"""FastAPI application factory for the RAGAS evaluation console.

The app mounts three JSON API routers and serves the single-page static
frontend. It imports rag_eval only lazily (inside the task manager worker), so
the server starts even when the evaluation dependencies are not yet installed.
"""

from __future__ import annotations

from pathlib import Path

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

from webapp.api import evaluations, llm_profiles, runs, scenarios

STATIC_DIR = Path(__file__).resolve().parent / "static"


def create_app() -> FastAPI:
    """Build and configure the FastAPI application instance."""
    app = FastAPI(
        title="Siemens RAGAS 评估控制台",
        description="RAGAS 评估子系统的可视化报告与评估触发控制台。",
        version="0.1.0",
    )

    app.include_router(runs.router)
    app.include_router(scenarios.router)
    app.include_router(evaluations.router)
    app.include_router(llm_profiles.router)

    @app.get("/api/health", tags=["meta"])
    def health() -> dict[str, str]:
        """Report basic liveness so the UI can confirm the server is reachable."""
        return {"status": "ok"}

    @app.get("/", include_in_schema=False)
    def index() -> FileResponse:
        """Serve the single-page console entry document."""
        return FileResponse(STATIC_DIR / "index.html")

    # Serve CSS/JS assets under /static while keeping API routes at /api.
    app.mount("/static", StaticFiles(directory=STATIC_DIR), name="static")

    return app


app = create_app()