/*=========================================================================

  Program: GDCM (Grassroots DICOM). A DICOM library

  Copyright (c) 2006-2011 Mathieu Malaterre
  All rights reserved.
  See Copyright.txt or http://gdcm.sourceforge.net/Copyright.html for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
#include "gdcmVM.h"
#include <assert.h>
#include <stdlib.h> // abort
#include <string.h> // strcmp

namespace gdcm
{

static const char *VMStrings[] = {
  "INVALID",
  "1",
  "2",
  "3",
  "4",
  "5",
  "6",
  "8",
  "9",
  "10",
  "12",
  "16",
  "18",
  "24",
  "28",
  "32",
  "35",
  "99",
  "256",
  "1-2",
  "1-3",
  "1-4",
  "1-5",
  "1-8",
  "1-32",
  "1-99",
  "1-n",
  "2-2n",
  "2-n",
  "3-4",
  "3-3n",
  "3-n",
  "4-4n",
  "6-6n",
  "7-7n",
  "30-30n",
  "47-47n",
  nullptr
};

unsigned int VM::GetLength() const
{
  unsigned int len;
  switch(VMField)
    {
  case VM::VM1:
    len = VMToLength<VM::VM1>::Length;
    break;
  case VM::VM2:
    len = VMToLength<VM::VM2>::Length;
    break;
  case VM::VM3:
    len = VMToLength<VM::VM3>::Length;
    break;
  case VM::VM4:
    len = VMToLength<VM::VM4>::Length;
    break;
  case VM::VM5:
    len = VMToLength<VM::VM5>::Length;
    break;
  case VM::VM6:
    len = VMToLength<VM::VM6>::Length;
    break;
  case VM::VM8:
    len = VMToLength<VM::VM8>::Length;
    break;
  case VM::VM9:
    len = VMToLength<VM::VM9>::Length;
    break;
  case VM::VM10:
    len = VMToLength<VM::VM10>::Length;
    break;
  case VM::VM12:
    len = VMToLength<VM::VM12>::Length;
    break;
  case VM::VM16:
    len = VMToLength<VM::VM16>::Length;
    break;
  case VM::VM18:
    len = VMToLength<VM::VM18>::Length;
    break;
  case VM::VM24:
    len = VMToLength<VM::VM24>::Length;
    break;
  case VM::VM28:
    len = VMToLength<VM::VM28>::Length;
    break;
  case VM::VM32:
    len = VMToLength<VM::VM32>::Length;
    break;
  case VM::VM35:
    len = VMToLength<VM::VM35>::Length;
    break;
  case VM::VM99:
    len = VMToLength<VM::VM99>::Length;
    break;
  case VM::VM256:
    len = VMToLength<VM::VM256>::Length;
    break;
  case VM::VM0:
  case VM::VM1_2:
  case VM::VM1_3:
  case VM::VM1_4:
  case VM::VM1_5:
  case VM::VM1_8:
  case VM::VM1_32:
  case VM::VM1_99:
  case VM::VM1_n:
  case VM::VM2_2n:
  case VM::VM2_n:
  case VM::VM3_4:
  case VM::VM3_3n:
  case VM::VM3_n:
  case VM::VM4_4n:
  case VM::VM6_6n:
  case VM::VM7_7n:
    return 0;
  default:
    len = 0;
    assert(0);
    }
  assert( len );
  return len;
}

unsigned int VM::GetIndex(VMType vm)
{
  assert( vm <= VM_END );
  unsigned int l;
  switch(vm)
    {
  case VM0:
    l = 0;
    break;
  case VM1_2:
    l = 19;
    break;
  case VM1_3:
    l = 20;
    break;
  case VM1_4:
    l = 21;
    break;
  case VM1_5:
    l = 22;
    break;
  case VM1_8:
    l = 23;
    break;
  case VM1_32:
    l = 24;
    break;
  case VM1_99:
    l = 25;
    break;
  case VM1_n:
    l = 26;
    break;
  case VM2_2n:
    l = 27;
    break;
  case VM2_n:
    l = 28;
    break;
  case VM3_4:
    l = 29;
    break;
  case VM3_3n:
    l = 30;
    break;
  case VM3_n:
    l = 31;
    break;
  case VM4_4n:
    l = 32;
    break;
  case VM6_6n:
    l = 33;
    break;
  case VM7_7n:
    l = 34;
    break;
  case VM30_30n:
    l = 35;
    break;
  case VM47_47n:
    l = 36;
    break;
  case VM_END:
    l = 37;
    break;
  default:
      {
      unsigned int a = (unsigned int)vm;
      for (l = 0; a > 1; ++l)
        a >>= 1;
      l++;
      }
    }
  return l;
}

const char *VM::GetVMString(VMType vm)
{
  unsigned int idx = GetIndex(vm);
  assert( idx < sizeof(VMStrings) / sizeof(VMStrings[0]) );
  //assert( idx );
  return VMStrings[idx];
}

