fairmondo/fairmondo

#   Copyright (c) 2012-2017, Fairmondo eG.  This file is
#   licensed under the GNU Affero General Public License version 3 or later.
#   See the COPYRIGHT file for details.

class CartCheckoutForm
  PERMITTED_UPDATE_PARAMS = %i(
    unified_transport unified_payment unified_payment_method tos_accepted message
  ).freeze
  PERMITTED_CHECKOUT_SESSION_PARAMS = %i(
    unified_transport_maximum_articles
    unified_transport_provider
    unified_transport_price_cents
    free_transport_at_price_cents
  ).freeze

  include AddressParams
  include BusinessTransactionParams

  attr_accessor :session, :cart, :form_objects, :checkout, :payment_address, :transport_address

  def initialize session, cart, checkout
    self.session = session
    self.cart = cart
    self.checkout = checkout # determines if we are checking out or not

    # setting the default value for the fields to true if possible
    # will be overwritten by any params or session params
    cart.line_item_groups.each do |group|
      group.unified_transport = group.transport_can_be_unified?
      group.unified_payment = group.payment_can_be_unified?
      group.buyer_id = cart.user_id
    end

    if cart.user.standard_address && cart.user.standard_address.valid?
      self.payment_address = cart.user.standard_address
    else
      self.payment_address = cart.user.addresses.build
    end
  end

  def session_valid?
    build_form_objects_from session[:cart_checkout]
    unless session[:cart_checkout].empty?
      get_seller_specifics_from session
      return valid?
    end
    nil # for safety
  end

  def process params
    build_form_objects_from checkout ? session[:cart_checkout] : params
    return :invalid unless valid?
    if checkout
      get_seller_specifics_from session
      cart.buy
    else
      session[:cart_checkout] = params # save form data in session
      save_seller_specifics_in session
      :saved_in_session
    end
  end

  # for formtastic
  def persisted?
    false
  end

  def needs_new_payment_address?
    self.payment_address.new_record?
  end

  def same_transport_address?
    self.transport_address == self.payment_address
  end

  private

  def build_form_objects_from params
    self.form_objects = []

    # build address if present
    create_payment_address(params) if params[:address] && needs_new_payment_address?

    assign_transport_address(params[:transport_address_id])

    self.cart.line_item_groups.each do |group|
      update_line_item_group group, params
    end
  end

  def valid?
    invalid_objects = form_objects.select { |object| !object.valid? }
    invalid_objects.empty?
  end

  def update_line_item_group group, params
    # builds business_transactions
    group.line_items.each do |item|
      transaction_params = params[:line_items][item.id.to_s] rescue nil
      create_business_transaction_for group, item, transaction_params
    end

    # assigns attributes to line_item_groups
    group_params = params[:line_item_groups][group.id.to_s] if params[:line_item_groups]
    group.assign_attributes(group_params.permit(*PERMITTED_UPDATE_PARAMS)) if group_params
    group.payment_address = self.payment_address
    group.transport_address = self.transport_address
    group.buyer_id = cart.user_id
    self.form_objects << group
  end

  def create_business_transaction_for group, item, transaction_params
    business_transaction =
      if transaction_params
        group.business_transactions.build(transaction_params.require(:business_transaction).permit(*BUSINESS_TRANSACTION_PARAMS))
      else
        group.business_transactions.build
      end
    item.business_transaction = business_transaction
    business_transaction.quantity_bought = item.requested_quantity
    business_transaction.article = item.article
    self.form_objects << business_transaction
  end

  def create_payment_address address_params
    self.payment_address.assign_attributes(address_params.require(:address).permit(*ADDRESS_PARAMS))
    # save this to the db if validations do not fail
    saved = self.payment_address.save
    self.form_objects << self.payment_address # for form logic purposes
    # set this as the users new standard address (to discuss)
    self.cart.user.update_attribute(:standard_address_id, self.payment_address.id) if saved
  end

  def assign_transport_address address_id
    if address_id && address_id != '0'
      self.transport_address = cart.user.addresses.find address_id
    else
      self.transport_address = self.payment_address
    end
  end

  def save_seller_specifics_in session
    session[:cart_checkout][:sellers] ||= {}
    @cart.line_item_groups.each do |group|
      seller = group.seller
      attributes = {}
      [:unified_transport_maximum_articles,
       :unified_transport_provider,
       :unified_transport_price_cents].each do |attribute|
        attributes[attribute] = seller.send(attribute)
      end
      attributes[:free_transport_at_price_cents] = seller.free_transport_at_price_cents  if seller.free_transport_available
      session[:cart_checkout][:sellers][seller.id.to_s] = attributes
    end
  end

  def get_seller_specifics_from session
    @cart.line_item_groups.each do |group|
      seller = group.seller
      checkout_session_params = session[:cart_checkout][:sellers][seller.id.to_s]
      group.assign_attributes(checkout_session_params.permit(*PERMITTED_CHECKOUT_SESSION_PARAMS))
    end
  end
end