/**
 *  @file GasKinetics.cpp 
 *
 * Homogeneous kinetics in ideal gases
 * 
 */

// Copyright 2001  California Institute of Technology

#include "GasKinetics.h"

#include "ReactionData.h"
#include "Enhanced3BConc.h"
#include "ThirdBodyMgr.h"
#include "RateCoeffMgr.h"

//#include "../user/grirxnstoich.h"

#include <iostream>
using namespace std;


namespace Cantera {


    /**
     * Construct an empty reaction mechanism.
     */    
    GasKinetics::
    GasKinetics(thermo_t* thermo) :
        Kinetics(),
        m_kk(0), 
        m_nfall(0), 
        m_nirrev(0), 
        m_nrev(0),
        m_finalized(false)
    {
        if (thermo != 0) addPhase(*thermo);
        m_kdata = new GasKineticsData;
        m_kdata->m_temp = 0.0;
        m_rxnstoich = new ReactionStoichMgr;
    }

    GasKinetics::
    ~GasKinetics() {delete m_kdata; delete m_rxnstoich;}

    /**
     * Update temperature-dependent portions of reaction rates and
     * falloff functions.
     */
    void GasKinetics::
    update_T() {}

    void GasKinetics::
    update_C() {}

    void GasKinetics::
    _update_rates_T() {
        doublereal T = thermo().temperature();
        m_kdata->m_logStandConc = log(thermo().standardConcentration()); 
        doublereal logT = log(T);
        if (!m_kdata->m_rfn.empty()) {
          m_rates.update(T, logT, &m_kdata->m_rfn[0]);
        }
        if (!m_kdata->m_rfn_low.empty()) {
          m_falloff_low_rates.update(T, logT, &m_kdata->m_rfn_low[0]);
          m_falloff_high_rates.update(T, logT, &m_kdata->m_rfn_high[0]);
        }
        if (!m_kdata->falloff_work.empty()) {
          m_falloffn.updateTemp(T, &m_kdata->falloff_work[0]);
        }
        m_kdata->m_temp = T;
        updateKc();
        m_kdata->m_ROP_ok = false;
    }

    /**
     * Update properties that depend on concentrations. Currently only
     * the enhanced collision partner concentrations are updated here.
     */         
    void GasKinetics::
    _update_rates_C() {
        thermo().getActivityConcentrations(&m_conc[0]);
        doublereal ctot = thermo().molarDensity();
        if (!m_kdata->concm_3b_values.empty()) {
          m_3b_concm.update(m_conc, ctot, &m_kdata->concm_3b_values[0]);
        }
        if (!m_kdata->concm_falloff_values.empty()) {
          m_falloff_concm.update(m_conc, ctot,
            &m_kdata->concm_falloff_values[0]);
        }
        m_kdata->m_ROP_ok = false;
    }

    /**
     * Update the equilibrium constants in molar units.
     */
    void GasKinetics::updateKc() {
        int i, irxn;
        vector_fp& m_rkc = m_kdata->m_rkcn;
        
        thermo().getStandardChemPotentials(&m_grt[0]);
        fill(m_rkc.begin(), m_rkc.end(), 0.0);

        // compute Delta G^0 for all reversible reactions
        m_rxnstoich->getRevReactionDelta(m_ii, &m_grt[0], &m_rkc[0]);
 
        doublereal logStandConc = m_kdata->m_logStandConc;
        doublereal rrt = 1.0/(GasConstant * thermo().temperature());
        for (i = 0; i < m_nrev; i++) {
            irxn = m_revindex[i];
            m_rkc[irxn] = exp(m_rkc[irxn]*rrt - m_dn[irxn]*logStandConc);
        }

        for(i = 0; i != m_nirrev; ++i) {
            m_rkc[ m_irrev[i] ] = 0.0;
        }
    }

    /**
     * Get the equilibrium constants of all reactions, whether
     * reversible or not.
     */
    void GasKinetics::getEquilibriumConstants(doublereal* kc) {
        int i;
        _update_rates_T();
        vector_fp& rkc = m_kdata->m_rkcn;
        //thermo().getGibbs_RT(m_grt.begin());
        thermo().getStandardChemPotentials(&m_grt[0]);
        fill(rkc.begin(), rkc.end(), 0.0);
        
