import pytest

from hypothesis import given, assume, settings
from hypothesis import strategies as st

from rpython.flowspace.model import Variable
from rpython.flowspace.operation import op
from rpython.translator.translator import TranslationContext
from rpython.annotator.model import *
from rpython.annotator.annrpython import BlockedInference
from rpython.annotator.listdef import ListDef
from rpython.annotator import unaryop, binaryop  # for side-effects

@pytest.fixture()
def annotator():
    t = TranslationContext()
    return t.buildannotator()


listdef1 = ListDef(None, SomeTuple([SomeInteger(nonneg=True), SomeString()]))
listdef2 = ListDef(None, SomeTuple([SomeInteger(nonneg=False), SomeString()]))

s1 = SomeType()
s2 = SomeInteger(nonneg=True)
s3 = SomeInteger(nonneg=False)
s4 = SomeList(listdef1)
s5 = SomeList(listdef2)
s6 = SomeImpossibleValue()
slist = [s1, s2, s3, s4, s6]  # not s5 -- unionof(s4,s5) modifies s4 and s5


class C(object):
    pass

def test_equality():
    assert s1 != s2 != s3 != s4 != s5 != s6
    assert s1 == SomeType()
    assert s2 == SomeInteger(nonneg=True)
    assert s3 == SomeInteger(nonneg=False)
    assert s4 == SomeList(listdef1)
    assert s5 == SomeList(listdef2)
    assert s6 == SomeImpossibleValue()

def test_contains():
    assert ([(s,t) for s in slist for t in slist if s.contains(t)] ==
            [(s1, s1),                               (s1, s6),
                       (s2, s2),                     (s2, s6),
                       (s3, s2), (s3, s3),           (s3, s6),
                                           (s4, s4), (s4, s6),
                                                     (s6, s6)])

def test_signedness():
    assert not SomeInteger(unsigned=True).contains(SomeInteger())
    assert SomeInteger(unsigned=True).contains(SomeInteger(nonneg=True))

def test_commonbase_simple():
    class A0:
        pass
    class A1(A0):
        pass
    class A2(A0):
        pass
    class B1(object):
        pass
    class B2(object):
        pass
    try:
        class B3(object, A0):
            pass
    except TypeError:    # if A0 is also a new-style class, e.g. in PyPy
        class B3(A0, object):
            pass
    assert commonbase(A1, A2) is A0
    assert commonbase(A1, A0) is A0
    assert commonbase(A1, A1) is A1
    assert commonbase(A2, B2) is object
    assert commonbase(A2, B3) is A0

def test_list_union():
    listdef1 = ListDef('dummy', SomeInteger(nonneg=True))
    listdef2 = ListDef('dummy', SomeInteger(nonneg=False))
    s1 = SomeList(listdef1)
    s2 = SomeList(listdef2)
    assert s1 != s2
    s3 = unionof(s1, s2)
    assert s1 == s2 == s3

def test_list_contains():
    listdef1 = ListDef(None, SomeInteger(nonneg=True))
    s1 = SomeList(listdef1)
    listdef2 = ListDef(None, SomeInteger(nonneg=False))
    s2 = SomeList(listdef2)
    assert s1 != s2
    assert not s2.contains(s1)
    assert s1 != s2
    assert not s1.contains(s2)
    assert s1 != s2

def test_nan():
    f1 = SomeFloat()
    f1.const = float("nan")
    f2 = SomeFloat()
    f2.const = float("nan")
    assert f1.contains(f1)
    assert f2.contains(f1)
    assert f1.contains(f2)

def const_float(x):
    s = SomeFloat()
    s.const = x
    return s

def const_int(n):
    s = SomeInteger(nonneg=(n >= 0))
    s.const = n
    return s

def const_str(x):
    no_nul = not '\x00' in x
    if len(x) == 1:
        result = SomeChar(no_nul=no_nul)
    else:
        result = SomeString(no_nul=no_nul)
    result.const = x
    return result

