#include <stdio.h>

extern "C" void ScaLBL_D3Q7_AAodd_IonConcentration(int *neighborList,
                                                   double *dist, double *Den,
                                                   int start, int finish,
                                                   int Np) {
    int n, nread;
    double fq, Ci;
    for (n = start; n < finish; n++) {

        // q=0
        fq = dist[n];
        Ci = fq;

        // q=1
        nread = neighborList[n];
        fq = dist[nread];
        Ci += fq;

        // q=2
        nread = neighborList[n + Np];
        fq = dist[nread];
        Ci += fq;

        // q=3
        nread = neighborList[n + 2 * Np];
        fq = dist[nread];
        Ci += fq;

        // q=4
        nread = neighborList[n + 3 * Np];
        fq = dist[nread];
        Ci += fq;

        // q=5
        nread = neighborList[n + 4 * Np];
        fq = dist[nread];
        Ci += fq;

        // q=6
        nread = neighborList[n + 5 * Np];
        fq = dist[nread];
        Ci += fq;

        Den[n] = Ci;
    }
}

extern "C" void ScaLBL_D3Q7_AAeven_IonConcentration(double *dist, double *Den,
                                                    int start, int finish,
                                                    int Np) {
    int n;
    double fq, Ci;
    for (n = start; n < finish; n++) {

        // q=0
        fq = dist[n];
        Ci = fq;

        // q=1
        fq = dist[2 * Np + n];
        Ci += fq;

        // q=2
        fq = dist[1 * Np + n];
        Ci += fq;

        // q=3
        fq = dist[4 * Np + n];
        Ci += fq;

        // q=4
        fq = dist[3 * Np + n];
        Ci += fq;

        // q=5
        fq = dist[6 * Np + n];
        Ci += fq;

        // q=6
        fq = dist[5 * Np + n];
        Ci += fq;

        Den[n] = Ci;
    }
}

extern "C" void ScaLBL_D3Q7_AAodd_Ion(int *neighborList, double *dist,
                                      double *Den, double *FluxDiffusive,
                                      double *FluxAdvective,
                                      double *FluxElectrical, double *Velocity,
                                      double *ElectricField, double Di, int zi,
                                      double rlx, double Vt, int start,
                                      int finish, int Np) {
    int n;
    double Ci;
    double ux, uy, uz;
    double uEPx, uEPy, uEPz; //electrochemical induced velocity
    double Ex, Ey, Ez;       //electrical field
    double flux_diffusive_x, flux_diffusive_y, flux_diffusive_z;
    double f0, f1, f2, f3, f4, f5, f6;
    int nr1, nr2, nr3, nr4, nr5, nr6;

    for (n = start; n < finish; n++) {

        //Load data
        Ci = Den[n];
        Ex = ElectricField[n + 0 * Np];
        Ey = ElectricField[n + 1 * Np];
        Ez = ElectricField[n + 2 * Np];
        ux = Velocity[n + 0 * Np];
        uy = Velocity[n + 1 * Np];
        uz = Velocity[n + 2 * Np];
        uEPx = zi * Di / Vt * Ex;
        uEPy = zi * Di / Vt * Ey;
        uEPz = zi * Di / Vt * Ez;

        // q=0
        f0 = dist[n];
        // q=1
        nr1 = neighborList[n]; // neighbor 2 ( > 10Np => odd part of dist)
        f1 = dist[nr1];        // reading the f1 data into register fq
        // q=2
        nr2 = neighborList[n + Np]; // neighbor 1 ( < 10Np => even part of dist)
        f2 = dist[nr2];             // reading the f2 data into register fq
        // q=3
        nr3 = neighborList[n + 2 * Np]; // neighbor 4
        f3 = dist[nr3];
        // q=4
        nr4 = neighborList[n + 3 * Np]; // neighbor 3
        f4 = dist[nr4];
        // q=5
        nr5 = neighborList[n + 4 * Np];
        f5 = dist[nr5];
        // q=6
        nr6 = neighborList[n + 5 * Np];
        f6 = dist[nr6];

