTypes<int8_t>();
          verifyIntegerTypes<uint8_t>();
          verifyIntegerTypes<int16_t> ();
          verifyIntegerTypes<uint16_t>();
          verifyIntegerTypes<int32_t> ();
          verifyIntegerTypes<uint32_t>();
          verifyIntegerTypes<int64_t> ();
          verifyIntegerTypes<uint64_t>();
        }
      
      
      void
      simpleDemonstration ()
        {
          CHECK (10 == cyclicWrap (10,10,15));
          CHECK (11 == cyclicWrap (11,10,15));
          CHECK (12 == cyclicWrap (12,10,15));
          CHECK (13 == cyclicWrap (13,10,15));
          CHECK (14 == cyclicWrap (14,10,15));
          CHECK (10 == cyclicWrap (15,10,15));
          CHECK (11 == cyclicWrap (16,10,15));
          CHECK (12 == cyclicWrap (17,10,15));
          CHECK (13 == cyclicWrap (18,10,15));
          CHECK (14 == cyclicWrap (19,10,15));
          CHECK (10 == cyclicWrap (20,10,15));
          
          CHECK (10 == cyclicWrap ( 0,10,15));
          CHECK (14 == cyclicWrap (-1,10,15));
        }
      
      
      template<typename I>
      void
      verifyIntegerTypes ()
        {
          const I LOWER(-100);   // note: expected to wrap for unsigned types
          const I UPPER(LOWER+5);
          
          auto cyc = [&](I val){ return cyclicWrap (I(val), LOWER,UPPER); };
          
          CHECK (LOWER   == cyc(LOWER+0) );
          CHECK (LOWER+1 == cyc(LOWER+1) );
          CHECK (LOWER+2 == cyc(LOWER+2) );
          CHECK (LOWER+3 == cyc(LOWER+3) );
          CHECK (LOWER+4 == cyc(LOWER+4) );
          CHECK (LOWER   == cyc(LOWER+5) );
          
          CHECK (LOWER   == cyc(LOWER-5) );
          CHECK (LOWER+1 == cyc(LOWER-4) );
          CHECK (LOWER+2 == cyc(LOWER-3) );
          CHECK (LOWER+3 == cyc(LOWER-2) );
          CHECK (LOWER+4 == cyc(LOWER-1) );
          
          
          CHECK (isLimited (LOWER, cyc(_MAX<I>), UPPER));
          CHECK (isLimited (LOWER, cyc(_MIN<I>), UPPER));
          
          CHECK (isLimited (LOWER, cyc(_MAX<I>-1), UPPER));
          CHECK (isLimited (LOWER, cyc(_MIN<I>+1), UPPER));
          
          I dist = LOWER - _MIN<I>;  // guaranteed to be positive and representable in-domain
          I step = (dist / 5) * 5;   // the next applicable grid point
          I excess = dist - step;
          I offset = 5 - excess;     // flip orientation (since the input val lies below LOWER)
          
          CHECK (LOWER + offset == cyc(_MIN<I>) );
        }
    };
  
  
  
  LAUNCHER (CyclicWrap_test, "unit common");
  
  
}} // namespace util::test