
#include "globals.h"

#define MOVE_TO_INT(mv, player)   \
   ((mv).mask_index-1)*g_board_size[(player)]+((mv).array_index-1)

#define TABLE_SET_KEY(table,index,k)                          \
   table[index].key[0] = k[0], table[index].key[1] = k[1],    \
   table[index].key[2] = k[2], table[index].key[3] = k[3]; 

#define TABLE_CMP_KEY(table,index,k)                              \
   (table[index].key[0] == k[0] && table[index].key[1] == k[1] && \
    table[index].key[2] == k[2] && table[index].key[3] == k[3]) 


#define STORE_ENTRY(x)                                          \
  index = (x).code;                                             \
                                                                \
  if(TABLE_CMP_KEY(g_trans_table, index, (x).key)               \
     || g_trans_table[index].nodes <= nodes){                   \
    TABLE_SET_KEY(g_trans_table, index, (x).key);               \
    g_trans_table[index].nodes     =nodes;                      \
    g_trans_table[index].best_move =MOVE_TO_INT(best,player);   \
    g_trans_table[index].depth     =depth;                      \
    g_trans_table[index].whos_turn =player;                     \
    g_trans_table[index].value     =value;                      \
    if     (value>=beta) g_trans_table[index].type =LOWER;      \
    else if(value>alpha) g_trans_table[index].type =EXACT;      \
    else                 g_trans_table[index].type =UPPER;      \
    return;                                                     \
  }


extern void
hashstore(s32bit value, s32bit alpha, s32bit beta,
          u32bit nodes, s32bit depth, Move best, s32bit player)
{
  s32bit index;

  STORE_ENTRY(g_norm_hashkey);
  STORE_ENTRY(g_flipV_hashkey);
  STORE_ENTRY(g_flipH_hashkey);
  STORE_ENTRY(g_flipVH_hashkey);
}


#define INT_TO_MOVE(mv, int, player)                    \
   (mv).mask_index = ((int)/g_board_size[(player)])+1;  \
   (mv).array_index = ((int)%g_board_size[(player)])+1

#define LOOKUP_ENTRY(x)                                                 \
  index = (x).code;                                                     \
  if(TABLE_CMP_KEY(g_trans_table, index, (x).key)                       \
     && g_trans_table[index].whos_turn == player ) {                    \
    /* found matching entry.*/                                          \
                                                                        \
    /* If nothing else we can use this entry to give us a good move. */ \
    INT_TO_MOVE(*force_first, g_trans_table[index].best_move, player);  \
                                                                        \
    /* use value if depth >= than the depth remaining in our search. */    \
    if(g_trans_table[index].depth >= depth_remaining) {                 \
                                                                        \
      /* if the value is exact we can use it. */                          \
      if(g_trans_table[index].type == EXACT) {                          \
        *value=g_trans_table[index].value;                              \
        return 1;                                                       \
      }                                                                 \
                                                                        \
      /* if value is a lower bound we can possibly use it. */             \
      if(g_trans_table[index].type == LOWER) {                          \
        if(g_trans_table[index].value>=(*beta)){                        \
          *value=g_trans_table[index].value;                            \
          return 1;                                                     \
        }                                                               \
        if(g_trans_table[index].value>(*alpha)){                        \
          *alpha=g_trans_table[index].value;                            \
        }                                                               \
        return 0;                                                       \
      }                                                                 \
                                                                        \
      /* if value is a upper bound we can possibly use it. */             \
      if(g_trans_table[index].type == UPPER) {                          \
        if(g_trans_table[index].value<=(*alpha)){                       \
          *value=g_trans_table[index].value;                            \
          return 1;                                                     \
        }                                                               \
        if(g_trans_table[index].value<(*beta)){                         \
          *beta=g_trans_table[index].value;                             \
        }                                                               \
        return 0;                                                       \
      }                                                                 \
    }                                                                   \
  }


extern s32bit
hashlookup(s32bit *value, s32bit *alpha, s32bit *beta,
           s32bit depth_remaining, Move *force_first, s32bit player)
{
  s32bit index;
  
  LOOKUP_ENTRY(g_norm_hashkey);
  LOOKUP_ENTRY(g_flipV_hashkey);
  LOOKUP_ENTRY(g_flipH_hashkey);
  LOOKUP_ENTRY(g_flipVH_hashkey);

  return 0;
}