#ifndef HYPERION_LAYOUT_H
#define HYPERION_LAYOUT_H
#include <stdbool.h>
#include <stddef.h>
#include <stdlib.h>
#include <dlfcn.h>
#include <math.h>
typedef struct {unsigned char a,b;unsigned weight;} LedBlend;
/* Measured G4 rim samples, independent of LED count and wiring order. */
static const struct {double position;unsigned char region;} rim[]={
 {0.2078431373,7},{0.3176470588,3},{0.5490196078,11},{0.7529411765,12},
 {0.8392156863,13},{1.4941176471,10},{2.1843137255,9},{2.5490196078,1},
 {2.8666666667,5},{3.4,15}
};
static double screen_perimeter(double x,double y){
 double distances[]={y,1-x,1-y,x},positions[]={x,1+y,3-x,4-y};unsigned edge=0;
 for(unsigned i=1;i<4;i++)if(distances[i]<distances[edge])edge=i;
 return positions[edge]>=4?positions[edge]-4:positions[edge];
}
static LedBlend layout_blend(double x,double y){
 double t=screen_perimeter(x,y);unsigned n=sizeof(rim)/sizeof(*rim),right=0;
 while(right<n && rim[right].position<=t)right++;
 right%=n;unsigned left=(right+n-1)%n;
 double span=rim[right].position-rim[left].position,distance=t-rim[left].position;
 if(span<=0)span+=4;
 if(distance<0)distance+=4;
 return (LedBlend){rim[left].region,rim[right].region,(unsigned)(distance/span*65535+0.5)};
}
/* Use the TV's JSON-C library; validate every rectangle before replacing the
 * layout. The safety limit is independent of the installed LED count. */
static bool layout_from_json(const char *text,LedBlend **result,unsigned *count){
 void *lib=dlopen("libjson-c.so.5",RTLD_NOW);if(!lib)return false;
 void *(*parse)(const char*)=dlsym(lib,"json_tokener_parse");
 int (*get)(const void*,const char*,void**)=dlsym(lib,"json_object_object_get_ex");
 int (*type)(const void*)=dlsym(lib,"json_object_get_type");
 size_t (*length)(const void*)=dlsym(lib,"json_object_array_length");
 void *(*at)(const void*,size_t)=dlsym(lib,"json_object_array_get_idx");
 double (*number)(const void*)=dlsym(lib,"json_object_get_double");
 int (*put)(void*)=dlsym(lib,"json_object_put");
 if(!parse||!get||!type||!length||!at||!number||!put){dlclose(lib);return false;}
 void *root=parse(text),*info=NULL,*leds=NULL;bool valid=root && type(root)==4 && get(root,"info",&info) && type(info)==4 && get(info,"leds",&leds) && type(leds)==5;
 size_t n=valid?length(leds):0;valid=valid && n>0 && n<=16384;
 LedBlend *mapping=valid?calloc(n,sizeof(*mapping)):NULL;valid=valid && mapping;
 const char *keys[]={"hmin","hmax","vmin","vmax"};
 for(size_t i=0;valid && i<n;i++){
  void *led=at(leds,i);double coordinates[4];valid=led && type(led)==4;
  for(unsigned c=0;valid && c<4;c++){
   void *v=NULL;valid=get(led,keys[c],&v) && (type(v)==2||type(v)==3);
   if(valid){coordinates[c]=number(v);valid=isfinite(coordinates[c]) && coordinates[c]>=0 && coordinates[c]<=1;}
  }
  if(valid)valid=coordinates[0]<=coordinates[1] && coordinates[2]<=coordinates[3];
  if(valid)mapping[i]=layout_blend((coordinates[0]+coordinates[1])/2,(coordinates[2]+coordinates[3])/2);
 }
 if(root)put(root);
 dlclose(lib);
 if(!valid){free(mapping);return false;}
 *result=mapping;*count=(unsigned)n;return true;
}
#endif