/*
  Copyright 2012 SINTEF ICT, Applied Mathematics.

  This file is part of the Open Porous Media project (OPM).

  OPM 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 3 of the License, or
  (at your option) any later version.

  OPM 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 OPM.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <opm/core/fluid/SatFuncGwseg.hpp>
#include <opm/core/fluid/blackoil/BlackoilPhases.hpp>
#include <opm/core/fluid/SaturationPropsFromDeck.hpp>
#include <opm/core/grid.h>
#include <opm/core/fluid/blackoil/phaseUsageFromDeck.hpp>
#include <opm/core/utility/buildUniformMonotoneTable.hpp>
#include <opm/core/utility/ErrorMacros.hpp>
#include <iostream>

namespace Opm
{




    void SatFuncGwsegUniform::init(const EclipseGridParser& deck,
                                   const int table_num,
                                   const PhaseUsage phase_usg,
                                   const int samples)
    {
        phase_usage = phase_usg;
        double swco = 0.0;
        double swmax = 1.0;
        if (phase_usage.phase_used[Aqua]) {
            const SWOF::table_t& swof_table = deck.getSWOF().swof_;
            const std::vector<double>& sw = swof_table[table_num][0];
            const std::vector<double>& krw = swof_table[table_num][1];
            const std::vector<double>& krow = swof_table[table_num][2];
            const std::vector<double>& pcow = swof_table[table_num][3];
            buildUniformMonotoneTable(sw, krw,  samples, krw_);
            buildUniformMonotoneTable(sw, krow, samples, krow_);
            buildUniformMonotoneTable(sw, pcow, samples, pcow_);
            krocw_ = krow[0]; // At connate water -> ecl. SWOF
            swco = sw[0];
            smin_[phase_usage.phase_pos[Aqua]] = sw[0];
            swmax = sw.back();
            smax_[phase_usage.phase_pos[Aqua]] = sw.back();
        }
        if (phase_usage.phase_used[Vapour]) {
            const SGOF::table_t& sgof_table = deck.getSGOF().sgof_;
            const std::vector<double>& sg = sgof_table[table_num][0];
            const std::vector<double>& krg = sgof_table[table_num][1];
            const std::vector<double>& krog = sgof_table[table_num][2];
            const std::vector<double>& pcog = sgof_table[table_num][3];
            buildUniformMonotoneTable(sg, krg,  samples, krg_);
            buildUniformMonotoneTable(sg, krog, samples, krog_);
            buildUniformMonotoneTable(sg, pcog, samples, pcog_);
            smin_[phase_usage.phase_pos[Vapour]] = sg[0];
            if (std::fabs(sg.back() + swco - 1.0) > 1e-3) {
                THROW("Gas maximum saturation in SGOF table = " << sg.back() <<
                      ", should equal (1.0 - connate water sat) = " << (1.0 - swco));
            }
            smax_[phase_usage.phase_pos[Vapour]] = sg.back();
        }
        // These only consider water min/max sats. Consider gas sats?
        smin_[phase_usage.phase_pos[Liquid]] = 1.0 - swmax;
        smax_[phase_usage.phase_pos[Liquid]] = 1.0 - swco;
    }


    void SatFuncGwsegUniform::evalKr(const double* s, double* kr) const
    {
        if (phase_usage.num_phases == 3) {
            // Relative permeability model based on segregation of water
            // and gas, with oil present in both water and gas zones.
            const double swco = smin_[phase_usage.phase_pos[Aqua]];
            const double sw = std::max(s[Aqua], swco);
            const double sg = s[Vapour];
            // xw and xg are the fractions occupied by water and gas zones.
            const double eps = 1e-6;
            const double xw = (sw - swco) / std::max(sg + sw - swco, eps);
            const double xg = 1 - xw;
            const double ssw = sg + sw;
            const double ssg = sw - swco + sg;
            const double krw = krw_(ssw);
            const double krg = krg_(ssg);
            const double krow = krow_(ssw);
            const double krog = krog_(ssg);
            kr[Aqua]   = xw*krw;
            kr[Vapour] = xg*krg;
            kr[Liquid] = xw*krow + xg*krog;
            return;
        }
        // We have a two-phase situation. We know that oil is active.
        if (phase_usage.phase_used[Aqua]) {
            int wpos = phase_usage.phase_pos[Aqua];
            int opos = phase_usage.phase_pos[Liquid];
            double sw = s[wpos];
            double krw = krw_(sw);
            double krow = krow_(sw);
            kr[wpos] = krw;
            kr[opos] = krow;
        } else {
            ASSERT(phase_usage.phase_used[Vapour]);
            int gpos = phase_usage.phase_pos[Vapour];
            int opos = phase_usage.phase_pos[Liquid];
            double sg = s[gpos];
            double krg = krg_(sg);
            double krog = krog_(sg);
            kr[gpos] = krg;
            kr[opos] = krog;
        }
    }


