module ActsAsAccount
  class Journal < ActiveRecord::Base
    self.table_name = :acts_as_account_journals

    has_many :postings, :class_name => 'ActsAsAccount::Posting'
    has_many :accounts, :through => :postings

    class << self
      private :new
      private :create
      private :create!

      def current
        Thread.current[:acts_as_account_current] ||= create!
      end

      def clear_current
        Thread.current[:acts_as_account_current] = nil
      end
    end

    def transfers
      postings.each_slice(2).map { |postings| Transfer.new(*postings) }
    end

    def transfer(amount, from_account, to_account, reference = nil, valuta = Time.now)
      transaction do
        if (amount < 0)
          # change order if amount is negative
          amount, from_account, to_account = -amount, to_account, from_account
        end

        if logger
          logger.debug(
            [
              "ActsAsAccount::Journal.transfer",
              "amount: #{amount}",
              "from: #{from_account.id}",
              "to: #{to_account.id}",
              "reference: #{reference.class.name}(#{reference&.id})",
              "valuta: #{valuta}",
            ].join(' ')
          )
        end

        # To avoid possible deadlocks we need to ensure that the locking order
        # is always the same therfore the sort by id.
        if ActsAsAccount.configuration.persist_attributes_on_account
          [from_account, to_account].sort_by(&:id).each(&:lock!)
        end

        posting1 = build_posting(-amount,  from_account,   to_account, reference, valuta)
        posting2 = build_posting( amount,    to_account, from_account, reference, valuta)

        result = postings.model.insert_all([ posting1.attributes.compact, posting2.attributes.compact ])

        update_attributes_on(from_account, -amount)
        update_attributes_on(to_account,    amount)

        !!result
      end
    end

    private

      def build_posting(amount, account, other_account, reference, valuta)
        postings.build(
          :amount        => amount,
          :account       => account,
          :other_account => other_account,
          :reference     => reference,
          :valuta        => valuta
        )
      end

      def update_attributes_on(account, amount)
        return unless ActsAsAccount.configuration.persist_attributes_on_account

        account.class.update_counters account.id, postings_count: 1, balance: amount
      end
  end
end