#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <apc/ir.h>
#include <unistd.h>

struct cdat*
alloc_cdat(void);
struct odat*
alloc_odat(void);
void
alloc_vdat(void);
struct link*
alloc_link(void);
struct ref*
alloc_ref(void);
struct cdat*
curr_cdat(void);
struct odat*
curr_odat(void);
struct vdat*
curr_vdat(void);
struct set*
curr_set(void);
struct ref*
prev_ref(void);
struct model*
curr_model(void);
void
inc_posts(void);

#define PAGES_PER_CHUNK 16

#define CURR_CDAT  (*cdat_stackp)
//"type free" chunk stacking
struct chunk_stack
{ void* chunks[MAX_CHUNKS];
  void* csp;             //chunk stack pointer
  void* dsp[MAX_CHUNKS]; //dat stack pointer (per chunk)
  int max_dats;        //num dats in a chunk
} ocs, vcs, ccs, rcs, lcs, pcs;         //odat, vdat, and cdat, ref, link, post stacks

//type safety handled by macro expansion
#define CURRENT_CHUNK(STACK) ( (void*) (STACK).csp - (void*) (STACK).chunks - 1)
#define CHUNKS_LEN(STACK)    ( (void*) (STACK).csp - (void*) (STACK).chunks)
#define CHUNK_FULL(STACK, TYPE)   ( (CURRENT_DAT(STACK,TYPE) - (TYPE) CURRENT_CHUNK(STACK)) \
                                   >= (STACK).max_dats )
#define CSP_PUSH(STACK)     (++(STACK).csp = malloc(pagesize * PAGES_PER_CHUNK))
#define CURRENT_DAT(STACK,TYPE) ((TYPE) (STACK).dsp[CHUNKS_LEN(STACK)])
#define PREVIOUS_DAT(STACK,TYPE) ((TYPE) (STACK).dsp[CHUNKS_LEN(STACK)]-1)
#define INCREMENT_DAT(STACK,TYPE) (++CURRENT_DAT(STACK,TYPE))
//Stack-specific macros
#define CURRENT_ODAT() (CURRENT_DAT(ocs,struct odat*))
#define CURRENT_VDAT() (CURRENT_DAT(vcs,struct vdat*))
#define CURRENT_CDAT() (CURRENT_DAT(ccs,struct cdat*))
#define CURRENT_LINK()  (CURRENT_DAT(lcs,struct link*))
#define CURRENT_POST()  (CURRENT_DAT(pcs,struct ref*))
#define CURRENT_REF()  (CURRENT_DAT(rcs,struct ref*))
#define PREVIOUS_REF()  (PREVIOUS_DAT(rcs, struct ref*))
//Metadata
#define CURRENT_SET()  (CURRENT_CDAT()->set_list[CURRENT_CDAT()->num_sets])
#define CURRENT_MODEL() (CURRENT_VDAT()->model_list[CURRENT_VDAT()->num_models])


#define CURR_QUAD  (CURR_ODAT->quad_file)

long pagesize;

int pages_per_chunk = 10;

int num_cdats = 0;
int curr_max_cdats = PTRS_IN_PAGE;

struct cdat* cdat_buf[PTRS_IN_PAGE];
struct cdat* cdat_stack[PTRS_IN_PAGE];
struct cdat** cdat_stackp;

int num_odats = 0;

int num_vdats = 0;

int num_refs = 0;
uint64_t ss_ref_id = 0x00FFFFFF; /* system space for ref_ids */

int num_posts = -1;
int curr_max_posts = PTRS_IN_PAGE;
struct ref* post_buf[PTRS_IN_PAGE];


int num_links = -1;
int curr_max_links = PTRS_IN_PAGE;
struct link* link_buf[PTRS_IN_PAGE];


/* The initalization function of the IR. */
int
ir_init()
{

  /* Init root cdat and stack */
  char root[4] = "root";

  if( (cdat_buf[num_cdats] = (struct cdat*) malloc(sizeof(struct cdat))) == NULL)
    {
      perror("malloc root class failed\n");
      return -1;
    }
  cdat_buf[num_cdats]->idx = num_cdats;
  memmove(cdat_buf[num_cdats]->name, root, 4);

  cdat_stackp = cdat_stack;
  *cdat_stackp++ = cdat_buf[num_cdats++];

  pagesize = sysconf(_SC_PAGESIZE);

  return 0;

}

void
ir_quit()
{
  int i;

  for(i = 0; i <= num_odats ; i++)
    {
    }
  for(i = 0; i <= num_cdats; i++)
    {
    }
  for(i = 0; i <= num_vdats; i++)
    {
    }
  for(i = 0; i <= num_refs; i++)
    {
    }
  for(i = 0; i<= num_links; i++)
    {
    }
  for(i = 0; i<= num_posts; i++)
    {
    }

}

//TODO: FREE MEMORY!
struct cdat*
alloc_cdat()
{
  num_cdats++;
  if(curr_max_cdats <= num_cdats)
    { if( (realloc((void*) cdat_buf, PTRS_IN_PAGE * 4)) == NULL)
        perror("realloc cdat_buf failed");
      curr_max_cdats += PTRS_IN_PAGE;
      if( (realloc( (void*) cdat_stack, PTRS_IN_PAGE * 4)) == NULL) //increase cdat_stack also
        perror("realloc cdat_stack failed");
    }
  if( (CURR_CDAT = (struct cdat*) malloc(sizeof (struct cdat)) ) == NULL )
    perror("malloc cdat failed");

  return CURR_CDAT;

}
struct odat*
alloc_odat
()
{
  if(CHUNK_FULL(ocs, struct odat*))
      CSP_PUSH(ocs);
  else
    INCREMENT_DAT(ocs, struct odat*);

  return CURRENT_ODAT();
}

void
alloc_vdat
()
{
  num_vdats++;

  if(CHUNK_FULL(vcs, struct vdat*))
    CSP_PUSH(vcs);
  else
    INCREMENT_DAT(vcs, struct vdat*);

}

struct link*
alloc_link
()
{
  num_links++;

  if(CHUNK_FULL(lcs, struct link*))
    CSP_PUSH(lcs);
  else
    INCREMENT_DAT(lcs, struct link*);

  return CURRENT_LINK();
}

struct ref*
alloc_ref
()
{
  num_refs++;
  if(CHUNK_FULL(rcs, struct link*))
    CSP_PUSH(rcs);
  else
    INCREMENT_DAT(rcs, struct link*);

  if(num_refs % 16 == 0)
    { CURRENT_POST() = CURRENT_REF();
      inc_posts();
    }

  return CURRENT_REF();
}

void
inc_posts()
{
  num_posts++;

  if(CHUNK_FULL(pcs, struct ref*))
    {CSP_PUSH(pcs);}
  else
    INCREMENT_DAT(pcs, struct ref*);


}

struct cdat*
curr_cdat
()
{
  return CURR_CDAT;
}

struct odat*
curr_odat
()
{
  return CURRENT_ODAT();
}
struct vdat*
curr_vdat
()
{
  return CURRENT_VDAT();
}
struct set*
curr_set
()
{
  return &CURRENT_SET();
}
struct ref*
prev_ref
()
{
  return PREVIOUS_REF();
}
struct model*
curr_model
()
{
  return &CURRENT_MODEL();
}