From 4f5cb7d1e421a593cc54d9d1d0aab34870c12a35 Mon Sep 17 00:00:00 2001
From: Re-bin <xubinrencs@gmail.com>
Date: Sat, 21 Feb 2026 06:39:04 +0000
Subject: [PATCH] style(filesystem): simplify best-match loop

---
 nanobot/agent/tools/filesystem.py | 23 +++++++----------------
 1 file changed, 7 insertions(+), 16 deletions(-)

diff --git a/nanobot/agent/tools/filesystem.py b/nanobot/agent/tools/filesystem.py
index e6c407e..9c169e4 100644
--- a/nanobot/agent/tools/filesystem.py
+++ b/nanobot/agent/tools/filesystem.py
@@ -172,30 +172,21 @@ class EditFileTool(Tool):
         """Build a helpful error when old_text is not found."""
         lines = content.splitlines(keepends=True)
         old_lines = old_text.splitlines(keepends=True)
-
-        best_ratio = 0.0
-        best_start = 0
         window = len(old_lines)
 
+        best_ratio, best_start = 0.0, 0
         for i in range(max(1, len(lines) - window + 1)):
-            chunk = lines[i : i + window]
-            ratio = difflib.SequenceMatcher(None, old_lines, chunk).ratio()
+            ratio = difflib.SequenceMatcher(None, old_lines, lines[i : i + window]).ratio()
             if ratio > best_ratio:
-                best_ratio = ratio
-                best_start = i
+                best_ratio, best_start = ratio, i
 
         if best_ratio > 0.5:
-            best_chunk = lines[best_start : best_start + window]
-            diff = difflib.unified_diff(
-                old_lines, best_chunk,
+            diff = "\n".join(difflib.unified_diff(
+                old_lines, lines[best_start : best_start + window],
                 fromfile="old_text (provided)", tofile=f"{path} (actual, line {best_start + 1})",
                 lineterm="",
-            )
-            diff_str = "\n".join(diff)
-            return (
-                f"Error: old_text not found in {path}.\n"
-                f"Best match ({best_ratio:.0%} similar) at line {best_start + 1}:\n{diff_str}"
-            )
+            ))
+            return f"Error: old_text not found in {path}.\nBest match ({best_ratio:.0%} similar) at line {best_start + 1}:\n{diff}"
         return f"Error: old_text not found in {path}. No similar text found. Verify the file content."