foodsoft/app/models/ordergroup.rb

# == Schema Information
# Schema version: 20090120184410
#
# Table name: groups
#
#  id                  :integer(4)      not null, primary key
#  type                :string(255)     default(""), not null
#  name                :string(255)     default(""), not null
#  description         :string(255)
#  actual_size         :integer(4)
#  account_balance     :decimal(8, 2)   default(0.0), not null
#  account_updated     :datetime
#  created_on          :datetime        not null
#  role_admin          :boolean(1)      not null
#  role_suppliers      :boolean(1)      not null
#  role_article_meta   :boolean(1)      not null
#  role_finance        :boolean(1)      not null
#  role_orders         :boolean(1)      not null
#  weekly_task         :boolean(1)
#  weekday             :integer(4)
#  task_name           :string(255)
#  task_description    :string(255)
#  task_required_users :integer(4)      default(1)
#  deleted_at          :datetime
#

# Ordergroups can order, they are "children" of the class Group
# 
# Ordergroup have the following attributes, in addition to Group
# * account_balance (decimal)
# * account_updated (datetime)
# * actual_size (int) : how many persons are ordering through the Ordergroup
class Ordergroup < Group
  acts_as_paranoid                    # Avoid deleting the ordergroup for consistency of order-results
  extend ActiveSupport::Memoizable    # Ability to cache method results. Use memoize :expensive_method

  has_many :financial_transactions
  has_many :group_orders
  has_many :orders, :through => :group_orders

  validates_inclusion_of :actual_size, :in => 1..99 
  validates_numericality_of :account_balance, :message => 'ist keine gültige Zahl'

  attr_accessible :actual_size, :account_updated
  

  def value_of_open_orders(exclude = nil)
    group_orders.open.reject{|go| go == exclude}.collect(&:price).sum
  end
  
  def value_of_finished_orders(exclude = nil)
    group_orders.finished.reject{|go| go == exclude}.collect(&:price).sum
  end

  # Returns the available funds for this order group (the account_balance minus price of all non-closed GroupOrders of this group).
  # * exclude (GroupOrder): exclude this GroupOrder from the calculation
  def get_available_funds(exclude = nil)
    account_balance - value_of_open_orders(exclude) - value_of_finished_orders(exclude)
  end
  memoize :get_available_funds

  # Creates a new FinancialTransaction for this Ordergroup and updates the account_balance accordingly.
  # Throws an exception if it fails.
  def addFinancialTransaction(amount, note, user)
    transaction do      
      trans = FinancialTransaction.new(:ordergroup => self, :amount => amount, :note => note, :user => user)
      trans.save!
      self.account_balance += trans.amount
      self.account_updated = trans.created_on
      save!
      notifyNegativeBalance(trans) 
    end
  end
  
  # Returns all GroupOrders by this group that are currently running.
  def findCurrent
    group_orders.find(:all, :conditions => ["orders.finished = ? AND orders.starts < ? AND (orders.ends IS NULL OR orders.ends > ?)", false, Time.now, Time.now], :include => :order)
  end
  
  #find expired (lapsed) but not manually finished orders
  def findExpiredOrders
    group_orders.find(:all, :conditions => ["orders.ends < ?", Time.now], :include => :order, :order => 'orders.ends DESC')
  end
  
  # Returns all GroupOrderResults by this group that are finished but not booked yet.
  def findFinishedNotBooked 
    GroupOrderResult.find(:all, 
                          :conditions => ["group_order_results.group_name = ? AND group_order_results.order_id = orders.id AND orders.finished = ? AND orders.booked = ? ", self.name, true, false],
                          :include => :order,
                          :order => 'orders.ends DESC')
  end
  
  # Returns all GroupOrderResults for booked orders
  def findBookedOrders(limit = false, offset = 0)
    GroupOrderResult.find(:all,
                         :conditions => ["group_order_results.group_name = ? AND group_order_results.order_id = orders.id AND orders.finished = ? AND orders.booked = ? ", self.name, true, true],
                         :include => :order,
                         :order => "orders.ends DESC",
                         :limit => limit, 
                         :offset => offset)
  end
  
 private
  
  # If this order group's account balance is made negative by the given/last transaction, 
  # a message is sent to all users who have enabled notification.
  def notifyNegativeBalance(transaction)
    # Notify only when order group had a positive balance before the last transaction:
    if (transaction.amount < 0 && self.account_balance < 0 && self.account_balance - transaction.amount >= 0) 
      users = self.users.reject { |u| u.settings["notify.negativeBalance"] != '1' }
      unless users.empty?
        Message.from_template(
          'negative_balance', 
          {:group => self, :transaction => transaction}, 
          {:recipients_ids => users.collect(&:id), :subject => "Gruppenkonto im Minus"}
        ).save!
      end
    end
  end
  
end