I want a messaging function in my padel app that you can message your friends that you added in your account and make group $,$ i need it works properly in flutter, right each class in seperAte $,$ use fire base, and the chat must be saved somewhere i guess, i need it properly done please I want each class written and the main should run the chat screen It should use real time cloud update and show what should each class be $,$ do it well and i'll give a good review I should be able to create new chat and new group chat with my friends use firebase as well $,$ please make it work