import base64
from typing import Any

from fansifter_common.adapters.db.base import Database
from mypy_boto3_kms import KMSClient
from twilio.request_validator import RequestValidator as TwilioRequestValidator

from app.adapters.db.twilio.repositories import TwilioAccountRepository
from app.exceptions import RequestValidationError


class RequestValidator:
    def __init__(
        self,
        db: Database,
        accounts_repository: TwilioAccountRepository,
        kms_client: KMSClient,
        kms_key_id: str,
    ) -> None:
        self.db = db
        self.accounts_repository = accounts_repository
        self.kms_client = kms_client
        self.kms_key_id = kms_key_id
        self.validators: dict[str, TwilioRequestValidator] = {}

    def validate(self, url: str, request: dict[str, Any], signature: str) -> None:
        validator = self.get_validator(request.get("AccountSid"))
        validation_passed = validator.validate(url, request, signature)
        if not validation_passed:
            raise RequestValidationError("Request validation failed")

    def get_validator(self, account_sid: str | None) -> TwilioRequestValidator:
        if not account_sid:
            raise ValueError("AccountSid is required")

        if account_sid not in self.validators:
            auth_token = self.get_auth_token(account_sid)
            self.validators[account_sid] = TwilioRequestValidator(auth_token)
        return self.validators[account_sid]

    def get_auth_token(self, account_sid: str) -> str:
        with self.db.session_factory():
            account = self.accounts_repository.get_by_account_sid(account_sid)
        if account:
            response = self.kms_client.decrypt(
                CiphertextBlob=base64.b64decode(account.auth_token),
                KeyId=self.kms_key_id,
            )
            return response.get("Plaintext").decode("utf-8")
        raise ValueError("Account not found")