import re
from typing import Dict

def classify_structural(tag: str, description: str, main_nom: str = "") -> Dict:
    """
    형강(STRUCTURAL) 분류기
    규격 예: H-BEAM 100x100x6x8
    """
    desc_upper = description.upper()
    
    # 1. 타입 식별
    struct_type = "UNKNOWN"
    if "H-BEAM" in desc_upper or "H-SECTION" in desc_upper: struct_type = "H-BEAM"
    elif "ANGLE" in desc_upper or "L-SECTION" in desc_upper: struct_type = "ANGLE"
    elif "CHANNEL" in desc_upper or "C-SECTION" in desc_upper: struct_type = "CHANNEL"
    elif "BEAM" in desc_upper: struct_type = "I-BEAM"

    # 2. 규격 추출
    # 패턴: 100x100, 100x100x6x8, 50x50x5T, H-200x200
    dimension = ""
    # 숫자와 x 또는 *로 구성된 패턴, 앞에 H- 등이 붙을 수 있음
    dim_match = re.search(r'(?:H-|L-|C-)?(\d+(?:\.\d+)?(?:\s*[X\*]\s*\d+(?:\.\d+)?){1,3})', desc_upper)
    if dim_match:
        dimension = dim_match.group(1).replace("*", "x")

    return {
        "category": "STRUCTURAL",
        "overall_confidence": 0.9,
        "details": {
            "type": struct_type,
            "dimension": dimension
        }
    }