module ActiveShipping #:nodoc:
  class RateEstimate
    attr_reader :origin         # Location objects
    attr_reader :destination
    attr_reader :package_rates  # array of hashes in the form of {:package => <Package>, :rate => 500}
    attr_reader :carrier        # Carrier.name ('USPS', 'FedEx', etc.)
    attr_reader :service_name   # name of service ("First Class Ground", etc.)
    attr_reader :service_code
    attr_reader :currency       # 'USD', 'CAD', etc.
    # http://en.wikipedia.org/wiki/ISO_4217
    attr_reader :shipping_date
    attr_reader :delivery_date  # Usually only available for express shipments
    attr_reader :delivery_range # Min and max delivery estimate in days
    attr_reader :negotiated_rate
    attr_reader :insurance_price

    def initialize(origin, destination, carrier, service_name, options = {})
      @origin, @destination, @carrier, @service_name = origin, destination, carrier, service_name
      @service_code = options[:service_code]
      if options[:package_rates]
        @package_rates = options[:package_rates].map { |p| p.update(:rate => Package.cents_from(p[:rate])) }
      else
        @package_rates = Array(options[:packages]).map { |p| {:package => p} }
      end
      @total_price = Package.cents_from(options[:total_price])
      @negotiated_rate = options[:negotiated_rate] ? Package.cents_from(options[:negotiated_rate]) : nil
      @currency = ActiveUtils::CurrencyCode.standardize(options[:currency])
      @delivery_range = options[:delivery_range] ? options[:delivery_range].map { |date| date_for(date) }.compact : []
      @shipping_date = date_for(options[:shipping_date])
      @delivery_date = @delivery_range.last
      @insurance_price = Package.cents_from(options[:insurance_price])
    end

    def total_price
      @total_price || @package_rates.sum { |p| p[:rate] }
    rescue NoMethodError
      raise ArgumentError.new("RateEstimate must have a total_price set, or have a full set of valid package rates.")
    end
    alias_method :price, :total_price

    def add(package, rate = nil)
      cents = Package.cents_from(rate)
      raise ArgumentError.new("New packages must have valid rate information since this RateEstimate has no total_price set.") if cents.nil? and total_price.nil?
      @package_rates << {:package => package, :rate => cents}
      self
    end

    def packages
      package_rates.map { |p| p[:package] }
    end

    def package_count
      package_rates.length
    end

    private

    def date_for(date)
      date && DateTime.strptime(date.to_s, "%Y-%m-%d")
    rescue ArgumentError
      nil
    end
  end
end