"""Unified adapter contract for Bridge V1.2.

Every adapter must expose:
    execute(prompt: str) -> AdapterResult

AdapterResult fields:
    response  - string output on success, None on error
    error     - error message on failure, None on success
    exit_code - 0 = success, non-zero = failure
    mode      - "real" or "stub"
    metadata  - adapter-specific extra data (e.g. agent_run_id)
"""
from __future__ import annotations

from dataclasses import dataclass, field
from typing import Any, Optional


@dataclass
class AdapterResult:
    response: Optional[str]
    error: Optional[str]
    exit_code: int
    mode: str  # "real" | "stub"
    metadata: dict[str, Any] = field(default_factory=dict)

    @property
    def ok(self) -> bool:
        return self.exit_code == 0 and self.error is None