from __future__ import annotations

import tomllib
from dataclasses import dataclass
from pathlib import Path

from .config import config_path


@dataclass(frozen=True)
class PolicyProfile:
    name: str
    allow: frozenset[str]
    require_human: frozenset[str]
    safety_gated_max_attempts: int = 0
    delivery_ack_mode: str = "injected"


DEFAULT = PolicyProfile(
    "default",
    frozenset({"statehub_read", "repo_inspect", "repo_edit", "local_checks", "state_updates", "coordination_messages", "tmux_wake", "transient_retry"}),
    frozenset({"secrets", "destructive", "live_external", "scope_change", "ambiguous_ownership", "external_publish", "financial", "legal"}),
)


def load_profile(path: Path | None = None, selected: str = "default") -> PolicyProfile:
    path = path or config_path()
    if not path.exists():
        return DEFAULT
    with path.open("rb") as stream:
        data = tomllib.load(stream)
    profile = data.get("policy", {}).get("profiles", {}).get(selected)
    if not profile:
        if selected == "default":
            return DEFAULT
        raise ValueError(f"unknown policy profile: {selected}")
    attempts = int(profile.get("safety_gated_max_attempts", 0))
    if not 0 <= attempts <= 9:
        raise ValueError("safety_gated_max_attempts must be between 0 and 9")
    ack_mode = profile.get("delivery_ack_mode", "injected")
    if ack_mode not in {"injected", "acknowledged"}:
        raise ValueError("delivery_ack_mode must be injected or acknowledged")
    return PolicyProfile(selected, frozenset(profile.get("allow", [])), frozenset(profile.get("require_human", [])), attempts, ack_mode)