Don't call a riichi for a pair wait (except chitoitsu)

project/mahjong/ai/main.py

@@ -104,7 +104,7 @@ def discard_tile(self):
 
         we_can_call_riichi = shanten == 0 and self.player.can_call_riichi()
         # current strategy can affect on our discard options
-        # and don't use strategy specific choices for calling riichi
+        # so, don't use strategy specific choices for calling riichi
         if self.current_strategy and not we_can_call_riichi:
             results = self.current_strategy.determine_what_to_discard(self.player.closed_hand,
                                                                       results,
@@ -234,6 +234,28 @@ def estimate_hand_value(self, win_tile):
                                                         dora_indicators=self.player.table.dora_indicators)
         return result
 
+    def should_call_riichi(self):
+        # empty waiting can be found in some cases
+        if not self.waiting:
+            return False
+
+        # we have a good wait, let's riichi
+        if len(self.waiting) > 1:
+            return True
+
+        waiting = self.waiting[0]
+        tiles_34 = TilesConverter.to_34_array(self.player.closed_hand)
+        count_of_pairs = len([x for x in range(0, 34) if tiles_34[x] == 2])
+
+        # pair wait is really easy to improve,
+        # so let's not riichi it
+        # but for chitoitsu we can call a riichi
+        is_pair_wait = tiles_34[waiting] == 1
+        if is_pair_wait and count_of_pairs != 6:
+            return False
+
+        return True
+
     @property
     def valued_honors(self):
         return [CHUN, HAKU, HATSU, self.player.table.round_wind, self.player.player_wind]

project/mahjong/ai/tests/tests_riichi.py

@@ -0,0 +1,36 @@
+# -*- coding: utf-8 -*-
+import unittest
+
+from mahjong.ai.discard import DiscardOption
+from mahjong.ai.main import MainAI
+from mahjong.ai.shanten import Shanten
+from mahjong.constants import EAST, SOUTH, WEST, NORTH, HAKU, HATSU, CHUN, FIVE_RED_SOU
+from mahjong.player import Player
+from mahjong.table import Table
+from utils.tests import TestMixin
+
+
+class CallRiichiTestCase(unittest.TestCase, TestMixin):
+
+    def test_should_call_riichi_and_tanki_wait(self):
+        table = Table()
+        table.count_of_remaining_tiles = 60
+        player = Player(table, 0, 0, False)
+        player.scores = 25000
+
+        tiles = self._string_to_136_array(sou='123456', pin='12345', man='34')
+        tile = self._string_to_136_tile(pin='6')
+        player.init_hand(tiles)
+        player.draw_tile(tile)
+        player.discard_tile()
+
+        self.assertEqual(player.can_call_riichi(), False)
+
+        tiles = self._string_to_136_array(sou='1133557799', pin='113')
+        tile = self._string_to_136_tile(pin='6')
+        player.init_hand(tiles)
+        player.draw_tile(tile)
+        player.discard_tile()
+
+        # for chitoitsu it is ok to have a pair wait
+        self.assertEqual(player.can_call_riichi(), True)

project/mahjong/player.py

@@ -145,7 +145,7 @@ def discard_tile(self, tile=None):
         return tile_to_discard
 
     def can_call_riichi(self):
-        return all([
+        result = all([
             self.in_tempai,
 
             not self.in_riichi,
@@ -155,6 +155,8 @@ def can_call_riichi(self):
             self.table.count_of_remaining_tiles > 4
         ])
 
+        return result and self.ai.should_call_riichi()
+
     def try_to_call_meld(self, tile, is_kamicha_discard):
         return self.ai.try_to_call_meld(tile, is_kamicha_discard)
 

project/mahjong/tests/tests_player.py

@@ -18,6 +18,7 @@ def test_can_call_riichi_and_tempai(self):
         player.in_riichi = False
         player.scores = 2000
         player.table.count_of_remaining_tiles = 40
+        player.ai.waiting = [1, 2]
 
         self.assertEqual(player.can_call_riichi(), False)
 
@@ -33,6 +34,7 @@ def test_can_call_riichi_and_already_in_riichi(self):
         player.in_riichi = True
         player.scores = 2000
         player.table.count_of_remaining_tiles = 40
+        player.ai.waiting = [1, 2]
 
         self.assertEqual(player.can_call_riichi(), False)
 
@@ -48,6 +50,7 @@ def test_can_call_riichi_and_scores(self):
         player.in_riichi = False
         player.scores = 0
         player.table.count_of_remaining_tiles = 40
+        player.ai.waiting = [1, 2]
 
         self.assertEqual(player.can_call_riichi(), False)
 
@@ -63,6 +66,7 @@ def test_can_call_riichi_and_remaining_tiles(self):
         player.in_riichi = False
         player.scores = 2000
         player.table.count_of_remaining_tiles = 3
+        player.ai.waiting = [1, 2]
 
         self.assertEqual(player.can_call_riichi(), False)
 
@@ -79,6 +83,7 @@ def test_can_call_riichi_and_open_hand(self):
         player.scores = 2000
         player.melds = [1]
         player.table.count_of_remaining_tiles = 40
+        player.ai.waiting = [1, 2]
 
         self.assertEqual(player.can_call_riichi(), False)