"""Workspace-independent authority/network/Gitea ref sentinel."""

from __future__ import annotations

from dataclasses import dataclass
from pathlib import Path
import subprocess
from typing import Callable, Mapping


class SentinelError(RuntimeError):
    pass


@dataclass(frozen=True, slots=True)
class SentinelInputs:
    authority_git_dir: Path
    gitea_remote: str
    gitea_api: str
    ref: str
    expected_oid: str


@dataclass(frozen=True, slots=True)
class SentinelResult:
    authority_oid: str | None
    network_oid: str | None
    gitea_oid: str | None
    equal: bool
    error: str | None = None


def authority_oid(inputs: SentinelInputs) -> str:
    result = subprocess.run(
        ["git", "--git-dir", str(inputs.authority_git_dir), "rev-parse", inputs.ref],
        text=True,
        capture_output=True,
        check=False,
    )
    if result.returncode != 0:
        raise SentinelError("AUTHORITY_REF_UNAVAILABLE")
    return result.stdout.strip()


def evaluate(
    inputs: SentinelInputs,
    *,
    network_reader: Callable[[str, str], str | None],
    gitea_reader: Callable[[str, str], str | None],
) -> SentinelResult:
    try:
        local = authority_oid(inputs)
        network = network_reader(inputs.gitea_remote, inputs.ref)
        gitea = gitea_reader(inputs.gitea_api, inputs.ref)
        equal = local == network == gitea == inputs.expected_oid
        return SentinelResult(local, network, gitea, equal, None if equal else "OID_MISMATCH")
    except SentinelError as exc:
        return SentinelResult(None, None, None, False, str(exc))