"""The public surface for model invocation.

Other modules import `call_model` and use it without knowing which backend is
configured. Switching backends means changing one assignment here.
"""

from .base import Message, ModelBackend, ModelRequest, ModelResponse
from .claude_code import ClaudeCodeBackend

_backend: ModelBackend = ClaudeCodeBackend()


def call_model(request: ModelRequest) -> ModelResponse:
    """Invoke the configured model backend."""
    return _backend.call(request)


__all__ = [
    "Message",
    "ModelBackend",
    "ModelRequest",
    "ModelResponse",
    "call_model",
]