"""
AFI conformance — same @client fixture, same Mizan IR (KDL), both adapters.

Gates that mizan-django and mizan-fastapi emit byte-equivalent IR
for the same registered functions. If this passes, the codegen
produces identical TypeScript output regardless of backend
(codegen is deterministic over IR input).

Substrate-level gate, not e2e. Catches adapter symmetry problems —
type-introspection divergence, ordering non-determinism — without
running a real frontend or backend.
"""

from __future__ import annotations

import os
import subprocess
import sys
from pathlib import Path

import pytest


HERE = Path(__file__).parent
DJANGO_MANAGE = HERE / "django_app" / "manage.py"


def _fetch_django_ir() -> str:
    """Spawn Django's management command and parse stdout as KDL."""
    result = subprocess.run(
        [sys.executable, str(DJANGO_MANAGE), "export_mizan_ir"],
        capture_output=True,
        text=True,
        check=False,
        env={**os.environ, "PYTHONDONTWRITEBYTECODE": "1"},
    )
    if result.returncode != 0:
        pytest.fail(
            f"export_mizan_ir failed:\nstdout:\n{result.stdout}\nstderr:\n{result.stderr}",
        )
    return result.stdout


def _fetch_fastapi_ir() -> str:
    """Build the FastAPI app inline (fresh registry) and call build_ir()."""
    sys.path.insert(0, str(HERE))
    try:
        from mizan_core.registry import clear_registry
        from mizan_core.ir import build_ir
        from fastapi_app import make_app

        clear_registry()
        make_app()
        return build_ir()
    finally:
        sys.path.remove(str(HERE))


@pytest.fixture(scope="module")
def ir_pair() -> tuple[str, str]:
    return _fetch_django_ir(), _fetch_fastapi_ir()


class IRParityTests:
    """The Mizan IR is the contract — both backends must emit the same KDL."""

    def test_ir_bytes_match(self, ir_pair):
        django, fastapi = ir_pair
        assert django == fastapi, (
            "Django and FastAPI emit divergent Mizan IR for the same "
            "registered functions. Substrate gate is now red."
        )