{
    "bsonType": "object",
    "required": ["user_id", "article_id"],
    "permission": {
        "read": "doc.user_id == auth.uid || 'admin' in auth.role", // 用户仅查看自己记录
        "create": "auth.uid != null && doc.user_id == auth.uid", // 只能为自己点赞
        "update": false, // 点赞记录不可修改
        "delete": "auth.uid != null && doc.user_id == auth.uid" // 只能取消自己的点赞
    },
    "properties": {
        "_id": {
            "description": "系统自动生成的文档ID",
            "bsonType": "string"
        },
        "user_id": {
            "bsonType": "string",
            "description": "点赞用户ID",
            "foreignKey": "uni-id-users._id",
            "forceDefaultValue": {
                "$env": "uid"
            }
        },
        "article_id": {
            "bsonType": "string",
            "description": "被点赞的文章ID",
            "foreignKey": "uni-cms-articles._id"
        },
        "create_time": {
            "bsonType": "timestamp",
            "description": "点赞时间",
            "defaultValue": {
                "$env": "now"
            },
            "errorMessage": "时间戳必须为有效数值"
        }
    },
    "indexes": [
        {
            "IndexName": "user_article_unique",
            "MgoKeySchema": {
                "MgoIndexKeys": [
                    {
                        "Name": "user_id",
                        "Direction": "1"
                    },
                    {
                        "Name": "article_id",
                        "Direction": "1"
                    }
                ],
                "MgoIsUnique": true
            }
        }
    ]
}