#include <stdlib.h>

#include "state_db.h"
#include "memory.h"

StateDB
create_stateDB()
{
    StateDB s = (StateDB)malloc(sizeof(StateNode));
    if (!s) die_exit("Cann't alloc state db node.");
    return s;
}

static MemoryPtr mem_db;

static int state_count0;

void
reset_state_count()
{
    state_count0 = 0;
}

int
state_count()
{
    return state_count0;
}


/*

    lookup_StateDB(struct state *s, StateDB *parent, StatePtr *out)

    s->memory points the real memory
    if s is new, it is copied in the database (parent).
    if s is in the database, existing state is returned.

    if return value is 0, it returns new state.
    if out is null, no copy_state is created. (lookup mode)

    Founded state or newly created state is returned in out.
    
 */

int
lookup_StateDB(StateDB s, StateDB *parent, StateDB *out)
{
    StateDB db;
    int r;

    while(1) {
      db = *parent;
      if (!db) {
	    /* not found */
        if (out) {
          db = create_stateDB();
          db->left = db->right = 0;
          db->memory = copy_memory(s->memory,&mem_db);
          db->hash = s->hash;
          state_count0 ++;
          *parent = db;
          *out = db;
        }
        return 0;
      }
      if (s->hash == db->hash) {
          r =  cmp_memory(s->memory,db->memory);
      } else
          r =  (s->hash > db->hash)? 1 : -1;
      if(!r) {
          /* bingo */
          if (out) *out = db;
          return 1;
      } else if (r>0) {
          parent = &db->left;
      } else if (r<0) {
          parent = &db->right;
      }
    }
}

/* end */