from __future__ import annotations

import importlib
import importlib.util
import logging
import sys
from pathlib import Path

logger = logging.getLogger(__name__)


class PluginLoader:
    async def load(self, entry_file: str) -> object:
        try:
            path = Path(entry_file)
            if path.exists() and path.is_file():
                module_name = entry_file.replace("/", ".").replace("\\", ".").removesuffix(".py")
                if module_name in sys.modules:
                    return sys.modules[module_name]

                spec = importlib.util.spec_from_file_location(module_name, str(path))
                if spec and spec.loader:
                    module = importlib.util.module_from_spec(spec)
                    sys.modules[module_name] = module
                    spec.loader.exec_module(module)
                    return module

            module_name = entry_file.replace("/", ".").replace("\\", ".").removesuffix(".py")
            return importlib.import_module(module_name)
        except Exception as exc:
            logger.error("failed to load plugin module %s: %s", entry_file, exc)
            raise

    def extract_adapter_class(self, module: object) -> type | None:
        for attr_name in dir(module):
            if attr_name.startswith("_"):
                continue
            attr = getattr(module, attr_name, None)
            if attr is None or not isinstance(attr, type):
                continue
            if not hasattr(attr, "get_default_config"):
                continue
            if not hasattr(attr, "capabilities"):
                continue
            if not hasattr(attr, "open") or not hasattr(attr, "close"):
                continue
            return attr
        return None