from const import gray_1d


def _validate_integer(value, name):
    if not isinstance(value, int):
        raise ValueError(f'{name} must be an integer')


def _validate_range(value, name, min_val=None, max_val=None):
    if max_val is not None and value > max_val:
        raise ValueError(f'{name} must be \u2265 {max_val}')
    if min_val is not None and value < min_val:
        raise ValueError(f'{name} must be \u2264 {min_val}')


def gray_1d_input_validation(k, symbol):
    _validate_integer(symbol, 'symbol')
    _validate_integer(k, 'k')
    _validate_range(k, 'k', min_val=1)
    _validate_range(symbol, 'symbol', min_val=0, max_val=2**k-1)


def next_symbol(k, symbol):
    bits = format(symbol, 'b').zfill(k)
    b0 = int(bits[0])
    new_symbol = int(bits[1:], 2)
    return b0,new_symbol


def gray_2d_input_validation(n, m, symbol):
    _validate_integer(n, 'n')
    _validate_integer(m, 'm')
    _validate_integer(symbol, 'symbol')
    _validate_range(n, 'n', min_val=0)
    min_m = 0 if n > 0 else 1
    _validate_range(m, 'm', min_val=min_m)
    _validate_range(symbol, 'symbol', min_val=0, max_val=2**(m+n)-1)


def gray_2d_handle_1d(n, m, symbol):
    n,m,swapped = m,n,True if n == 0 else n,m,False  # swap n and m if n is zero -> if only one > 0, it's n
    if m == 0:
        return (gray_1d(n, symbol),None) if swapped else (None,gray_1d(n, symbol))
    else:
        return None


def split_symbol(n, m, symbol):
    bits = format(symbol, 'b').zfill(n+m)
    symbol_i = int(bits[:n], 2)
    symbol_q = int(bits[n:], 2)
    return symbol_i,symbol_q