"""
Command-format shims — applied to clean_msg (protocol fields already stripped)
before forwarding to the native host, and to responses before sending back.

Add one entry per breaking command-format change:
    ("X.Y.Z", request_fn, response_fn)

- request_fn(msg: dict) -> dict   or None
- response_fn(resp: bytes, command: str) -> bytes   or None

Entries must stay in ascending version order.
adapt_request walks forward (oldest first); adapt_response walks backward.

Current baseline: 0.9.3 — no command-format shims needed yet.
"""
from __future__ import annotations
from typing import Callable
from browser_cli.version_manager import parse_version


# ── registry ──────────────────────────────────────────────────────────────────

_COMPAT: list[tuple[str, Callable[[dict], dict] | None, Callable[[bytes, str], bytes] | None]] = [
    # ("1.0.0", _req_1_0_0, _resp_1_0_0),
]


def adapt_request(msg: dict, client_version: str) -> dict:
    """Upgrade a client message to the current browser command format."""
    cv = parse_version(client_version)
    for version, req_fn, _ in _COMPAT:
        if cv < parse_version(version) and req_fn is not None:
            msg = req_fn(msg)
    return msg


def adapt_response(resp: bytes, command: str, client_version: str) -> bytes:
    """Downgrade a native-host response to the format the client expects."""
    cv = parse_version(client_version)
    for version, _, resp_fn in reversed(_COMPAT):
        if cv < parse_version(version) and resp_fn is not None:
            resp = resp_fn(resp, command)
    return resp