import pytest
from unittest.mock import MagicMock
from app.services.revision_comparator import RevisionComparator

@pytest.fixture
def mock_db():
    return MagicMock()

@pytest.fixture
def comparator(mock_db):
    return RevisionComparator(mock_db)

def test_generate_material_hash(comparator):
    """해시 생성 로직 테스트"""
    # 1. 기본 케이스
    desc = "PIPE 100A SCH40"
    size = "100A"
    mat = "A105"
    hash1 = comparator._generate_material_hash(desc, size, mat)
    
    # 2. 공백/대소문자 차이 (정규화 확인)
    hash2 = comparator._generate_material_hash("  pipe 100a sch40  ", "100A", "a105")
    assert hash1 == hash2, "공백과 대소문자는 무시되어야 합니다."
    
    # 3. None 값 처리 (Robustness)
    hash3 = comparator._generate_material_hash(None, None, None)
    assert isinstance(hash3, str)
    assert len(hash3) == 32 # MD5 checking
    
    # 4. 빈 문자열 처리
    hash4 = comparator._generate_material_hash("", "", "")
    assert hash3 == hash4, "None과 빈 문자열은 동일하게 처리되어야 합니다."

def test_extract_size_from_description(comparator):
    """사이즈 추출 로직 테스트"""
    # 1. inch patterns
    assert comparator._extract_size_from_description('PIPE 1/2" SCH40') == '1/2"'
    assert comparator._extract_size_from_description('ELBOW 1.5inch 90D') == '1.5inch'
    
    # 2. mm patterns
    assert comparator._extract_size_from_description('Plate 100mm') == '100mm'
    assert comparator._extract_size_from_description('Bar 50.5 MM') == '50.5 MM'
    
    # 3. A patterns
    assert comparator._extract_size_from_description('PIPE 100A') == '100A'
    assert comparator._extract_size_from_description('FLANGE 50 A') == '50 A'
    
    # 4. DN patterns
    assert comparator._extract_size_from_description('VALVE DN100') == 'DN100'
    
    # 5. Dimensions
    assert comparator._extract_size_from_description('GASKET 10x20') == '10x20'
    assert comparator._extract_size_from_description('SHEET 10*20') == '10*20'
    
    # 6. No match
    assert comparator._extract_size_from_description('Just Text') == ""
    assert comparator._extract_size_from_description(None) == ""

def test_extract_material_from_description(comparator):
    """재질 추출 로직 테스트"""
    # 1. Standard materials
    assert comparator._extract_material_from_description('PIPE A106 Gr.B') == 'A106 Gr.B' # Should match longer first if implemented correctly
    assert comparator._extract_material_from_description('FLANGE A105') == 'A105'
    
    # 2. Stainless Steel
    assert comparator._extract_material_from_description('PIPE SUS304L') == 'SUS304L'
    assert comparator._extract_material_from_description('PIPE SS316') == 'SS316'
    
    # 3. Case Insensitivity
    assert comparator._extract_material_from_description('pipe sus316l') == 'SUS316L'
    
    # 4. Partial matches (should prioritize specific)
    # If "A106" is checked before "A106 Gr.B", it might return "A106". 
    # The implementation list order matters.
    # In our impl: "A106 Gr.B" is before "A106", so it should work.
    assert comparator._extract_material_from_description('Material A106 Gr.B Spec') == 'A106 Gr.B'

def test_compare_materials_logic_flow(comparator):
    """비교 로직 통합 테스트"""
    previous_confirmed = {
        "revision": "Rev.0",
        "confirmed_at": "2024-01-01",
        "items": [
            {
                "specification": "PIPE 100A A106",
                "size": "100A",
                "material": "A106",  # Extraction will find 'A106' from 'PIPE 100A A106'
                "bom_quantity": 10.0
            }
        ]
    }
    
    # Case 1: Identical (Normalized)
    new_materials_same = [{"description": "pipe 100a", "quantity": 10.0}] 
    # Note: extraction logic needs to find size/mat from description to match hash.
    # "pipe 100a" -> size="100A", mat="" (A106 not in desc)
    # The hash will be MD5("pipe 100a|100a|")
    # Previous hash was MD5("pipe 100a|100a|a106")
    # They WON'T match if extraction fails to find "A106".
    
