#ifndef HYPERDRM_DIAGNOSTICS_H
#define HYPERDRM_DIAGNOSTICS_H
/* An independent nonblocking connection. Tests never send colors or acquire
 * capture. Work per timer iteration is bounded to keep output responsive. */
typedef enum {TEST_IDLE,TEST_CONNECT,TEST_SEND,TEST_LOGIN,TEST_LAYOUT,TEST_DONE,TEST_FAILED} TestStage;
typedef struct {
 int fd;TestStage stage,after_send;TargetConfig target;
 uint64_t started,deadline,elapsed;unsigned leds;
 char request[384],error[128];size_t sent,used;char *response;
 LedBlend *mapping;
} ReceiverProbe;
static ReceiverProbe connection_test={.fd=-1};
static const char *probe_stage_name(const ReceiverProbe *probe){
 static const char *names[]={"Not tested","Connecting","Sending request","Checking authentication","Reading LED layout","Passed","Failed"};
 return names[probe->stage];
}
static bool probe_busy(const ReceiverProbe *probe){return probe->stage>=TEST_CONNECT && probe->stage<=TEST_LAYOUT;}
static void probe_close(ReceiverProbe *probe){if(probe->fd>=0)close(probe->fd);probe->fd=-1;free(probe->mapping);probe->mapping=NULL;free(probe->response);probe->response=NULL;memset(probe->request,0,sizeof(probe->request));memset(probe->target.token,0,sizeof(probe->target.token));}
static void probe_finish(ReceiverProbe *probe,const char *error,uint64_t now){
 probe_close(probe);probe->elapsed=now-probe->started;
 probe->stage=error?TEST_FAILED:TEST_DONE;
 snprintf(probe->error,sizeof(probe->error),"%s",error?error:"");
}
static void probe_request(ReceiverProbe *probe,bool login,uint64_t now){
 if(login)snprintf(probe->request,sizeof(probe->request),"{\"command\":\"authorize\",\"subcommand\":\"login\",\"token\":\"%s\"}\n",probe->target.token);
 else snprintf(probe->request,sizeof(probe->request),"{\"command\":\"serverinfo\"}\n");
 probe->sent=probe->used=0;probe->after_send=login?TEST_LOGIN:TEST_LAYOUT;
 probe->stage=TEST_SEND;probe->deadline=now+3000;
}
static bool probe_begin(ReceiverProbe *probe,const TargetConfig *target,uint64_t now){
 if(probe_busy(probe))return false;
 probe_close(probe);memset(probe,0,sizeof(*probe));probe->fd=-1;
 probe->target=*target;probe->started=now;
 probe->response=malloc(2*1024*1024+1);
 if(!probe->response){probe_finish(probe,"Cannot allocate connection test buffer",now);return true;}
 probe->fd=target_open(target);
 if(probe->fd<0){probe_finish(probe,"Cannot open receiver connection",now);return true;}
 probe->stage=TEST_CONNECT;probe->deadline=now+3000;return true;
}
static void probe_tick(ReceiverProbe *probe,PlaybackJson *json,uint64_t now){
 if(!probe_busy(probe))return;
 if(now>=probe->deadline){probe_finish(probe,"Receiver timed out",now);return;}
 int fd=probe->fd;
 if(probe->stage==TEST_CONNECT){
  struct pollfd p={fd,POLLOUT,0};int error=0;socklen_t size=sizeof(error);
  if(poll(&p,1,0)<=0)return;
  if(getsockopt(fd,SOL_SOCKET,SO_ERROR,&error,&size)!=0 || error){probe_finish(probe,"Receiver connection refused or unreachable",now);return;}
  probe_request(probe,probe->target.token[0]!=0,now);return;
 }
 if(probe->stage==TEST_SEND){
  size_t length=strlen(probe->request);
  ssize_t n=send(fd,probe->request+probe->sent,length-probe->sent,MSG_NOSIGNAL);
  if(n<0 && (errno==EAGAIN || errno==EWOULDBLOCK || errno==EINTR))return;
  if(n<=0){probe_finish(probe,"Receiver closed the test connection",now);return;}
  probe->sent+=(size_t)n;
  if(probe->sent==length){probe->stage=probe->after_send;probe->deadline=now+3000;memset(probe->request,0,sizeof(probe->request));}
  return;
 }
 size_t available=2*1024*1024-probe->used;if(available>65536)available=65536;
 if(!available){probe_finish(probe,"Receiver response exceeds 2 MiB",now);return;}
 ssize_t n=recv(fd,probe->response+probe->used,available,0);
 if(n<0 && (errno==EAGAIN || errno==EWOULDBLOCK || errno==EINTR))return;
 if(n<=0){probe_finish(probe,"Receiver closed the test connection",now);return;}
 probe->used+=(size_t)n;probe->response[probe->used]=0;
 char *end=strchr(probe->response,'\n');if(!end)return;*end=0;
 void *root=json->parse(probe->response);bool success=playback_true(json,root,"success");if(root)json->put(root);
 if(!success){probe_finish(probe,probe->stage==TEST_LOGIN?"Receiver authentication failed":"Receiver rejected serverinfo; check authorization",now);return;}
 if(probe->stage==TEST_LOGIN){probe_request(probe,false,now);return;}
 LedBlend *mapping=NULL;unsigned count=0;
 if(!layout_from_json(probe->response,&mapping,&count)){probe_finish(probe,"Receiver returned an invalid or empty LED layout",now);return;}
 probe->leds=count;probe_finish(probe,NULL,now);probe->mapping=mapping;
}
static inline const char *test_stage_name(void){return probe_stage_name(&connection_test);}
static inline bool test_busy(void){return probe_busy(&connection_test);}
static inline void test_close(void){probe_close(&connection_test);}
static inline bool test_begin(const TargetConfig *target,uint64_t now){return probe_begin(&connection_test,target,now);}
static inline void test_tick(PlaybackJson *json,uint64_t now){probe_tick(&connection_test,json,now);}
#endif