"""Shared agent surface.

``BaseAgent`` is the structural contract every backend-specific agent
honours. Subclasses add **capabilities as fields** (``ClaudeAgent.cwd``,
``RaycastAgent.streaming``) - backends dispatch on type, not on a runtime
matrix.
"""

from __future__ import annotations

from dataclasses import dataclass

from pydantic import BaseModel, ConfigDict


@dataclass(frozen=True, slots=True)
class ExposedMcp:
    """Reference to an ``McpServer`` (by name) exposed to a single agent.

    ``tools`` is an allowlist of tool names (``None`` = every tool);
    ``deny`` is a tuple of ``fnmatch`` patterns removed on top of that,
    e.g. ``("delete_*",)``.
    """

    name: str
    tools: tuple[str, ...] | None = None
    deny: tuple[str, ...] = ()


class BaseAgent(BaseModel):
    """Common fields. Concrete backends subclass and add capabilities."""

    model_config = ConfigDict(frozen=True, arbitrary_types_allowed=True)

    name: str
    model: str
    system_prompt: str
    expose_mcps: tuple[ExposedMcp, ...] = ()
    accept_client_tools: bool = False