        // compute diffusive flux
        flux_diffusive_x = (1.0 - 0.5 * rlx) * ((f1 - f2) - ux * Ci);
        flux_diffusive_y = (1.0 - 0.5 * rlx) * ((f3 - f4) - uy * Ci);
        flux_diffusive_z = (1.0 - 0.5 * rlx) * ((f5 - f6) - uz * Ci);
        FluxDiffusive[n + 0 * Np] = flux_diffusive_x;
        FluxDiffusive[n + 1 * Np] = flux_diffusive_y;
        FluxDiffusive[n + 2 * Np] = flux_diffusive_z;
        FluxAdvective[n + 0 * Np] = ux * Ci;
        FluxAdvective[n + 1 * Np] = uy * Ci;
        FluxAdvective[n + 2 * Np] = uz * Ci;
        FluxElectrical[n + 0 * Np] = uEPx * Ci;
        FluxElectrical[n + 1 * Np] = uEPy * Ci;
        FluxElectrical[n + 2 * Np] = uEPz * Ci;

        // q=0
        dist[n] = f0 * (1.0 - rlx) + rlx * 0.25 * Ci;

        // q = 1
        dist[nr2] =
            f1 * (1.0 - rlx) + rlx * 0.125 * Ci * (1.0 + 4.0 * (ux + uEPx));

        // q=2
        dist[nr1] =
            f2 * (1.0 - rlx) + rlx * 0.125 * Ci * (1.0 - 4.0 * (ux + uEPx));

        // q = 3
        dist[nr4] =
            f3 * (1.0 - rlx) + rlx * 0.125 * Ci * (1.0 + 4.0 * (uy + uEPy));

        // q = 4
        dist[nr3] =
            f4 * (1.0 - rlx) + rlx * 0.125 * Ci * (1.0 - 4.0 * (uy + uEPy));

        // q = 5
        dist[nr6] =
            f5 * (1.0 - rlx) + rlx * 0.125 * Ci * (1.0 + 4.0 * (uz + uEPz));

        // q = 6
        dist[nr5] =
            f6 * (1.0 - rlx) + rlx * 0.125 * Ci * (1.0 - 4.0 * (uz + uEPz));
    }
}

extern "C" void ScaLBL_D3Q7_AAeven_Ion(
    double *dist, double *Den, double *FluxDiffusive, double *FluxAdvective,
    double *FluxElectrical, double *Velocity, double *ElectricField, double Di,
    int zi, double rlx, double Vt, int start, int finish, int Np) {
    int n;
    double Ci;
    double ux, uy, uz;
    double uEPx, uEPy, uEPz; //electrochemical induced velocity
    double Ex, Ey, Ez;       //electrical field
    double flux_diffusive_x, flux_diffusive_y, flux_diffusive_z;
    double f0, f1, f2, f3, f4, f5, f6;

    for (n = start; n < finish; n++) {

        //Load data
        Ci = Den[n];
        Ex = ElectricField[n + 0 * Np];
        Ey = ElectricField[n + 1 * Np];
        Ez = ElectricField[n + 2 * Np];
        ux = Velocity[n + 0 * Np];
        uy = Velocity[n + 1 * Np];
        uz = Velocity[n + 2 * Np];
        uEPx = zi * Di / Vt * Ex;
        uEPy = zi * Di / Vt * Ey;
        uEPz = zi * Di / Vt * Ez;

        f0 = dist[n];
        f1 = dist[2 * Np + n];
        f2 = dist[1 * Np + n];
        f3 = dist[4 * Np + n];
        f4 = dist[3 * Np + n];
        f5 = dist[6 * Np + n];
        f6 = dist[5 * Np + n];

