Private message plugin for nopCommerce project

Need to create a plugin for nopCommerce 4.0 platform. It is must work as a private message system on [login to view URL] or [login to view URL] Each product page must have a links - "Contact seller" (Vendor) and "Report item" similar as it is at [login to view URL] By clicking on "Contact seller", the user will be redirected on page-form (first uploaded picture). There must be multiply topics type for make a choice (topic must be available to create in Admin cabinet/plugins/PM. Each sent mail will be send to addressee PM section ([login to view URL]). Each mail must get a theme ( item number/item name/topic name). Each gust received mail will be highlighted (as "unread"). Signs - unread/read is like on third picture. User will be available to receive a mail to PM (as default) and, there will be available to mark checkbox "Receive a notification about received message to external mail box" and a field to add an email address for receive notifications. Link "Report item" will give a possibility to write notification to Admins PM box. The form for write a report item must have a topics similar as "Contact seller" form. Admin must have a possibility to create a topic for "Report item" form. Each form (Contact seller/Report item) must have a key - "attach a photo" Additionally, Admin must receive all sent mails copy by users (Vendor/Customer) in his [login to view URL] mails section. BEWARE! I will not review any offer with a price that exceed a maximum price an offered by this job description. If you do not want to do a job or you think, it is "must cost more", DO NOT send me any mails or offers. Do not tell me something like - "my work cost .....usd per hour" I do not pay for your work time! I will pay for RESULT exactly.