"""UPC Validator."""

"""
-- Query to retrieve list of UPCS
    SELECT r.manufacturer_upc FROM releases r
    INNER JOIN distribution_format df
    ON df.distribution_format_id = r.distribution_format_id
    WHERE
        df.context_type = 'physical'
    AND
        r.manufacturer_upc IS NOT NULL
    AND
        r.manufacturer_upc != ''
    AND
        r.manufacturer_upc != r.display_upc;
"""

test_upcs = [
    '796030114977', '190374000000', '190374000017', '190374000024',
    '190374000031', '190374000048', '190374000055', '190374000062',
    '190374000079', '190374000086', '190374000093', '234232425223',
    '5023001900421', '647587625345', '9781901447111'
]


def index_is_odd(i):
    """Test oddness of index."""
    return i % 2 == 1


def validate_upc(upc):
    """Validate UPC."""
    total = 0
    check_digit = int(upc[-1])
    for i, digit in enumerate(upc[:-1][::-1]):
        total += (int(digit) if index_is_odd(i) else (int(digit) * 3))
    total %= 10
    calculated_check_digit = 10 - total if total else 0

    return calculated_check_digit == check_digit


def validate_list_of_upcs(upcs):
    """Validate list of upcs."""
    return [upc for upc in upcs if not validate_upc(upc)]


print(validate_list_of_upcs(test_upcs))