//# UnitMap.cc: defines the UnitMap class containing standard unit definitions
//# Copyright (C) 1994-2002,2007,2016
//# 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/Quanta/UnitMap.h>
#include <casacore/casa/Utilities/MUString.h>
#include <casacore/casa/Utilities/Regex.h>
#include <casacore/casa/iostream.h>

namespace casacore { //# NAMESPACE CASACORE - BEGIN

// Initialize statics.
std::mutex UnitMap::fitsMutex;


  

UnitMap::UnitMap() {}

UnitMap::~UnitMap() {
}

Bool UnitMap::getCache(const String& s, UnitVal &val) {
  map<String, UnitVal>& mapCache = getMapCache();
  map<String, UnitVal>::iterator pos = mapCache.find(s);
  if (pos == mapCache.end()) {
    val = UnitVal();
    return False;
  }
  val = pos->second;
  return True;
}

Bool UnitMap::getPref(const String& s, UnitName &name, UMaps* maps) {
  // maps can be passed in to avoid recursive getUnit calls during static initialization.
  UMaps& mapsref = (maps ? *maps : getMaps());
  map<String, UnitName>& mapPref = mapsref.mapPref;
  map<String, UnitName>::iterator pos = mapPref.find(s);
  if (pos == mapPref.end()) {
    name = UnitName();
    return False;
  }
  name = pos->second;
  return True;
}

Bool UnitMap::getUnit(const String& s, UnitName &name, UMaps* maps) {
  // maps can be passed in to avoid recursive getUnit calls during static initialization.
  UMaps& mapsref = (maps ? *maps : getMaps());
  map<String, UnitName>& mapUser = mapsref.mapUser;
  map<String, UnitName>& mapCust = mapsref.mapCust;
  map<String, UnitName>& mapSI   = mapsref.mapSI;
  map<String, UnitName>::iterator pos;
  if ((pos = mapUser.find(s)) != mapUser.end() ||
      (pos = mapCust.find(s)) != mapCust.end() ||
      (pos = mapSI.find(s)) != mapSI.end()) {
  } else {    
    name = UnitName();
    return False;
  }
  name = pos->second;
  return True;
}

void UnitMap::putCache(const String& s, const UnitVal& val) {
  map<String, UnitVal>& mapCache = getMapCache();
  if (! s.empty()) {
    mapCache.insert(map<String, UnitVal>::value_type(s,val));
  }
}

void UnitMap::putUser(const String& s, const UnitVal& val) {
  const String empty("");
  UnitMap::putUser(s, val, empty);
}

void UnitMap::putUser(const String& s, const UnitVal& val,
		      const String& name) {
  UnitName loc(s,val,name);
  UnitMap::putUser(loc);
}

void UnitMap::putUser(const UnitName& name) {
  map<String, UnitName>& mapUser = getMaps().mapUser;
  map<String, UnitName>& mapCust = getMaps().mapCust;
  map<String, UnitName>& mapSI   = getMaps().mapSI;
  map<String, UnitName>::iterator pos;
  if ((pos = mapUser.find(name.getName())) != mapUser.end() ||
      (pos = mapCust.find(name.getName())) != mapCust.end() ||
      (pos = mapSI.find(name.getName())) != mapSI.end()) clearCache();
  mapUser.insert(map<String, UnitName>::value_type(name.getName(), name));
}

void UnitMap::removeUser(const String& s) {
  map<String, UnitName>& mapUser = getMaps().mapUser;
  map<String, UnitName>::iterator pos = mapUser.find(s);
  if (pos != mapUser.end()) {
    mapUser.erase(pos);
    clearCache();
  }
}

void UnitMap::removeUser(const UnitName& name) {
  UnitMap::removeUser(name.getName());
}

const String &UnitMap::getStringFITS(uInt which) {
  static const String FITSstring[N_FITS] = {
    "beam",
    "d",
    "deg",
    "deg",
    "Hz",
    "Jy",
    "K",
    "K",
    "km",
    "m",
    "m",
    "Pa",
    "pixel",
    "s",
    "s",
    "s",
    "V",
    "a",
    "a"
  };
  return FITSstring[which];
}

