from __future__ import annotations

import hashlib
import time
from typing import Any


class ExecApproval:
    PENDING_TTL = 300

    def __init__(self) -> None:
        self._pending: dict[str, dict[str, Any]] = {}

    def create_approval_request(
        self,
        chat_guid: str,
        command: str,
        context: dict[str, Any] | None = None,
    ) -> str:
        request_id = hashlib.sha256(f"{chat_guid}:{command}:{time.monotonic()}".encode()).hexdigest()[:16]

        self._pending[request_id] = {
            "chat_guid": chat_guid,
            "command": command,
            "context": context or {},
            "status": "pending",
            "created_at": time.monotonic(),
        }
        return request_id

    def approve(self, request_id: str) -> bool:
        entry = self._pending.get(request_id)
        if entry is None:
            return False
        if entry["status"] != "pending":
            return False
        if time.monotonic() - entry["created_at"] > self.PENDING_TTL:
            del self._pending[request_id]
            return False
        entry["status"] = "approved"
        return True

    def reject(self, request_id: str) -> bool:
        entry = self._pending.get(request_id)
        if entry is None:
            return False
        if entry["status"] != "pending":
            return False
        entry["status"] = "rejected"
        return True

    def get_request(self, request_id: str) -> dict[str, Any] | None:
        return self._pending.get(request_id)

    def cleanup(self) -> None:
        now = time.monotonic()
        expired = [
            k for k, v in self._pending.items() if now - v["created_at"] > self.PENDING_TTL or v["status"] != "pending"
        ]
        for k in expired:
            del self._pending[k]