import secrets
import time

from .defaults import PAIRING_CODE_LENGTH, PAIRING_CODE_TTL


class BlueskyPairing:
    id_label = "DID"

    def __init__(self):
        self._pending: dict[str, dict] = {}

    def generate_code(self, sender_did: str, sender_handle: str = "") -> str:
        self._cleanup_expired()

        code = secrets.token_hex(PAIRING_CODE_LENGTH // 2)[:PAIRING_CODE_LENGTH].upper()
        self._pending[code] = {
            "did": sender_did,
            "handle": sender_handle,
            "created_at": time.time(),
        }
        return code

    def verify_code(self, code: str) -> dict | None:
        self._cleanup_expired()
        return self._pending.pop(code, None)

    def normalize_allow_entry(self, entry: str) -> str:
        return entry.replace("did:", "").strip().lower()

    def get_pending(self) -> list[dict]:
        self._cleanup_expired()
        return [{"code": code, **entry} for code, entry in self._pending.items()]

    def _cleanup_expired(self):
        now = time.time()
        expired = [code for code, entry in self._pending.items() if now - entry["created_at"] > PAIRING_CODE_TTL]
        for code in expired:
            del self._pending[code]