relations.rb

class Client < ActiveRecord::Base
  has_many :accounts
end

class Account < ActiveRecord::Base
  belongs_to :client
  has_many :invoices
  has_many :payments
end

class Invoice < ActiveRecord::Base
  belongs_to :account
  has_many :line_items
  has_many :invoice_payments
end

class LineItem < ActiveRecord::Base
  belongs_to :invoice
end

class Payment < ActiveRecord::Base
  belongs_to :account
  has_many :invoice_payments
end

class InvoicePayment < ActiveRecord::Base
  belongs_to :invoice
  belongs_to :payment
end

This is the data model I've come up with to track invoices and payments for a client managing many accounts. The customer has requested that all "InvoicePayments" be reviewed before they take effect.

The customer workflow goes like this:

• Customer collects payments throughout the day (checks are mailed in)
• Customer enters in payments per account
• The program automatically distributes the payment among the account's open invoices as InvoicePayments in with 'approved' as false
• After the customer finishes entering all the payments, they view a report of the unapproved InvoicePayments and verify that the program's total InvoicePayments match up with the hand-verified total of all the checks they received that day
• The customer approves the pending InvoicePayments (bulk operation)
• The program marks the unapproved InvoicePayments as approved

The tricky part is how to display the summary of unapproved InvoicePayments, by account then by invoice. Should I be selecting the InvoicePayments that are unapproved, then working back through the relationships? Or maybe set a flag on accounts with unapproved InvoicePayments, so I'm not checking through all the accounts to see if they have an unapproved InvoicePayment.