module ActsAsPurchasable
  extend ActiveSupport::Concern

  module ActiveRecord
    def acts_as_purchasable(*options)
      @acts_as_purchasable = options || []
      include ::ActsAsPurchasable
    end
  end

  included do
    has_many :orders, :through => :order_items, :class_name => 'Effective::Order'
    has_many :order_items, :as => :purchasable, :class_name => 'Effective::OrderItem'
    has_many :cart_items, :as => :purchasable, :dependent => :delete_all, :class_name => 'Effective::CartItem'

    validates_with Effective::SoldOutValidator, :on => :create

    # Database max integer value is 2147483647.  So let's round that down and use a max/min of $20 million (2000000000)
    validates :price, :presence => true, :numericality => { less_than_or_equal_to: 2000000000, message: 'maximum price is $20,000,000' }

    validates :tax_exempt, :inclusion => {:in => [true, false]}

    # These are breaking on the check for quanitty_enabled?.  More research is due
    validates :quantity_purchased, :numericality => {:allow_nil => true}, :if => proc { |purchasable| (purchasable.quantity_enabled? rescue false) }
    validates :quantity_max, :numericality => {:allow_nil => true}, :if => proc { |purchasable| (purchasable.quantity_enabled? rescue false) }

    scope :purchased, -> { joins(:order_items).joins(:orders).where(:orders => {:purchase_state => EffectiveOrders::PURCHASED}).uniq }
    scope :purchased_by, lambda { |user| joins(:order_items).joins(:orders).where(:orders => {:user_id => user.try(:id), :purchase_state => EffectiveOrders::PURCHASED}).uniq }
    scope :sold, -> { purchased() }
    scope :sold_by, lambda { |user| joins(:order_items).joins(:orders).where(:order_items => {:seller_id => user.try(:id)}).where(:orders => {:purchase_state => EffectiveOrders::PURCHASED}).uniq }

    scope :not_purchased, -> { where('id NOT IN (?)', purchased.pluck(:id).presence || [0]) }
    scope :not_purchased_by, lambda { |user| where('id NOT IN (?)', purchased_by(user).pluck(:id).presence || [0]) }
  end

  module ClassMethods
    def after_purchase(&block)
      send :define_method, :after_purchase do |order, order_item| self.instance_exec(order, order_item, &block) end
    end

    def after_decline(&block)
      send :define_method, :after_decline do |order, order_item| self.instance_exec(order, order_item, &block) end
    end
  end

  # Regular instance methods
  def is_effectively_purchasable?
    true
  end

  def price
    self[:price] || 0
  end

  # If I have a column type of Integer, and I'm passed a non-Integer, convert it here
  def price=(value)
    integer_column = ((column_for_attribute('price').try(:type) rescue nil) == :integer) # Rails built in method to lookup datatype

    if integer_column == false
      super
    elsif value.kind_of?(Integer)
      super
    elsif value.kind_of?(String) && !value.include?('.') # Looks like an integer
      super
    else # Could be Float, BigDecimal, or String like 9.99
      super((value.to_f * 100.0).to_i)
    end
  end

  def title
    self[:title] || to_s
  end

  def tax_exempt
    self[:tax_exempt] || false
  end

  def tax_rate
    @tax_rate ||= (
      self.instance_exec(self, &EffectiveOrders.tax_rate_method).to_f.tap do |rate|
        raise ArgumentError.new("expected EffectiveOrders.tax_rate_method to return a value between 0 and 1. Received #{rate}. Please return 0.05 for 5% tax.") if (rate > 1.0 || rate < 0.0)
      end
    )
  end

  def seller
    if EffectiveOrders.stripe_connect_enabled
      raise 'acts_as_purchasable object requires the seller be defined to return the User selling this item.  This is only a requirement when using StripeConnect.'
    end
  end

  def purchased?
    @is_purchased ||= orders.any? { |order| order.purchased? }
  end

  def purchased_at
    @purchased_at ||= orders.map { |order| order.purchased_at if order.purchased? }.compact.sort.first
  end

  def purchased_by?(user)
    orders.any? { |order| order.purchased? && order.user_id == user.id }
  end

  def purchased_orders
    orders.select { |order| order.purchased? }
  end

  def purchased_order
    purchased_orders.first
  end

  def quantity_enabled?
    self.respond_to?(:quantity_enabled) ? quantity_enabled == true : false
  end

  def quantity_remaining
    (quantity_max - quantity_purchased) rescue 0
  end

  def sold_out?
    quantity_enabled? ? (quantity_remaining == 0) : false
  end

  def purchased!(order = nil, order_item = nil)
    after_purchase(order, order_item) if self.respond_to?(:after_purchase)
    save!
  end

  def declined!(order = nil, order_item = nil)
    after_decline(order, order_item) if self.respond_to?(:after_decline)
    save!
  end

  # Override me if this is a digital purchase.
  def purchased_download_url
    false
  end

end