        // compute Delta G^0 for all reactions
        m_rxnstoich->getReactionDelta(m_ii, &m_grt[0], &rkc[0]);
 
        doublereal logStandConc = m_kdata->m_logStandConc;
        doublereal rrt = 1.0/(GasConstant * thermo().temperature());
        for (i = 0; i < m_ii; i++) {
            kc[i] = exp(-rkc[i]*rrt + m_dn[i]*logStandConc);
        }

        // force an update of T-dependent properties, so that m_rkcn will
        // be updated before it is used next.
        m_kdata->m_temp = 0.0;
    }

    /**
     *
     * getDeltaGibbs():
     *
     * Return the vector of values for the reaction gibbs free energy
     * change
     * These values depend upon the concentration
     * of the ideal gas.
     *
     *  units = J kmol-1
     */
    void GasKinetics::getDeltaGibbs(doublereal* deltaG) {
	/*
	 * Get the chemical potentials of the species in the 
	 * ideal gas solution.
	 */
	thermo().getChemPotentials(&m_grt[0]);
	/*
	 * Use the stoichiometric manager to find deltaG for each
	 * reaction.
	 */
	m_rxnstoich->getReactionDelta(m_ii, &m_grt[0], deltaG);
    }
    
    /**
     *
     * getDeltaEnthalpy():
     * 
     * Return the vector of values for the reactions change in
     * enthalpy.
     * These values depend upon the concentration
     * of the solution.
     *
     *  units = J kmol-1
     */
    void GasKinetics::getDeltaEnthalpy(doublereal* deltaH) {
	/*
	 * Get the partial molar enthalpy of all species in the 
	 * ideal gas.
	 */
	thermo().getPartialMolarEnthalpies(&m_grt[0]);
	/*
	 * Use the stoichiometric manager to find deltaG for each
	 * reaction.
	 */
	m_rxnstoich->getReactionDelta(m_ii, &m_grt[0], deltaH);
    }

    /************************************************************************
     *
     * getDeltaEntropy():
     *
     * Return the vector of values for the reactions change in
     * entropy.
     * These values depend upon the concentration
     * of the solution.
     *
     *  units = J kmol-1 Kelvin-1
     */
    void GasKinetics::getDeltaEntropy( doublereal* deltaS) {
	/*
	 * Get the partial molar entropy of all species in the
	 * solid solution.
	 */
	thermo().getPartialMolarEntropies(&m_grt[0]);
	/*
	 * Use the stoichiometric manager to find deltaS for each
	 * reaction.
	 */
	m_rxnstoich->getReactionDelta(m_ii, &m_grt[0], deltaS);
    }

    /**
     *
     * getDeltaSSGibbs():
     *
     * Return the vector of values for the reaction 
     * standard state gibbs free energy change.
     * These values don't depend upon the concentration
     * of the solution.
     *
     *  units = J kmol-1
     */
    void GasKinetics::getDeltaSSGibbs(doublereal* deltaG) {
	/*
	 *  Get the standard state chemical potentials of the species.
         *  This is the array of chemical potentials at unit activity 
	 *  We define these here as the chemical potentials of the pure
	 *  species at the temperature and pressure of the solution.
	 */
        thermo().getStandardChemPotentials(&m_grt[0]);
	/*
	 * Use the stoichiometric manager to find deltaG for each
	 * reaction.
	 */
	m_rxnstoich->getReactionDelta(m_ii, &m_grt[0], deltaG);
    }

    /**
     *
     * getDeltaSSEnthalpy():
     *
     * Return the vector of values for the change in the
     * standard state enthalpies of reaction.
     * These values don't depend upon the concentration
     * of the solution.
     *
     *  units = J kmol-1
     */
    void GasKinetics::getDeltaSSEnthalpy(doublereal* deltaH) {
	/*
	 *  Get the standard state enthalpies of the species.
         *  This is the array of chemical potentials at unit activity 
	 *  We define these here as the enthalpies of the pure
	 *  species at the temperature and pressure of the solution.
	 */
	thermo().getEnthalpy_RT(&m_grt[0]);
	doublereal RT = thermo().temperature() * GasConstant;
	for (int k = 0; k < m_kk; k++) {
	  m_grt[k] *= RT;
	}
	/*
	 * Use the stoichiometric manager to find deltaG for each
	 * reaction.
	 */
	m_rxnstoich->getReactionDelta(m_ii, &m_grt[0], deltaH);
    }

