from typing import Callable, TypeVar

from returns.io import IOResultE
from returns.pointfree import bind_result
from returns.result import ResultE
from typing_extensions import reveal_type

T1 = TypeVar("T1")
T2 = TypeVar("T2")
T3 = TypeVar("T3")
T4 = TypeVar("T4")


# this works correctly
def test(
    i: int,
    f1: Callable[[int], str],
    f2: Callable[[str], IOResultE[int]],
    f3: Callable[[int], ResultE[str]],
) -> IOResultE[str]:
    f1_res = f1(i)
    f2_res = f2(f1_res)
    f3_res = bind_result(f3)(f2_res)
    reveal_type(f3_res)
    return f3_res


# this passes typecheck with returns.io.IOResult[T3`-3, builtins.Exception]
def test_generic(
    i: T1,
    f1: Callable[[T1], IOResultE[T2]],
    f2: Callable[[T2], ResultE[T3]],
) -> IOResultE[T3]:
    f1_res = f1(i)
    f2_res = bind_result(f2)(f1_res)
    reveal_type(f2_res)
    return f2_res


# this fails typecheck with returns.io.IOResult[returns.io.IOResult[Any, Any], builtins.Exception]
def test_generic2(
    i: T1,
    f1: Callable[[T1], T2],
    f2: Callable[[T2], IOResultE[T3]],
    f3: Callable[[T3], ResultE[T4]],
) -> IOResultE[T4]:
    f1_res = f1(i)
    f2_res = f2(f1_res)
    f3_res = bind_result(f3)(f2_res)
    reveal_type(f3_res)
    return f3_res