from typing import Iterator

import sqlmodel
from sqlalchemy.future import Engine

from . import models


def get_master_pass(
    engine: Engine,
    user_id: int,
) -> tuple[bytes, bytes] | None:
    """Gets master pass. Returns tuple of salt and password
    or None if it wasn't found"""
    statement = sqlmodel.select(models.MasterPass).where(
        models.MasterPass.user_id == user_id,
    )
    with sqlmodel.Session(engine) as session:
        result = session.exec(statement).first()
    if result is None:
        return
    return (result.salt, result.password_hash)


def get_accounts(
    engine: Engine,
    user_id: int,
    *,
    to_sort: bool = False,
) -> list[str]:
    """Gets list of account names"""
    statement = sqlmodel.select(models.Account.name).where(
        models.Account.user_id == user_id,
    )
    if to_sort:
        statement = statement.order_by(models.Account.name)
    with sqlmodel.Session(engine) as session:
        result = session.exec(statement).fetchall()
    return result


def get_all_accounts(
    engine: Engine, user_id: int
) -> Iterator[tuple[str, bytes, bytes, bytes]]:
    """Returns an iterator of tuples, where values represent account's
    name, salt, encrypted login and encrypted password"""
    statement = (
        sqlmodel.select(models.Account)
        .where(
            models.Account.user_id == user_id,
        )
        .order_by(models.Account.name)
    )
    with sqlmodel.Session(engine) as session:
        result = session.exec(statement).fetchall()
    yield from (
        (
            account.name,
            account.salt,
            account.enc_login,
            account.enc_password,
        )
        for account in result
    )


def get_account_info(
    engine: Engine, user_id: int, name: str
) -> tuple[bytes, bytes, bytes]:
    """Gets account info. Returns tuple of salt, login and password
    or None if it wasn't found"""
    statement = sqlmodel.select(models.Account).where(
        models.Account.user_id == user_id,
        models.Account.name == name,
    )
    with sqlmodel.Session(engine) as session:
        result = session.exec(statement).first()
        if result is None:
            return
        return (result.salt, result.enc_login, result.enc_password)