commited on 20240509

system/board.cc

 #include "board.h"
 #include <string>
-#include <regex>
 
-board::board(){
+board::board():
+    last_move(0,0)
+{
+    last_move_en_passant_eligible = false;
     white_pieces = {};
     for(int i = 0; i < 8; i++){
         white_pieces.push_back(new pawn(true,coordinates(i,1)));
@@ -180,16 +182,35 @@ void board::move(coordinates move_from, coordinates move_to){
     board_data[move_to.get_x()][move_to.get_y()] = board_data[move_from.get_x()][move_from.get_y()];
     board_data[move_to.get_x()][move_to.get_y()]->move(move_to,false);
     board_data[move_from.get_x()][move_from.get_y()] = nullptr;
+    last_move.move(move_to);
+    // last_move_en_passant_eligible attribute update if the piece moved is a pawn and it moves 2 cases.
+    last_move_en_passant_eligible = (board_data[move_to.get_x()][move_to.get_y()]->get_type() == pawn_type)&&
+    (abs(move_to.get_y() - move_from.get_y()) == 2);
 }
 
-/// @brief Check if an input is conform
-/// @param cmd the input string
-/// @return a boolean indicating if the input is conform
-bool correct_input(std::string const & cmd){
-    std::regex mouvmtpattern("[a-h][1-8][a-h][1-8]");
-    std::regex kingcastlemouvmtpattern("(O|o|0)-(O|o|0)");
-    std::regex queencastlemouvmtpattern("(O|o|0)-(O|o|0)-(O|o|0)");
-    return regex_match(cmd,mouvmtpattern) || regex_match(cmd,kingcastlemouvmtpattern) || regex_match(cmd,queencastlemouvmtpattern);
+bool board::is_en_passant_legal(coordinates move_from, coordinates move_to, bool white_move){
+    // We successively check all conditions
+    // First, checking the moving piece type
+    if(board_data[move_from.get_x()][move_from.get_y()]->get_type() != pawn_type){
+        return false;
+    }
+    // The en passant move is the same as the attack one
+    if(!board_data[move_from.get_x()][move_from.get_y()]->is_possible_attack(move_to)){
+        return false;
+    }
+    // The captured piece need to be the last played one, and be en_passant eligible
+    if((last_move.get_x() != move_to.get_x()) || (last_move.get_y() != move_from.get_y()) || !last_move_en_passant_eligible){
+        return false;
+    }
+    // The captured piece need to be one the same x of the destination, and on the same y of the starting point, and the opposite color
+    if(board_data[move_to.get_x()][move_from.get_y()]->get_color() == white_move){
+        return false;
+    }
+    // The captured piece need to be one the same x of the destination, and on the same y of the starting point, and a pawn
+    if(board_data[move_to.get_x()][move_from.get_y()]->get_type() != pawn_type){
+        return false;
+    }
+    return true;
 }
 
 /// @brief Check if a move is legal
@@ -210,11 +231,20 @@ bool board::is_legal(coordinates move_from, coordinates move_to, bool white_move
     std::vector<coordinates> empty_check = {};
     if(board_data[move_to.get_x()][move_to.get_y()] == nullptr){
         //Destination case is empty
-        if(!board_data[move_from.get_x()][move_from.get_y()]->is_possible(move_to)){
-            // The normal move isn't possible
-            return false;
+        if(is_en_passant_legal(move_from,move_to,white_move)){
+            // The en-passant special case, we capture the corresponding pawn
+            erase_piece(coordinates(move_to.get_x(),move_from.get_y()));
+            board_data[move_to.get_x()][move_from.get_y()] = nullptr;
+        }else{
+            if(!board_data[move_from.get_x()][move_from.get_y()]->is_possible(move_to)){
+                // The normal move isn't possible
+                return false;
+            }
         }
+        
         board_data[move_from.get_x()][move_from.get_y()]->needed_space(move_to, &empty_check);
+
+
     }else{
         if(board_data[move_to.get_x()][move_to.get_y()]->get_color() == white_move){
             //Destination case support a piece of the same color, wrong move
@@ -251,6 +281,9 @@ coordinates get_coord_from_string(std::string move){
     return coordinates(result_x,result_y);
 }
 
