"""STRATEGY_ID and external-token presence helpers.

Phase1 (product plan): missing STRATEGY_ID → process must fail to start
(exit non-zero). Values are never logged or returned in responses.
"""

from __future__ import annotations

import os
import sys
from typing import Optional

# Community alias order (level C); we only check presence, never echo values.
_TOKEN_ENV_KEYS = (
    "XC_TOKEN_FILE",
    "XC_TOKEN",
    "MODELHUB_XC_TOKEN",
    "EXTERNAL_SERVICE_TOKEN",
)


def get_strategy_id() -> Optional[str]:
    """Return STRATEGY_ID if set and non-empty after strip; else None."""
    raw = os.environ.get("STRATEGY_ID")
    if raw is None:
        return None
    value = raw.strip()
    return value if value else None


def require_strategy_id() -> str:
    """Return STRATEGY_ID or exit the process with a non-zero status.

    Does not print the value. Safe for startup path.
    """
    sid = get_strategy_id()
    if sid is None:
        print(
            "ERROR: STRATEGY_ID is required and must be non-empty. "
            "Refusing to start (Phase1 contract).",
            file=sys.stderr,
        )
        sys.exit(1)
    return sid


def strategy_id_present() -> bool:
    return get_strategy_id() is not None


def _token_from_file(path: str) -> bool:
    """True if path exists and has non-empty content (value never read into logs)."""
    try:
        if not path or not os.path.isfile(path):
            return False
        with open(path, "r", encoding="utf-8") as fh:
            content = fh.read().strip()
        return bool(content)
    except OSError:
        return False


def external_service_token_present() -> bool:
    """Whether any known token env / file alias is present (boolean only)."""
    for key in _TOKEN_ENV_KEYS:
        raw = os.environ.get(key)
        if raw is None:
            continue
        value = raw.strip()
        if not value:
            continue
        if key == "XC_TOKEN_FILE":
            if _token_from_file(value):
                return True
            continue
        # Reject obvious placeholders (community practice, level C)
        lowered = value.lower()
        if lowered in ("tmp", "placeholder", "changeme", "xxx"):
            continue
        return True
    return False