Which design pattern I can use for this project?

I will develop a document management application. Users will upload documents to the application. The document can be in any format.

The client portfolio of the application consists of holdings. Users in the human resources, sales and information technologies departments within the Holding can use the application.

The document uploaded by each user is uploaded to the folder of the department they work in. Users can open the document and make changes through the application. This change consists of changing the document name for now. A version of the document is created with each change.

Users can revert to previous versions if they wish. The application has a report section that shows how many users and documents there are. When the user and the document are added, the numbers here must be updated instantly. The application should log when users upload and modify documents. It should also log errors that may occur during operation. To perform these log operations The log library detailed below should be used. However, this library should be developed so that it can be used in other projects.

The data that should be in the system while writing the log are the log message, the user who performed the operation, the log date and the log level. Developers who will use this library should be able to add different data to them if they wish, or change the name of the data containing this information. The system should be able to log data in HTML or Text format. Developers using the library should be able to choose from these formats. Logs can be written to a file or to a database. The system should support MSSQL and Oracle databases. It should be noted that there may be different databases in the projects to be used. When the database preference is made, the connection settings to be used will be taken.

Developers using the library should be able to do the work they want before or after logging. For example, when logging the file, it should be able to make folders and filings as it wishes. The system should be able to view the recorded logs. Developers using the library should be able to customize when viewing logs if they wish. They can view it as it is or by changing the font size and color. One can change, just as both can change.

When using this log library, settings such as in which format the log will be and which source it will be saved should be defined in a config file. This config file can be XML or JSON. In whatever format the developer uses the config file, he should have the settings read by calling the appropriate structure in the system. If logging to the database is preferred, the connection string information should be transferred to the system via this config file.