# app.py
import os
from pathlib import Path
from flask import Flask, send_from_directory, render_template_string, abort

# Configure where built frontend lives
DIST_DIR = Path(__file__).parent.joinpath("dist")

app = Flask(
    __name__,
    static_folder=str(DIST_DIR),   # serve static files from dist/
    static_url_path=""             # serve them from root (so /assets/... works)
)

@app.route("/", defaults={"path": ""})
@app.route("/<path:path>")
def serve_spa(path: str):
    """
    Serve files from dist/ when they exist.
    If a file doesn't exist, serve index.html (SPA fallback).
    If dist/index.html is missing, show a helpful message.
    """
    # If dist doesn't exist or index.html missing, show message.
    index_file = DIST_DIR / "index.html"
    if not index_file.exists():
        msg = """
        <h2>Static frontend not found (dist/index.html)</h2>
        <p>The Space is running but the built frontend (dist/) is missing.</p>
        <p>Possible fixes:</p>
        <ol>
          <li>Ensure your GitHub Actions builds the Vite app and copies <code>dist/</code> into the Space repo root.</li>
          <li>Or manually build locally and copy the <code>dist/</code> contents into this repo.</li>
        </ol>
        <p>Once <code>dist/index.html</code> is present, the app will be served automatically.</p>
        """
        return render_template_string(msg), 200

    # If path points to an existing file in dist => serve it
    target = DIST_DIR.joinpath(path)
    if path != "" and target.exists() and target.is_file():
        # send direct file, preserves mime types
        return send_from_directory(str(DIST_DIR), path)

    # Otherwise return index.html (SPA fallback)
    return send_from_directory(str(DIST_DIR), "index.html")


# Health endpoint (optional)
@app.route("/_health")
def health():
    return {"status": "ok"}, 200


if __name__ == "__main__":
    # When launched by HF Spaces, this script will be executed directly.
    # Use environment PORT if provided, else default 7860.
    port = int(os.environ.get("PORT", 7860))
    app.run(host="0.0.0.0", port=port)