from flask import Flask, send_from_directory, request, jsonify, session

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
from .routes.auth import bp as auth_bp
from .config import SECRET_KEY
from .admin import ensure_admin_file


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

    app.secret_key = SECRET_KEY

    # 确保管理员文件存在（仅存储哈希）
    ensure_admin_file()

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

    @app.before_request
    def require_login():
        # 仅保护 API，登录接口与静态资源除外
        path = request.path or ""
        if request.method == "OPTIONS":
            return None
        if path.startswith("/api/auth"):
            return None
        if not path.startswith("/api"):
            return None
        if session.get("user"):
            return None
        return jsonify({"error": "未登录"}), 401

    # 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