import io
from typing import Iterable, Self

import pydantic

from .classes import DecryptedAccount


class _Account(pydantic.BaseModel):
    name: str
    login: str
    password: str

    def to_usual_account(self, user_id: int) -> DecryptedAccount:
        return DecryptedAccount(
            user_id=user_id,
            name=self.name,
            login=self.login,
            password=self.password,
        )

    @classmethod
    def from_usual_account(cls, account: DecryptedAccount) -> Self:
        return cls(
            name=account.name,
            login=account.login,
            password=account.password,
        )


class _Accounts(pydantic.BaseModel):
    accounts: list[_Account] = pydantic.Field(default_factory=list)


def _accounts_list_to_json(accounts: Iterable[DecryptedAccount]) -> str:
    result = _Accounts(
        accounts=[_Account.from_usual_account(i) for i in accounts],
    ).json(ensure_ascii=False)
    return result


def json_to_accounts(json_: str, user_id: int) -> list[DecryptedAccount]:
    accounts = _Accounts.parse_raw(json_)
    return [account.to_usual_account(user_id) for account in accounts.accounts]


def accounts_to_json(accounts: Iterable[DecryptedAccount]) -> io.StringIO:
    file = io.StringIO(_accounts_list_to_json(accounts))
    file.name = "passwords.json"
    return file