#!/usr/bin/env ruby

require 'amazon_product'
require 'csv'

AWSKey    = ''
AWSSecret = ''

AWSAssociateTags = {
  :de => '',
  :uk => '',
  :us => ''
}

Config = {
  1 => ['de', 'Amazon.de (Germany)'],
  2 => ['uk', 'Amazon.co.uk (Great Britain)'],
  3 => ['us', 'Amazon.com (US)']
}

class CsvFile
  Fields = {
    'URL'           => %w(DetailPageURL),
    'ASIN'          => %w(ASIN),
    'Product Group' => %w(ItemAttributes ProductGroup),
    'Title'         => %w(ItemAttributes Title)
  }

  def initialize
    @content = [Fields.keys]
  end

  def add_item(item)
    @content << Fields.values.map do |attrs|
      attrs.inject item do |value, attr|
        value[attr]
      end
    end
  end

  def write_file!
    filename = "amazon_export_#{Time.now.strftime('%Y-%m-%dT%H-%M-%S')}.csv"

    CSV.open filename, 'wb' do |csv|
      @content.each do |row|
        csv << row
      end
    end

    puts "File #{filename} created!"
  end
end

q, config = nil, nil

puts 'Please select language:'

begin
  Config.each do |i, (locale, text)|
    puts "(#{i}) #{text}"
  end

  config_number = gets.strip

  if Config.has_key?(config_number.to_i)
    config = Config[config_number.to_i]
  else
    puts "Please enter one of the following options: #{Config.keys.join(', ')}"
  end
end while config.nil?

puts "\nPlease enter search term(s):"

begin
  q = gets.strip

  puts 'Please enter one or more serch terms!' if q.length == 0
end while q.length == 0

req = AmazonProduct[config[0]]

req.configure do |c|
  c.key    = AWSKey
  c.secret = AWSSecret
  c.tag    = AWSAssociateTags[config[0].to_sym]
end

puts "\nCreating CSV file, please wait..."

csv_file = CsvFile.new

(1..10).each do |item_page|
  resp = req.search('All',
    :keywords  => q,
    :item_page => item_page
  )

  next unless resp.valid? && !resp.has_errors?

  resp.each('Item') do |item|
    csv_file.add_item item
  end
end

csv_file.write_file!