mcesptool/src/mcp_esptool_server/middleware/middleware_factory.py

"""
Middleware Factory

Provides factory methods for creating appropriate middleware instances
based on target CLI tools and operation context.
"""

import logging
from typing import Any
from uuid import uuid4

from fastmcp import Context

from .esptool_middleware import ESPToolMiddleware
from .logger_interceptor import LoggerInterceptor, ToolNotFoundError

logger = logging.getLogger(__name__)


class MiddlewareFactory:
    """Factory for creating CLI tool middleware instances"""

    # Registry of available middleware classes
    _middleware_registry: dict[str, type[LoggerInterceptor]] = {
        "esptool": ESPToolMiddleware,
    }

    @classmethod
    def create_middleware(
        cls, tool_name: str, context: Context, operation_id: str | None = None, **kwargs
    ) -> LoggerInterceptor:
        """
        Create middleware instance for specified CLI tool

        Args:
            tool_name: Name of the CLI tool (e.g., 'esptool')
            context: FastMCP context for logging and user interaction
            operation_id: Unique identifier for this operation
            **kwargs: Additional parameters for middleware initialization

        Returns:
            Configured middleware instance

        Raises:
            ToolNotFoundError: If tool is not supported
        """
        if tool_name not in cls._middleware_registry:
            available_tools = ", ".join(cls._middleware_registry.keys())
            raise ToolNotFoundError(
                f"No middleware available for tool: {tool_name}. Available tools: {available_tools}"
            )

        # Generate operation ID if not provided
        if operation_id is None:
            operation_id = f"{tool_name}_{uuid4().hex[:8]}"

        # Get middleware class and create instance
        middleware_class = cls._middleware_registry[tool_name]

        try:
            middleware = middleware_class(context, operation_id, **kwargs)
            logger.info(f"Created {tool_name} middleware with operation ID: {operation_id}")
            return middleware

        except Exception as e:
            logger.error(f"Failed to create {tool_name} middleware: {e}")
            raise ToolNotFoundError(f"Failed to initialize {tool_name} middleware: {e}")

    @classmethod
    def register_middleware(cls, tool_name: str, middleware_class: type[LoggerInterceptor]) -> None:
        """
        Register a new middleware class for a CLI tool

        Args:
            tool_name: Name of the CLI tool
            middleware_class: Middleware class that extends LoggerInterceptor
        """
        if not issubclass(middleware_class, LoggerInterceptor):
            raise ValueError(f"Middleware class must extend LoggerInterceptor: {middleware_class}")

        cls._middleware_registry[tool_name] = middleware_class
        logger.info(f"Registered middleware for tool: {tool_name}")

    @classmethod
    def get_supported_tools(cls) -> dict[str, str]:
        """
        Get list of supported CLI tools and their descriptions

        Returns:
            Dictionary mapping tool names to descriptions
        """
        tool_descriptions = {
            "esptool": "ESP32/ESP8266 programming and debugging tool",
        }

        return {
            tool: tool_descriptions.get(tool, "CLI tool integration")
            for tool in cls._middleware_registry.keys()
        }

    @classmethod
    def is_tool_supported(cls, tool_name: str) -> bool:
        """Check if a CLI tool is supported by middleware"""
        return tool_name in cls._middleware_registry

    @classmethod
    def create_esptool_middleware(
        cls, context: Context, operation_id: str | None = None, **kwargs
    ) -> ESPToolMiddleware:
        """
        Convenience method to create ESPTool middleware with proper typing

        Args:
            context: FastMCP context
            operation_id: Optional operation identifier
            **kwargs: Additional ESPTool-specific parameters

        Returns:
            Configured ESPToolMiddleware instance
        """
        middleware = cls.create_middleware("esptool", context, operation_id, **kwargs)
        return middleware  # Type checker knows this is ESPToolMiddleware

    @classmethod
    def get_middleware_info(cls, tool_name: str) -> dict[str, Any]:
        """
        Get information about a specific middleware

        Args:
            tool_name: Name of the CLI tool

        Returns:
            Dictionary with middleware information
        """
        if not cls.is_tool_supported(tool_name):
            return {"error": f"Tool not supported: {tool_name}"}

        middleware_class = cls._middleware_registry[tool_name]

        # Create temporary instance to get interaction points
        # (without context, for info purposes only)
        try:
            # Use a dummy context for information gathering
            class DummyContext:
                pass

            temp_instance = middleware_class(DummyContext(), "info_query")
            interaction_points = temp_instance.get_interaction_points()
        except Exception:
            interaction_points = []

        return {
            "tool_name": tool_name,
            "middleware_class": middleware_class.__name__,
            "description": cls.get_supported_tools()[tool_name],
            "interaction_points": interaction_points,
            "module": middleware_class.__module__,
        }