From 367f8a5da8640257a93a8a63c48e6c0ab87ed5cc Mon Sep 17 00:00:00 2001
From: Terry Hearst <thearst3rd@gmail.com>
Date: Sun, 8 Aug 2021 23:53:45 -0400
Subject: [PATCH 1/2] Add "SearchDepth" UCI option

---
 communication.py    | 29 +++++++++++++++++++++++++----
 test/test_engine.py |  6 +++---
 2 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/communication.py b/communication.py
index c6fd594..a9aa7fc 100644
--- a/communication.py
+++ b/communication.py
@@ -9,12 +9,13 @@ def talk():
     The main input/output loop.
     This implements a slice of the UCI protocol.
     """
+    global search_depth
     board = chess.Board()
-    depth = get_depth()
+    search_depth = get_depth()
 
     while True:
         msg = input()
-        command(depth, board, msg)
+        command(search_depth, board, msg)
 
 
 def command(depth: int, board: chess.Board, msg: str):
@@ -26,6 +27,8 @@ def command(depth: int, board: chess.Board, msg: str):
     tokens = msg.split(" ")
     while "" in tokens:
         tokens.remove("")
+    if len(tokens) <= 0:
+        return
 
     if msg == "quit":
         sys.exit()
@@ -33,6 +36,7 @@ def command(depth: int, board: chess.Board, msg: str):
     if msg == "uci":
         print("id name Andoma")  # Andrew/Roma -> And/oma
         print("id author Andrew Healey & Roma Parramore")
+        print("option name SearchDepth type spin default 3 min 1 max 20")
         print("uciok")
         return
 
@@ -43,7 +47,7 @@ def command(depth: int, board: chess.Board, msg: str):
     if msg == "ucinewgame":
         return
 
-    if msg.startswith("position"):
+    if tokens[0] == "position":
         if len(tokens) < 2:
             return
 
@@ -69,12 +73,29 @@ def command(depth: int, board: chess.Board, msg: str):
         # Non-standard command, but supported by Stockfish and helps debugging
         print(board)
         print(board.fen())
+        print(f"Depth: {depth}")
 
-    if msg[0:2] == "go":
+    if tokens[0] == "go":
         _move = next_move(depth, board)
         print(f"bestmove {_move}")
         return
 
+    if tokens[0] == "setoption":
+        if len(tokens) < 3 or tokens[1] != "name":
+            return
+
+        if tokens[2] == "SearchDepth":
+            if len(tokens) < 5 or tokens[3] != "value":
+                return
+            new_depth = int(tokens[4])
+            if new_depth < 1 or new_depth > 20:
+                return
+            global search_depth
+            search_depth = new_depth
+        else:
+            # "SearchDepth" is the only option we support currently
+            return
+
 
 def get_depth() -> int:
     parser = argparse.ArgumentParser()
diff --git a/test/test_engine.py b/test/test_engine.py
index 2d10c7c..a42a67f 100644
--- a/test/test_engine.py
+++ b/test/test_engine.py
@@ -13,9 +13,9 @@ def test_uci_command(self):
         board = chess.Board()
         with patch("sys.stdout", new=StringIO()) as patched_output:
             command(3, board, "uci")
-            lines = patched_output.getvalue().strip().split("\n")
-            self.assertEqual(len(lines), 3)
-            self.assertEqual(lines[2], "uciok")
+            lines = patched_output.getvalue().strip().splitlines()
+            self.assertEqual(len(lines), 4)
+            self.assertEqual(lines[-1], "uciok")
 
     def test_position_startpos_command(self):
         """

From dbe10ec0529e536263c9890a21379fd978443d8e Mon Sep 17 00:00:00 2001
From: Terry Hearst <thearst3rd@gmail.com>
Date: Mon, 9 Aug 2021 00:18:09 -0400
Subject: [PATCH 2/2] Fix mypy issue

---
 communication.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/communication.py b/communication.py
index a9aa7fc..8f515d9 100644
--- a/communication.py
+++ b/communication.py
@@ -4,6 +4,9 @@
 from movegeneration import next_move
 
 
+search_depth: int
+
+
 def talk():
     """
     The main input/output loop.