    /*********************************************************************
     *
     * getDeltaSSEntropy():
     *
     * Return the vector of values for the change in the
     * standard state entropies for each reaction.
     * These values don't depend upon the concentration
     * of the solution.
     *
     *  units = J kmol-1 Kelvin-1
     */
    void GasKinetics::getDeltaSSEntropy(doublereal* deltaS) {
	/*
	 *  Get the standard state entropy of the species.
	 *  We define these here as the entropies of the pure
	 *  species at the temperature and pressure of the solution.
	 */
	thermo().getEntropy_R(&m_grt[0]);
	doublereal R = GasConstant;
	for (int k = 0; k < m_kk; k++) {
	  m_grt[k] *= R;
	}
	/*
	 * Use the stoichiometric manager to find deltaS for each
	 * reaction.
	 */
	m_rxnstoich->getReactionDelta(m_ii, &m_grt[0], deltaS);
    }

    void GasKinetics::processFalloffReactions() {

        int i;
        const vector_fp& fc = m_kdata->concm_falloff_values;
        const array_fp& m_rf_low = m_kdata->m_rfn_low;
        const array_fp& m_rf_high = m_kdata->m_rfn_high;

        // use m_ropr for temporary storage of reduced pressure
        array_fp& pr = m_kdata->m_ropr;

        array_fp& ropf = m_kdata->m_ropf;

        for (i = 0; i < m_nfall; i++) {
            pr[i] = fc[i] * m_rf_low[i] / m_rf_high[i];
        }

        double* falloff_work =
            (m_kdata->falloff_work.empty()) ? 0 : &m_kdata->falloff_work[0];
        m_falloffn.pr_to_falloff(&pr[0], falloff_work);
        
        for (i = 0; i < m_nfall; i++) {
            pr[i] *= m_rf_high[i]; 
        }

        scatter_copy(pr.begin(), pr.begin() + m_nfall, 
            ropf.begin(), m_fallindx.begin());
    }


    void GasKinetics::updateROP() {

        _update_rates_T();
        _update_rates_C();

        if (m_kdata->m_ROP_ok) return;

        const vector_fp& rf = m_kdata->m_rfn;
        const vector_fp& m_rkc = m_kdata->m_rkcn;
        array_fp& ropf = m_kdata->m_ropf;
        array_fp& ropr = m_kdata->m_ropr;
        array_fp& ropnet = m_kdata->m_ropnet;

        // copy rate coefficients into ropf
        copy(rf.begin(), rf.end(), ropf.begin());

        // multiply ropf by enhanced 3b conc for all 3b rxns
        if (!m_kdata->concm_3b_values.empty()) {
          m_3b_concm.multiply( &ropf[0], &m_kdata->concm_3b_values[0] );
        }

        if (m_nfall) {
          processFalloffReactions();
        }

        // multiply by perturbation factor
        multiply_each(ropf.begin(), ropf.end(), m_perturb.begin());
           
        // copy the forward rates to the reverse rates                
        copy(ropf.begin(), ropf.end(), ropr.begin());
        
        // for reverse rates computed from thermochemistry, multiply
        // the forward rates copied into m_ropr by the reciprocals of
        // the equilibrium constants
        multiply_each(ropr.begin(), ropr.end(), m_rkc.begin());

        // multiply ropf by concentration products
        m_rxnstoich->multiplyReactants(&m_conc[0], &ropf[0]); 
        //m_reactantStoich.multiply(m_conc.begin(), ropf.begin()); 

        // for reversible reactions, multiply ropr by concentration
        // products
        m_rxnstoich->multiplyRevProducts(&m_conc[0], &ropr[0]); 
        //m_revProductStoich.multiply(m_conc.begin(), ropr.begin());

        for (int j = 0; j != m_ii; ++j) {
            ropnet[j] = ropf[j] - ropr[j];
        }

        m_kdata->m_ROP_ok = true;
    }

    /**
     *
     * getFwdRateConstants():
     *
     * Update the rate of progress for the reactions.
     * This key routine makes sure that the rate of progress vectors
     * located in the solid kinetics data class are up to date.
     */
    void GasKinetics::
    getFwdRateConstants(doublereal *kfwd) {
        _update_rates_T();
	_update_rates_C();

	// copy rate coefficients into ropf
	const vector_fp& rf = m_kdata->m_rfn;
	array_fp& ropf = m_kdata->m_ropf;
        copy(rf.begin(), rf.end(), ropf.begin());

        // multiply ropf by enhanced 3b conc for all 3b rxns
        if (!m_kdata->concm_3b_values.empty()) {
          m_3b_concm.multiply(&ropf[0], &m_kdata->concm_3b_values[0] );
        }