    void SatFuncGwsegUniform::evalKrDeriv(const double* s, double* kr, double* dkrds) const
    {
        const int np = phase_usage.num_phases;
        std::fill(dkrds, dkrds + np*np, 0.0);

        if (np == 3) {
            // Relative permeability model based on segregation of water
            // and gas, with oil present in both water and gas zones.
            const double swco = smin_[phase_usage.phase_pos[Aqua]];
            const double sw = std::max(s[Aqua], swco);
            const double sg = s[Vapour];
            // xw and xg are the fractions occupied by water and gas zones.
            const double eps = 1e-6;
            const double xw = (sw - swco) / std::max(sg + sw - swco, eps);
            const double xg = 1 - xw;
            const double ssw = sg + sw;
            const double ssg = sw - swco + sg;
            const double krw = krw_(ssw);
            const double krg = krg_(ssg);
            const double krow = krow_(ssw);
            const double krog = krog_(ssg);
            kr[Aqua]   = xw*krw;
            kr[Vapour] = xg*krg;
            kr[Liquid] = xw*krow + xg*krog;

            // Derivatives.
            const double dkrww = krw_.derivative(ssw);
            const double dkrgg = krg_.derivative(ssg);
            const double dkrow = krow_.derivative(ssw);
            const double dkrog = krog_.derivative(ssg);
            const double d = ssg; // = sw - swco + sg (using 'd' for consistency with mrst docs).
            dkrds[Aqua   + Aqua*np]   =  (xg/d)*krw + xw*dkrww;
            dkrds[Aqua   + Vapour*np] = -(xw/d)*krw + xw*dkrww;
            dkrds[Liquid + Aqua*np]   =  (xg/d)*krow + xw*dkrow - (xg/d)*krog + xg*dkrog;
            dkrds[Liquid + Vapour*np] = -(xw/d)*krow + xw*dkrow + (xw/d)*krog + xg*dkrog;
            dkrds[Vapour + Aqua*np]   = -(xg/d)*krg + xg*dkrgg;
            dkrds[Vapour + Vapour*np] =  (xw/d)*krg + xg*dkrgg;
            return;
        }
        // We have a two-phase situation. We know that oil is active.
        if (phase_usage.phase_used[Aqua]) {
            int wpos = phase_usage.phase_pos[Aqua];
            int opos = phase_usage.phase_pos[Liquid];
            double sw = s[wpos];
            double krw = krw_(sw);
            double dkrww = krw_.derivative(sw);
            double krow = krow_(sw);
            double dkrow = krow_.derivative(sw);
            kr[wpos] = krw;
            kr[opos] = krow;
            dkrds[wpos + wpos*np] = dkrww;
            dkrds[opos + wpos*np] = dkrow; // Row opos, column wpos, fortran order.
        } else {
            ASSERT(phase_usage.phase_used[Vapour]);
            int gpos = phase_usage.phase_pos[Vapour];
            int opos = phase_usage.phase_pos[Liquid];
            double sg = s[gpos];
            double krg = krg_(sg);
            double dkrgg = krg_.derivative(sg);
            double krog = krog_(sg);
            double dkrog = krog_.derivative(sg);
            kr[gpos] = krg;
            kr[opos] = krog;
            dkrds[gpos + gpos*np] = dkrgg;
            dkrds[opos + gpos*np] = dkrog;
        }

    }


    void SatFuncGwsegUniform::evalPc(const double* s, double* pc) const
    {
        pc[phase_usage.phase_pos[Liquid]] = 0.0;
        if (phase_usage.phase_used[Aqua]) {
            int pos = phase_usage.phase_pos[Aqua];
            pc[pos] = pcow_(s[pos]);
        }
        if (phase_usage.phase_used[Vapour]) {
            int pos = phase_usage.phase_pos[Vapour];
            pc[pos] = pcog_(s[pos]);
        }
    }

    void SatFuncGwsegUniform::evalPcDeriv(const double* s, double* pc, double* dpcds) const
    {
        // The problem of determining three-phase capillary pressures
        // is very hard experimentally, usually one extends two-phase
        // data (as for relative permeability).
        // In our approach the derivative matrix is quite sparse, only
        // the diagonal elements corresponding to non-oil phases are
        // (potentially) nonzero.
        const int np = phase_usage.num_phases;
        std::fill(dpcds, dpcds + np*np, 0.0);
        pc[phase_usage.phase_pos[Liquid]] = 0.0;
        if (phase_usage.phase_used[Aqua]) {
            int pos = phase_usage.phase_pos[Aqua];
            pc[pos] = pcow_(s[pos]);
            dpcds[np*pos + pos] = pcow_.derivative(s[pos]);
        }
        if (phase_usage.phase_used[Vapour]) {
            int pos = phase_usage.phase_pos[Vapour];
            pc[pos] = pcog_(s[pos]);
            dpcds[np*pos + pos] = pcog_.derivative(s[pos]);
        }
    }