Bool UnitMap::getNameFITS(const UnitName *&name, uInt which) {
  static const UnitName FITSunit[N_FITS] = {
    UnitName("BEAM",	UnitVal(1.0, getStringFITS(0)),	"dimensionless beam"),
    UnitName("DAYS", 	UnitVal(1.0, getStringFITS(1)),	"day"),
    UnitName("DEGREES", UnitVal(1.0, getStringFITS(2)),	"degree"),
    UnitName("DEG",	UnitVal(1.0, getStringFITS(3)),	"degree"),
    UnitName("HZ",	UnitVal(1.0, getStringFITS(4)),	"hertz"),
    UnitName("JY",	UnitVal(1.0, getStringFITS(5)),	"jansky"),
    UnitName("KELVINS",	UnitVal(1.0, getStringFITS(6)),	"kelvin"),
    UnitName("KELVIN",	UnitVal(1.0, getStringFITS(7)),	"kelvin"),
    UnitName("KM",	UnitVal(1.0, getStringFITS(8)),	"km"),
    UnitName("METERS",	UnitVal(1.0, getStringFITS(9)),	"meter"),
    UnitName("M",	UnitVal(1.0, getStringFITS(10)),"meter"),
    UnitName("PASCAL",	UnitVal(1.0, getStringFITS(11)),"pascal"),
    UnitName("PIXEL",   UnitVal(1.0, getStringFITS(12)),"dimensionless pixel"),
    UnitName("SECONDS",	UnitVal(1.0, getStringFITS(13)),"second"),
    UnitName("SEC",	UnitVal(1.0, getStringFITS(14)),"second"),
    UnitName("S",	UnitVal(1.0, getStringFITS(15)),"second"),
    UnitName("VOLTS",	UnitVal(1.0, getStringFITS(16)),"volt"),
    UnitName("YEARS",	UnitVal(1.0, getStringFITS(17)),"year"),
    UnitName("YEAR",	UnitVal(1.0, getStringFITS(18)),"year")
  };
  if (which >= N_FITS) {
    return False;
  }
  name = &FITSunit[which];
  return True;
}

void UnitMap::addFITS() {
  UMaps& maps = getMaps();
  // Could be optimized using C++11 std::call_once(), but infrequently called.
  // If to be optimized, do note clearFITS() below (but not used atm).
  // Double checked locking is unsafe pre-C++11!
  std::lock_guard<std::mutex> lock(UnitMap::fitsMutex);
  if (! maps.doneFITS) {
    uInt cnt = 0;
    const UnitName *Fname;
    while (UnitMap::getNameFITS(Fname, cnt)) {
      UnitMap::putUser(*Fname);
      cnt++;
    }
    maps.doneFITS = True;
  }
}

void UnitMap::clearFITS() {
  UMaps& maps = getMaps();
  std::lock_guard<std::mutex> lock(UnitMap::fitsMutex);
  if (maps.doneFITS) {
    uInt cnt = 0;
    const UnitName *Fname;
    while (UnitMap::getNameFITS(Fname, cnt)) {
      UnitMap::removeUser(*Fname);
      cnt++;
    }
    maps.doneFITS = False;
  }
}

Unit UnitMap::fromFITS(const Unit &un) {
  static const Regex sepa("[^a-zA-Z]");
  MUString mus(un.getName());
  String y;
  String z;
  const UnitName *nam;
  while (!mus.eos()) {
    if (mus.testChar(sepa)) y += String(mus.getChar());
    else {
      z = mus.getAlpha();
      for (uInt i=0; i<N_FITS; i++) {
	getNameFITS(nam, i);
	if (z == nam->getName()) {
	  z =  getStringFITS(i);
	  break;
	}
      }
      y += z;
    }
  }
  return Unit(y);
}

Unit UnitMap::toFITS(const Unit &un) {
  static const Regex sepa("[^a-zA-Z]");
  MUString mus(un.getName());
  String y;
  String z;
  const UnitName *nam;
  while (!mus.eos()) {
    if (mus.testChar(sepa)) y += String(mus.getChar());
    else {
      z = mus.getAlpha();
      for (Int i=N_FITS-1; i>= 0; i--) {
	if (z == getStringFITS(i)) {
	  getNameFITS(nam, i);
	  z =  nam->getName();
	  break;
	}
      }
      y += z;
    }
  }
  return Unit(y);
}

