from importlib.util import module_from_spec, spec_from_file_location
import logging
from os import getcwd, walk
from pathlib import Path
from types import ModuleType
from typing import List, Union

logger = logging.getLogger(__name__)


# Import functions
# Took from https://stackoverflow.com/a/57892961
def get_py_files(src: Union[str, Path]) -> List[str]:
    cwd = getcwd()  # Current Working directory
    py_files = []

    for root, dirs, files in walk(src):
        py_files.extend(
            Path(f"{cwd}/{root}/{file}") for file in files if file.endswith(".py")
        )

    return py_files


def dynamic_import(module_name: str, py_path: str) -> Union[ModuleType, None]:
    try:
        module_spec = spec_from_file_location(module_name, py_path)

        if module_spec is None:
            raise RuntimeError(
                f"Module spec from module name {module_name} and path {py_path} is None"
            )

        module = module_from_spec(module_spec)

        if module_spec.loader is None:
            logger.warning(
                "Could not load extension %s due to spec loader being None.",
                module_name,
            )
            return

        module_spec.loader.exec_module(module)

        return module
    except SyntaxError:
        logger.warning(
            "Could not load extension %s due to invalid syntax. Check logs/errors.log for details.",
            module_name,
        )
        return
    except Exception as exc:
        logger.warning("Could not load extension %s due to %s", module_name, exc)
        return


def dynamic_import_from_src(src: Union[str, Path], star_import=False) -> None:
    my_py_files = get_py_files(src)

    for py_file in my_py_files:
        module_name = Path(py_file).stem

        logger.debug("Importing %s extension...", module_name)

        imported_module = dynamic_import(module_name, py_file)

        if imported_module != None:
            if star_import:
                for obj in dir(imported_module):
                    globals()[obj] = imported_module.__dict__[obj]
            else:
                globals()[module_name] = imported_module

        logger.info("Successfully loaded %s extension", module_name)

    return