import ast

import pytest

from common.ast_utils import NamesWithAttributesVisitor, UnreferencedNamesVisitor, UnreferencedVariablesVisitor, \
    WhereConstraintVisitor


@pytest.mark.parametrize("source, expected", [
    ("a,b", {"a", "b"}),
    ("isinstance(a, int)", {"isinstance", "a", "int"}),
    ("date.today()", {"date"}),
    ("test()", {"test"}),
    ("sheerka.test()", {"sheerka"}),
    ("for i in range(10): pass", set()),
    ("func(x=a, y=b)", {"func", "a", "b"}),

])
def test_i_can_get_unreferenced_names_from_simple_expressions(source, expected):
    ast_ = ast.parse(source)
    visitor = UnreferencedNamesVisitor()
    visitor.visit(ast_)

    assert visitor.names == expected


def test_name_with_attribute():
    # Looks for all attributes for a given name
    ast_ = ast.parse("foo.bar.baz", "<src>", mode="exec")
    assert NamesWithAttributesVisitor().get_sequences(ast_, "foo") == [["foo", "bar", "baz"]]

    # It parses all expressions / statements
    ast_ = ast.parse("foo.bar.baz; one.two.three; foo.bar", "<src>", mode="exec")
    assert NamesWithAttributesVisitor().get_sequences(ast_, "foo") == [["foo", "bar", "baz"], ["foo", "bar"]]


@pytest.mark.parametrize("source, expected", [
    ("a,b", {"a", "b"}),
    ("isinstance(a, int)", {"a", "int"}),
    ("date.today()", set()),
    ("test()", set()),
    ("sheerka.test()", set()),
    ("for i in range(10): pass", set()),
    ("func(x=a, y=b)", {"a", "b", "x", "y"}),
])
def test_i_can_get_unreferenced_variables_from_simple_expressions(source, expected):
    ast_ = ast.parse(source)
    visitor = UnreferencedVariablesVisitor()
    visitor.visit(ast_)

    assert visitor.names == expected


def test_i_can_get_where_constraints():
    expr = "a == 2"
    ast_tree = ast.parse(expr, f"<user input>", 'eval')
    visitor = WhereConstraintVisitor(ast_tree)

    res = visitor.get_constraints()
    assert res == {"a": [WhereConstraintVisitor.WhereConstraint("a == 2")]}
    assert isinstance(res["a"][0].ast_tree, ast.Expression)


def test_i_can_get_where_constraints_when_and():
    expr = "a == 2 and isinstance(b, Concept)"
    ast_tree = ast.parse(expr, f"<user input>", 'eval')
    visitor = WhereConstraintVisitor(ast_tree)

    res = visitor.get_constraints()
    assert res == {"a": [WhereConstraintVisitor.WhereConstraint("a == 2")],
                   "b": [WhereConstraintVisitor.WhereConstraint("isinstance(b, Concept)")],
                   "Concept": [WhereConstraintVisitor.WhereConstraint("isinstance(b, Concept)")]}

    assert isinstance(res["a"][0].ast_tree, ast.Expression)
    assert isinstance(res["b"][0].ast_tree, ast.Expression)
    assert isinstance(res["Concept"][0].ast_tree, ast.Expression)


def test_i_can_get_where_constraint_when_name_is_reference_several_times():
    expr = "isinstance(a, int) and a == 2"
    ast_tree = ast.parse(expr, f"<user input>", 'eval')
    visitor = WhereConstraintVisitor(ast_tree)

    res = visitor.get_constraints()
    assert res == {"a": [WhereConstraintVisitor.WhereConstraint("isinstance(a, int)"),
                         WhereConstraintVisitor.WhereConstraint("a == 2")],
                   "int": [WhereConstraintVisitor.WhereConstraint("isinstance(a, int)")]}

    assert isinstance(res["a"][0].ast_tree, ast.Expression)
    assert isinstance(res["a"][1].ast_tree, ast.Expression)
    assert isinstance(res["int"][0].ast_tree, ast.Expression)


def test_i_cannot_get_constraint_when_or():
    expr = "isinstance(a, int) or a == 2"
    ast_tree = ast.parse(expr, f"<user input>", 'eval')
    visitor = WhereConstraintVisitor(ast_tree)

    with pytest.raises(NotImplementedError):
        visitor.get_constraints()