//# Unit.cc: defines the Unit class
//# Copyright (C) 1994-1999,2001,2004,2008
//# Associated Universities, Inc. Washington DC, USA.
//#
//# This library is free software; you can redistribute it and/or modify it
//# under the terms of the GNU Library General Public License as published by
//# the Free Software Foundation; either version 2 of the License, or (at your
//# option) any later version.
//#
//# This library 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 Library General Public
//# License for more details.
//#
//# You should have received a copy of the GNU Library General Public License
//# along with this library; if not, write to the Free Software Foundation,
//# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
//#
//# Correspondence concerning AIPS++ should be addressed as follows:
//#        Internet email: aips2-request@nrao.edu.
//#        Postal address: AIPS++ Project Office
//#                        National Radio Astronomy Observatory
//#                        520 Edgemont Road
//#                        Charlottesville, VA 22903-2475 USA
//#
//# $Id$

//# Includes

#include <casacore/casa/Exceptions/Error.h>
#include <casacore/casa/Quanta/Unit.h>
#include <casacore/casa/Utilities/Regex.h>
#include <casacore/casa/OS/malloc.h>
#include <stdlib.h>
#include <string.h>

namespace casacore { //# NAMESPACE CASACORE - BEGIN

Unit::Unit() 
: uName(), uVal() {}

Unit::Unit(const Unit &other) 
: uName(), uVal() {
    uName = other.uName;
    uVal = other.uVal;
}

Unit::Unit(const std::string &other) 
: uName(other), uVal() {
    check();
}

Unit::Unit(const char *other) 
: uName(other), uVal() {
    check();
}

Unit::Unit(const  char *other, Int len) 
: uName(other, len), uVal() {
    check();
}

Unit::Unit(char other) 
: uName(other), uVal() {
    check();
}

Unit::~Unit() {}


Unit &Unit::operator=(const Unit &other) {
    if (this != &other) {
        uName = other.uName;
	uVal = other.uVal;
    }
    return *this;
}

Bool Unit::operator==(const Unit &other) const {
    return (uVal == other.uVal);
}

Bool Unit::operator!=(const Unit &other) const {
    return (uVal != other.uVal);
}

Bool Unit::empty() const{
    return (uName.empty());
}

const UnitVal &Unit::getValue() const {
    return uVal;
}

const String &Unit::getName() const {
    return uName;
}

void Unit::setValue(const UnitVal &in) {
    uVal = in;
}

void Unit::setName(const String &in) {
    uName = in;
}

//#  --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---
//#  The following functions are designed to replace (in two passes)
//#  the following regular expression operations...
//#  (written by Darrell Schiebel)
//#  --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---
//#  static Regex f1("\\*\\*"); static String sf1("");
//#  static Regex f2("\\^"); static String sf2("");
//#  static Regex f3("\\*"); static String sf3(".");
//#  static Regex f4(" */ *"); static String sf4("/");
//#  static Regex f5("//"); static String sf5(".");
//#  static Regex f6("\\.*/\\.*"); static String sf6("/");
//#  static Regex sp(" +"); static String ssp(".");
//#  static Regex pd("\\.+"); static String spd(".");
//#  static Regex bp("^\\.+"); static String sbp("");
//#  static Regex ep("\\.+$"); static String ebp("");
//#  ...
//#  uName.gsub(f1, sf1);
//#  uName.gsub(f2, sf2);
//#  uName.gsub(f3, sf3);
//#  uName.gsub(f4, sf4);
//#  uName.gsub(f5, sf5);
//#  uName.gsub(f6, sf6);
//#  uName.gsub(sp, ssp);
//#  uName.gsub(pd, spd);
//#  uName.gsub(bp, sbp);
//#  uName.gsub(ep, ebp);
//#  --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---

void pass_one( const char *source, char *dest )
{
  while ( *source ) { 
    switch ( *source ) {
    case '^':
      ++source;
      continue;                          /** f2 **/
    case '*':
      switch ( *++source ) {
      case '*':
        ++source;
        continue;                        /** f1 **/
      default:
        *dest++ = '.';                   /** f3 **/
        continue;
      }
    case ' ': {
      char dotslash = '.';
      while ( *source == ' ' || *source == '/' ) {
        if ( *source++ == '/' ) {
          dotslash = '/';
        }
      }
      *dest++ = dotslash;                /** f4, sp **/
      continue;
    }
    case '/':
      switch ( *++source ) {
      case '/':
        ++source;
        *dest++ = '.';
        continue;                        /** f5 **/
      default:
        *dest++ = '/';
        continue;
      }
    default:
      *dest++ = *source++;
      continue;
    }
  }
  *dest = '\0';
}

void pass_two( char *source, char *dest )
{
  while ( *source == '.' ) ++source;     /** bp **/
  if ( *source ) {
    for ( char *end = source + strlen(source) - 1; end != source; --end ) {
      if ( *end == '.' ) {
	*end = '\0';                     /** ep **/
      } else {
	break;
      }
    }
    while ( *source ) {                  /** f6 **/
      switch ( *source ) {
      case '.': {
	bool go = true;
	char dotslash = '.';
	while ( *source && go ) {
	  switch ( *source ) {
	  case '/':
	    dotslash = '/';     // fall through
	  case '.':
	    ++source;
	    continue;
	  default:
	    go = false;
	    continue;
	  }
	}
	*dest++ = dotslash;              /** f4, pd **/
	continue;
      }
      default:
	*dest++ = *source++;
	continue;
      }
    }
  }
  *dest = '\0';
}


void Unit::check()
{
  if (!UnitVal::check(uName, uVal)) {
    throw (AipsError("Unit::check Illegal unit string '" +
		     uName + "'"));
  }
  char stackbuf1[200];
  char stackbuf2[200];
  char *b1, *b2;
  /* avoid heap allocations for common small strings */
  if (uName.size() < sizeof(stackbuf1)) {
    strcpy(stackbuf1, uName.c_str());
    b1 = &stackbuf1[0];
    b2 = &stackbuf2[0];
  }
  else {
    b1 = strdup(uName.c_str());
    b2 = (char*) malloc((uName.size()+1)*sizeof(char));
  }
  pass_one(b1,b2);
  pass_two(b2,b1);
  uName = b1;
  if (b1 != &stackbuf1[0]) {
    free(b1);
    free(b2);
  }
}

} //# NAMESPACE CASACORE - END