"""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`` allowlists tool names (``None`` = all); ``deny`` removes
    ``fnmatch`` patterns on top, 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

    @property
    def thinking_is_progress(self) -> bool:
        """Whether non-empty thinking is text for the human rather than reasoning."""
        return False