from __future__ import annotations

from pathlib import Path

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import FileResponse, JSONResponse
from fastapi.staticfiles import StaticFiles

from live_prototype import build_live_prototype_payload
from settings import get_settings

BASE_DIR = Path(__file__).resolve().parent
DIST_DIR = BASE_DIR / "frontend" / "dist"


def create_app() -> FastAPI:
    app = FastAPI(title="Robot U Community Prototype")

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

    @app.get("/health")
    async def health() -> JSONResponse:
        return JSONResponse({"status": "ok"})

    @app.get("/api/prototype")
    async def prototype() -> JSONResponse:
        return JSONResponse(await build_live_prototype_payload(get_settings()))

    if DIST_DIR.exists():
        assets_dir = DIST_DIR / "assets"
        if assets_dir.exists():
            app.mount("/assets", StaticFiles(directory=str(assets_dir)), name="assets")

        @app.get("/{full_path:path}")
        async def spa_fallback(full_path: str) -> FileResponse:
            candidate = DIST_DIR / full_path
            if candidate.is_file():
                return FileResponse(str(candidate))

            response = FileResponse(str(DIST_DIR / "index.html"))
            response.headers["Cache-Control"] = "no-store, no-cache, must-revalidate"
            response.headers["Pragma"] = "no-cache"
            response.headers["Expires"] = "0"
            return response

    return app


app = create_app()