fix(search): robust color filter — strip 'Màu' prefix, VN→EN mapping, diacritics fallback

backend/agent/tools/tool_module/search_engine.py

@@ -177,8 +177,46 @@ def _build_fixed_clauses(inf: InferredSearch, params: list) -> list[str]:
         clauses.append("age_by_product = %s")
     
     if inf.master_color:
-        params.append(f"%{inf.master_color}%"); params.append(f"%{inf.master_color}%")
-        clauses.append("(master_color LIKE %s OR product_color_name LIKE %s)")
+        # ── Robust Color Filter ──
+        # AI có thể output "Màu đen", "đen", "black" — DB lưu "Đen/ Black"
+        # Cần strip prefix + map VN→EN + bỏ dấu → thử tất cả patterns
+        import unicodedata as _ucd
+        COLOR_VN_TO_EN = {
+            "đỏ": "red", "do": "red", "trắng": "white", "trang": "white",
+            "đen": "black", "den": "black", "xanh": "blue", "xanh dương": "blue",
+            "xanh da trời": "blue", "xanh lá": "green", "xanh la": "green",
+            "hồng": "pink", "hong": "pink", "tím": "purple", "tim": "purple",
+            "cam": "orange", "vàng": "yellow", "vang": "yellow",
+            "nâu": "brown", "nau": "brown", "xám": "gray", "xam": "gray",
+            "be": "beige", "kem": "cream", "bạc": "silver", "bac": "silver",
+            "vàng đồng": "gold", "vang dong": "gold",
+        }
+        c_raw = inf.master_color.strip()
+        # Strip "Màu " / "màu " prefix (AI hay thêm)
+        import re as _re
+        c_clean = _re.sub(r'^[Mm]àu\s+', '', c_raw)
+        # Bỏ dấu tiếng Việt
+        c_no_accent = "".join(
+            ch for ch in _ucd.normalize("NFD", c_clean.lower())
+            if _ucd.category(ch) != "Mn"
+        ).strip()
+        # Map sang English
+        en_color = COLOR_VN_TO_EN.get(c_clean.lower()) or COLOR_VN_TO_EN.get(c_no_accent)
+
+        color_or_parts = []
+        # Pattern 1: cleaned Vietnamese (e.g. "đen" matches "Đen/ Black")
+        color_or_parts.append("(LOWER(master_color) LIKE %s OR LOWER(product_color_name) LIKE %s)")
+        params.extend([f"%{c_clean.lower()}%", f"%{c_clean.lower()}%"])
+        # Pattern 2: no-accent fallback (e.g. "den" matches)
+        if c_no_accent != c_clean.lower():
+            color_or_parts.append("(LOWER(master_color) LIKE %s OR LOWER(product_color_name) LIKE %s)")
+            params.extend([f"%{c_no_accent}%", f"%{c_no_accent}%"])
+        # Pattern 3: English color (e.g. "black" matches "Đen/ Black")
+        if en_color:
+            color_or_parts.append("(LOWER(master_color) LIKE %s OR LOWER(product_color_name) LIKE %s)")
+            params.extend([f"%{en_color}%", f"%{en_color}%"])
+
+        clauses.append("(" + " OR ".join(color_or_parts) + ")")
 
     if inf.price_min is not None:
         params.append(inf.price_min); clauses.append("sale_price >= %s")