// File: crn_strutils.cpp

// See Copyright Notice and license at the end of inc/crnlib.h

#include "crn_core.h"

#include "crn_strutils.h"



namespace crnlib

{

   char* crn_strdup(const char* pStr)

   {

      if (!pStr)

         pStr = "";



      size_t l = strlen(pStr) + 1;

      char *p = (char *)crnlib_malloc(l);

      if (p)

         memcpy(p, pStr, l);



      return p;

   }



   int crn_stricmp(const char *p, const char *q)

   {

      return _stricmp(p, q);

   }



   char* strcpy_safe(char* pDst, uint dst_len, const char* pSrc)

   {

      CRNLIB_ASSERT(pDst && pSrc && dst_len);

      if (!dst_len)

         return pDst;



      char* q = pDst;

      char c;



      do

      {

         if (dst_len == 1)

         {

            *q++ = '\0';

            break;

         }



         c = *pSrc++;

         *q++ = c;



         dst_len--;



      } while (c);



      CRNLIB_ASSERT((q - pDst) <= (int)dst_len);



      return pDst;

   }



   bool int_to_string(int value, char* pDst, uint len)

   {

      CRNLIB_ASSERT(pDst);



      const uint cBufSize = 16;

      char buf[cBufSize];



      uint j = static_cast<uint>((value < 0) ? -value : value);



      char* p = buf + cBufSize - 1;



      *p-- = '\0';



      do

      {

         *p-- = static_cast<uint8>('0' + (j % 10));

         j /= 10;

      } while (j);



      if (value < 0)

         *p-- = '-';



      const size_t total_bytes = (buf + cBufSize - 1) - p;

      if (total_bytes > len)

         return false;



      for (size_t i = 0; i < total_bytes; i++)

         pDst[i] = p[1 + i];



      return true;

   }



   bool uint_to_string(uint value, char* pDst, uint len)

   {

      CRNLIB_ASSERT(pDst);



      const uint cBufSize = 16;

      char buf[cBufSize];



      char* p = buf + cBufSize - 1;



      *p-- = '\0';



      do

      {

         *p-- = static_cast<uint8>('0' + (value % 10));

         value /= 10;

      } while (value);



      const size_t total_bytes = (buf + cBufSize - 1) - p;

      if (total_bytes > len)

         return false;



      for (size_t i = 0; i < total_bytes; i++)

         pDst[i] = p[1 + i];



      return true;

   }



   bool string_to_int(const char*& pBuf, int& value)

   {

      value = 0;



      CRNLIB_ASSERT(pBuf);

      const char* p = pBuf;



      while (*p && isspace(*p))

         p++;



      uint result = 0;

      bool negative = false;



      if (!isdigit(*p))

      {

         if (p[0] == '-')

         {

            negative = true;

            p++;

         }

         else

            return false;

      }



      while (*p && isdigit(*p))

      {

         if (result & 0xE0000000U)

            return false;



         const uint result8 = result << 3U;

         const uint result2 = result << 1U;



         if (result2 > (0xFFFFFFFFU - result8))

            return false;



         result = result8 + result2;



         uint c = p[0] - '0';

         if (c > (0xFFFFFFFFU - result))

            return false;



         result += c;



         p++;

      }



      if (negative)

      {

         if (result > 0x80000000U)

         {

            value = 0;

            return false;

         }

         value = -static_cast<int>(result);

      }

      else

      {

         if (result > 0x7FFFFFFFU)

         {

            value = 0;

            return false;

         }

         value = static_cast<int>(result);

      }



      pBuf = p;



      return true;

   }



   bool string_to_int64(const char*& pBuf, int64& value)

   {

      value = 0;



      CRNLIB_ASSERT(pBuf);

      const char* p = pBuf;



      while (*p && isspace(*p))

         p++;



      uint64 result = 0;

      bool negative = false;



      if (!isdigit(*p))

      {

         if (p[0] == '-')

