from abc import ABC, abstractmethod
from typing import NamedTuple


class ToolCall(NamedTuple):
    name: str
    args: dict
    result: str | None = None


class AgentResult(NamedTuple):
    response: str
    tool_calls: list[ToolCall]


class Agent(ABC):
    """Common interface for all agent implementations under test."""

    def __init__(self, mcp_url: str):
        self.mcp_url = mcp_url

    @abstractmethod
    def run(self, user_prompt: str) -> AgentResult:
        """Run the agent on a prompt and return the response and ordered tool calls."""
        ...