It is required to improve the chat plugin for the OSClass CMS.
As far as I understand, a PHP developer is needed.
There is a demo site http://s1029757642.online.de/im-threads
Here you can see the front end and what functionality the chat currently has.
The chat module needs to be improved according to the technical specifications:

Search through all messages and user names. Ajax loading, without the need to press the OK button
User/company name with whom the correspondence is taking place. Clickable. Leads to the user's public page. Below it - currently online / was online xxx minutes ago / hour etc. Module functionality.
Here is a dropdown menu. There is a button “block user” from the standard module functionality. There is also a “report” button. To implement it in the admin panel, add the corresponding section in the chat module, similar to how the report on the ad is implemented. Plus, it displays a counter in the admin panel header (for example, like spam)
Checkbox “select all chats”
Here:
one active button for chat with the “support” user. Essentially a regular chat, just for quick access.
inactive button by default “delete chat”. When selected one/several/all, it deletes them
Display the product card from which the message was sent.
Display:
avatar
user name
title
last message
The active chat will be highlighted
The chat that the mouse is hovered over is highlighted lighter
The chat with unread messages has bold font.
Time since the last message. Rounding to the minute, then to the hour, then to days, then to years.
Above the avatar, display a green dot “user online”, as in the plugin.
Standard. We write on the left, they write on the right. As in the chat plugin.
Avatar only for the interlocutor, we just have texts in bubbles
Standard plugin interface, file sending.
Send button. Also triggered on ctrl+enter
When sending a message, a popup message does not appear at the top as by default.
The setting “notifications enable/disable” from the plugin goes to a new menu tab “notification settings”. Later, other settings will also be added there.
The result of the work is a module, not a patch for the entire CMS, which will also be installed on the site and work correctly according to the technical specifications. Essentially, almost all functions are there, it is necessary to change the visual component and a bit of the logic of operation.