from pathlib import Path
from typing import Any, Iterator, List

import pytest
from langchain_core.documents import Document

from langchain_community.document_loaders import DirectoryLoader


def test_raise_error_if_path_not_exist() -> None:
    loader = DirectoryLoader("./not_exist_directory")
    with pytest.raises(FileNotFoundError) as e:
        loader.load()

    assert str(e.value) == "Directory not found: './not_exist_directory'"


def test_raise_error_if_path_is_not_directory() -> None:
    loader = DirectoryLoader(__file__)
    with pytest.raises(ValueError) as e:
        loader.load()

    assert str(e.value) == f"Expected directory, got file: '{__file__}'"


class CustomLoader:
    """Test loader. Mimics interface of existing file loader."""

    def __init__(self, path: Path, **kwargs: Any) -> None:
        """Initialize the loader."""
        self.path = path

    def load(self) -> List[Document]:
        """Load documents."""
        with open(self.path, "r") as f:
            return [Document(page_content=f.read())]

    def lazy_load(self) -> Iterator[Document]:
        raise NotImplementedError("CustomLoader does not implement lazy_load()")


def test_exclude_ignores_matching_files(tmp_path: Path) -> None:
    txt_file = tmp_path / "test.txt"
    py_file = tmp_path / "test.py"
    txt_file.touch()
    py_file.touch()
    loader = DirectoryLoader(
        str(tmp_path),
        exclude=["*.py"],
        loader_cls=CustomLoader,  # type: ignore
    )
    data = loader.load()
    assert len(data) == 1


def test_exclude_as_string_converts_to_sequence() -> None:
    loader = DirectoryLoader("./some_directory", exclude="*.py")
    assert loader.exclude == ("*.py",)