# encoding: utf-8
#
class Order < ActiveRecord::Base

  # Associations
  has_many :order_articles, :dependent => :destroy
  has_many :articles, :through => :order_articles
  has_many :group_orders, :dependent => :destroy
  has_many :ordergroups, :through => :group_orders
  has_one :invoice
  has_many :comments, :class_name => "OrderComment", :order => "created_at"
  has_many :stock_changes
  belongs_to :supplier
  belongs_to :updated_by, :class_name => 'User', :foreign_key => 'updated_by_user_id'
  belongs_to :created_by, :class_name => 'User', :foreign_key => 'created_by_user_id'

  # Validations
  validates_presence_of :starts
  validate :starts_before_ends, :include_articles
  validate :keep_ordered_articles

  # Callbacks
  after_save :save_order_articles, :update_price_of_group_orders

  # Finders
  scope :open, where(state: 'open').order('ends DESC')
  scope :finished, where("orders.state = 'finished' OR orders.state = 'closed'").order('ends DESC')
  scope :finished_not_closed, where(state: 'finished').order('ends DESC')
  scope :closed, where(state: 'closed').order('ends DESC')
  scope :stockit, where(supplier_id: 0).order('ends DESC')

  def stockit?
    supplier_id == 0
  end

  def name
    stockit? ? I18n.t('orders.model.stock') : supplier.name
  end

  def articles_for_ordering
    if stockit?
      # make sure to include those articles which are no longer available
      # but which have already been ordered in this stock order
      StockArticle.available.all(:include => :article_category,
        :order => 'article_categories.name, articles.name').reject{ |a|
        a.quantity_available <= 0 and not a.ordered_in_order?(self)
      }.group_by { |a| a.article_category.name }
    else
      supplier.articles.available.all.group_by { |a| a.article_category.name }
    end
  end

  # Save ids, and create/delete order_articles after successfully saved the order
  def article_ids=(ids)
    @article_ids = ids
  end

  def article_ids
    @article_ids ||= order_articles.map { |a| a.article_id.to_s }
  end

  # Returns an array of article ids that lead to a validation error.
  def erroneous_article_ids
    @erroneous_article_ids ||= []
  end

  def open?
    state == "open"
  end

  def finished?
    state == "finished"
  end

  def closed?
    state == "closed"
  end

  def expired?
    !ends.nil? && ends < Time.now
  end

  # search GroupOrder of given Ordergroup
  def group_order(ordergroup)
    group_orders.where(:ordergroup_id => ordergroup.id).first
  end

  # Returns OrderArticles in a nested Array, grouped by category and ordered by article name.
  # The array has the following form:
  # e.g: [["drugs",[teethpaste, toiletpaper]], ["fruits" => [apple, banana, lemon]]]
  def articles_grouped_by_category
    @articles_grouped_by_category ||= order_articles.
        includes([:article_price, :group_order_articles, :article => :article_category]).
        order('articles.name').
        group_by { |a| a.article.article_category.name }.
        sort { |a, b| a[0] <=> b[0] }
  end

  def articles_sort_by_category
    order_articles.all(:include => [:article], :order => 'articles.name').sort do |a,b|
      a.article.article_category.name <=> b.article.article_category.name
    end
  end

  # Returns the defecit/benefit for the foodcoop
  # Requires a valid invoice, belonging to this order
  #FIXME: Consider order.foodcoop_result
  def profit(options = {})
    markup = options[:without_markup] || false
    if invoice
      groups_sum = markup ? sum(:groups_without_markup) : sum(:groups)
      groups_sum - invoice.net_amount
    end
  end

  # Returns the all round price of a finished order
  # :groups returns the sum of all GroupOrders
  # :clear returns the price without tax, deposit and markup
  # :gross includes tax and deposit. this amount should be equal to suppliers bill
  # :fc, guess what...
  def sum(type = :gross)
    total = 0
    if type == :net || type == :gross || type == :fc
      for oa in order_articles.ordered.includes(:article, :article_price)
        quantity = oa.units_to_order * oa.price.unit_quantity
        case type
          when :net
            total += quantity * oa.price.price
          when :gross
            total += quantity * oa.price.gross_price
          when :fc
            total += quantity * oa.price.fc_price
        end
      end
    elsif type == :groups || type == :groups_without_markup
      for go in group_orders.includes(group_order_articles: {order_article: [:article, :article_price]})
        for goa in go.group_order_articles
          case type
            when :groups
              total += goa.result * goa.order_article.price.fc_price
            when :groups_without_markup
              total += goa.result * goa.order_article.price.gross_price
          end
        end
      end
    end
    total
  end

