from __future__ import annotations

import os
from typing import Any


def resolve_bot_token(config: dict[str, Any], account_id: str = "default") -> str | None:
    accounts = config.get("accounts", {})
    account_cfg = accounts.get(account_id, {})

    token = account_cfg.get("bot_token")
    if token:
        return token

    token = config.get("bot_token")
    if token:
        return token

    token_file = account_cfg.get("token_file") or config.get("token_file")
    if token_file and os.path.isfile(token_file):
        with open(token_file) as f:
            return f.read().strip()

    env_token = os.getenv("TELEGRAM_BOT_TOKEN")
    if env_token:
        return env_token

    env_prefix = os.getenv("TELEGRAM_BOT_TOKEN_PREFIX", "")
    env_suffix = account_id.upper()
    env_key = f"{env_prefix}_{env_suffix}" if env_prefix else f"TELEGRAM_BOT_TOKEN_{env_suffix}"
    env_token = os.getenv(env_key)
    if env_token:
        return env_token

    return None


def resolve_token_source(config: dict[str, Any], account_id: str = "default") -> str:
    accounts = config.get("accounts", {})
    account_cfg = accounts.get(account_id, {})

    if account_cfg.get("bot_token"):
        return f"accounts.{account_id}.bot_token"
    if config.get("bot_token"):
        return "config.bot_token"
    if account_cfg.get("token_file") or config.get("token_file"):
        return "token_file"
    return "env.TELEGRAM_BOT_TOKEN"