Add support for a 'history' command

[loudgame] / loa-board.c

diff --git a/loa-board.c b/loa-board.c
index 8ea6f99d36bb45ad758011bee975ef57faf3c86a..21f4302ffaf676283c0e7b1495f5839f191d0194 100644 (file)
--- a/loa-board.c
+++ b/loa-board.c
@@ -17,14 +17,93 @@
  * Author: Carl Worth <cworth@cworth.org>
  */
 
+#include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <assert.h>
+#include <string.h>
+#include <ctype.h>
 
 #include <glib.h>
 
 #include "loa-board.h"
 
+static loa_bool_t
+loa_move_is_valid (const loa_move_t *move)
+{
+    return (move->x1 >= 0 && move->x1 < LOA_BOARD_SIZE &&
+           move->y1 >= 0 && move->y1 < LOA_BOARD_SIZE &&
+           move->x2 >= 0 && move->x2 < LOA_BOARD_SIZE &&
+           move->y2 >= 0 && move->y2 < LOA_BOARD_SIZE);
+}
+
+const char *
+loa_move_to_string (const loa_move_t *move)
+{
+#define LOA_MOVE_STRING_SIZE 6
+    static char move_string[LOA_MOVE_STRING_SIZE];
+
+    if (! loa_move_is_valid (move)) {
+       strcpy (move_string, "***");
+       return move_string;
+    }
+
+    snprintf (move_string, LOA_MOVE_STRING_SIZE,
+             "%c%d%c%c%d",
+             'a' + move->x1, LOA_BOARD_SIZE - move->y1,
+             move->is_capture ? 'x' : '-',
+             'a' + move->x2, LOA_BOARD_SIZE - move->y2);
+
+    return move_string;
+}
+
+loa_bool_t
+loa_move_init_from_string (loa_move_t *move, const char *string)
+{
+    char xc1, xc2, sep;
+    int x1, y1, x2, y2;
+    int matched;
+
+    /* Avoid returning uninitialized data on error. */
+    move->x1 = 0;
+    move->y1 = 0;
+    move->x2 = 0;
+    move->y2 = 0;
+    move->is_capture = 0;
+
+    matched = sscanf (string, "%c%d%c%c%d", &xc1, &y1, &sep, &xc2, &y2);
+    if (matched != 5)
+       return FALSE;
+
+    x1 = tolower (xc1) - 'a';
+    x2 = tolower (xc2) - 'a';
+    y1 = LOA_BOARD_SIZE - y1;
+    y2 = LOA_BOARD_SIZE - y2;
+
+    if (x1 < 0 || x1 >= LOA_BOARD_SIZE ||
+       y1 < 0 || y1 >= LOA_BOARD_SIZE ||
+       x2 < 0 || x2 >= LOA_BOARD_SIZE ||
+       y2 < 0 || y2 >= LOA_BOARD_SIZE)
+    {
+       return FALSE;
+    }
+
+    if (sep != '-' && sep != 'x' && sep != 'X')
+       return FALSE;
+
+    move->x1 = x1;
+    move->y1 = y1;
+    move->x2 = x2;
+    move->y2 = y2;
+
+    if (sep == 'x' || sep == 'X')
+       move->is_capture = TRUE;
+    else
+       move->is_capture = FALSE;
+
+    return TRUE;
+}
+
 /* Given an (x,y) position on the board, return the index of the array
  * used to count pieces in diagonal rows running from upper-left to
  * lower-right, (like a grave accent: à or like a backslash: \).
@@ -89,6 +168,22 @@ loa_board_remove_piece (loa_board_t *board, int x, int y)
 
 void
 loa_board_init (loa_board_t *board)
+{
+    board->moves = NULL;
+    board->moves_size = 0;
+
+    loa_board_reset (board);
+}
+
+void
+loa_board_fini (loa_board_t *board)
+{
+    if (board->moves)
+       free (board->moves);
+}
+
+void
+loa_board_reset (loa_board_t *board)
 {
     int i, x, y;
 
@@ -116,6 +211,9 @@ loa_board_init (loa_board_t *board)
        loa_board_add_piece (board, LOA_BOARD_SIZE - 1, i, LOA_CELL_WHITE);
     }
 
+    /* Leave board->moves and board->moves_size as allocated */
+    board->num_moves = 0;
+
     board->player = LOA_PLAYER_BLACK;
 }
 
@@ -177,22 +275,25 @@ loa_board_is_won (loa_board_t *board, int x, int y)
 }
 
 static loa_bool_t
-loa_board_move_legal (loa_board_t *board,
-                     int x1, int y1,
-                     int x2, int y2,
-                     char **error)
+loa_board_move_legal (loa_board_t       *board,
+                     const loa_move_t   *move,
+                     char              **error)
 {
     int x, y;
+    int x1, y1, x2, y2;
     int dx, dy;
     int step_x, step_y;
 
-    if (x1 < 0 || y1 < 0 || x1 >= LOA_BOARD_SIZE || y1 >= LOA_BOARD_SIZE ||
-       x2 < 0 || y2 < 0 || x2 >= LOA_BOARD_SIZE || y2 >= LOA_BOARD_SIZE)
+    if (! loa_move_is_valid (move))
     {
        *error = "Invalid coordinates (not on board)";
        return FALSE;
     }
 
+    x1 = move->x1;
+    y1 = move->y1;
+    x2 = move->x2;
+    y2 = move->y2;
 
     if (board->cells[x1][y1] == LOA_CELL_EMPTY) {
        *error = "There is no piece there to move";
@@ -285,6 +386,31 @@ loa_board_pass (loa_board_t *board)
     return TRUE;
 }
 
+/* Once the move is validated and executed, append it to the moves
+ * array that stores the move history. */
+static void
+loa_board_add_move_to_history (loa_board_t     *board,
+                              const loa_move_t *move)
+{
+    board->num_moves++;
+
+    if (board->num_moves > board->moves_size) {
+       if (board->moves_size)
+           board->moves_size *= 2;
+       else
+           board->moves_size = 20;
+
+       board->moves = realloc (board->moves,
+                               board->moves_size * sizeof (loa_move_t));
+       if (board->moves == NULL) {
+           fprintf (stderr, "Out of memory.\n");
+           exit (1);
+       }
+    }
+
+    board->moves[board->num_moves - 1] = *move;
+}
+
 int
 loa_board_move (loa_board_t *board,
                int x1, int y1,
@@ -292,13 +418,30 @@ loa_board_move (loa_board_t *board,
                char **error)
 {
     loa_cell_t cell;
+    loa_move_t move;
 
-    if (! loa_board_move_legal (board, x1, y1, x2, y2, error))
+    move.x1 = x1;
+    move.y1 = y1;
+    move.x2 = x2;
+    move.y2 = y2;
+
+    if (! loa_board_move_legal (board, &move, error))
        return FALSE;
 
     cell = loa_board_remove_piece (board, x1, y1);
-    loa_board_remove_piece (board, x2, y2);
-    loa_board_add_piece (board, x2, y2, cell);
+    assert (cell == board->player);
+
+    cell = loa_board_remove_piece (board, x2, y2);
+    if (cell == LOA_CELL_EMPTY) {
+       move.is_capture = FALSE;
+    } else {
+       assert (cell != board->player);
+       move.is_capture = TRUE;
+    }
+
+    loa_board_add_piece (board, x2, y2, board->player);
+
+    loa_board_add_move_to_history (board, &move);
 
     loa_board_next_player (board);