    # Let's provide description that allows extraction to work fully
    new_materials_full = [{"description": "PIPE 100A A106", "quantity": 10.0}]
    
    result = comparator.compare_materials(previous_confirmed, new_materials_full)
    assert result["unchanged_count"] == 1
    
    # Case 2: Quantity Changed
    new_materials_qty = [{"description": "PIPE 100A A106", "quantity": 20.0}]
    result = comparator.compare_materials(previous_confirmed, new_materials_qty)
    assert result["changed_count"] == 1
    assert result["changed_materials"][0]["change_type"] == "QUANTITY_CHANGED"
    
    # Case 3: New Item
    new_materials_new = [{"description": "NEW ITEM SUS304", "quantity": 1.0}]
    result = comparator.compare_materials(previous_confirmed, new_materials_new)
    assert result["new_count"] == 1

def test_compare_materials_fuzzy_match(comparator):
    """Fuzzy Matching 테스트"""
    previous_confirmed = {
        "revision": "Rev.0",
        "confirmed_at": "2024-01-01",
        "items": [
            {
                "specification": "PIPE 100A SCH40 A106",
                "size": "100A",
                "material": "A106",
                "bom_quantity": 10.0
            }
        ]
    }
    
    # 오타가 포함된 유사 자재 (PIPEE -> PIPE, A106 -> A106)
    # 정규화/해시는 다르지만 텍스트 유사도는 높음
    new_materials_typo = [{
        "description": "PIPEE 100A SCH40 A106", 
        "quantity": 10.0
    }]
    
    # RapidFuzz가 설치되어 있어야 동작
    try:
        import rapidfuzz
        result = comparator.compare_materials(previous_confirmed, new_materials_typo)
        
        # 해시는 다르므로 new_count에 포함되거나 유사 자재로 분류됨
        # 구현에 따라 "new_materials" 리스트에 "change_type": "NEW_BUT_SIMILAR" 로 들어감
        assert result["new_count"] == 1
        new_item = result["new_materials"][0]
        assert new_item["change_type"] == "NEW_BUT_SIMILAR"
        assert new_item["similarity_score"] > 85
        
    except ImportError:
        pytest.skip("rapidfuzz not installed")

def test_extract_size_word_boundary(comparator):
    """Regex Word Boundary 테스트"""
    # 1. mm boundary check
    # "100mm" -> ok, "100mm2" -> fail if boundary used
    assert comparator._extract_size_from_description("100mm") == "100mm"
    # assert comparator._extract_size_from_description("100mmm") == "" # This depends on implementation strictness
    
    # 2. inch boundary
    assert comparator._extract_size_from_description("1/2 inch") == "1/2 inch"
    
    # 3. DN boundary
    assert comparator._extract_size_from_description("DN100") == "DN100"
    # "DN100A" should ideally not match DN100 if we want strictness, or it might match 100A.


def test_dynamic_material_loading(comparator, mock_db):
    """DB 기반 동적 자재 로딩 테스트"""
    # Mocking DB result
    # fetchall returns list of rows (tuples)
    mock_db.execute.return_value.fetchall.return_value = [
        ("TITANIUM_GR2",),
        ("INCONEL625",),
    ]
    
    # 1. Check if DB loaded materials are correctly extracted
    # Test with a material that is ONLY in the mocked DB response, not in default list
    description = "PIPE 100A TITANIUM_GR2"
    material = comparator._extract_material_from_description(description)
    assert material == "TITANIUM_GR2"
    
    # Verify DB execute was called
    assert mock_db.execute.called

    # 2. Test fallback mechanism (simulate DB connection failure)
    # mock_db.execute.side_effect = Exception("DB Connection Error")
    # Reset mock to raise exception on next call
    mock_db.execute.side_effect = Exception("DB Fail")
    
    # SUS316L is in the default fallback list
    description_fallback = "PIPE 100A SUS316L"
    material_fallback = comparator._extract_material_from_description(description_fallback)
    
    # Should still work using default list
    assert material_fallback == "SUS316L"