    // ====== Methods for SatFuncGwsegNonuniform ======





    void SatFuncGwsegNonuniform::init(const EclipseGridParser& deck,
                                      const int table_num,
                                      const PhaseUsage phase_usg,
                                      const int /*samples*/)
    {
        phase_usage = phase_usg;
        double swco = 0.0;
        double swmax = 1.0;
        if (phase_usage.phase_used[Aqua]) {
            const SWOF::table_t& swof_table = deck.getSWOF().swof_;
            const std::vector<double>& sw = swof_table[table_num][0];
            const std::vector<double>& krw = swof_table[table_num][1];
            const std::vector<double>& krow = swof_table[table_num][2];
            const std::vector<double>& pcow = swof_table[table_num][3];
            krw_ = NonuniformTableLinear<double>(sw, krw);
            krow_ = NonuniformTableLinear<double>(sw, krow);
            pcow_ = NonuniformTableLinear<double>(sw, pcow);
            krocw_ = krow[0]; // At connate water -> ecl. SWOF
            swco = sw[0];
            smin_[phase_usage.phase_pos[Aqua]] = sw[0];
            swmax = sw.back();
            smax_[phase_usage.phase_pos[Aqua]] = sw.back();
        }
        if (phase_usage.phase_used[Vapour]) {
            const SGOF::table_t& sgof_table = deck.getSGOF().sgof_;
            const std::vector<double>& sg = sgof_table[table_num][0];
            const std::vector<double>& krg = sgof_table[table_num][1];
            const std::vector<double>& krog = sgof_table[table_num][2];
            const std::vector<double>& pcog = sgof_table[table_num][3];
            krg_ = NonuniformTableLinear<double>(sg, krg);
            krog_ = NonuniformTableLinear<double>(sg, krog);
            pcog_ = NonuniformTableLinear<double>(sg, pcog);
            smin_[phase_usage.phase_pos[Vapour]] = sg[0];
            if (std::fabs(sg.back() + swco - 1.0) > 1e-3) {
                THROW("Gas maximum saturation in SGOF table = " << sg.back() <<
                      ", should equal (1.0 - connate water sat) = " << (1.0 - swco));
            }
            smax_[phase_usage.phase_pos[Vapour]] = sg.back();
        }
        // These only consider water min/max sats. Consider gas sats?
        smin_[phase_usage.phase_pos[Liquid]] = 1.0 - swmax;
        smax_[phase_usage.phase_pos[Liquid]] = 1.0 - swco;
    }


    void SatFuncGwsegNonuniform::evalKr(const double* s, double* kr) const
    {
        if (phase_usage.num_phases == 3) {
            // Relative permeability model based on segregation of water
            // and gas, with oil present in both water and gas zones.
            const double swco = smin_[phase_usage.phase_pos[Aqua]];
            const double sw = std::max(s[Aqua], swco);
            const double sg = s[Vapour];
            // xw and xg are the fractions occupied by water and gas zones.
            const double eps = 1e-6;
            const double xw = (sw - swco) / std::max(sg + sw - swco, eps);
            const double xg = 1 - xw;
            const double ssw = sg + sw;
            const double ssg = sw - swco + sg;
            const double krw = krw_(ssw);
            const double krg = krg_(ssg);
            const double krow = krow_(ssw);
            const double krog = krog_(ssg);
            kr[Aqua]   = xw*krw;
            kr[Vapour] = xg*krg;
            kr[Liquid] = xw*krow + xg*krog;
            return;
        }
        // We have a two-phase situation. We know that oil is active.
        if (phase_usage.phase_used[Aqua]) {
            int wpos = phase_usage.phase_pos[Aqua];
            int opos = phase_usage.phase_pos[Liquid];
            double sw = s[wpos];
            double krw = krw_(sw);
            double krow = krow_(sw);
            kr[wpos] = krw;
            kr[opos] = krow;
        } else {
            ASSERT(phase_usage.phase_used[Vapour]);
            int gpos = phase_usage.phase_pos[Vapour];
            int opos = phase_usage.phase_pos[Liquid];
            double sg = s[gpos];
            double krg = krg_(sg);
            double krog = krog_(sg);
            kr[gpos] = krg;
            kr[opos] = krog;
        }
    }


    void SatFuncGwsegNonuniform::evalKrDeriv(const double* s, double* kr, double* dkrds) const
    {
        const int np = phase_usage.num_phases;
        std::fill(dkrds, dkrds + np*np, 0.0);