	/*
	 * This routine is hardcoded to replace some of the values
	 * of the ropf vector.
	 */
        if (m_nfall) {
          processFalloffReactions();
        }

        // multiply by perturbation factor
        multiply_each(ropf.begin(), ropf.end(), m_perturb.begin());
       
	for (int i = 0; i < m_ii; i++) {
	  kfwd[i] = ropf[i];
	}
    }

    /**
     *
     * getRevRateConstants():
     *
     * Return a vector of the reverse reaction rate constants
     *
     * Length is the number of reactions. units depends
     * on many issues. Note, this routine will return rate constants
     * for irreversible reactions if the default for
     * doIrreversible is overridden.
     */
    void GasKinetics::
    getRevRateConstants(doublereal *krev, bool doIrreversible) {
	/*
	 * go get the forward rate constants. -> note, we don't
	 * really care about speed or redundancy in these
	 * informational routines.
	 */
        getFwdRateConstants(krev);

	if (doIrreversible) {
	  doublereal *tmpKc = &m_kdata->m_ropnet[0];
	  getEquilibriumConstants(tmpKc);
	  for (int i = 0; i < m_ii; i++) {
	    krev[i] /=  tmpKc[i];
	  }
	} else {
	  /*
	   * m_rkc[] is zero for irreversibly reactions
	   */
	  const vector_fp& m_rkc = m_kdata->m_rkcn;
	  for (int i = 0; i < m_ii; i++) {
              krev[i] *= m_rkc[i];
	  }
	}
    }

    void GasKinetics::
    addReaction(const ReactionData& r) {

        if (r.reactionType == ELEMENTARY_RXN)      addElementaryReaction(r);
        else if (r.reactionType == THREE_BODY_RXN) addThreeBodyReaction(r);
        else if (r.reactionType == FALLOFF_RXN)    addFalloffReaction(r);

        // operations common to all reaction types
        installReagents( r );
        installGroups(reactionNumber(), r.rgroups, r.pgroups);
        incrementRxnCount();
        m_rxneqn.push_back(r.equation);
    }


    void GasKinetics::
    addFalloffReaction(const ReactionData& r) {

        // install high and low rate coeff calculators

        size_t iloc = m_falloff_high_rates.install(m_nfall,
						   r.rateCoeffType,
						   r.rateCoeffParameters.size(),
						   &r.rateCoeffParameters[0] );
    
        m_falloff_low_rates.install( m_nfall, 
            r.rateCoeffType, r.auxRateCoeffParameters.size(), 
            DATA_PTR(r.auxRateCoeffParameters) );
                
        // add constant terms to high and low rate
        // coeff value vectors
        m_kdata->m_rfn_high.push_back(r.rateCoeffParameters[0]);
        m_kdata->m_rfn_low.push_back(r.auxRateCoeffParameters[0]);
                
        // add a dummy entry in m_rf, where computed falloff
        // rate coeff will be put
        m_kdata->m_rfn.push_back(0.0);
                
        // add this reaction number to the list of 
        // falloff reactions
        m_fallindx.push_back( reactionNumber() );
                
        // install the enhanced third-body concentration
        // calculator for this reaction
        m_falloff_concm.install( m_nfall, r.thirdBodyEfficiencies, 
            r.default_3b_eff);
                
        // install the falloff function calculator for
        // this reaction
        m_falloffn.install( m_nfall, r.falloffType, r.falloffParameters );
                
        // forward rxn order equals number of reactants, since rate
        // coeff is defined in terms of the high-pressure limit
        m_fwdOrder.push_back(r.reactants.size());

        // increment the falloff reaction counter
        ++m_nfall;
        registerReaction( reactionNumber(), FALLOFF_RXN, iloc);
    }


    void GasKinetics::
    addElementaryReaction(const ReactionData& r) {
        size_t iloc;

        // install rate coeff calculator
        iloc = m_rates.install( reactionNumber(),
            r.rateCoeffType, r.rateCoeffParameters.size(), 
            DATA_PTR(r.rateCoeffParameters) );

        // add constant term to rate coeff value vector
        m_kdata->m_rfn.push_back(r.rateCoeffParameters[0]);                

        // forward rxn order equals number of reactants
        m_fwdOrder.push_back(r.reactants.size());
        registerReaction( reactionNumber(), ELEMENTARY_RXN, iloc);
    }


    void GasKinetics::
    addThreeBodyReaction(const ReactionData& r) {
        size_t iloc;
        // install rate coeff calculator
        iloc = m_rates.install( reactionNumber(),
            r.rateCoeffType, r.rateCoeffParameters.size(),
            DATA_PTR(r.rateCoeffParameters) );

