from micrograd.engine import Value


def test_value_init():
    v = Value(1)
    assert v.data == 1


def test_value_repr():
    v = Value(2.0)
    assert "Value(data=2.0)" == repr(v)


def test_value_add():
    v1 = Value(2.0)
    v2 = Value(4.0)
    assert (v1 + v2).data == 6.0
    assert "Value(data=6.0)" == repr(v1 + v2)


def test_value_sub():
    v1 = Value(2.0)
    v2 = Value(4.0)
    assert (v1 - v2).data == -2.0
    assert "Value(data=-2.0)" == repr(v1 - v2)


def test_value_mul():
    v1 = Value(2.0)
    v2 = Value(4.0)
    v3 = Value(-1.0)
    assert (v1 * v2).data == 8.0
    assert (v1 * v3).data == -2.0


def test_value_mul_add():
    v1 = Value(2.0)
    v2 = Value(4.0)
    v3 = Value(-1.0)
    assert ((v1 * v3) + v2).data == 2.0


def test_children():
    v1 = Value(2.0)
    v2 = Value(4.0)
    out = v1 * v2
    assert len(out._prev) == 2
    assert v1 in out._prev
    assert v2 in out._prev


def test_operations():
    v1 = Value(2.0)
    v2 = Value(4.0)
    mul = v1 * v2
    add = v1 + v2
    assert mul._op == '*'
    assert add._op == '+'