def const_unicode(x):
    no_nul = not u'\x00' in x
    if len(x) == 1:
        result = SomeUnicodeCodePoint(no_nul=no_nul)
    else:
        result = SomeUnicodeString(no_nul=no_nul)
    result.const = x
    return result

def compatible(s1, s2):
    try:
        union(s1, s2)
    except UnionError:
        return False
    return True

def compatible_pair(pair_s):
    return compatible(*pair_s)

st_float = st.just(SomeFloat()) | st.builds(const_float, st.floats())
st_int = st.one_of(st.builds(SomeInteger, st.booleans(), st.booleans()),
                   st.builds(const_int, st.integers()))
st_bool = st.sampled_from([s_Bool, s_True, s_False])
st_numeric = st.one_of(st_float, st_int, st_bool)
st_str = (st.builds(SomeString, st.booleans(), st.booleans())
          | st.builds(const_str, st.binary()))
st_unicode = (st.builds(SomeUnicodeString, st.booleans(), st.booleans())
              | st.builds(const_unicode, st.text()))
st_simple = st.one_of(st_numeric, st_str, st_unicode, st.just(s_ImpossibleValue), st.just(s_None))

def valid_unions(st_ann):
    """From a strategy generating annotations, create a strategy returning
    unions of these annotations."""
    pairs = st.tuples(st_ann, st_ann)
    return pairs.filter(compatible_pair).map(lambda t: union(*t))


st_annotation = st.recursive(st_simple,
    lambda st_ann: valid_unions(st_ann) | st.builds(SomeTuple, st.lists(st_ann)),
    max_leaves=3)

@given(s=st_annotation)
def test_union_unary(s):
    assert union(s, s) == s
    assert union(s_ImpossibleValue, s) == s

@given(s1=st_annotation, s2=st_annotation)
def test_commutativity_of_union_compatibility(s1, s2):
    assert compatible(s1, s2) == compatible(s2, s1)

@given(st_annotation, st_annotation)
def test_union_commutative(s1, s2):
    try:
        s_union = union(s1, s2)
    except UnionError:
        assume(False)
    assert union(s2, s1) == s_union
    assert s_union.contains(s1)
    assert s_union.contains(s2)

@pytest.mark.xfail
@settings(max_examples=500)
@given(st_annotation, st_annotation, st_annotation)
def test_union_associative(s1, s2, s3):
    assume(compatible(s1, s2) and compatible(union(s1, s2), s3))
    assert union(union(s1, s2), s3) == union(s1, union(s2, s3))


@pytest.mark.xfail
@given(st_annotation, st_annotation)
def test_generalize_isinstance(annotator, s1, s2):
    try:
        s_12 = union(s1, s2)
    except UnionError:
        assume(False)
    assume(s1 != s_ImpossibleValue)
    from rpython.annotator.unaryop import s_isinstance
    s_int = annotator.bookkeeper.immutablevalue(int)
    s_res_12 = s_isinstance(annotator, s_12, s_int, [])
    s_res_1 = s_isinstance(annotator, s1, s_int, [])
    assert s_res_12.contains(s_res_1)

def compile_function(function, annotation=[]):
    t = TranslationContext()
    t.buildannotator().build_types(function, annotation)

class AAA(object):
    pass

def test_blocked_inference1(annotator):
    def blocked_inference():
        return AAA().m()

    with pytest.raises(AnnotatorError):
        annotator.build_types(blocked_inference, [])

def test_blocked_inference2(annotator):
    def blocked_inference():
        a = AAA()
        b = a.x
        return b

    with pytest.raises(AnnotatorError):
        annotator.build_types(blocked_inference, [])


def test_not_const():
    s_int = SomeInteger()
    s_int.const = 2
    assert s_int != SomeInteger()
    assert not_const(s_int) == SomeInteger()
    assert not_const(s_None) == s_None


