import pytest
from engine.id_parser import (
    validate_luhn,
    parse_id_number,
    extract_id_number,
    cross_validate,
    validate_id_for_country,
    _normalize_date,
    _check_date_transposition,
)


class TestValidateLuhn:
    def test_valid_id(self):
        # Known valid SA ID number
        assert validate_luhn("8801015800082") is True

    def test_invalid_id_bad_checksum(self):
        assert validate_luhn("8801015800083") is False

    def test_invalid_too_short(self):
        assert validate_luhn("880101580008") is False

    def test_invalid_too_long(self):
        assert validate_luhn("88010158000820") is False

    def test_invalid_non_digits(self):
        assert validate_luhn("880101580008A") is False

    def test_empty_string(self):
        assert validate_luhn("") is False

    def test_none(self):
        assert validate_luhn(None) is False

    def test_valid_female_citizen(self):
        assert validate_luhn("9202204720083") is True

    def test_valid_male_resident(self):
        assert validate_luhn("7801015800182") is True


class TestParseIdNumber:
    def test_male_citizen(self):
        result = parse_id_number("8801015800082")
        assert result["date_of_birth"] == "1988-01-01"
        assert result["sex"] == "Male"
        assert result["citizenship"] == "SA Citizen"
        assert result["is_valid"] is True

    def test_female(self):
        result = parse_id_number("9202204720083")
        assert result["sex"] == "Female"
        assert result["is_valid"] is True

    def test_permanent_resident(self):
        result = parse_id_number("7801015800182")
        assert result["citizenship"] == "Permanent Resident"

    def test_invalid_id(self):
        result = parse_id_number("1234567890123")
        assert result["is_valid"] is False

    def test_empty(self):
        result = parse_id_number("")
        assert result["is_valid"] is False
        assert result["date_of_birth"] is None


class TestExtractIdNumber:
    def test_find_in_clean_text(self):
        blocks = [
            ([[0, 0], [100, 0], [100, 20], [0, 20]], "IDENTITY NUMBER", 0.95),
            ([[0, 25], [200, 25], [200, 45], [0, 45]], "8801015800082", 0.92),
        ]
        id_num, conf = extract_id_number(blocks)
        assert id_num == "8801015800082"
        assert conf > 0

    def test_find_with_spaces(self):
        blocks = [
            ([[0, 0], [200, 0], [200, 20], [0, 20]], "8801 0158 0008 2", 0.85),
        ]
        id_num, conf = extract_id_number(blocks)
        assert id_num == "8801015800082"

    def test_find_with_dashes(self):
        blocks = [
            ([[0, 0], [200, 0], [200, 20], [0, 20]], "880101-5800-082", 0.85),
        ]
        id_num, conf = extract_id_number(blocks)
        assert id_num == "8801015800082"

    def test_no_valid_id(self):
        blocks = [
            ([[0, 0], [100, 0], [100, 20], [0, 20]], "REPUBLIC OF SOUTH AFRICA", 0.95),
            ([[0, 25], [100, 25], [100, 45], [0, 45]], "IDENTITY CARD", 0.90),
        ]
        id_num, conf = extract_id_number(blocks)
        assert id_num is None


class TestCrossValidate:
    def test_all_match(self):
        fields = {
            "date_of_birth": "01/01/1988",
            "sex": "Male",
            "citizenship_status": "SA Citizen",
        }
        parsed = {
            "date_of_birth": "1988-01-01",
            "sex": "Male",
            "citizenship": "SA Citizen",
            "is_valid": True,
        }
        result = cross_validate(fields, parsed)
        assert result["luhn_valid"] is True
        assert result["dob_cross_check"] is True
        assert result["gender_cross_check"] is True
        assert result["citizenship_cross_check"] is True

    def test_gender_mismatch(self):
        fields = {"sex": "Female"}
        parsed = {"sex": "Male", "is_valid": True}
        result = cross_validate(fields, parsed)
        assert result["gender_cross_check"] is False


class TestNormalizeDate:
    def test_iso_format(self):
        assert _normalize_date("1988-01-01") == "1988-01-01"

    def test_slash_format(self):
        assert _normalize_date("01/01/1988") == "1988-01-01"

    def test_dash_dmy(self):
        assert _normalize_date("01-01-1988") == "1988-01-01"

    def test_invalid(self):
        assert _normalize_date("not a date") is None


class TestDateTransposition:
    def test_exact_match(self):
        result = _check_date_transposition("01/01/1988", "1988-01-01")
        assert result["exact_match"] is True
        assert result["transposed_match"] is False

    def test_transposed_day_month(self):
        # OCR reads "1988-05-03" but ID actually encodes 1988-03-05 (day/month swapped)
        result = _check_date_transposition("1988-05-03", "1988-03-05")
        assert result["transposed_match"] is True
        assert result["corrected_date"] == "1988-03-05"

    def test_no_match(self):
        result = _check_date_transposition("15/06/1990", "1988-01-01")
        assert result["exact_match"] is False
        assert result["transposed_match"] is False

    def test_none_input(self):
        result = _check_date_transposition(None, "1988-01-01")
        assert result["exact_match"] is False

    def test_unambiguous_date_not_transposed(self):
        # Day=25 can't be a month, so transposition shouldn't match
        result = _check_date_transposition("25/06/1990", "1990-06-25")
        assert result["exact_match"] is True


class TestValidateIdForCountry:
    def test_sa_valid(self):
        result = validate_id_for_country("8801015800082", "ZAF")
        assert result["valid"] is True
        assert result["method"] == "luhn"

    def test_sa_invalid_luhn(self):
        result = validate_id_for_country("8801015800083", "ZAF")
        assert result["valid"] is False

    def test_nigeria_valid(self):
        result = validate_id_for_country("12345678901", "NGA")
        assert result["valid"] is True
        assert result["method"] == "regex"

    def test_nigeria_invalid_too_short(self):
        result = validate_id_for_country("1234567890", "NGA")
        assert result["valid"] is False

    def test_kenya_valid(self):
        result = validate_id_for_country("12345678", "KEN")
        assert result["valid"] is True

    def test_zimbabwe_valid(self):
        result = validate_id_for_country("12345678A12", "ZWE")
        assert result["valid"] is True

    def test_zimbabwe_invalid(self):
        result = validate_id_for_country("12345678112", "ZWE")
        assert result["valid"] is False

    def test_uganda_valid(self):
        result = validate_id_for_country("AB123456789012", "UGA")
        assert result["valid"] is True

    def test_zambia_valid(self):
        result = validate_id_for_country("1234567890", "ZMB")
        assert result["valid"] is True

    def test_unknown_country_passes(self):
        result = validate_id_for_country("ANY123", "XXX")
        assert result["valid"] is True
        assert result["method"] == "no_rules"

    def test_empty_id_fails(self):
        result = validate_id_for_country("", "ZAF")
        assert result["valid"] is False


class TestCrossValidateTransposition:
    def test_transposed_dob_auto_corrected(self):
        # OCR extracted date has day/month swapped compared to ID-encoded date
        fields = {
            "date_of_birth": "1988-05-03",
            "sex": "Male",
        }
        parsed = {
            "date_of_birth": "1988-03-05",
            "sex": "Male",
            "citizenship": "SA Citizen",
            "is_valid": True,
        }
        result = cross_validate(fields, parsed)
        assert result["dob_cross_check"] is True
        assert result["dob_transposed"] is True
        # The field should be corrected in-place to match the ID
        assert fields["date_of_birth"] == "1988-03-05"