Cloud application to store files in prefix folders -- 2

We want to develop cloud based application We would have individual cloud access to our clients by cloud computing. Each client would have seperate access to their files Each client would have numerous client or case. They should be able to create a unique ID for that case (case under that particular client) And each case created would automatically have pre fixed folder category ( directory). The client can add document for that particular case in its specific folder. the client can access 24 x 7 the account and can search their document on certain filtering technique. This found document can be share by email, download, deleted or changed.