        // add constant term to rate coeff value vector
        m_kdata->m_rfn.push_back(r.rateCoeffParameters[0]);                

        // forward rxn order equals number of reactants + 1
        m_fwdOrder.push_back(r.reactants.size() + 1);

        m_3b_concm.install( reactionNumber(), r.thirdBodyEfficiencies, 
            r.default_3b_eff );
        registerReaction( reactionNumber(), THREE_BODY_RXN, iloc);
    }

        
    void GasKinetics::installReagents(const ReactionData& r) {
            
        m_kdata->m_ropf.push_back(0.0);     // extend by one for new rxn
        m_kdata->m_ropr.push_back(0.0);
        m_kdata->m_ropnet.push_back(0.0);
        size_t n, ns, m;
	doublereal nsFlt;
	doublereal reactantGlobalOrder = 0.0;
	doublereal productGlobalOrder  = 0.0;
	size_t rnum = reactionNumber();

        std::vector<size_t> rk;
        size_t nr = r.reactants.size();
        for (n = 0; n < nr; n++) {
            nsFlt = r.rstoich[n];
	    reactantGlobalOrder += nsFlt;
	    ns = (size_t) nsFlt;
	    if ((doublereal) ns != nsFlt) {
	      if (ns < 1) {
		ns = 1;
	      }
	    }
            if (r.rstoich[n] != 0.0) 
                m_rrxn[r.reactants[n]][rnum] += r.rstoich[n];
            for (m = 0; m < ns; m++) {
                rk.push_back(r.reactants[n]);
            }
        }
        m_reactants.push_back(rk);

        std::vector<size_t> pk;
        size_t np = r.products.size();
        for (n = 0; n < np; n++) {
            nsFlt = r.pstoich[n];
	    productGlobalOrder += nsFlt;
            ns = (size_t) nsFlt;
            if ((double) ns != nsFlt) {
	      if (ns < 1) {
		ns = 1;
	      }
	    }
            if (r.pstoich[n] != 0.0) 
                m_prxn[r.products[n]][rnum] += r.pstoich[n];
            for (m = 0; m < ns; m++) {
                pk.push_back(r.products[n]);
            }
        }
        m_products.push_back(pk);

        m_kdata->m_rkcn.push_back(0.0);

        m_rxnstoich->add(reactionNumber(), r);

        if (r.reversible) {
	  m_dn.push_back(productGlobalOrder - reactantGlobalOrder);
	  m_revindex.push_back(reactionNumber());
	  m_nrev++;
        }
        else {
	  m_dn.push_back(productGlobalOrder - reactantGlobalOrder);
	  m_irrev.push_back( reactionNumber() );
	  m_nirrev++;
        }        
    }


    void GasKinetics::installGroups(int irxn, 
        const vector<grouplist_t>& r, const vector<grouplist_t>& p) {
        if (!r.empty()) {
            writelog("installing groups for reaction "+int2str(reactionNumber()));
            m_rgroups[reactionNumber()] = r;
            m_pgroups[reactionNumber()] = p;
        }
    }


    void GasKinetics::init() { 
        m_kk = thermo().nSpecies();
        m_rrxn.resize(m_kk);
        m_prxn.resize(m_kk);
        m_conc.resize(m_kk);
        m_grt.resize(m_kk);
        m_kdata->m_logp_ref = log(thermo().refPressure()) - log(GasConstant);
    }

    void GasKinetics::finalize() {
        if (!m_finalized) {
            //            int i, j, nr, np;
            m_kdata->falloff_work.resize(
				static_cast<size_t>(m_falloffn.workSize()));
            m_kdata->concm_3b_values.resize(
				static_cast<size_t>(m_3b_concm.workSize()));
            m_kdata->concm_falloff_values.resize(
				static_cast<size_t>(m_falloff_concm.workSize()));

//             for (i = 0; i < m_ii; i++) {
//                 nr = m_reactants[i].size();
//                 for (j = 0; j < nr; j++) {
//                     m_rstoich[i][m_reactants[i][j]]++;
//                 }
//                 np = m_products[i].size();
//                 for (j = 0; j < np; j++) {
//                     m_pstoich[i][m_products[i][j]]++;
//                 }
//             }
            //m_rxnstoich->write("c.cpp");
            m_finalized = true;
        }
    }

    bool GasKinetics::ready() const {
        return (m_finalized);
    }

}