+/// @brief retrieve the king coordinates
+/// @param white_king if the selected king is white
+/// @return the coordinates of the selected king
 coordinates board::get_king_coord(bool white_king){
     coordinates result (0,0);
     if(white_king){

system/board.h

@@ -24,6 +24,8 @@ class board{
         piece * board_data[8][8];
         std::vector<piece*> white_pieces;
         std::vector<piece*> black_pieces;
+        coordinates last_move;
+        bool last_move_en_passant_eligible;
     public:
         board();
         void print();
@@ -34,10 +36,10 @@ class board{
         void erase_piece(coordinates coord);
         coordinates get_king_coord(bool white_king);
         bool is_check(bool white_king);
+        bool is_en_passant_legal(coordinates move_from, coordinates move_to, bool white_move);
 };
 
 void print_neutral_endl();
-bool correct_input(std::string const & cmd);
 void print_line_separator(bool inverted);
 coordinates get_coord_from_string(std::string move);
 

system/utilities.cc

@@ -78,4 +78,38 @@ void terminal_set_background_color(terminal_color color){
 /// @brief reset all terminal attributes
 void terminal_reset_all(){
     std::cout << "\033[0m";
+}
+
+/// @brief Check if an input is conform
+/// @param cmd the input string
+/// @return a boolean indicating if the input is conform
+bool correct_input(std::string const & cmd){
+    std::regex mouvmtpattern("[a-h][1-8][a-h][1-8]");
+    std::regex kingcastlemouvmtpattern("(O|o|0)-(O|o|0)");
+    std::regex queencastlemouvmtpattern("(O|o|0)-(O|o|0)-(O|o|0)");
+    return regex_match(cmd,mouvmtpattern) || regex_match(cmd,kingcastlemouvmtpattern) || regex_match(cmd,queencastlemouvmtpattern);
+}
+
+/// @brief Check if an input corresponds to a standard move
+/// @param cmd the input string
+/// @return a boolean indicating if the input is a standard move
+bool standard_input(std::string const & cmd){
+    std::regex mouvmtpattern("[a-h][1-8][a-h][1-8]");
+    return regex_match(cmd,mouvmtpattern);
+}
+
+/// @brief Check if an input correponds to a king castling move
+/// @param cmd the input string
+/// @return a boolean indicating if the input is a king castling move
+bool king_castle_input(std::string const & cmd){
+    std::regex kingcastlemouvmtpattern("(O|o|0)-(O|o|0)");
+    return regex_match(cmd,kingcastlemouvmtpattern);
+}
+
+/// @brief Check if an input corresponds to a queen castling move
+/// @param cmd the input string
+/// @return a boolean indicating if the input is a queen castling move
+bool queen_castle_input(std::string const & cmd){
+    std::regex queencastlemouvmtpattern("(O|o|0)-(O|o|0)-(O|o|0)");
+    return regex_match(cmd,queencastlemouvmtpattern);
 }
\ No newline at end of file

system/utilities.h

 #ifndef UTILITIES
 #define UTILITIES
 #include "coordinates.h"
+#include <regex>
 
 /// @brief a type for terminal colors, used in the print functions.
 enum terminal_color { terminal_black, terminal_red, terminal_green, terminal_yellow, terminal_blue, terminal_magenta, terminal_cyan, terminal_white };
@@ -9,5 +10,9 @@ bool is_corresponding(coordinates start, coordinates end, coordinates movement);
 void terminal_set_text_color(terminal_color color);
 void terminal_set_background_color(terminal_color color);
 void terminal_reset_all();
+bool correct_input(std::string const & cmd);
+bool standard_input(std::string const & cmd);
+bool king_castle_input(std::string const & cmd);
+bool queen_castle_input(std::string const & cmd);
 
 #endif
\ No newline at end of file