from pathlib import Path

from flask import Flask, send_from_directory

from .config import PROJECT_ROOT
from .routes.chat import bp as chat_bp
from .routes.faq import bp as faq_bp
from .routes.conversation import bp as convo_bp


def create_app():
    dist_dir = PROJECT_ROOT / "frontend" / "dist"
    app = Flask(
        __name__,
        static_folder=str(dist_dir),
        template_folder=str(dist_dir),
    )

    # 注册路由
    app.register_blueprint(chat_bp)
    app.register_blueprint(faq_bp)
    app.register_blueprint(convo_bp)

    # 前端静态资源 & SPA 回退
    @app.route("/", defaults={"path": ""})
    @app.route("/<path:path>")
    def serve_frontend(path: str):
        target = dist_dir / (path or "index.html")
        if target.exists():
            return send_from_directory(dist_dir, path or "index.html")
        return send_from_directory(dist_dir, "index.html")

    return app