"""DM Pairing flow for Synology Chat security policy.

Handles the complete pairing lifecycle: unknown user triggers pairing request,
approval adds user to allowlist, denial blocks permanently.
Includes standardized approval/denial message templates for user notification.
"""

from __future__ import annotations

from typing import Any

from yuxi.utils.logging_config import logger

_PAIRING_APPROVED_MESSAGE = "ForcePilot: your access has been approved. You may now interact with the bot."
_PAIRING_DENIED_MESSAGE = "ForcePilot: your access request has been denied."


class PairingManager:
    def __init__(self, security_policy):
        self._policy = security_policy
        self._pairing_requests: dict[str, dict[str, Any]] = {}

    def request_pairing(self, user_id: str, metadata: dict[str, Any] | None = None) -> dict[str, Any]:
        request_id = f"pairing:{user_id}"
        self._pairing_requests[request_id] = {
            "user_id": user_id,
            "status": "pending",
            "metadata": metadata or {},
        }
        logger.info(f"[SynologyChat] Pairing requested for user {user_id}")
        return {"request_id": request_id, "status": "pending", "user_id": user_id}

    def approve(self, user_id: str) -> dict[str, Any]:
        request_id = f"pairing:{user_id}"
        if request_id not in self._pairing_requests:
            return {"status": "error", "message": f"No pairing request for user {user_id}"}
        self._pairing_requests[request_id]["status"] = "approved"
        self._policy.approve_pairing(user_id)
        logger.info(f"[SynologyChat] Pairing approved for user {user_id}")
        return {
            "request_id": request_id,
            "status": "approved",
            "user_id": user_id,
            "approved_message": _PAIRING_APPROVED_MESSAGE,
        }

    def deny(self, user_id: str) -> dict[str, Any]:
        request_id = f"pairing:{user_id}"
        if request_id not in self._pairing_requests:
            return {"status": "error", "message": f"No pairing request for user {user_id}"}
        self._pairing_requests[request_id]["status"] = "denied"
        self._policy.deny_pairing(user_id)
        logger.info(f"[SynologyChat] Pairing denied for user {user_id}")
        return {
            "request_id": request_id,
            "status": "denied",
            "user_id": user_id,
            "denied_message": _PAIRING_DENIED_MESSAGE,
        }

    def get_pending(self) -> list[dict[str, Any]]:
        return [r for r in self._pairing_requests.values() if r["status"] == "pending"]

    def get_status(self, user_id: str) -> dict[str, Any]:
        request_id = f"pairing:{user_id}"
        return self._pairing_requests.get(request_id, {"status": "not_requested", "user_id": user_id})