void UnitMap::clearCache() {
  getMapCache().clear();
}

void UnitMap::listPref() {
  listPref(cout);
}

void UnitMap::listPref(ostream &os) {
  map<String, UnitName>& mapPref = getMaps().mapPref;
  for (map<String, UnitName>::iterator i=mapPref.begin();
       i != mapPref.end(); ++i) {
    os << "    " << i->second << endl;
  }
}

void UnitMap::listDef() {
  listDef(cout);
}

void UnitMap::listDef(ostream &os) {
  map<String, UnitName>& mapDef = getMaps().mapDef;
  for (map<String, UnitName>::iterator i=mapDef.begin();
       i != mapDef.end(); ++i) {
    os << "    " << i->second << endl;
  }
}

void UnitMap::listSI() {
  listSI(cout);
}

void UnitMap::listSI(ostream &os) {
  map<String, UnitName>& mapSI = getMaps().mapSI;
  for (map<String, UnitName>::iterator i=mapSI.begin();
       i != mapSI.end(); ++i) {
    os << "    " << i->second << endl;
  }
}

void UnitMap::listCust() {
  listCust(cout);
}

void UnitMap::listCust(ostream &os) {
  map<String, UnitName>& mapCust = getMaps().mapCust;
  for (map<String, UnitName>::iterator i=mapCust.begin();
       i != mapCust.end(); ++i) {
    os << "    " << i->second << endl;
  }
}

void UnitMap::listUser() {
  listUser(cout);
}

void UnitMap::listUser(ostream &os) {
  map<String, UnitName>& mapUser = getMaps().mapUser;
  for (map<String, UnitName>::iterator i=mapUser.begin();
       i != mapUser.end(); ++i) {
    os << "    " << i->second << endl;
  }
}

void UnitMap::list() {
  list(cout);
}

void UnitMap::list(ostream &os) {
  UMaps& maps = getMaps();
  os  << "Prefix table (" << maps.mapPref.size() << "):" << endl;
  listPref(os);
  os  << "Defining unit table (" << maps.mapDef.size() << "):" << endl;
  listDef(os);
  os << "SI unit table (" << maps.mapSI.size() << "):" << endl;
  listSI(os);
  os  << "Customary unit table (" << maps.mapCust.size() << "):" << endl;
  listCust(os);
  os  << "User unit table (" << maps.mapUser.size() << "):" << endl;
  listUser(os);
}

void UnitMap::listCache() {
  listCache(cout);
}

void UnitMap::listCache(ostream &os) {
  map<String, UnitVal>& mapCache = getMapCache();
  os  << "Cached unit table (" << mapCache.size() << "):" << endl;
  for (map<String, UnitVal>::iterator i=mapCache.begin();
       i != mapCache.end(); ++i) {
    os << "    " <<
      UnitName(i->first, i->second) << endl;
  }
}

const map<String, UnitName> &UnitMap::givePref() {
  return getMaps().mapPref;
}

const map<String, UnitName> &UnitMap::giveDef() {
  return getMaps().mapDef;
}
const map<String, UnitName> &UnitMap::giveSI() {
  return getMaps().mapSI;
}

const map<String, UnitName> &UnitMap::giveCust() {
  return getMaps().mapCust;
}

const map<String, UnitName> &UnitMap::giveUser() {
  return getMaps().mapUser;
}

const map<String, UnitVal> &UnitMap::giveCache() {
  return getMapCache();
}

UMaps& UnitMap::getMaps()
{
  // Note that C++11 guarantees that the static is initialized only once,
  // even in a multi-threaded program.
  // But no recursivity should occur.
  static UMaps maps;
  return maps;
}

map<String, UnitVal>& UnitMap::getMapCache()
{
  // Note that C++11 guarantees that the static is initialized only once,
  // even in a multi-threaded program.
  static map<String, UnitVal> mapCache;
  return mapCache;
}

void UMaps::init()
{
  // Initialize the maps
  // Known prefixes
  UnitMap::initUMPrefix (*this);
  // Defining SI units
  UnitMap::initUMSI1 (*this);
  UnitMap::initUMSI2 (*this);
  // non-SI customary units
  UnitMap::initUMCust1 (*this);
  UnitMap::initUMCust2 (*this);
  UnitMap::initUMCust3 (*this);
  // FITS not done yet.
  doneFITS = False;
}

} //# NAMESPACE CASACORE - END