How to give different permission programmatically on Document Library for different group users?

I have document library & 3 groups(AdminGroup,Reviewer,Distributor). I have already give a permission on groups, AdminGroup has Full Control, Reviewer has Reader & Distributor has None :

 roleDefinition = web.RoleDefinitions.GetByType(SPRoleType.Administrator); // Admin
 roleDefinition = web.RoleDefinitions.GetByType(SPRoleType.Reader); // Reviewer
 roleDefinition = web.RoleDefinitions.GetByType(SPRoleType.None); // Distributor

Now, I want to give permission on document library that :

• If anyone upload document it's Draft version should only visible to Reviewer,Admin & owner of the document. Distributor user can't see it if he is not owner.


• Reviewer Group's user can only view/edit the document & publish it but can't Approve/Reject it.


• Admin has full control. He can Add/Edit/View & Approve/reject the document.


• Distributor Group's user can only view his own documents & Approved documents.