"""MAS mode contract v0.1: email hands a case to another mode, or works
inside a control flow it does not own (`mas-modes-v0.1-spec/CONTRACT.md`).

`schema/` and `conformance/` are vendored unchanged from the bundle.
"""

from __future__ import annotations

import json
from functools import lru_cache
from importlib import resources

CONTRACT_VERSION = "0.1"


def _load(name: str):
    return json.loads(resources.files(__name__).joinpath(name).read_text(encoding="utf-8"))


@lru_cache(maxsize=None)
def _validator(schema_file: str):
    from jsonschema import Draft202012Validator
    return Draft202012Validator(_load(f"schema/{schema_file}"))


def message_errors(msg: dict) -> list[str]:
    """Schema errors for a contract message; empty if valid."""
    return [e.message for e in _validator("mas-modes-v0.1.schema.json").iter_errors(msg)]


def event_errors(event: dict) -> list[str]:
    """Schema errors for a normalized gateway event; empty if valid."""
    return [e.message for e in _validator("mas-event-v0.1.schema.json").iter_errors(event)]


def transitions() -> dict:
    return _load("conformance/transitions.json")


def message_fixtures() -> dict:
    return _load("conformance/messages.json")


def flow_fixtures() -> list[dict]:
    return _load("conformance/flows.json")["flows"]