"""Runtime configuration resolved from environment and repo layout.

Nothing here is a secret. Backend auth (named providers in engine_auth) is
resolved lazily inside the backend adapter, never cached on disk by this module.
"""
from __future__ import annotations

import os
from dataclasses import dataclass
from pathlib import Path


def repo_root() -> Path:
    """Repo root = nearest ancestor containing pyproject.toml (fallback: cwd)."""
    here = Path(__file__).resolve()
    for parent in (here, *here.parents):
        if (parent / "pyproject.toml").exists():
            return parent
    return Path.cwd()


def _positive_int(raw: str, default: int = 1) -> int:
    """Parse a positive approval threshold. Anything malformed keeps the default."""
    try:
        value = int(raw)
    except (TypeError, ValueError):
        return default
    return value if value >= 1 else default


@dataclass(frozen=True)
class Config:
    catalog_dir: Path
    policy_dir: Path
    evidence_dir: Path
    hub_url: str
    bao_addr: str
    topic_id: str
    approval_url: str = ""
    approval_token_file: Path | None = None
    approval_client_secret_file: Path | None = None
    keycape_token_url: str = ""
    keycape_issuer: str = ""
    keycape_client_secret_file: Path | None = None
    openbao_jwt_login_file: Path | None = None
    # PIP/PDP join (SECRETS-WP-0007-T04 / SECRETS-WP-0008-T02). All absent by
    # default: an unset value fails production closed exactly as before.
    authorization_subject_id: str = ""
    authorization_subject_type: str = ""
    authorization_policy_package: str = ""
    authorization_policy_version: str = ""
    authorization_min_approvals: int = 1
    pdp_url: str = ""
    pdp_token_file: Path | None = None

    @classmethod
    def load(cls) -> "Config":
        root = repo_root()
        token_file = os.environ.get("SECRETS_ENGINE_APPROVAL_TOKEN_FILE", "")
        approval_secret = os.environ.get("SECRETS_ENGINE_APPROVAL_CLIENT_SECRET_FILE", "")
        keycape_secret = os.environ.get("SECRETS_ENGINE_KEYCAPE_CLIENT_SECRET_FILE", "")
        jwt_login = os.environ.get("SECRETS_ENGINE_OPENBAO_JWT_LOGIN", "")
        pdp_token = os.environ.get("SECRETS_ENGINE_PDP_TOKEN_FILE", "")
        return cls(
            catalog_dir=Path(os.environ.get("SECRETS_ENGINE_CATALOG", root / "catalog")),
            policy_dir=Path(os.environ.get("SECRETS_ENGINE_POLICIES", root / "policies")),
            evidence_dir=Path(os.environ.get("SECRETS_ENGINE_EVIDENCE", root / ".evidence")),
            hub_url=os.environ.get("SECRETS_ENGINE_HUB_URL", "http://127.0.0.1:8000"),
            bao_addr=os.environ.get("BAO_ADDR", os.environ.get("VAULT_ADDR", "http://127.0.0.1:8200")),
            topic_id=os.environ.get(
                "SECRETS_ENGINE_TOPIC_ID", "cee7bedf-2b48-46ef-8601-006474f2ad7a"
            ),
            approval_url=os.environ.get("SECRETS_ENGINE_APPROVAL_URL", ""),
            approval_token_file=Path(token_file) if token_file else None,
            approval_client_secret_file=Path(approval_secret) if approval_secret else None,
            keycape_token_url=os.environ.get("SECRETS_ENGINE_KEYCAPE_TOKEN_URL", ""),
            keycape_issuer=os.environ.get("SECRETS_ENGINE_KEYCAPE_ISSUER", ""),
            keycape_client_secret_file=Path(keycape_secret) if keycape_secret else None,
            openbao_jwt_login_file=Path(jwt_login) if jwt_login else None,
            authorization_subject_id=os.environ.get(
                "SECRETS_ENGINE_AUTHORIZATION_SUBJECT_ID", ""
            ),
            authorization_subject_type=os.environ.get(
                "SECRETS_ENGINE_AUTHORIZATION_SUBJECT_TYPE", ""
            ),
            authorization_policy_package=os.environ.get(
                "SECRETS_ENGINE_AUTHORIZATION_POLICY_PACKAGE", ""
            ),
            authorization_policy_version=os.environ.get(
                "SECRETS_ENGINE_AUTHORIZATION_POLICY_VERSION", ""
            ),
            authorization_min_approvals=_positive_int(
                os.environ.get("SECRETS_ENGINE_AUTHORIZATION_MIN_APPROVALS", "")
            ),
            pdp_url=os.environ.get("SECRETS_ENGINE_PDP_URL", ""),
            pdp_token_file=Path(pdp_token) if pdp_token else None,
        )