def test_nonnulify():
    s = SomeString(can_be_None=True).nonnulify()
    assert s.can_be_None is True
    assert s.no_nul is True
    s = SomeChar().nonnulify()
    assert s.no_nul is True

def test_SomeException_union(annotator):
    bk = annotator.bookkeeper
    someinst = lambda cls, **kw: SomeInstance(bk.getuniqueclassdef(cls), **kw)
    s_inst = someinst(Exception)
    s_exc = bk.new_exception([ValueError, IndexError])
    assert union(s_exc, s_inst) == s_inst
    assert union(s_inst, s_exc) == s_inst
    s_nullable = union(s_None, bk.new_exception([ValueError]))
    assert isinstance(s_nullable, SomeInstance)
    assert s_nullable.can_be_None
    s_exc1 = bk.new_exception([ValueError])
    s_exc2 = bk.new_exception([IndexError])
    union(s_exc1, s_exc2) == union(s_exc2, s_exc1)

def contains_s(s_a, s_b):
    if s_b is None:
        return True
    elif s_a is None:
        return False
    else:
        return s_a.contains(s_b)

def annotate_op(ann, hlop, args_s):
    for v_arg, s_arg in zip(hlop.args, args_s):
        ann.setbinding(v_arg, s_arg)
    with ann.bookkeeper.at_position(None):
        try:
            ann.consider_op(hlop)
        except BlockedInference:
            # BlockedInference only stops annotation along the normal path,
            # but not along the exceptional one.
            pass
    return hlop.result.annotation, ann.get_exception(hlop)

def test_generalize_getitem_dict(annotator):
    bk = annotator.bookkeeper
    hlop = op.getitem(Variable(), Variable())
    s_int = SomeInteger()
    with bk.at_position(None):
        s_empty_dict = bk.newdict()
    s_value, s_exc = annotate_op(annotator, hlop, [s_None, s_int])
    s_value2, s_exc2 = annotate_op(annotator, hlop, [s_empty_dict, s_int])
    assert contains_s(s_value2, s_value)
    assert contains_s(s_exc2, s_exc)

def test_generalize_getitem_list(annotator):
    bk = annotator.bookkeeper
    hlop = op.getitem(Variable(), Variable())
    s_int = SomeInteger()
    with bk.at_position(None):
        s_empty_list = bk.newlist()
    s_value, s_exc = annotate_op(annotator, hlop, [s_None, s_int])
    s_value2, s_exc2 = annotate_op(annotator, hlop, [s_empty_list, s_int])
    assert contains_s(s_value2, s_value)
    assert contains_s(s_exc2, s_exc)

def test_generalize_getitem_string(annotator):
    hlop = op.getitem(Variable(), Variable())
    s_int = SomeInteger()
    s_str = SomeString(can_be_None=True)
    s_value, s_exc = annotate_op(annotator, hlop, [s_None, s_int])
    s_value2, s_exc2 = annotate_op(annotator, hlop, [s_str, s_int])
    assert contains_s(s_value2, s_value)
    assert contains_s(s_exc2, s_exc)

def test_generalize_string_concat(annotator):
    hlop = op.add(Variable(), Variable())
    s_str = SomeString(can_be_None=True)
    s_value, s_exc = annotate_op(annotator, hlop, [s_None, s_str])
    s_value2, s_exc2 = annotate_op(annotator, hlop, [s_str, s_str])
    assert contains_s(s_value2, s_value)
    assert contains_s(s_exc2, s_exc)

def test_getitem_dict(annotator):
    bk = annotator.bookkeeper
    hlop = op.getitem(Variable(), Variable())
    with bk.at_position(None):
        s_dict = bk.newdict()
    s_dict.dictdef.generalize_key(SomeString())
    s_dict.dictdef.generalize_value(SomeInteger())
    s_result, _ = annotate_op(annotator, hlop, [s_dict, SomeString()])
    assert s_result == SomeInteger()
