"""Application factory wiring the FastAPI instance for DDD layers."""

from __future__ import annotations

from collections.abc import AsyncIterator, Callable

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware

from src.routing import api_router as root_api_router

try:
    # canonical health package
    from src.health import register_health_routes as _core_register_health_routes
except ImportError:  # pragma: no cover - health package not generated yet

    def _register_health_routes(_: FastAPI) -> None:
        return None

else:

    def _register_health_routes(app: FastAPI) -> None:
        try:
            _core_register_health_routes(app)
        except Exception:  # pragma: no cover - defensive best-effort registration
            return None


LifespanHandler = Callable[[FastAPI], AsyncIterator[None]]


def create_app(
    *,
    title: str,
    description: str,
    version: str,
    lifespan: LifespanHandler | None = None,
) -> FastAPI:
    """Build the FastAPI application configured with shared middlewares and routers."""

    app = FastAPI(
        title=title,
        description=description,
        version=version,
        docs_url="/docs",
        redoc_url="/redoc",
        lifespan=lifespan,
    )

    app.add_middleware(
        CORSMiddleware,
        allow_origins=["*"],
        allow_credentials=True,
        allow_methods=["*"],
        allow_headers=["*"],
    )

    app.include_router(root_api_router, prefix="/api")
    _register_health_routes(app)

    return app