"""JWT 认证中间件：校验 Token，注入 user_id。

支持两种模式：
1. 登录模式：通过 JWT Token 认证
2. 访客模式：未携带 Token 时自动生成匿名用户（GUEST_MODE=true 时启用）
"""
import json
import os
import jwt
import uuid
from functools import wraps
from flask import request, jsonify, current_app


def _is_guest_mode_enabled() -> bool:
    """判断是否开启访客模式。"""
    env_value = os.environ.get("GUEST_MODE", "")
    if env_value:
        return env_value.lower() == "true"

    config_value = current_app.config.get("GUEST_MODE", False)
    if isinstance(config_value, bool):
        return config_value
    return str(config_value).lower() == "true"


def jwt_required(f):
    """装饰器：校验 JWT Token，将 user_id 注入 request。

    如果 GUEST_MODE=true，未携带 Token 时自动使用匿名用户。
    """
    @wraps(f)
    def decorated(*args, **kwargs):
        auth_header = request.headers.get("Authorization", "")

        # 没有 Token
        if not auth_header.startswith("Bearer "):
            # 访客模式：使用固定的匿名用户 ID（基于 cookie 或 session）
            if _is_guest_mode_enabled():
                # 使用固定的 guest ID（基于 cookie）
                guest_id = request.cookies.get("guest_id")
                if not guest_id:
                    guest_id = uuid.uuid4().hex[:8]
                request.user_id = f"guest_{guest_id}"
                request.user_role = "client"
                response = f(*args, **kwargs)
                # 设置 cookie，确保后续请求使用相同的 guest ID
                from flask import make_response
                if isinstance(response, tuple):
                    resp, status_code = response
                    resp = make_response(resp, status_code)
                elif hasattr(response, 'set_cookie'):
                    resp = response
                else:
                    resp = make_response(response)
                resp.set_cookie("guest_id", guest_id, max_age=365*24*60*60)  # 1年
                return resp
            return jsonify({"code": 1002, "message": "未授权", "data": None}), 401

        token = auth_header[7:]

        # 访客模式：前端发送 Bearer guest_<id> 格式的 Token
        if token.startswith("guest_"):
            if _is_guest_mode_enabled():
                request.user_id = token  # 使用完整的 guest_xxx 作为 user_id
                request.user_role = "client"
                request.user_department = ""
                return f(*args, **kwargs)
            return jsonify({"code": 1002, "message": "未授权", "data": None}), 401

        # 检查 Token 黑名单
        try:
            from insurance.db.compat import redis_client
            if redis_client.get(f"token:blacklist:{token}"):
                return jsonify({"code": 1002, "message": "Token 已失效", "data": None}), 401
        except Exception as e:
            import logging
            logging.warning(f"Token 黑名单检查失败（Redis 可能不可用）: {e}")

        # 校验 Token
        secret = current_app.config.get("JWT_SECRET", "change-this")
        try:
            payload = jwt.decode(token, secret, algorithms=["HS256"])
            request.user_id = payload["user_id"]
            request.user_role = payload.get("role", "")
            request.user_department = payload.get("department", "")
        except jwt.ExpiredSignatureError:
            return jsonify({"code": 1003, "message": "Token 已过期", "data": None}), 401
        except jwt.InvalidTokenError:
            return jsonify({"code": 1002, "message": "Token 无效", "data": None}), 401

        return f(*args, **kwargs)
    return decorated


def admin_required(f):
    """装饰器：要求管理员或超级管理员权限。"""
    @wraps(f)
    @jwt_required
    def decorated(*args, **kwargs):
        if request.user_role not in ("super_admin", "admin"):
            return jsonify({"code": 1004, "message": "权限不足", "data": None}), 403
        return f(*args, **kwargs)
    return decorated


def super_admin_required(f):
    """装饰器：要求超级管理员权限。"""
    @wraps(f)
    @jwt_required
    def decorated(*args, **kwargs):
        if request.user_role != "super_admin":
            return jsonify({"code": 1004, "message": "权限不足", "data": None}), 403
        return f(*args, **kwargs)
    return decorated


def permission_required(permission: str):
    """权限校验装饰器：查询 insurance_roles 表校验权限。

    用法:
        @app.route("/admin/users")
        @permission_required("user_manage")
        def list_users():
            ...
    """
    def decorator(f):
        @wraps(f)
        @jwt_required
        def decorated(*args, **kwargs):
            role_name = request.user_role
            if not role_name:
                return jsonify({"code": 1004, "message": "权限不足", "data": None}), 403

            # super_admin 和 admin 拥有所有权限
            if role_name in ("super_admin", "admin"):
                return f(*args, **kwargs)

            # 从数据库查询角色权限
            try:
                from insurance.models.role import Role
                from insurance.db.compat import db
                role = db.session.query(Role).filter_by(name=role_name).first()
                if role:
                    perms = json.loads(role.permissions) if role.permissions else []
                    if "*" in perms or permission in perms:
                        return f(*args, **kwargs)
            except Exception as e:
                import logging
                logging.warning(f"权限校验查询失败: {e}")

            return jsonify({"code": 1004, "message": "权限不足", "data": None}), 403
        return decorated
    return decorator


def get_user_permissions(role_name: str) -> list:
    """获取指定角色的权限列表。

    返回:
        list: 权限字符串列表，如 ["chat", "kb_manage"]
    """
    if role_name in ("super_admin", "admin"):
        return ["*"]
    try:
        from insurance.models.role import Role
        from insurance.db.compat import db
        role = db.session.query(Role).filter_by(name=role_name).first()
        if role:
            return json.loads(role.permissions) if role.permissions else []
    except Exception:
        pass
    return []


def get_data_scope():
    """获取当前用户的数据权限范围。

    返回:
        dict: 包含 scope (all/team/self) 和 department 字段
    """
    role = getattr(request, "user_role", "")
    user_id = getattr(request, "user_id", "")

    # 超级管理员和管理员：查看所有数据
    if role in ("super_admin", "admin"):
        return {"scope": "all", "department": None, "user_id": None}

    # 销售主管：查看本部门数据
    if role == "manager":
        # 从JWT或数据库获取department
        department = getattr(request, "user_department", None)
        if not department:
            try:
                from insurance.models.wecom_user import WeComUserMapping
                from insurance.db.compat import db
                user = db.session.query(WeComUserMapping).filter_by(username=user_id).first()
                if user:
                    department = user.department
            except Exception:
                pass
        return {"scope": "team", "department": department, "user_id": None}

    # 销售人员和其他角色：只看自己的数据
    return {"scope": "self", "department": None, "user_id": user_id}