        // compute diffusive flux
        flux_diffusive_x = (1.0 - 0.5 * rlx) * ((f1 - f2) - ux * Ci);
        flux_diffusive_y = (1.0 - 0.5 * rlx) * ((f3 - f4) - uy * Ci);
        flux_diffusive_z = (1.0 - 0.5 * rlx) * ((f5 - f6) - uz * Ci);
        FluxDiffusive[n + 0 * Np] = flux_diffusive_x;
        FluxDiffusive[n + 1 * Np] = flux_diffusive_y;
        FluxDiffusive[n + 2 * Np] = flux_diffusive_z;
        FluxAdvective[n + 0 * Np] = ux * Ci;
        FluxAdvective[n + 1 * Np] = uy * Ci;
        FluxAdvective[n + 2 * Np] = uz * Ci;
        FluxElectrical[n + 0 * Np] = uEPx * Ci;
        FluxElectrical[n + 1 * Np] = uEPy * Ci;
        FluxElectrical[n + 2 * Np] = uEPz * Ci;

        // q=0
        dist[n] = f0 * (1.0 - rlx) + rlx * 0.25 * Ci;

        // q = 1
        dist[1 * Np + n] =
            f1 * (1.0 - rlx) + rlx * 0.125 * Ci * (1.0 + 4.0 * (ux + uEPx));

        // q=2
        dist[2 * Np + n] =
            f2 * (1.0 - rlx) + rlx * 0.125 * Ci * (1.0 - 4.0 * (ux + uEPx));

        // q = 3
        dist[3 * Np + n] =
            f3 * (1.0 - rlx) + rlx * 0.125 * Ci * (1.0 + 4.0 * (uy + uEPy));

        // q = 4
        dist[4 * Np + n] =
            f4 * (1.0 - rlx) + rlx * 0.125 * Ci * (1.0 - 4.0 * (uy + uEPy));

        // q = 5
        dist[5 * Np + n] =
            f5 * (1.0 - rlx) + rlx * 0.125 * Ci * (1.0 + 4.0 * (uz + uEPz));

        // q = 6
        dist[6 * Np + n] =
            f6 * (1.0 - rlx) + rlx * 0.125 * Ci * (1.0 - 4.0 * (uz + uEPz));
    }
}

extern "C" void ScaLBL_D3Q7_Ion_Init(double *dist, double *Den, double DenInit,
                                     int Np) {
    int n;
    for (n = 0; n < Np; n++) {
        dist[0 * Np + n] = 0.25 * DenInit;
        dist[1 * Np + n] = 0.125 * DenInit;
        dist[2 * Np + n] = 0.125 * DenInit;
        dist[3 * Np + n] = 0.125 * DenInit;
        dist[4 * Np + n] = 0.125 * DenInit;
        dist[5 * Np + n] = 0.125 * DenInit;
        dist[6 * Np + n] = 0.125 * DenInit;
        Den[n] = DenInit;
    }
}

extern "C" void ScaLBL_D3Q7_Ion_Init_FromFile(double *dist, double *Den,
                                              int Np) {
    int n;
    double DenInit;
    for (n = 0; n < Np; n++) {
        DenInit = Den[n];
        dist[0 * Np + n] = 0.25 * DenInit;
        dist[1 * Np + n] = 0.125 * DenInit;
        dist[2 * Np + n] = 0.125 * DenInit;
        dist[3 * Np + n] = 0.125 * DenInit;
        dist[4 * Np + n] = 0.125 * DenInit;
        dist[5 * Np + n] = 0.125 * DenInit;
        dist[6 * Np + n] = 0.125 * DenInit;
    }
}

extern "C" void ScaLBL_D3Q7_Ion_ChargeDensity(double *Den,
                                              double *ChargeDensity,
                                              int IonValence, int ion_component,
                                              int start, int finish, int Np) {

    int n;
    double Ci; //ion concentration of species i
    double CD; //charge density
    double CD_tmp;
    double F =
        96485.0; //Faraday's constant; unit[C/mol]; F=e*Na, where Na is the Avogadro constant

    for (n = start; n < finish; n++) {
        Ci = Den[n + ion_component * Np];
        CD = ChargeDensity[n];
        CD_tmp = F * IonValence * Ci;
        ChargeDensity[n] = CD * (ion_component > 0) + CD_tmp;
    }
}