import logging
import re

from engine.id_parser import validate_luhn

logger = logging.getLogger(__name__)


def _parse_pdf417(data: str) -> dict | None:
    """Parse SA smart card PDF417 barcode data.

    The SA smart card PDF417 contains identity fields separated by
    specific delimiters. Format varies but typically contains
    surname, names, ID number, sex, DOB, nationality, etc.
    """
    if not data or len(data) < 13:
        return None

    result = {
        "source": "pdf417",
        "id_number": None,
        "surname": None,
        "names": None,
        "sex": None,
        "date_of_birth": None,
        "nationality": None,
        "country_of_birth": None,
        "citizenship_status": None,
    }

    # Try to find 13-digit ID number anywhere in the data
    id_matches = re.findall(r"\d{13}", data.replace(" ", ""))
    for candidate in id_matches:
        if validate_luhn(candidate):
            result["id_number"] = candidate
            break

    # SA smart card PDF417 typically uses field separators
    # Common formats: pipe-delimited, or fixed-position fields
    parts = None
    for sep in ["|", "\t", "\n", "\r"]:
        candidate_parts = [p.strip() for p in data.split(sep) if p.strip()]
        if len(candidate_parts) >= 4:
            parts = candidate_parts
            break

    if parts and len(parts) >= 4:
        # Try to map parts to fields based on content patterns
        for part in parts:
            cleaned = part.strip()
            if not cleaned:
                continue

            # ID number (13 digits)
            digits_only = re.sub(r"\D", "", cleaned)
            if len(digits_only) == 13 and validate_luhn(digits_only) and not result["id_number"]:
                result["id_number"] = digits_only
                continue

            # Sex
            upper = cleaned.upper()
            if upper in ("M", "MALE"):
                result["sex"] = "Male"
                continue
            if upper in ("F", "FEMALE"):
                result["sex"] = "Female"
                continue

            # Nationality / citizenship
            if upper in ("RSA", "SOUTH AFRICA", "SA CITIZEN", "CITIZEN"):
                if not result["nationality"]:
                    result["nationality"] = "South African"
                if not result["citizenship_status"]:
                    result["citizenship_status"] = "SA Citizen"
                continue

            # Date pattern (YYYY-MM-DD or DD-MM-YYYY or YYYYMMDD)
            date_match = re.match(r"(\d{4})[/-](\d{2})[/-](\d{2})", cleaned)
            if date_match and not result["date_of_birth"]:
                result["date_of_birth"] = f"{date_match.group(1)}-{date_match.group(2)}-{date_match.group(3)}"
                continue

            date_match = re.match(r"(\d{2})[/-](\d{2})[/-](\d{4})", cleaned)
            if date_match and not result["date_of_birth"]:
                result["date_of_birth"] = f"{date_match.group(3)}-{date_match.group(2)}-{date_match.group(1)}"
                continue

    # If we got an ID number, derive fields from it as validation/fallback
    if result["id_number"]:
        from engine.id_parser import parse_id_number
        parsed = parse_id_number(result["id_number"])
        if not result["date_of_birth"] and parsed.get("date_of_birth"):
            result["date_of_birth"] = parsed["date_of_birth"]
        if not result["sex"] and parsed.get("sex"):
            result["sex"] = parsed["sex"]
        if not result["citizenship_status"] and parsed.get("citizenship"):
            result["citizenship_status"] = parsed["citizenship"]
        return result

    return None


def _parse_code39(data: str) -> dict | None:
    """Parse Code 39 barcode — typically contains only the ID number."""
    digits_only = re.sub(r"\D", "", data)

    if len(digits_only) == 13 and validate_luhn(digits_only):
        from engine.id_parser import parse_id_number
        parsed = parse_id_number(digits_only)
        return {
            "source": "code39",
            "id_number": digits_only,
            "surname": None,
            "names": None,
            "sex": parsed.get("sex"),
            "date_of_birth": parsed.get("date_of_birth"),
            "nationality": None,
            "country_of_birth": None,
            "citizenship_status": parsed.get("citizenship"),
        }

    return None