"""
Flask application factory for Garmin Health Lab.

Run directly (`python app.py`) for development, or serve with Gunicorn:
    gunicorn wsgi:app -b 0.0.0.0:5000
"""
import os

from flask import Flask, jsonify, send_from_directory
from flask_cors import CORS

import db
from config import CORS_ORIGINS, PORT, STATIC_DIR
from routes import auth, garmin, health, analysis


def create_app():
    app = Flask(__name__)
    CORS(app, resources={r"/api/*": {"origins": CORS_ORIGINS}}, supports_credentials=True)

    # Create tables once at startup (idempotent).
    db.init_db()

    # In production the built React app is served by this same process, so the
    # deployment is a single port with no reverse proxy to configure. In
    # development STATIC_DIR does not exist and the CRA dev server serves the
    # UI instead — hence the guard rather than an unconditional route.
    has_ui = bool(STATIC_DIR) and os.path.isfile(os.path.join(STATIC_DIR, "index.html"))

    @app.route("/")
    def index():
        if has_ui:
            return send_from_directory(STATIC_DIR, "index.html")
        return jsonify({"name": "Garmin Health Lab API", "version": "1.0.0"})

    @app.route("/api/health/status")
    def health_status():
        return jsonify({"status": "ok", "db": db.DB_TYPE})

    app.register_blueprint(auth.bp, url_prefix="/api/auth")
    app.register_blueprint(garmin.bp, url_prefix="/api/garmin")
    app.register_blueprint(health.bp, url_prefix="/api/health")
    app.register_blueprint(analysis.bp, url_prefix="/api/analysis")

    @app.errorhandler(404)
    def not_found(_e):
        # API paths always answer in JSON. Everything else falls through to the
        # SPA so client-side routes (/settings, /recommendations, ...) survive a
        # page reload instead of 404-ing.
        from flask import request

        if has_ui and not request.path.startswith("/api/"):
            asset = request.path.lstrip("/")
            if asset and os.path.isfile(os.path.join(STATIC_DIR, asset)):
                return send_from_directory(STATIC_DIR, asset)
            return send_from_directory(STATIC_DIR, "index.html")
        return jsonify({"error": "not found"}), 404

    @app.errorhandler(500)
    def server_error(_e):
        return jsonify({"error": "internal error"}), 500

    return app


app = create_app()


if __name__ == "__main__":
    app.run(host="0.0.0.0", port=PORT, debug=False)