From e93d09f939c63e1814eae8e4c95859f8ed0c0296 Mon Sep 17 00:00:00 2001
From: Tibor Bizjak <tibor.bizjak@gmail.com>
Date: Tue, 3 Sep 2019 23:33:24 +0200
Subject: [PATCH] Added possible moves for king and pawn

---
 chess.py | 42 ++++++++++++++++++++++++++++++++++++++----
 1 file changed, 38 insertions(+), 4 deletions(-)

diff --git a/chess.py b/chess.py
index 13f4296..df9ef53 100644
--- a/chess.py
+++ b/chess.py
@@ -84,6 +84,9 @@ class Game:
     def occupying(self, piece):
         return [sq for sq in squares if self.board[sq] == piece]
 
+    def is_attacked(self, sq):
+        return False
+
     def possible_moves(self, sq):
         def is_possible(target):
             return target in squares and \
@@ -111,10 +114,37 @@ class Game:
             vecs = [ldvecs, rdvecs, negatevs(ldvecs), negatevs(rdvecs)]
             return sum(map(are_possible, vecs), [])
 
-        piece = self.board[sq].piece
+        board = self.board
+        piece = board[sq].piece
+        color = board[sq].color
 
         if piece == "pawn":
-            pass
+            r = []
+            direction = (0,1)
+            if color == "black":
+                direction = (0, -1)
+            frwd  = addv(sq, direction)
+            jump = addv(frwd, direction)
+            eatl = addv(frwd, (-1, 0))
+            eatr = addv(frwd,  (1, 0))
+
+            if is_possible(frwd) and self.is_empty(frwd):
+                r.append(frwd)
+            checklr = lambda x: is_possible(x) \
+                                and \
+                                not self.is_empty(x) \
+                                and \
+                                board[x].color != color
+            if checklr(eatl):
+                r.append(eatl)
+            if checklr(eatr):
+                r.append(eatr)
+            is_on_pawn_rank = (color == "black" and sq[1]=='7') \
+                              or \
+                              (color == "white" and sq[1]=='2')
+            if is_possible(jump) and frwd in r and self.is_empty(jump) and is_on_pawn_rank:
+                r.append(jump)
+            return r
         elif piece == "knight":
             vecs =  list(product((1,-1), (2,-2)))
             vecs += list(product((2,-2), (1,-1)))
@@ -125,6 +155,10 @@ class Game:
             return possible_bishop()
         elif piece == "queen":
             return possible_bishop() + possible_rook()
+        elif piece == "king":
+            vecs = product([-1, 0, 1], [-1, 0, 1])
+            return [sq for sq in addvs(sq, vecs)
+                       if is_possible(sq) and not self.is_attacked(sq)]
 
 
 
@@ -132,8 +166,8 @@ def test():
     game = Game()
     assert len(squares) == 8**2
     assert sum(map(len, init_positions.values())) == 8*4
-    game.board["d4"] = Piece("black", "bishop")
+    game.board["d3"] = Piece("black", "queen")
     print(game)
-    print (game.possible_moves("d4"))
+    print (game.possible_moves("d2"))
 
 test()