import logging
from typing import Callable, Dict

import vllm.envs as envs

logger = logging.getLogger(__name__)

# make sure one process only loads plugins once
plugins_loaded = False


def load_plugins_by_group(group: str) -> Dict[str, Callable]:
    import sys
    if sys.version_info < (3, 10):
        from importlib_metadata import entry_points
    else:
        from importlib.metadata import entry_points

    allowed_plugins = envs.VLLM_PLUGINS

    discovered_plugins = entry_points(group=group)
    if len(discovered_plugins) == 0:
        logger.debug("No plugins for group %s found.", group)
        return {}
    logger.info("Available plugins for group %s:", group)
    for plugin in discovered_plugins:
        logger.info("name=%s, value=%s", plugin.name, plugin.value)
    if allowed_plugins is None:
        logger.info("all available plugins for group %s will be loaded.",
                    group)
        logger.info("set environment variable VLLM_PLUGINS to control"
                    " which plugins to load.")
    plugins = {}
    for plugin in discovered_plugins:
        if allowed_plugins is None or plugin.name in allowed_plugins:
            try:
                func = plugin.load()
                plugins[plugin.name] = func
                logger.info("plugin %s loaded.", plugin.name)
            except Exception:
                logger.exception("Failed to load plugin %s", plugin.name)
    return plugins


def load_general_plugins():
    """WARNING: plugins can be loaded for multiple times in different
    processes. They should be designed in a way that they can be loaded
    multiple times without causing issues.
    """
    global plugins_loaded
    if plugins_loaded:
        return
    plugins_loaded = True
    plugins = load_plugins_by_group(group='vllm.general_plugins')
    # general plugins, we only need to execute the loaded functions
    for func in plugins.values():
        func()