Find conversation thread between 2 users excluding group conversations

I have a basic private messaging system which is capable of having 1 to 1 conversations and group conversations.

Currently I have a "Send Message" widget box across the site where the user can type in the name of the user and send a message to them which begins a "1 to 1" conversation thread.

What I need this widget to do is, when a message is sent, check to see if a conversation between the two users already exists, and if it does, add the new message to the already existing conversation thread. If the conversation does not exist, then start a new thread.

My main issue is, how can I exclude checking group conversation threads where both users are participants.

A snippet of the 2 relevant tables are as follows:

threads Table:

• Title
• Type

thread_participants Table

• thread_id
• user_id

The thread "type" determines if the thread is a "single" (1-1 conversation) or "group" conversation.

My theory is to search through the thread table finding where two users are in the same thread however I am unsure how I can do this using eloquent in my controller.

Hope that is clear. Thanks

via Chebli Mohamed