import re

# ---------------------------------------------------------------------------
# Reconstructed from master.ipynb (cells 182-189).
# extract_attributes(desc) -> dict of parsed spec fields
# attribute_score(attrs1, attrs2) -> weighted similarity in [0, 1]
# ---------------------------------------------------------------------------

PATTERNS = {
    # Item Type
    "ITEM": r"^([A-Z]+,[A-Z]+)",

    # Application
    "TYPE": r"TYPE(?:/APPLICATION)?[:=]\s*(.+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Sizes
    "SIZE": r"SIZE[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",
    "RUN SIZE": r"RUN SIZE[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",
    "BRANCH SIZE": r"BRANCH SIZE[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Pressure
    "RATING": r"RATING(?:/SCHEDULE)?[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",
    "PRESSURE CLASS": r"CLASS[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Schedule
    "SCHEDULE": r"SCH(?:EDULE)?\.?\s*([0-9A-Z\-]+)",

    # Material
    "MATERIAL": r"MATERIAL[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Grade
    "GRADE": r"GRADE[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Specification
    "SPECIFICATION": r"SPECIFICATION[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Standards
    "STANDARD": r"(ASME\s*B[0-9.\-]+|ASTM\s*A[0-9A-Z\-]+|API\s*[0-9A-Z\-]+|ANSI\s*B[0-9.\-]+|USAS\s*B[0-9.\-]+)",

    # Connection
    "CONNECTION": r"CONNECTION[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # End Connection
    "END CONNECTION": r"END CONNECTION[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Radius
    "RADIUS": r"RADIUS[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Degree
    "DEGREE": r"DEGREE[:=]\s*([0-9]+)",

    # Face
    "FACE": r"FACE[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Ends
    "ENDS": r"ENDS[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Bore
    "BORE": r"BORE[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Thickness
    "THICKNESS": r"THICKNESS[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Length
    "LENGTH": r"LENGTH[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Diameter
    "DIAMETER": r"DIAMETER[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Manufacturer
    "MANUFACTURER": r"MANUFACTURER(?: CODE)?[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Thread
    "THREAD": r"THREAD(?: TYPE)?[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Seal
    "SEAL": r"SEAL[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Seat
    "SEAT": r"SEAT[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Disc
    "DISC": r"DISC[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Stem
    "STEM": r"STEM[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Body
    "BODY": r"BODY[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",

    # Trim
    "TRIM": r"TRIM[:=]\s*([^:]+?)(?=\s+[A-Z][A-Z /-]*:|$)",
}

WEIGHTS = {
    "ITEM": 0.05,
    "TYPE": 0.05,
    "SIZE": 0.15,
    "RUN SIZE": 0.08,
    "BRANCH SIZE": 0.08,
    "RATING": 0.12,
    "PRESSURE CLASS": 0.06,
    "SCHEDULE": 0.05,
    "MATERIAL": 0.08,
    "GRADE": 0.06,
    "SPECIFICATION": 0.05,
    "STANDARD": 0.04,
    "CONNECTION": 0.04,
    "END CONNECTION": 0.03,
    "RADIUS": 0.03,
    "DEGREE": 0.02,
    "FACE": 0.02,
    "ENDS": 0.02,
    "BORE": 0.02,
    "THICKNESS": 0.02,
    "LENGTH": 0.02,
    "DIAMETER": 0.02,
    "MANUFACTURER": 0.02,
    "THREAD": 0.02,
    "SEAL": 0.01,
    "SEAT": 0.01,
    "DISC": 0.01,
    "STEM": 0.01,
    "BODY": 0.01,
    "TRIM": 0.01,
}

NORMALIZATION = {
    # ---------- MATERIAL ----------
    "SS": "STAINLESS STEEL",
    "S.S": "STAINLESS STEEL",
    "STAINLESS STEEL": "STAINLESS STEEL",

    "CS": "CARBON STEEL",
    "C.S": "CARBON STEEL",
    "CARBON STEEL": "CARBON STEEL",

    "MS": "MILD STEEL",
    "M.S": "MILD STEEL",

    "GI": "GALVANIZED IRON",

    # ---------- CONNECTION ----------
    "BW": "BUTT WELD",
    "BUTT WELD": "BUTT WELD",

    "SW": "SOCKET WELD",
    "SOCKET WELD": "SOCKET WELD",

    "THD": "THREADED",
    "NPT": "THREADED",
    "BSP": "THREADED",

    "RF": "RAISED FACE",
    "FF": "FLAT FACE",
    "RTJ": "RING TYPE JOINT",

    # ---------- RADIUS ----------
    "SR": "SHORT",
    "SHORT RADIUS": "SHORT",
    "SHORT": "SHORT",

    "LR": "LONG",
    "LONG RADIUS": "LONG",
    "LONG": "LONG",

    # ---------- PRESSURE ----------
    "150#": "150 LB",
    "300#": "300 LB",
    "600#": "600 LB",
    "900#": "900 LB",
    "1500#": "1500 LB",
    "2500#": "2500 LB",

    # ---------- GRADE ----------
    "304 SS": "F304",
    "SS304": "F304",
    "304": "F304",

    "316 SS": "F316",
    "SS316": "F316",
    "316": "F316",

    # ---------- SCHEDULE ----------
    "SCH40": "SCH 40",
    "SCH80": "SCH 80",
    "SCH160": "SCH 160",

    # ---------- DEGREE ----------
    "90 DEG": "90",
    "45 DEG": "45",
}


def extract_attributes(desc):
    desc = str(desc).upper()
    attrs = {}
    for key, pattern in PATTERNS.items():
        m = re.search(pattern, desc)
        attrs[key] = m.group(1).strip() if m else ""
    return attrs


def normalize_value(value):
    value = str(value).upper().strip()
    value = re.sub(r"\s+", " ", value)
    value = value.replace('"', " IN")
    value = value.replace("''", " IN")
    value = value.replace("INCH", "IN")
    value = value.replace("IN.", "IN")
    value = value.strip()

    if value in NORMALIZATION:
        value = NORMALIZATION[value]

    return value


def normalize_attributes(attrs):
    return {key: normalize_value(value) for key, value in attrs.items()}


def attribute_score(a, b):
    a = normalize_attributes(a)
    b = normalize_attributes(b)

    score = 0
    total = 0

    for key, weight in WEIGHTS.items():
        total += weight
        if a.get(key, "") == b.get(key, "") and a.get(key, "") != "":
            score += weight

    return score / total