"""
This is new module that we intend to GROW from test_events.py.

It will contain schemas (aka validators) for Zulip events.

Right now it's only intended to be used by test code.
"""
from typing import Dict, Sequence, Tuple

from zerver.lib.validator import Validator, check_dict_only, check_int


def check_events_dict(
    required_keys: Sequence[Tuple[str, Validator[object]]],
    optional_keys: Sequence[Tuple[str, Validator[object]]] = [],
) -> Validator[Dict[str, object]]:
    """
    This is just a tiny wrapper on check_dict, but it provides
    some minor benefits:

        - mark clearly that the schema is for a Zulip event
        - make sure there's a type field
        - add id field automatically
        - sanity check that we have no duplicate keys (we
          should just make check_dict do that, eventually)

    """
    rkeys = [key[0] for key in required_keys]
    okeys = [key[0] for key in optional_keys]
    keys = rkeys + okeys
    assert len(keys) == len(set(keys))
    assert "type" in rkeys
    assert "id" not in keys
    return check_dict_only(
        required_keys=list(required_keys) + [("id", check_int)],
        optional_keys=optional_keys,
    )