        if (np == 3) {
            // Relative permeability model based on segregation of water
            // and gas, with oil present in both water and gas zones.
            const double swco = smin_[phase_usage.phase_pos[Aqua]];
            const double sw = std::max(s[Aqua], swco);
            const double sg = s[Vapour];
            // xw and xg are the fractions occupied by water and gas zones.
            const double eps = 1e-6;
            const double xw = (sw - swco) / std::max(sg + sw - swco, eps);
            const double xg = 1 - xw;
            const double ssw = sg + sw;
            const double ssg = sw - swco + sg;
            const double krw = krw_(ssw);
            const double krg = krg_(ssg);
            const double krow = krow_(ssw);
            const double krog = krog_(ssg);
            kr[Aqua]   = xw*krw;
            kr[Vapour] = xg*krg;
            kr[Liquid] = xw*krow + xg*krog;

            // Derivatives.
            const double dkrww = krw_.derivative(ssw);
            const double dkrgg = krg_.derivative(ssg);
            const double dkrow = krow_.derivative(ssw);
            const double dkrog = krog_.derivative(ssg);
            const double d = ssg; // = sw - swco + sg (using 'd' for consistency with mrst docs).
            dkrds[Aqua   + Aqua*np]   =  (xg/d)*krw + xw*dkrww;
            dkrds[Aqua   + Vapour*np] = -(xw/d)*krw + xw*dkrww;
            dkrds[Liquid + Aqua*np]   =  (xg/d)*krow + xw*dkrow - (xg/d)*krog + xg*dkrog;
            dkrds[Liquid + Vapour*np] = -(xw/d)*krow + xw*dkrow + (xw/d)*krog + xg*dkrog;
            dkrds[Vapour + Aqua*np]   = -(xg/d)*krg + xg*dkrgg;
            dkrds[Vapour + Vapour*np] =  (xw/d)*krg + xg*dkrgg;
            return;
        }
        // We have a two-phase situation. We know that oil is active.
        if (phase_usage.phase_used[Aqua]) {
            int wpos = phase_usage.phase_pos[Aqua];
            int opos = phase_usage.phase_pos[Liquid];
            double sw = s[wpos];
            double krw = krw_(sw);
            double dkrww = krw_.derivative(sw);
            double krow = krow_(sw);
            double dkrow = krow_.derivative(sw);
            kr[wpos] = krw;
            kr[opos] = krow;
            dkrds[wpos + wpos*np] = dkrww;
            dkrds[opos + wpos*np] = dkrow; // Row opos, column wpos, fortran order.
        } else {
            ASSERT(phase_usage.phase_used[Vapour]);
            int gpos = phase_usage.phase_pos[Vapour];
            int opos = phase_usage.phase_pos[Liquid];
            double sg = s[gpos];
            double krg = krg_(sg);
            double dkrgg = krg_.derivative(sg);
            double krog = krog_(sg);
            double dkrog = krog_.derivative(sg);
            kr[gpos] = krg;
            kr[opos] = krog;
            dkrds[gpos + gpos*np] = dkrgg;
            dkrds[opos + gpos*np] = dkrog;
        }

    }


    void SatFuncGwsegNonuniform::evalPc(const double* s, double* pc) const
    {
        pc[phase_usage.phase_pos[Liquid]] = 0.0;
        if (phase_usage.phase_used[Aqua]) {
            int pos = phase_usage.phase_pos[Aqua];
            pc[pos] = pcow_(s[pos]);
        }
        if (phase_usage.phase_used[Vapour]) {
            int pos = phase_usage.phase_pos[Vapour];
            pc[pos] = pcog_(s[pos]);
        }
    }

    void SatFuncGwsegNonuniform::evalPcDeriv(const double* s, double* pc, double* dpcds) const
    {
        // The problem of determining three-phase capillary pressures
        // is very hard experimentally, usually one extends two-phase
        // data (as for relative permeability).
        // In our approach the derivative matrix is quite sparse, only
        // the diagonal elements corresponding to non-oil phases are
        // (potentially) nonzero.
        const int np = phase_usage.num_phases;
        std::fill(dpcds, dpcds + np*np, 0.0);
        pc[phase_usage.phase_pos[Liquid]] = 0.0;
        if (phase_usage.phase_used[Aqua]) {
            int pos = phase_usage.phase_pos[Aqua];
            pc[pos] = pcow_(s[pos]);
            dpcds[np*pos + pos] = pcow_.derivative(s[pos]);
        }
        if (phase_usage.phase_used[Vapour]) {
            int pos = phase_usage.phase_pos[Vapour];
            pc[pos] = pcog_(s[pos]);
            dpcds[np*pos + pos] = pcog_.derivative(s[pos]);
        }
    }





} // namespace Opm