#include <stdlib.h>
#include <stdint.h>

/* 16 bits arranged as follows:

   MSB  : capstone or standing stone
   14-11: number of stones in the cell, 0x0-0xA valid, 0xF means empty
   0-10 : stack, LSB is top

*/
typedef uint16_t cell_t;

#define CELL_EMPTY_VALUE   0b0111100000000000
#define CELL_MASK_CAPSTAND 0b1000000000000000
#define CELL_MASK_COUNT    CELL_EMPTY_VALUE
#define CELL_MASK_STACK    0b0000011111111111
#define CELL_MASK_NOTSTACK 0b1111100000000000

#define CELL_COUNT_MAX     0b0101000000000000
#define CELL_COUNT_INC     0b0000100000000000
#define CELL_COUNT_SHIFT   11

#define CELL_IS_EMPTY(x)     ((x) == CELL_EMPTY_VALUE)
#define CELL_IS_CAPSTAND(x)  ((x) & CELL_MASK_CAPSTAND)
#define CELL_TOP_IS_BLACK(x) ((x) & 1)
#define CELL_TOP_IS_WHITE(x) (~(CELL_TOP_IS_BLACK(x)))

#define CELL_SET_TOP_BLACK(x) ((x) |= 0x0001)
#define CELL_SET_TOP_WHITE(x) ((x) &= 0xFFFE)
#define CELL_SET_CAPSTAND(x)  ((x) |= CELL_MASK_CAPSTAND)

#define CELL_GET_COUNT(x)    ((uint8_t)(((x) & CELL_MASK_COUNT) >> CELL_COUNT_SHIFT))
#define CELL_GET_STACK(x)    ((x) & CELL_MASK_STACK)
#define CELL_GET_NOTSTACK(x) ((x) & CELL_MASK_NOTSTACK)

enum ACTION_RESULT { A_OK, A_ILLEGAL, A_OVERFLOW };

typedef cell_t* board_t;
typedef uint64_t bit_board_t; // 8x8 board is exactly 8 bytes :)

#define BITBOARD_SET(bb,location) ((bb) |= 1ULL << (location))
#define BITBOARD_RST(bb,location) ((bb) &= ~(1ULL << (location)))

enum STONE_VARIANT { STONE_FLAT, STONE_STANDING, STONE_CAPSTONE };
#define STONE_IS_CAPSTAND(s) ((s == STONE_CAPSTONE) || (s == STONE_STANDING))

// Taking actions
enum ACTION_RESULT try_place_stone(board_t board, bit_board_t *capstand,
                                   const uint8_t location, const uint8_t colour,
                                   const enum STONE_VARIANT stone);

// enum ACTION_RESULT move_stack(board_t *board, bit_board *capstand, uint8_t source, uint);

// Querying things