"""Tests for common practical conventions of all printers."""

from diofant import (Derivative, Function, Integral, bell, besselj, cos, exp,
                     legendre, oo, symbols)
from diofant.printing.conventions import requires_partial, split_super_sub


__all__ = ()


def test_super_sub():
    assert split_super_sub('beta_13_2') == ('beta', [], ['13', '2'])
    assert split_super_sub('beta_132_20') == ('beta', [], ['132', '20'])
    assert split_super_sub('beta_13') == ('beta', [], ['13'])
    assert split_super_sub('x_a_b') == ('x', [], ['a', 'b'])
    assert split_super_sub('x_1_2_3') == ('x', [], ['1', '2', '3'])
    assert split_super_sub('x_a_b1') == ('x', [], ['a', 'b1'])
    assert split_super_sub('x_a_1') == ('x', [], ['a', '1'])
    assert split_super_sub('x_1_a') == ('x', [], ['1', 'a'])
    assert split_super_sub('x_1^aa') == ('x', ['aa'], ['1'])
    assert split_super_sub('x_1__aa') == ('x', ['aa'], ['1'])
    assert split_super_sub('x_11^a') == ('x', ['a'], ['11'])
    assert split_super_sub('x_11__a') == ('x', ['a'], ['11'])
    assert split_super_sub('x_a_b_c_d') == ('x', [], ['a', 'b', 'c', 'd'])
    assert split_super_sub('x_a_b^c^d') == ('x', ['c', 'd'], ['a', 'b'])
    assert split_super_sub('x_a_b__c__d') == ('x', ['c', 'd'], ['a', 'b'])
    assert split_super_sub('x_a^b_c^d') == ('x', ['b', 'd'], ['a', 'c'])
    assert split_super_sub('x_a__b_c__d') == ('x', ['b', 'd'], ['a', 'c'])
    assert split_super_sub('x^a^b_c_d') == ('x', ['a', 'b'], ['c', 'd'])
    assert split_super_sub('x__a__b_c_d') == ('x', ['a', 'b'], ['c', 'd'])
    assert split_super_sub('x^a^b^c^d') == ('x', ['a', 'b', 'c', 'd'], [])
    assert split_super_sub('x__a__b__c__d') == ('x', ['a', 'b', 'c', 'd'], [])
    assert split_super_sub('alpha_11') == ('alpha', [], ['11'])
    assert split_super_sub('alpha_11_11') == ('alpha', [], ['11', '11'])
    assert split_super_sub('') == ('', [], [])


def test_requires_partial():
    x, y, t, nu = symbols('x y t nu')
    n = symbols('n', integer=True)

    f = x * y
    assert requires_partial(Derivative(f, x)) is True
    assert requires_partial(Derivative(f, y)) is True

    # integrating out one of the variables
    assert requires_partial(Derivative(Integral(exp(-x * y), (x, 0, oo)), y, evaluate=False)) is False

    # bessel function with smooth parameter
    f = besselj(nu, x)
    assert requires_partial(Derivative(f, x)) is True
    assert requires_partial(Derivative(f, nu)) is True

    # bessel function with integer parameter
    f = besselj(n, x)
    assert requires_partial(Derivative(f, x)) is False
    # this is not really valid (differentiating with respect to an integer)
    # but there's no reason to use the partial derivative symbol there. make
    # sure we don't throw an exception here, though
    assert requires_partial(Derivative(f, n)) is False

    # bell polynomial
    f = bell(n, x)
    assert requires_partial(Derivative(f, x)) is False
    # again, invalid
    assert requires_partial(Derivative(f, n)) is False

    # legendre polynomial
    f = legendre(0, x)
    assert requires_partial(Derivative(f, x)) is False

    f = legendre(n, x)
    assert requires_partial(Derivative(f, x)) is False
    # again, invalid
    assert requires_partial(Derivative(f, n)) is False

    f = x ** n
    assert requires_partial(Derivative(f, x)) is False

    assert requires_partial(Derivative(Integral((x*y) ** n * exp(-x * y), (x, 0, oo)), y, evaluate=False)) is False

    # parametric equation
    f = (exp(t), cos(t))
    g = sum(f)
    assert requires_partial(Derivative(g, t)) is False

    # function of unspecified variables
    f = symbols('f', cls=Function)
    assert requires_partial(Derivative(f, x)) is False
    assert requires_partial(Derivative(f, x, y)) is True
