require 'open-uri'
require 'pp'
require 'rexml/document'
include REXML
require "win32/clipboard"
include Win32


def getPage(asin)
  uri = 'http://webservices.amazon.co.uk/onca/xml?Service=AWSECommerceService'
  uri = uri + '&AWSAccessKeyId=**PUT YOUR KEY HERE**'
  uri = uri + '&ResponseGroup=Small,ItemAttributes'
  uri = uri + "&Operation=ItemLookup&ItemId=#{asin}"
  string = ''
  open(uri) do |f|
    lines = f.readlines
    lines.each { |line| string += line }
    return string
  end
end

def getBookDetails()
  isbn = Clipboard.data 
  return ('%s is not a valid isbn' % isbn) if (not isValidISBN(isbn))
  asin = isbn.delete('-')
  doc = Document.new(getPage(asin))
  result = ''
  items = doc.elements.to_a('ItemLookupResponse/Items/Item')
  items.each do |item| 
  result += "<a href='http://www.amazon.co.uk/exec/obidos/ASIN/#{item.elements['ASIN'].text}/cockiandco-21'>"
  result += "#{item.elements['ItemAttributes/Title'].text}</a>\n"
  end
  Clipboard.set_data result
  return result
end 

def checkDigit(isbn)
    string = isbn.delete('-')[0..9]
    total = 0
    for i in 0..8
        char = string[i]
        total = total + (10 - i) * ('0123456789'.index(char))
    end
    return '0X987654321'[total % 11]
end

def isValidISBN(isbn)
    str = isbn.delete('-')[0..10]
    return ((str.length == 10) and (checkDigit(str) == str[9]))
end

print getBookDetails()