from __future__ import annotations

import json
import logging
import os
from pathlib import Path

logger = logging.getLogger(__name__)

CREDENTIAL_BACKUP_DIR = Path.home() / ".forcepilot" / "qqbot" / "credentials"


class CredentialBackup:
    def __init__(self, backup_dir: Path | None = None):
        self._backup_dir = backup_dir or CREDENTIAL_BACKUP_DIR
        self._backup_dir.mkdir(parents=True, exist_ok=True)

    def _backup_path(self, account_id: str) -> Path:
        safe_id = account_id.replace("/", "_").replace("\\", "_")
        return self._backup_dir / f"{safe_id}.json"

    def save(self, account_id: str, app_id: str, client_secret: str) -> None:
        path = self._backup_path(account_id)
        data = {
            "account_id": account_id,
            "app_id": app_id,
            "client_secret": client_secret,
        }
        try:
            path.write_text(json.dumps(data, ensure_ascii=False), encoding="utf-8")
            logger.debug("Credential backup saved for account '%s'", account_id)
        except OSError as e:
            logger.warning("Failed to save credential backup for '%s': %s", account_id, e)

    def load(self, account_id: str) -> dict | None:
        path = self._backup_path(account_id)
        if not path.exists():
            return None
        try:
            data = json.loads(path.read_text(encoding="utf-8"))
            if data.get("app_id") and data.get("client_secret"):
                logger.debug("Credential backup loaded for account '%s'", account_id)
                return data
        except (json.JSONDecodeError, OSError) as e:
            logger.warning("Failed to load credential backup for '%s': %s", account_id, e)
        return None

    def exists(self, account_id: str) -> bool:
        return self._backup_path(account_id).exists()

    def clear(self, account_id: str) -> None:
        path = self._backup_path(account_id)
        try:
            path.unlink(missing_ok=True)
            logger.debug("Credential backup cleared for account '%s'", account_id)
        except OSError as e:
            logger.warning("Failed to clear credential backup for '%s': %s", account_id, e)

    def clear_all(self) -> None:
        for path in self._backup_dir.glob("*.json"):
            try:
                path.unlink()
            except OSError:
                pass
        logger.debug("All credential backups cleared")