LineItem model

gistfile1.txt

class LineItem
  include Mongoid::Document
  include Mongoid::Timestamps

  TYPE = %w[income expense]
  INCOME = 0
  EXPENSE = 1

  TRANSFER_IN = 'Transfer In'
  TRANSFER_OUT = 'Transfer Out'

  field :type, :type => Integer, :default => 1
  field :amount, :type => BigDecimal, :default => 0
  field :event_date, :type => Date, :default => Time.now.to_date
  field :category_name
  field :payee_name
  field :comment

  field :balance, :type => BigDecimal
  field :virtual, :type => Boolean
  field :master, :type => Boolean

  belongs_to :spanned, :class_name => 'SpannedLineItem'

  scope :default_sort, desc(:event_date, :created_at)
  scope :regular, where(:master.ne => true)

  def type_name
    TYPE[type].capitalize
  end

  def income?
    type == INCOME
  end

  def expense?
    type == EXPENSE
  end

  # 1 for income, -1 for expense
  def multiplier
    type == EXPENSE ? -1 : 1
  end

  def event_date_string(str)
    event_date = Date.parse(str)
  end

  def self.reset_balance
    current_balance = 0

    default_sort.reverse.each do |item|

      if(!item.virtual)
        current_balance += item.amount * item.multiplier
      end

      if(item.balance != current_balance)
        item.balance = current_balance
        item.save
      end
    end
  end

  def clone_all
    attribute_values = attributes.select {|a| !%w(id, _id, created_at).include? a}
    attribute_values.delete('_id')
    LineItem.new attribute_values
  end

  def clone_new
    LineItem.new(:event_date => event_date)
  end

  # Spanning Support

  def span(months)
    spanned_line_item = SpannedLineItem.create(:master_line_item => self , :months => months)

    self.master = true
    self.spanned = spanned_line_item
    save

    monthly_amount = self.amount / months

    (1..months).collect do |month_num|
      virtual_line_item = clone_all
      virtual_line_item.amount = monthly_amount
      virtual_line_item.master = nil
      virtual_line_item.virtual = true
      virtual_line_item.event_date = event_date >> (month_num-1)
      virtual_line_item.spanned = spanned_line_item
      virtual_line_item.save
      virtual_line_item
    end

  end
  
  def is_spanned
    spanned != nil
  end

  def spanned_months
    spanned.months unless spanned.nil?
  end
  
end