VM::VMType VM::GetVMType(const char *vm)
{
  if(!vm) return VM::VM_END;
  if(!*vm) return VM::VM0; // ??
  for (int i = 0; VMStrings[i] != nullptr; i++)
    {
    //if (strncmp(VMStrings[i],vm,strlen(VMStrings[i])) == 0)
    if (strcmp(VMStrings[i],vm) == 0)
      {
      return (VM::VMType)(i);
      }
    }

  return VM::VM_END;
}

// FIXME IsValid will only work for VM defined in public dict...
bool VM::IsValid(int vm1, VMType vm2)
{
  bool r = false;
  assert( vm1 >= 0 ); // Still need to check Part 3
  // If you update the VMType, you need to update this code. Hopefully a compiler is
  // able to tell when a case is missing
  switch(vm2)
    {
  case VM1:
    r = vm1 == 1;
    break;
  case VM2:
    r = vm1 == 2;
    break;
  case VM3:
    r = vm1 == 3;
    break;
  case VM4:
    r = vm1 == 4;
    break;
  case VM5:
    r = vm1 == 5;
    break;
  case VM6:
    r = vm1 == 6;
    break;
  case VM8:
    r = vm1 == 8;
    break;
  case VM16:
    r = vm1 == 16;
    break;
  case VM24:
    r = vm1 == 24;
    break;
  case VM1_2:
    r = (vm1 == 1 || vm1 == 2);
    break;
  case VM1_3:
    r = (vm1 >= 1 && vm1 <= 3);
    break;
  case VM1_8:
    r = (vm1 >= 1 && vm1 <= 8);
    break;
  case VM1_32:
    r = (vm1 >= 1 && vm1 <= 32);
    break;
  case VM1_99:
    r = (vm1 >= 1 && vm1 <= 99);
    break;
  case VM1_n:
    r = (vm1 >= 1);
    break;
  case VM2_2n:
    r = (vm1 >= 2 && !(vm1%2) );
    break;
  case VM2_n:
    r = (vm1 >= 2);
    break;
  case VM3_3n:
    r = (vm1 >= 3 && !(vm1%3) );
    break;
  case VM3_n:
    r = (vm1 >= 3);
    break;
  default:
    assert(0); // should not happen
    }
  return r;
}

// TODO write some ugly macro to expand the template
//int VM::GetLength()
//{
//}

// This function should not be used in production code.
// Indeed this only return a 'guess' at the VM (ie. a lower bound)
VM::VMType VM::GetVMTypeFromLength(size_t length, unsigned int size)
{
  // Check first of length is a indeed a multiple of size and that length is != 0
  if ( !length || length % size ) return VM::VM0;
  const unsigned int ratio = (unsigned int)(length / size);
  //std::cerr << "RATIO=" << ratio << std::endl;
  switch( ratio )
    {
  case 1: return VM::VM1;
  case 2: return VM::VM2;
  case 3: return VM::VM3;
  case 4: return VM::VM4;
  case 5: return VM::VM5;
  case 6: return VM::VM6;
  case 8: return VM::VM8;
  case 9: return VM::VM9;
  case 16: return VM::VM16;
  case 24: return VM::VM24;
  case 32: return VM::VM32;
  default:
           return VM::VM1_n;
    }
}

size_t VM::GetNumberOfElementsFromArray(const char *array, size_t length)
{
  size_t c=0;
  if( !length || !array ) return 0;
  const char *parray = array;
  const char *end = array + length;
  bool valuefound = false;
  for(; parray != end; ++parray)
    {
    if( *parray == ' ' )
      {
      // space char do not count
      }
    else if( *parray == '\\' )
      {
      if( valuefound )
        {
        ++c;
        valuefound = false; // reset counter
        }
      }
    else
      {
      valuefound = true;
      }
    }
  if( valuefound ) ++c;
  return c;
}

bool VM::Compatible(VM const &vm) const
{
  // make sure that vm is a numeric value
  //assert( vm.VMField <= VM256 );
  if ( VMField == VM::VM0 ) return false; // nothing was found in the dict
  if ( vm == VM::VM0 ) return true; // the user was not able to compute the vm from the empty bytevalue
  // let's start with the easy case:
  if ( VMField == vm.VMField ) return true;
  bool r;
  switch(VMField)
    {
  case VM1_2:
    r = vm.VMField >= VM::VM1 && vm.VMField <= VM::VM2;
    break;
  case VM1_3:
    r = vm.VMField >= VM::VM1 && vm.VMField <= VM::VM3;
    break;
  case VM1_8:
    r = vm.VMField >= VM::VM1 && vm.VMField <= VM::VM8;
    break;
  case VM1_32:
    r = vm.VMField >= VM::VM1 && vm.VMField <= VM::VM32;
    break;
  case VM1_99:
    r = vm.VMField >= VM::VM1 && vm.VMField <= VM::VM99;
    break;
  case VM1_n:
    r = vm.VMField >= VM::VM1;
    break;
  case VM2_2n:
      {
      if( vm == VM1_n ) r  = true; // FIXME
      else r = vm.VMField >= VM::VM2 && !(vm.GetLength() % 2);
      }
    break;
  case VM2_n:
    r = vm.VMField >= VM::VM2;
    break;
  case VM3_4:
    r = vm.VMField == VM::VM3 || vm.VMField == VM::VM4;
    break;
  case VM3_3n:
    r = vm.VMField >= VM::VM3 && !(vm.GetLength() % 3);
    break;
  case VM3_n:
    r = vm.VMField >= VM::VM3;
    break;
  default:
    r = VMField == vm.VMField;
    }
  if( r )
    {
    assert( VMField & vm.VMField );
    }
  return r;
}

} // end namespace gdcm