         {

            negative = true;

            p++;

         }

         else

            return false;

      }



      while (*p && isdigit(*p))

      {

         if (result & 0xE000000000000000ULL)

            return false;



         const uint64 result8 = result << 3U;

         const uint64 result2 = result << 1U;



         if (result2 > (0xFFFFFFFFFFFFFFFFULL - result8))

            return false;



         result = result8 + result2;



         uint c = p[0] - '0';

         if (c > (0xFFFFFFFFFFFFFFFFULL - result))

            return false;



         result += c;



         p++;

      }



      if (negative)

      {

         if (result > 0x8000000000000000ULL)

         {

            value = 0;

            return false;

         }

         value = -static_cast<int64>(result);

      }

      else

      {

         if (result > 0x7FFFFFFFFFFFFFFFULL)

         {

            value = 0;

            return false;

         }

         value = static_cast<int64>(result);

      }



      pBuf = p;



      return true;

   }



   bool string_to_uint(const char*& pBuf, uint& value)

   {

      value = 0;



      CRNLIB_ASSERT(pBuf);

      const char* p = pBuf;



      while (*p && isspace(*p))

         p++;



      uint result = 0;



      if (!isdigit(*p))

         return false;



      while (*p && isdigit(*p))

      {

         if (result & 0xE0000000U)

            return false;



         const uint result8 = result << 3U;

         const uint result2 = result << 1U;



         if (result2 > (0xFFFFFFFFU - result8))

            return false;



         result = result8 + result2;



         uint c = p[0] - '0';

         if (c > (0xFFFFFFFFU - result))

            return false;



         result += c;



         p++;

      }



      value = result;



      pBuf = p;



      return true;

   }



   bool string_to_uint64(const char*& pBuf, uint64& value)

   {

      value = 0;



      CRNLIB_ASSERT(pBuf);

      const char* p = pBuf;



      while (*p && isspace(*p))

         p++;



      uint64 result = 0;



      if (!isdigit(*p))

         return false;



      while (*p && isdigit(*p))

      {

         if (result & 0xE000000000000000ULL)

            return false;



         const uint64 result8 = result << 3U;

         const uint64 result2 = result << 1U;



         if (result2 > (0xFFFFFFFFFFFFFFFFULL - result8))

            return false;



         result = result8 + result2;



         uint c = p[0] - '0';

         if (c > (0xFFFFFFFFFFFFFFFFULL - result))

            return false;



         result += c;



         p++;

      }



      value = result;



      pBuf = p;



      return true;

   }



   bool string_to_bool(const char* p, bool& value)

   {

      CRNLIB_ASSERT(p);



      value = false;



      if (_stricmp(p, "false") == 0)

         return true;



      if (_stricmp(p, "true") == 0)

      {

         value = true;

         return true;

      }



      const char* q = p;

      uint v;

      if (string_to_uint(q, v))

      {

         if (!v)

            return true;

         else if (v == 1)

         {

            value = true;

            return true;

         }

      }



      return false;

   }



   bool string_to_float(const char*& p, float& value, uint round_digit)

   {

      double d;

      if (!string_to_double(p, d, round_digit))

      {

         value = 0;

         return false;

      }

      value = static_cast<float>(d);

      return true;

   }



   bool string_to_double(const char*& p, double& value, uint round_digit)

   {

      return string_to_double(p, p + 128, value, round_digit);

   }



   // I wrote this approx. 20 years ago in C/assembly using a limited FP emulator package, so it's a bit crude.

   bool string_to_double(const char*& p, const char *pEnd, double& value, uint round_digit)

   {

      CRNLIB_ASSERT(p);



      value = 0;



      enum { AF_BLANK = 1, AF_SIGN = 2, AF_DPOINT = 3, AF_BADCHAR = 4, AF_OVRFLOW = 5, AF_EXPONENT = 6, AF_NODIGITS = 7 };

      int status = 0;



      const char* buf = p;



      int got_sign_flag = 0, got_dp_flag   = 0, got_num_flag  = 0;

      int got_e_flag = 0, got_e_sign_flag = 0, e_sign = 0;

      uint whole_count = 0, frac_count = 0;



      double whole = 0, frac = 0, scale = 1, exponent = 1;



      if (p >= pEnd)

