/*
 * Copyright 2005-2016 ECMWF.
 *
 * This software is licensed under the terms of the Apache Licence Version 2.0
 * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
 *
 * In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
 * virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
 */

#include "grib_api_internal.h"

/*
   This is used by make_class.pl

   START_CLASS_DEF
   CLASS      = nearest
   SUPER      = grib_nearest_class_gen
   IMPLEMENTS = init;destroy;find
   MEMBERS    = double* lats
   MEMBERS    = int  lats_count
   MEMBERS    = double* lons
   MEMBERS    = double* distances
   MEMBERS    = int* k
   MEMBERS    = int* j
   MEMBERS    = const char* Nj
   MEMBERS    = const char* pl
   MEMBERS    = const char* lonFirst
   MEMBERS    = const char* lonLast
   END_CLASS_DEF

 */

/* START_CLASS_IMP */

/*

Don't edit anything between START_CLASS_IMP and END_CLASS_IMP
Instead edit values between START_CLASS_DEF and END_CLASS_DEF
or edit "nearest.class" and rerun ./make_class.pl

*/


static void init_class              (grib_nearest_class*);

static int init               (grib_nearest* nearest,grib_handle* h,grib_arguments* args);
static int find(grib_nearest* nearest, grib_handle* h,double inlat, double inlon, unsigned long flags, double* outlats,double* outlons, double *values,double *distances, int *indexes,size_t *len);
static int destroy            (grib_nearest* nearest);

typedef struct grib_nearest_latlon_reduced{
  grib_nearest nearest;
/* Members defined in gen */
	const char* values_key;
	const char* radius;
	int cargs;
/* Members defined in latlon_reduced */
	double* lats;
	int  lats_count;
	double* lons;
	double* distances;
	int* k;
	int* j;
	const char* Nj;
	const char* pl;
	const char* lonFirst;
	const char* lonLast;
} grib_nearest_latlon_reduced;

extern grib_nearest_class* grib_nearest_class_gen;

static grib_nearest_class _grib_nearest_class_latlon_reduced = {
    &grib_nearest_class_gen,                         /* super                     */
    "latlon_reduced",                         /* name                      */
    sizeof(grib_nearest_latlon_reduced),      /* size of instance          */
    0,                              /* inited */
    &init_class,                    /* init_class */
    &init,                          /* constructor               */
    &destroy,                       /* destructor                */
    &find,                          /* find nearest              */
};

grib_nearest_class* grib_nearest_class_latlon_reduced = &_grib_nearest_class_latlon_reduced;


static void init_class(grib_nearest_class* c)
{
}
/* END_CLASS_IMP */

static int init(grib_nearest* nearest,grib_handle* h,grib_arguments* args)
{
  grib_nearest_latlon_reduced* self = (grib_nearest_latlon_reduced*) nearest;
  self->Nj  = grib_arguments_get_name(h,args,self->cargs++);
  self->pl  = grib_arguments_get_name(h,args,self->cargs++);
  self->lonFirst  = grib_arguments_get_name(h,args,self->cargs++);
  self->lonLast  = grib_arguments_get_name(h,args,self->cargs++);
  self->j=(int*)grib_context_malloc(h->context,2*sizeof(int));
  if (!self->j) return GRIB_OUT_OF_MEMORY;
  self->k=(int*)grib_context_malloc( nearest->context,4*sizeof(int));
  if (!self->k) return GRIB_OUT_OF_MEMORY;

  return 0;
}

static int find(grib_nearest* nearest, grib_handle* h,
                double inlat, double inlon,unsigned long flags,
                double* outlats,double* outlons, double *values,
                double *distances,int *indexes, size_t *len) {
  grib_nearest_latlon_reduced* self = (grib_nearest_latlon_reduced*) nearest;
  int ret=0,kk=0,ii=0,jj=0;
  int j=0;
  long* pla=NULL;
  long* pl=NULL;
  size_t nvalues=0;
  grib_iterator* iter=NULL;
  double lat=0,lon=0;
  long iradius;
  double radius;
  int ilat=0,ilon=0;

  if( (ret =  grib_get_size(h,self->values_key,&nvalues))!= GRIB_SUCCESS)
     return ret;
  nearest->values_count = nvalues;

