#include "save_layout.h"
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct {
  const uint8_t *bytes;
  size_t length,cursor;
  uint64_t version[2];
  unsigned reads;
} NativeReader;
extern void *factorio_map_header_original(void *,NativeReader *);
void native_map_header_read(NativeReader *r,void *out,size_t size) {
  assert(size==8 && r->reads<3 && r->cursor+size<=r->length);
  memcpy(out,r->bytes+r->cursor,size);r->cursor+=size;++r->reads;
}
int main(int argc,char **argv) {
  if(argc!=2) return 2;
  FactorioSaveLayout layout;
  assert(factorio_save_map_header(argv[1],&layout)==0);
  uint8_t *prefix=malloc(layout.next_offset);assert(prefix);
  assert(factorio_save_prefix(argv[1],prefix,layout.next_offset)==0);
  FactorioMapVersion v=layout.header.version;
  NativeReader reader={.bytes=prefix,.length=layout.next_offset,.cursor=layout.header_offset,
    .version={(uint64_t)v.major<<48|(uint64_t)v.minor<<32|(uint64_t)v.patch<<16|v.build,v.flag}};
  uint8_t native[48];memset(native,0xa5,sizeof(native));
  assert(factorio_map_header_original(native,&reader)==native);
  assert(reader.reads==3 && reader.cursor==layout.next_offset);
  assert(memcmp(native+16,layout.header.tick_fields,24)==0);
  for(unsigned i=40;i<48;++i) assert(native[i]==0xa5);
  free(prefix);
  printf("{\"status\":\"pass\",\"header_offset\":%zu,\"native_reads\":%u,"
    "\"constructor_values_match\":true,\"offset_authority\":\"recovered metadata layout; not full-engine execution\"}\n",
    layout.header_offset,reader.reads);
  return 0;
}