"""FastAPI application — HTTP surface for the registry.

T014 ships a minimal app with two routes:

* ``GET /`` — service banner.
* ``GET /health`` — registry liveness + DB connectivity + storage backend.

Richer endpoints (package CRUD, file upload, manifest retrieval, event
stream) land in workplan WP-0002. The app is built through
:func:`create_app` so tests can inject their own settings.
"""

from __future__ import annotations

from contextlib import asynccontextmanager
from typing import Any

from fastapi import Depends, FastAPI, Request

from artifactstore import __version__
from artifactstore.app import build_registry
from artifactstore.config import Settings
from artifactstore.registry import Registry

__all__ = ["app", "create_app"]


def get_registry(request: Request) -> Registry:
    return request.app.state.registry  # type: ignore[no-any-return]


def create_app(settings: Settings | None = None) -> FastAPI:
    """Build the FastAPI app. Lifespan owns the registry instance."""

    @asynccontextmanager
    async def lifespan(application: FastAPI) -> Any:
        registry = build_registry(settings)
        application.state.registry = registry
        try:
            yield
        finally:
            await registry.dispose()

    application = FastAPI(
        title="artifact-store",
        version=__version__,
        lifespan=lifespan,
    )

    @application.get("/")
    def root() -> dict[str, str]:
        return {
            "service": "artifact-store",
            "version": __version__,
            "status": "scaffold",
        }

    @application.get("/health")
    async def health(registry: Registry = Depends(get_registry)) -> dict[str, Any]:
        db_ok, db_detail = await registry.db_health()
        backend_status = await registry.backend_health()
        overall = "ok" if db_ok and backend_status.healthy else "degraded"
        return {
            "service": "artifact-store",
            "version": __version__,
            "status": overall,
            "db": {"healthy": db_ok, "detail": db_detail},
            "backend": {
                "backend_id": backend_status.backend_id,
                "healthy": backend_status.healthy,
                "detail": backend_status.detail,
                "free_bytes": backend_status.free_bytes,
                "total_bytes": backend_status.total_bytes,
            },
        }

    return application


app = create_app()