#include <errno.h>

#include <math.h>

#include "proj.h"

#include "proj_internal.h"

PROJ_HEAD(urmfps, "Urmaev Flat-Polar Sinusoidal") "\n\tPCyl, Sph\n\tn=";

PROJ_HEAD(wag1, "Wagner I (Kavrayskiy VI)") "\n\tPCyl, Sph";

namespace { // anonymous namespace

struct pj_urmfps {

    double n, C_y;

};

} // anonymous namespace

#define C_x 0.8773826753

#define Cy 1.139753528477

static PJ_XY urmfps_s_forward(PJ_LP lp, PJ *P) { /* Spheroidal, forward */

    PJ_XY xy = {0.0, 0.0};

    lp.phi = aasin(P->ctx,

                   static_cast<struct pj_urmfps *>(P->opaque)->n * sin(lp.phi));

    xy.x = C_x * lp.lam * cos(lp.phi);

    xy.y = static_cast<struct pj_urmfps *>(P->opaque)->C_y * lp.phi;

    return xy;

}

static PJ_LP urmfps_s_inverse(PJ_XY xy, PJ *P) { /* Spheroidal, inverse */

    PJ_LP lp = {0.0, 0.0};

    xy.y /= static_cast<struct pj_urmfps *>(P->opaque)->C_y;

    lp.phi = aasin(P->ctx,

                   sin(xy.y) / static_cast<struct pj_urmfps *>(P->opaque)->n);

    lp.lam = xy.x / (C_x * cos(xy.y));

    return lp;

}

static PJ *urmfps_setup(PJ *P) {

    static_cast<struct pj_urmfps *>(P->opaque)->C_y =

        Cy / static_cast<struct pj_urmfps *>(P->opaque)->n;

    P->es = 0.;

    P->inv = urmfps_s_inverse;

    P->fwd = urmfps_s_forward;

    return P;

}

PJ *PJ_PROJECTION(urmfps) {

    struct pj_urmfps *Q =

        static_cast<struct pj_urmfps *>(calloc(1, sizeof(struct pj_urmfps)));

    if (nullptr == Q)

        return pj_default_destructor(P, PROJ_ERR_OTHER /*ENOMEM*/);

    P->opaque = Q;

    if (!pj_param(P->ctx, P->params, "tn").i) {

        proj_log_error(P, _("Missing parameter n."));

        return pj_default_destructor(P, PROJ_ERR_INVALID_OP_MISSING_ARG);

    }

    Q->n = pj_param(P->ctx, P->params, "dn").f;

    if (Q->n <= 0. || Q->n > 1.) {

        proj_log_error(P,

                       _("Invalid value for n: it should be in ]0,1] range."));

        return pj_default_destructor(P, PROJ_ERR_INVALID_OP_ILLEGAL_ARG_VALUE);

    }

    return urmfps_setup(P);

}

PJ *PJ_PROJECTION(wag1) {

    struct pj_urmfps *Q =

        static_cast<struct pj_urmfps *>(calloc(1, sizeof(struct pj_urmfps)));

    if (nullptr == Q)

        return pj_default_destructor(P, PROJ_ERR_OTHER /*ENOMEM*/);

    P->opaque = Q;

    static_cast<struct pj_urmfps *>(P->opaque)->n =

        0.8660254037844386467637231707;

    return urmfps_setup(P);

}

#undef C_x

#undef Cy