  # Finishes this order. This will set the order state to "finish" and the end property to the current time.
  # Ignored if the order is already finished.
  def finish!(user)
    unless finished?
      Order.transaction do
        # set new order state (needed by notify_order_finished)
        update_attributes(:state => 'finished', :ends => Time.now, :updated_by => user)

        # Update order_articles. Save the current article_price to keep price consistency
        # Also save results for each group_order_result
        # Clean up
        order_articles.all(:include => :article).each do |oa|
          oa.update_attribute(:article_price, oa.article.article_prices.first)
          oa.group_order_articles.each do |goa|
            goa.save_results!
            # Delete no longer required order-history (group_order_article_quantities) and
            # TODO: Do we need articles, which aren't ordered? (units_to_order == 0 ?)
            #goa.group_order_article_quantities.clear
          end
        end

        # Update GroupOrder prices
        group_orders.each(&:update_price!)

        # Stats
        ordergroups.each(&:update_stats!)

        # Notifications
        Resque.enqueue(UserNotifier, FoodsoftConfig.scope, 'finished_order', self.id)
      end
    end
  end

  # Sets order.status to 'close' and updates all Ordergroup.account_balances
  def close!(user)
    raise I18n.t('orders.model.error_closed') if closed?
    transaction_note = I18n.t('orders.model.notice_close', :name => name,
                              :ends => ends.strftime(I18n.t('date.formats.default')))

    gos = group_orders.all(:include => :ordergroup)       # Fetch group_orders
    gos.each { |group_order| group_order.update_price! }  # Update prices of group_orders

    transaction do                                        # Start updating account balances
      for group_order in gos
        price = group_order.price * -1                    # decrease! account balance
        group_order.ordergroup.add_financial_transaction!(price, transaction_note, user)
      end

      if stockit?                                         # Decreases the quantity of stock_articles
        for oa in order_articles.all(:include => :article)
          oa.update_results!                              # Update units_to_order of order_article
          stock_changes.create! :stock_article => oa.article, :quantity => oa.units_to_order*-1
        end
      end

      self.update_attributes! :state => 'closed', :updated_by => user, :foodcoop_result => profit
    end
  end

  # Close the order directly, without automaticly updating ordergroups account balances
  def close_direct!(user)
    raise I18n.t('orders.model.error_closed') if closed?
    update_attributes! state: 'closed', updated_by: user
  end

  protected

  def starts_before_ends
    errors.add(:ends, I18n.t('articles.model.error_starts_before_ends')) if (ends && starts && ends <= starts)
  end

  def include_articles
    errors.add(:articles, I18n.t('articles.model.error_nosel')) if article_ids.empty?
  end

  def keep_ordered_articles
    chosen_order_articles = order_articles.find_all_by_article_id(article_ids)
    to_be_removed = order_articles - chosen_order_articles
    to_be_removed_but_ordered = to_be_removed.select { |a| a.quantity > 0 or a.tolerance > 0 }
    unless to_be_removed_but_ordered.empty?
      errors.add(:articles, "Die markierten Artikel wurden in der laufenden Bestellung bereits bestellt. Wenn Du sie hier abwählst, werden alle bestehenden Bestellungen dieses Artikels gelöscht. Bei Lagerbestellungen kann dies je nach Verwendung bedeuten, dass bereits gekaufte Artikel nicht abgerechnet werden!")
      @erroneous_article_ids = to_be_removed_but_ordered.map { |a| a.article_id }
    end
  end

  def save_order_articles
    # fetch selected articles
    articles_list = Article.find(article_ids)
    # create new order_articles
    (articles_list - articles).each { |article| order_articles.create(:article => article) }
    # delete old order_articles
    articles.reject { |article| articles_list.include?(article) }.each do |article|
      order_articles.detect { |order_article| order_article.article_id == article.id }.destroy
    end
  end

  private

  # Updates the "price" attribute of GroupOrders or GroupOrderResults
  # This will be either the maximum value of a current order or the actual order value of a finished order.
  def update_price_of_group_orders
    group_orders.each { |group_order| group_order.update_price! }
  end

end