basic bit board with fen loading

Missing moves loading

.gitignore

@@ -0,0 +1 @@
+/a.out

main.c

@@ -1,11 +1,50 @@
+#include <assert.h>
+#include <ctype.h>
+#include <stdbool.h>
+#include <stddef.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 
 #define BUFF_SIZE 4096
 
+typedef struct {
+  long long pawns;
+  long long knights;
+  long long bishops;
+  long long rooks;
+  long long queen;
+  long long king;
+} sets;
+
+typedef struct {
+  sets white;
+  sets black;
+  bool whiteToMove;
+} game;
+
+game *fenGame(char *str);
+
+void print_bitboard(long long bitboard) {
+  for (int i = 63; i >= 0; i--) {
+    // Check if the i-th bit is set
+    if ((bitboard >> i) & 1) {
+      printf("1 ");
+    } else {
+      printf("0 ");
+    }
+    // Print a newline every 8 bits (for rows)
+    if (i % 8 == 0) {
+      printf("\n");
+    }
+  }
+  printf("\n");
+}
+
 int main() {
   setbuf(stdin, NULL);
   setbuf(stdout, NULL);
+  game *g = NULL;
 
   char line[BUFF_SIZE];
   char *lineRest, *token;
@@ -19,12 +58,28 @@ int main() {
     token = strtok_r(line, " ", &lineRest);
     if (!strcmp("uci", token)) {
       printf("id name RatChess 0.0\n");
-      printf("id author rat<3\n\n");
+      printf("id author rat<3\n");
       printf("uciok\n");
     } else if (!strcmp("quit", token)) {
       return 0;
     } else if (!strcmp("setoption", token)) {
     } else if (!strcmp("position", token)) {
+      game *g;
+      token = strtok_r(lineRest, " ", &lineRest);
+      if (!strcmp("fen", token)) {
+        g = fenGame(lineRest + 1);
+        for (int i = 0; i < 6; i++)
+          token = strtok_r(lineRest, " ", &lineRest);
+      } else {
+        g = fenGame("rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1");
+      }
+      token = strtok_r(lineRest, " ", &lineRest);
+      if (!strcmp("moves", token)) {
+        // TODO
+      }
+      print_bitboard(g->white.pawns);
+      print_bitboard(g->black.pawns);
+
     } else if (!strcmp("ucinewgame", token)) {
     } else if (!strcmp("isready", token)) {
       printf("readyok\n");
@@ -34,3 +89,80 @@ int main() {
     }
   }
 }
+
+game *fenGame(char *str) {
+  int rank = 7;
+  int file = 0;
+  size_t pos = 0;
+  game *g;
+  g = malloc(sizeof(game));
+  memset(g, 0, sizeof(game));
+
+  while (str[pos] != '\0' && str[pos] != ' ') {
+    char current_char = *str;
+
+    if (isdigit(*str)) {
+      int empty_squares = *str - '0';
+      file += empty_squares;
+      str++;
+      continue;
+    }
+
+    if (current_char == '/') {
+      rank--;
+      file = 0;
+      str++;
+      continue;
+    }
+
+    long long bit = 1LL << (rank * 8 + file);
+    switch (*str) {
+    case 'P':
+      g->white.pawns |= bit;
+      break;
+    case 'N':
+      g->white.knights |= bit;
+      break;
+    case 'B':
+      g->white.bishops |= bit;
+      break;
+    case 'R':
+      g->white.rooks |= bit;
+      break;
+    case 'Q':
+      g->white.queen |= bit;
+      break;
+    case 'K':
+      g->white.king |= bit;
+      break;
+    case 'p':
+      g->black.pawns |= bit;
+      break;
+    case 'n':
+      g->black.knights |= bit;
+      break;
+    case 'b':
+      g->black.bishops |= bit;
+      break;
+    case 'r':
+      g->black.rooks |= bit;
+      break;
+    case 'q':
+      g->black.queen |= bit;
+      break;
+    case 'k':
+      g->black.king |= bit;
+      break;
+    default:
+      fprintf(stderr,
+              "Error: Unknown piece character in FEN: %c at position %zu\n",
+              *str, pos);
+      break;
+    }
+    file++;
+    str++;
+  }
+  str++;
+  g->whiteToMove = (*str == 'w') ? true : false;
+  return g;
+}