  if (grib_is_missing(h,self->radius,&ret)) {
    grib_context_log(h->context, GRIB_LOG_DEBUG,"Key '%s' is missing", self->radius);
    return ret ? ret : GRIB_GEOCALCULUS_PROBLEM;
  }

  if( (ret =  grib_get_long(h,self->radius,&iradius))!= GRIB_SUCCESS)
    return ret;
  radius=((double)iradius)/1000.0;

  if (!nearest->h || (flags & GRIB_NEAREST_SAME_GRID)==0) {
    double dummy=0;
    double olat=1.e10;
    long n=0;

	ilat=0,ilon=0;
    if (grib_is_missing(h,self->Nj,&ret)) {
      grib_context_log(h->context, GRIB_LOG_DEBUG,"Key '%s' is missing", self->Nj);
      return ret ? ret : GRIB_GEOCALCULUS_PROBLEM;
    }

    if( (ret =  grib_get_long(h,self->Nj,&n))!= GRIB_SUCCESS)
     return ret;
    self->lats_count=n;

    if (self->lats) grib_context_free(nearest->context,self->lats);
    self->lats=(double*)grib_context_malloc( nearest->context,
                               self->lats_count* sizeof(double));
    if (!self->lats) return GRIB_OUT_OF_MEMORY;

    if (self->lons) grib_context_free(nearest->context,self->lons);
    self->lons=(double*)grib_context_malloc( nearest->context,
                               nearest->values_count*sizeof(double));
    if (!self->lons) return GRIB_OUT_OF_MEMORY;

    iter=grib_iterator_new(h,0,&ret);
    if (ret) {
        grib_context_log(h->context,GRIB_LOG_ERROR,"unable to create iterator");
        return ret;
    }
    while(grib_iterator_next(iter,&lat,&lon,&dummy)) {
		if (olat!=lat) {
			self->lats[ilat++]=lat;
			olat=lat;
		}
      self->lons[ilon++]=lon;
    }
	self->lats_count=ilat;
	grib_iterator_delete(iter);
	
  }
  nearest->h=h;

  if (!self->distances || (flags & GRIB_NEAREST_SAME_POINT)==0
                       || (flags & GRIB_NEAREST_SAME_GRID)==0) {
    double* lons=NULL;
    int nlon=0;
    size_t plsize=0;
    long nplm1=0;
    int nearest_lons_found=0;
	double lon_first,lon_last;
	int islocal=0;
	long plmax;
	double dimin;

	if ((ret=grib_get_double(h,self->lonFirst,&lon_first))!=GRIB_SUCCESS) {
			grib_context_log(h->context,GRIB_LOG_ERROR,
				"grib_nearest_latlon_reduced.find(): unable to get %s %s\n",self->lonFirst,
				grib_get_error_message(ret));
			return ret;
	}
	if ((ret=grib_get_double(h,self->lonLast,&lon_last))!=GRIB_SUCCESS) {
			grib_context_log(h->context,GRIB_LOG_ERROR,
				"grib_nearest_latlon_reduced.find(): unable to get %s %s\n",self->lonLast,
				grib_get_error_message(ret));
			return ret;
	}

    plsize=self->lats_count;
	if( (ret=grib_get_size(h,self->pl,&plsize))!= GRIB_SUCCESS)
	       return ret;
    pla=(long*)grib_context_malloc(h->context,plsize*sizeof(long));
    if (!pla) return GRIB_OUT_OF_MEMORY;
    if( (ret=grib_get_long_array(h,self->pl,pla,&plsize))!= GRIB_SUCCESS)
       return ret;

	pl=pla;
	while ((*pl)==0) {pl++;}

	plmax=pla[0];
	for (j=0;j<plsize;j++) if (plmax<pla[j]) plmax=pla[j];
	dimin=360.0/plmax;

	if ( 360-fabs(lon_last-lon_first) < 2 * dimin ) {islocal=0;}
	else {islocal=1;}

	if (islocal) 
		for (j=0;j<plsize;j++) pla[j]--;

