module AmazonOrder
  class Client
    include AmazonAuth::CommonExtension

    attr_accessor :session, :options

    def initialize(options = {})
      @options = options
      @client = AmazonAuth::Client.new(@options)
      extend(AmazonAuth::SessionExtension)
    end

    def base_dir
      options.fetch(:base_dir, 'orders')
    end

    def year_from
      options.fetch(:year_from, Time.current.year)
    end

    def year_to
      options.fetch(:year_to, Time.current.year)
    end

    def limit
      options.fetch(:limit, 5)
    end

    def session
      @session ||= @client.session
    end

    def fetch_amazon_orders
      sign_in
      go_to_amazon_order_page
      year_to.to_i.downto(year_from.to_i) do |year|
        fetch_orders_for_year(year: year)
      end
    end

    def load_amazon_orders
      orders = []
      Dir.glob(file_glob_pattern).each do |filepath|
        log "Loading #{filepath}"
        parser = AmazonOrder::Parser.new(filepath)
        orders += parser.orders
      end
      orders.sort_by{|o| -o.fetched_at.to_i }.uniq(&:order_number)
    end

    def file_glob_pattern
      File.join(Capybara.save_path, base_dir, '*html')
    end

    def generate_csv
      writer.generate_csv
    end

    def writer
      @_writer ||= AmazonOrder::Writer.new(file_glob_pattern)
    end

    def sign_in
      @client.sign_in
    end

    def go_to_amazon_order_page
      link = links_for('a').find{|link| link =~ %r{/order-history} }
      session.visit link
    end

    def fetch_orders_for_year(options = {})
      year = options.fetch(:year, Time.current.year)
      if switch_year(year)
        save_page_for(year, current_page_node.try!(:text))
        while (node = next_page_node) do
          session.visit node.attr('href')
          save_page_for(year, current_page_node.text)
          break if limit && limit <= current_page_node.text.to_i
        end
      end
    end

    def switch_year(year)
      return true if year.to_i == selected_year
      session.first('.order-filter-dropdown .a-dropdown-prompt').click
      option = session.all('.a-popover-wrapper .a-dropdown-link').find{|e| e.text.gsub(/\D+/,'').to_i == year.to_i }
      return false if option.nil?
      option.click
      sleep 2
      log "Year:#{year} -> #{number_of_orders}"
      true
    rescue => e
      puts "#{e.message}\n#{e.backtrace.join("\n")}"
      false
    end

    def save_page_for(year, page)
      log "Saving year:#{year} page:#{page}"
      path = ['order', year.to_s, "p#{page}", Time.current.strftime('%Y%m%d%H%M%S')].join('-') + '.html'
      session.save_page(File.join(base_dir, path))
    end

    def selected_year
      wait_for_selector('#orderFilter')
      doc.css('#orderFilter option').find{|o| !o.attr('selected').nil? }.attr('value').gsub(/\D+/,'').to_i
    end

    def number_of_orders
      doc.css('#controlsContainer .num-orders').text.strip
    end

    def current_page_node
      wait_for_selector('.a-pagination .a-selected')
      doc.css('.a-pagination .a-selected a').first
    end

    def next_page_node
      wait_for_selector('.a-pagination .a-selected')
      doc.css('.a-pagination .a-selected ~ .a-normal').css('a').first
    end
  end
end