require 'safe_yaml'
SafeYAML::OPTIONS[:default_mode] = :safe

module NosOignons
  SUBSCRIPTIONS_ROOT = 'Membres'
  SUBSCRIPTION_FIELDS = [:name, :address, :email, :membership_fee_paid_on]
  SUBSCRIPTION_MANDATORY_FIELDS = [:name, :email]

  class Subscription < Struct.new(*SUBSCRIPTION_FIELDS)
    class << self
      def all
        Dir.glob("#{SUBSCRIPTIONS_ROOT}/*.mdwn").sort.collect do |file|
          subscription_id = File.basename(file).gsub(/\.mdwn$/, '')
          Subscription.new(subscription_id)
        end
      end

      def filename_for_id(subscription_id)
        "Membres/%06d.mdwn" % subscription_id
      end

      def read_from_git(ref, file)
        IO.popen(['git', 'show', "#{ref}:#{file}"]) do |f|
          subscription_id = File.basename(file).gsub(/\.mdwn$/, '')
          Subscription.new(subscription_id, f.read)
        end
      end
    end

    attr_reader :subscription_id

    def initialize(subscription_id, page_content=nil)
      unless subscription_id =~ /\A\d{6}\z/
        raise ArgumentError.new('bad subscription id format')
      end
      @subscription_id = subscription_id
      unless page_content
        page_content = File.open(Subscription.filename_for_id(subscription_id)).read
      end
      unless page_content.start_with?("---\n")
        raise ArgumentError.new('content is not a proper YAML document')
      end
      data = YAML.load(page_content)
      SUBSCRIPTION_FIELDS.each do |field|
        self[field] = data[field.to_s]
      end
      # Immutability for the win
      SUBSCRIPTION_FIELDS.each do |field|
        instance_eval{ undef :"#{field}=" }
      end
      SUBSCRIPTION_MANDATORY_FIELDS.each do |sym|
        raise ArgumentError.new('missing mandatory fields') unless self[sym]
      end
      if membership_fee_paid_on && !membership_fee_paid_on.is_a?(Date)
        raise ArgumentError.new('membership_fee_paid_on is not a date')
      end
    end

    def up_to_date?
      now = Time.now
      last_year = Time.new(now.year - 1, now.month, now.day).to_date
      membership_fee_paid_on && last_year < membership_fee_paid_on
    end
  end
end