      {

         status = AF_NODIGITS;

         goto af_exit;

      }



      while (*buf)

      {

         if (!isspace(*buf))

            break;

         if (++buf >= pEnd)

         {

            status = AF_NODIGITS;

            goto af_exit;

         }

      }



      p = buf;



      while (*buf)

      {

         p = buf;

         if (buf >= pEnd)

            break;



         int i = *buf++;



         switch (i)

         {

            case 'e':

            case 'E':

            {

              got_e_flag = 1;

              goto exit_while;

            }

            case '+':

            {

              if ((got_num_flag) || (got_sign_flag))

              {

                status = AF_SIGN;

                goto af_exit;

              }



              got_sign_flag = 1;



              break;

            }

            case '-':

            {

              if ((got_num_flag) || (got_sign_flag))

              {

                status = AF_SIGN;

                goto af_exit;

              }



              got_sign_flag = -1;



              break;

            }

            case '.':

            {

              if (got_dp_flag)

              {

                status = AF_DPOINT;

                goto af_exit;

              }



              got_dp_flag = 1;



              break;

            }

            default:

            {

              if ((i < '0') || (i > '9'))

                goto exit_while;

              else

              {

                i -= '0';



                got_num_flag = 1;



                if (got_dp_flag)

                {

                  if (frac_count < round_digit)

                  {

                    frac = frac * 10.0f + i;



                    scale = scale * 10.0f;

                  }

                  else if (frac_count == round_digit)

                  {

                    if (i >= 5)               /* check for round */

                      frac = frac + 1.0f;

                  }



                  frac_count++;

                }

                else

                {

                  whole = whole * 10.0f + i;



                  whole_count++;



                  if (whole > 1e+100)

                  {

                    status = AF_OVRFLOW;

                    goto af_exit;

                  }

                }

              }



              break;

            }

         }

      }



    exit_while:



      if (got_e_flag)

      {

         if ((got_num_flag == 0) && (got_dp_flag))

         {

            status = AF_EXPONENT;

            goto af_exit;

         }



         int e = 0;

         e_sign = 1;

         got_num_flag = 0;

         got_e_sign_flag = 0;



         while (*buf)

         {

            p = buf;

            if (buf >= pEnd)

               break;



            int i = *buf++;



            if (i == '+')

            {

              if ((got_num_flag) || (got_e_sign_flag))

              {

                status = AF_EXPONENT;

                goto af_exit;

              }



              e_sign = 1;

              got_e_sign_flag = 1;

            }

            else if (i == '-')

            {

              if ((got_num_flag) || (got_e_sign_flag))

              {

                status = AF_EXPONENT;

                goto af_exit;

              }



              e_sign = -1;

              got_e_sign_flag = 1;

            }

            else if ((i >= '0') && (i <= '9'))

            {

              got_num_flag = 1;



              if ((e = (e * 10) + (i - 48)) > 100)

              {

                status = AF_EXPONENT;

                goto af_exit;

              }

            }

            else

              break;

         }



         for (int i = 1; i <= e; i++)   /* compute 10^e */

            exponent = exponent * 10.0f;

      }



      if (((whole_count + frac_count) == 0) && (got_e_flag == 0))

      {

         status = AF_NODIGITS;

         goto af_exit;

      }



      if (frac)

         whole = whole + (frac / scale);



      if (got_e_flag)

      {

         if (e_sign > 0)

            whole = whole * exponent;

         else

            whole = whole / exponent;

      }



      if (got_sign_flag < 0)

         whole = -whole;



      value = whole;



   af_exit:

      return (status == 0);

   }



} // namespace crnlib