#ifndef KALAHA_H
#define KALAHA_H

/* Constants for the current player (kalaha_state.player). The value
 * PLAYERNONE is not allowed when calling any of the functions below,
 * but kalaha_end may set the current player to PLAYERNONE if no more
 * moves are possible. kalaha_collect will also set the current player
 * to PLAYERNONE.
 */
#define PLAYERNONE -1   /* It is no player's turn. */
#define PLAYERA 0       /* It is player A's turn. */
#define PLAYERB 1       /* It is player B's turn. */

/* These constants can be used as indices into kalaha_state.holes */
#define A1 0
#define A2 1
#define A3 2
#define A4 3
#define A5 4
#define A6 5
#define A7 6
#define B1 7
#define B2 8
#define B3 9
#define B4 10
#define B5 11
#define B6 12
#define B7 13


/* State of a Kalaha Game */
typedef struct {
	int player;        /* Current player, either PLAYERA of PLAYERB */
	int holes[14];     /* Number of pieces in each hole. */
} kalaha_state;

/* Allocate and init a new Kalaha game.
 * start_player should be either PLAYERA or PLAYERB.
 */
kalaha_state * kalaha_create (int start_player);

/* Check if more moves are possible for the current player.
 * Return Values:
 * 1   No more moves possible
 * 0   More moves possible
 * state->player will be set to PLAYERNONE if no more moves are possible.
 */
int kalaha_end (kalaha_state * state);

/* Collect the remaining pieces into A7 or B7 if no more moves are possible.
 * This function can be called even if more moves are possible. It will
 * move all pieces in A1..A6 into A7 and all pieces in B1..B6 to B7.
 * This function will set state->player to PLAYERNONE.
 */
void kalaha_collect (kalaha_state * state);

/* Make a kalaha move. Number is an integer in the range 1..6.
 * Which hole is emptied depends on the current player (state->player)
 * Return Values:
 * 0:  Illeagal move
 * 1:  Ok.
 * This function will also change state->player according to the rules.
 * This function will not detect if more moves are possible.
 */
int kalaha_move (kalaha_state * state, int number);

/* Evaluate the situation from the perspective of the current player.
 * The return value measures the goodness of the current situation.
 * If *bestmove will suggest a move that is considered best.
 * depth is the number of moves that we look ahead in order to
 * evaluate the current situation. A good value to use here is 6.
 * Larger values will leed to more accurate evaluation but also to
 * significantly increased calculation times. Increasing the value of
 * depth by one will increase the calculation time by a factor of 5-10.
 */
int Score (kalaha_state * state, int * bestmove, int depth);

#endif