"""FastAPI application factory.

Run with uvicorn's factory mode (no import-time DB side effects):

    uvicorn ams.api.app:create_app --factory --reload
"""

from __future__ import annotations

from pathlib import Path

from fastapi import FastAPI
from fastapi.responses import RedirectResponse
from fastapi.staticfiles import StaticFiles

from .. import __version__
from .db import configure, init_db
from .routes import diff, games, snapshots

_STATIC = Path(__file__).parent / "static"


def create_app(database_url: str | None = None) -> FastAPI:
    configure(database_url)
    init_db()

    app = FastAPI(title="ams — engine surface catalog", version=__version__)
    app.include_router(games.router)
    app.include_router(snapshots.router)
    app.include_router(diff.router)

    @app.get("/health", tags=["meta"])
    def health() -> dict[str, str]:
        return {"status": "ok", "version": __version__}

    @app.get("/", include_in_schema=False)
    def root() -> RedirectResponse:
        return RedirectResponse("/ui/")

    # The command-center UI (static HTML/CSS/JS, no build step) is served last so API
    # routes take precedence.
    app.mount("/ui", StaticFiles(directory=str(_STATIC), html=True), name="ui")
    return app