/*	ASCEND modelling environment
	Copyright (C) 2011 Carnegie Mellon University

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2, or (at your option)
	any later version.

	This program 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 General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*//** @file
This file contains declarations of the data structures passed to
functions that EVALUATE fluid properties. We allow from some preprocessing of
data loaded from input files, if deisred/needed.

Data declarations as provided in input files are given in filedata.h
*/

#ifndef FPROPS_RUNDATA_H
#define FPROPS_RUNDATA_H

#include "common.h"

/* TODO remove this dependency eventually (some helmholtz data objects are not yet being copied into new structures*/
#include "filedata.h"

/** Power terms for phi0 (including polynomial) */
typedef struct Cp0RunPowTerm_struct{
	double a;
	double p;
} Phi0RunPowTerm;

/** Planck-Einstein aka 'exponential' terms for phi0 */
typedef struct Cp0RunExpTerm_struct{
	double n;
	double gamma;
} Phi0RunExpTerm;

/**
	Runtime data for ideal gas properties, which are stored in the
	form of reduced ideal-gas compnent of helmholtz energy (see http://fprops.org)

	There is no 'R' or 'cp0star' in this structure. If cp0star != R in the filedata, that
	difference will be corrected for when this structure is created.
*/
typedef struct 	Phi0RunData_struct{
	double c;       /**< second integration constant in phi0, value determined by reference point for entropy */
	double m;       /**< first integration constant in phi0, value determined by reference point for enthalpy */

	unsigned np;    /**< number of power terms */
	Phi0RunPowTerm *pt; /**< power term data, may be NULL if np == 0 */
	unsigned ne;    /**< number of Planck-Einstein aka 'exponential' terms */
	Phi0RunExpTerm *et; /**< exponential term data, maybe NULL if ne == 0 */
} Phi0RunData;

typedef struct HelmholtzRunData_struct{
	double rho_star;/**< normalisation density, kg/m3 */
	double T_star;  /**< normalisation temperature, K */

	//REMOVED: double p_t; /**< triple-point pressure */

   	unsigned np;                 /**< number of power terms in residual equation */
	const HelmholtzPowTerm *pt;  /**< power term data for residual eqn, maybe NULL if np == 0 */
	unsigned ng;                 /**< number of critical terms of the first kind */
	const HelmholtzGausTerm *gt; /**< critical terms of the first kind */
	unsigned nc;                 /**< number of critical terms of the second kind */
	const HelmholtzCritTerm *ct; /**< critical terms of the second kind */
} HelmholtzRunData;

typedef struct PengrobRunData_struct{
	double aTc;   /**< value of 'a' when evaluated at T =  T_c */
	double b;     /**< coeficient 'b' in PR EOS */
	double kappa; /** parameter used in a(T) */
} PengrobRunData;

typedef union CorrelationUnion_union{
	HelmholtzRunData *helm;
	PengrobRunData *pengrob;
	/* maybe more later */
} CorrelationUnion;

/** All runtime 'core' data for all possible correlations, with exception of 
correlation-type-ID, function pointers and metadata (URLs, publications etc)

TODO FluidData (or PureFluid?) could/should be extended to include the following
frequently-calculated items:
	- fluid properties at triple point (rhoft, rhogt, pt...)
	- fluid properties at critical point (hc, ...)
	- accurate saturation curve data (interpolation/spline/something like that)
	- solutions of iterative solver results, eg (p,h) pairs.

This data would be held at this level unless it is correlation-specific in 
nature, in which case it would belong in lower-level rundata structures.

For fluids without phase change (incompressible, ideal), we
	- set T_c to zero,
	- use a value of 1 K for Tstar
	- provide a _sat SatEvalFn that always returns an error.
...but maybe there's a better way. It's up to the particular PropEvalFn to 
make use of Tstar or T_c as desired, but this data is stored here 
*/
typedef struct FluidData_struct{
	/* common data across all correlations */
	double R;     /**< specific gas constant */
	double M;     /**< molar mass, kg/kmol */
	double T_t;   /**< triple-point temperature */
	double T_c;   /**< critical temperature */
	double p_c;   /**< critical pressure */
	double rho_c; /**< critical density */
	double omega; /**< acentric factor (possibly calculated from correlation data)*/
	double Tstar;   /**< reference for reduced temperature */
	double rhostar; /**< reference for reduced density */
	Phi0RunData *cp0; /* data for ideal component of Helmholtz energy */
	ReferenceState ref0;
	/* correlation-specific stuff here */
	CorrelationUnion corr;
} FluidData;


/* Definition of a fluid property function pointer */
typedef double PropEvalFn(double T,double rho,const FluidData *data, FpropsError *err);

/** @return psat */
typedef double SatEvalFn(double T,double *rhof, double *rhog, const FluidData *data, FpropsError *err);

/**
	Structure containing all the necessary data and metadata for run-time
	calculation of fluid properties.
*/
typedef struct PureFluid_struct{
    const char *name;
	const char *source;
	EosType type;
	FluidData *data; // everything we need at runtime in the following functions should be in here
	//Pointers to departure functions
	PropEvalFn *p_fn;
	PropEvalFn *u_fn;
	PropEvalFn *h_fn;
	PropEvalFn *s_fn;
	PropEvalFn *a_fn;
	PropEvalFn *cv_fn;
	PropEvalFn *cp_fn;
	PropEvalFn *w_fn;
	PropEvalFn *g_fn;
	PropEvalFn *alphap_fn;
	PropEvalFn *betap_fn;
	PropEvalFn *dpdrho_T_fn; // this derivative is required for saturation properties by Akasaka method
	SatEvalFn *sat_fn; // function to return {psat,rhof,rhog}(T) for this pure fluid

	const ViscosityData *visc; // TODO should it be here? or inside FluidData?? probably yes, but needs review.
	const ThermalConductivityData *thcond; // TODO should it be here? probably yes, but needs review.
} PureFluid;

#endif