	/* printf("XXXX islocal=%d\n",islocal); */
    while (inlon<0) inlon+=360;
	while (inlon>360) inlon-=360;

	ilat=self->lats_count;
    if (self->lats[ilat-1] > self->lats[0]) {
       if (inlat < self->lats[0] || inlat > self->lats[ilat-1])
		   return GRIB_OUT_OF_AREA;
    } else {
      if (inlat > self->lats[0] || inlat < self->lats[ilat-1])
         return GRIB_OUT_OF_AREA;
    }

    if (!self->distances)
      self->distances=(double*)grib_context_malloc( nearest->context,4*sizeof(double));
    if (!self->distances) return GRIB_OUT_OF_MEMORY;

    grib_binary_search(self->lats,ilat-1,inlat,
                                &(self->j[0]),&(self->j[1]));

	nlon=0;
	for (jj=0;jj<self->j[0];jj++) nlon+=pl[jj];
	nplm1=pl[self->j[0]]-1;

    lons=self->lons+nlon;

    nearest_lons_found=0;
    if (lons[nplm1]>lons[0]) {
      if (inlon< lons[0] || inlon > lons[nplm1]) {
        if (lons[nplm1]-lons[0]-360 <=
             lons[nplm1]-lons[nplm1-1]) {
           self->k[0]=0;
           self->k[1]=nplm1;
           nearest_lons_found=1;
         } else return GRIB_OUT_OF_AREA;
       }
    } else {
      if (inlon >lons[0] || inlon< lons[nplm1]) {
         if (lons[0]-lons[nplm1]-360 <=
             lons[0]-lons[1]) {
           self->k[0]=0;
           self->k[1]=nplm1;
           nearest_lons_found=1;
         } else return GRIB_OUT_OF_AREA;
       }
    }

    if (!nearest_lons_found) {
      grib_binary_search(lons,pl[self->j[0]]-1,inlon,
                                &(self->k[0]),&(self->k[1]));
	}
    self->k[0]+=nlon;
    self->k[1]+=nlon;

	nlon=0;
	for (jj=0;jj<self->j[1];jj++) nlon+=pl[jj];
	nplm1=pl[self->j[1]]-1;

    lons=self->lons+nlon;

    nearest_lons_found=0;
    if (lons[nplm1]>lons[0]) {
      if (inlon<lons[0] || inlon>lons[nplm1]) {
        if (lons[nplm1]-lons[0]-360 <=
             lons[nplm1]-lons[nplm1-1]) {
           self->k[2]=0;
           self->k[3]=nplm1;
           nearest_lons_found=1;
         } else return GRIB_OUT_OF_AREA;
       }
    } else {
      if (inlon>lons[0] || inlon<lons[nplm1]) {
         if (lons[0]-lons[nplm1]-360 <=
             lons[0]-lons[1]) {
           self->k[2]=0;
           self->k[3]=nplm1;
           nearest_lons_found=1;
         } else return GRIB_OUT_OF_AREA;
       }
    }

    if (!nearest_lons_found) {
      grib_binary_search(lons,pl[self->j[1]]-1,inlon,
                                &(self->k[2]),&(self->k[3]));
	}

    self->k[2]+=nlon;
    self->k[3]+=nlon;

    kk=0;
    for (jj=0;jj<2;jj++) {
      for (ii=0;ii<2;ii++) {
        self->distances[kk]=grib_nearest_distance(radius,inlon,inlat,
                     self->lons[self->k[kk]],self->lats[self->j[jj]]);
        kk++;
      }
    }

    grib_context_free(h->context,pla);
  }

  kk=0;
  for (jj=0;jj<2;jj++) {
    for (ii=0;ii<2;ii++) {
      distances[kk]=self->distances[kk];
      outlats[kk]=self->lats[self->j[jj]];
      outlons[kk]=self->lons[self->k[kk]];
      grib_get_double_element_internal(h,self->values_key,self->k[kk],&(values[kk]));
      indexes[kk]=self->k[kk];
      kk++;
    }
  }

  return GRIB_SUCCESS;
}

static int destroy(grib_nearest* nearest) {
  grib_nearest_latlon_reduced* self = (grib_nearest_latlon_reduced*) nearest;
  if (self->lats) grib_context_free(nearest->context,self->lats);
  if (self->lons) grib_context_free(nearest->context,self->lons);
  if (self->j) grib_context_free(nearest->context,self->j);
  if (self->k) grib_context_free(nearest->context,self->k);
  if (self->distances) grib_context_free(nearest->context,self->distances);

  return GRIB_SUCCESS;
}
