From 91953ef64d02a4bbffcbf449cae815ed66de93e5 Mon Sep 17 00:00:00 2001
From: Fabro <noreply@fabro.sh>
Date: Thu, 4 Jun 2026 18:53:21 +0000
Subject: [PATCH] fabro(01KT9YT14FHDYA4VTV9DSFG0FY): impl_logic (succeeded)
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Fabro-Run: 01KT9YT14FHDYA4VTV9DSFG0FY
Fabro-Completed: 9
Fabro-Checkpoint: 916c46b57a6bcf612fe0db0729a9f2675d63105c

⚒️ Generated with [Fabro](https://fabro.sh)
---
 card-game-app/src/card_game_tui/domain.py | 48 +++++++++++++++++++++++
 card-game-app/tests/test_domain.py        | 38 ++++++++++++++++++
 2 files changed, 86 insertions(+)

diff --git a/card-game-app/src/card_game_tui/domain.py b/card-game-app/src/card_game_tui/domain.py
index fe733cef3..f1dd717f2 100644
--- a/card-game-app/src/card_game_tui/domain.py
+++ b/card-game-app/src/card_game_tui/domain.py
@@ -376,3 +376,51 @@ class GameState:
     def check_win(self) -> bool:
         """Returns True if all 52 cards are in the Foundations."""
         return all(len(self.foundations[suit]) == 13 for suit in Suit)
+
+    def check_loss(self) -> bool:
+        """
+        Returns True if the game is lost (i.e. not won and no legal moves can be made).
+        """
+        if self.check_win():
+            return False
+
+        # Check all possible moves from freecells
+        for i in range(4):
+            if self.freecells[i] is not None:
+                from_pos = Position(LocationType.FREECELL, i)
+                # To tableau
+                for j in range(8):
+                    if self.validate_move(from_pos, Position(LocationType.TABLEAU, j), 1):
+                        return False
+                # To other freecells
+                for j in range(4):
+                    if i != j and self.validate_move(from_pos, Position(LocationType.FREECELL, j), 1):
+                        return False
+                # To foundations
+                for j in range(4):
+                    if self.validate_move(from_pos, Position(LocationType.FOUNDATION, j), 1):
+                        return False
+
+        # Check all possible moves from tableaus
+        for i in range(8):
+            col_len = len(self.tableaus[i])
+            if col_len > 0:
+                from_pos = Position(LocationType.TABLEAU, i)
+                # Check different move counts
+                for count in range(1, col_len + 1):
+                    # To other tableaus
+                    for j in range(8):
+                        if i != j and self.validate_move(from_pos, Position(LocationType.TABLEAU, j), count):
+                            return False
+                    # To freecells
+                    if count == 1:
+                        for j in range(4):
+                            if self.validate_move(from_pos, Position(LocationType.FREECELL, j), 1):
+                                return False
+                    # To foundations
+                    if count == 1:
+                        for j in range(4):
+                            if self.validate_move(from_pos, Position(LocationType.FOUNDATION, j), 1):
+                                return False
+
+        return True
diff --git a/card-game-app/tests/test_domain.py b/card-game-app/tests/test_domain.py
index 0fa4360ed..c507ddc8a 100644
--- a/card-game-app/tests/test_domain.py
+++ b/card-game-app/tests/test_domain.py
@@ -347,3 +347,41 @@ def test_win_detection():
     # Remove one card
     state.foundations[Suit.HEARTS].pop()
     assert state.check_win() is False
+
+def test_check_loss_not_lost():
+    # A standard freshly-dealt game should not be in a loss state (usually has legal moves)
+    state = GameState()
+    assert state.check_loss() is False
+
+def test_check_loss_won():
+    # A won game is not lost
+    state = GameState()
+    for suit in Suit:
+        state.foundations[suit] = [Card(suit, rank) for rank in Rank]
+    assert state.check_loss() is False
+
+def test_check_loss_is_lost():
+    state = GameState()
+    # Clear tableaus and freecells, and foundations
+    state.freecells = [None] * 4
+    state.tableaus = [[] for _ in range(8)]
+    state.foundations = {suit: [] for suit in Suit}
+
+    # Lock everything:
+    # Fill all 4 freecells with Kings of Diamonds
+    state.freecells = [Card(Suit.DIAMONDS, Rank.KING)] * 4
+
+    # Fill all 8 tableaus with at least one King of Diamonds
+    for i in range(8):
+        state.tableaus[i] = [Card(Suit.DIAMONDS, Rank.KING)]
+
+    # Now there are:
+    # - No empty tableaus
+    # - No empty freecells
+    # - No Aces on top of tableaus or in freecells (all are Kings of Diamonds)
+    # So:
+    # - Cannot move to freecells (all occupied)
+    # - Cannot move to foundations (only Kings, no Aces)
+    # - Cannot move to tableaus (all top cards are King of Diamonds, can't build King on King, and no empty columns)
+    # This state should be a lost/locked state!
+    assert state.check_loss() is True