/**
 * @file ct_defs.h
 * This file contains definitions of terms that are used in internal
 * routines and are unlikely to need modifying (text for module physConstants (see \ref physConstants) is found here).
 * This file is included
 * in every file that is in the Cantera Namespace.
 *
 * All physical constants are stored here.
 * The module physConstants is defined here.
 */

// This file is part of Cantera. See License.txt in the top-level directory or
// at http://www.cantera.org/license.txt for license and copyright information.

#ifndef CT_DEFS_H
#define CT_DEFS_H

#include "config.h"

#include <cmath>

// STL includes
#include <cstdlib>
#include <vector>
#include <map>
#include <string>
#include <algorithm>
#include <memory>

/**
 * Namespace for the Cantera kernel.
 */
namespace Cantera
{

using std::shared_ptr;
using std::make_shared;
using std::unique_ptr;
using std::isnan; // workaround for bug in libstdc++ 4.8

/*!
 * All physical constants are stored here.
 *
 * @defgroup physConstants Physical Constants
 * %Cantera uses the MKS system of units. The unit for moles
 * is defined to be the kmol. All values of physical constants
 * are consistent with the 2010 CODATA recommendations.
 * @ingroup globalData
 * @{
 */

//! Pi
const doublereal Pi = 3.14159265358979323846;

/*!
 *   @name Variations of the Gas Constant
 * %Cantera uses the MKS system of units. The unit for moles
 * is defined to be the kmol.
 */
//@{

//! Avogadro's Number [number/kmol]
const doublereal Avogadro = 6.02214129e26;

/// Universal Gas Constant. [J/kmol/K]
const doublereal GasConstant = 8314.4621;

const doublereal logGasConstant = std::log(GasConstant);

//! One atmosphere [Pa]
const doublereal OneAtm = 1.01325e5;
const doublereal OneBar = 1.0E5;

//! Universal gas constant in cal/mol/K
const doublereal GasConst_cal_mol_K = GasConstant / 4184.0;

//! Boltzmann's constant [J/K]
const doublereal Boltzmann = GasConstant / Avogadro;

/// Planck's constant. [J-s]
const doublereal Planck = 6.62607009e-34; // J-s
const doublereal Planck_bar = Planck / (2 * Pi); // m2-kg/s

/// log(k/h)
const doublereal logBoltz_Planck = std::log(Boltzmann / Planck); // ln(k_B/h)
/// Stefan-Boltzmann constant
const doublereal StefanBoltz = 5.670373e-8;

//@}
/// @name Electron Properties
//@{
const doublereal ElectronCharge = 1.602176565e-19; // C
const doublereal ElectronMass = 9.10938291e-31; // kg
const doublereal Faraday = ElectronCharge * Avogadro;
//@}

/// @name Electromagnetism
/// %Cantera uses the MKS unit system.
//@{

/// Speed of Light (m/s).
const doublereal lightSpeed = 299792458.0;

/// Permeability of free space \f$ \mu_0 \f$ in N/A^2.
const doublereal permeability_0 = 4.0e-7*Pi;

/// Permittivity of free space \f$ \epsilon_0 \f$ in F/m.
const doublereal epsilon_0 = 1.0 / (lightSpeed*lightSpeed*permeability_0);

//@}
//@}

/*!
 * @name Thermodynamic Equilibrium Constraints
 * Integer numbers representing pairs of thermodynamic variables
 * which are held constant during equilibration.
 */
//@{
const int TV = 100, HP = 101, SP = 102, PV = 103, TP = 104, UV = 105,
          ST = 106, SV = 107, UP = 108, VH = 109, TH = 110, SH = 111,
          PX = 112, TX = 113;
const int VT = -100, PH = -101, PS = -102, VP = -103, PT = -104,
          VU = -105, TS = -106, VS = -107, PU = -108, HV = -109,
          HT = -110, HS = -111, XP = -112, XT = -113;
//@}

//! smallest number to compare to zero.
const doublereal SmallNumber = 1.e-300;
//! largest number to compare to inf.
const doublereal BigNumber = 1.e300;
//! largest x such that exp(x) is valid
const doublereal MaxExp = 690.775527898;

//! Fairly random number to be used to initialize variables against
//! to see if they are subsequently defined.
const doublereal Undef = -999.1234;

//! Small number to compare differences of mole fractions against.
/*!
 * This number is used for the interconversion of mole fraction and mass
 * fraction quantities when the molecular weight of a species is zero. It's also
 * used for the matrix inversion of transport properties when mole fractions
 * must be positive.
 */
const doublereal Tiny = 1.e-20;

//! Map connecting a string name with a double.
/*!
 * This is used mostly to assign concentrations and mole fractions to species.
 */
typedef std::map<std::string, doublereal> compositionMap;

//! Map from string names to doubles. Used for defining species mole/mass
//! fractions, elemental compositions, and reaction stoichiometries.
typedef std::map<std::string, doublereal> Composition;

//! Turn on the use of stl vectors for the basic array type within cantera
//! Vector of doubles.
typedef std::vector<double> vector_fp;
//! Vector of ints
typedef std::vector<int> vector_int;

//! A grouplist is a vector of groups of species
typedef std::vector<std::vector<size_t> > grouplist_t;

//! index returned by functions to indicate "no position"
const size_t npos = static_cast<size_t>(-1);

} // namespace

#endif
