Class: Alexandria::Amazon::Ecs

Inherits:
Object
  • Object
show all
Includes:
Logging
Defined in:
lib/alexandria/book_providers/amazon_ecs_util.rb

Defined Under Namespace

Classes: Response

Constant Summary collapse

SERVICE_URLS = 
{
  us: "http://webservices.amazon.com/onca/xml?Service=AWSECommerceService",
  uk: "http://webservices.amazon.co.uk/onca/xml?Service=AWSECommerceService",
  ca: "http://webservices.amazon.ca/onca/xml?Service=AWSECommerceService",
  de: "http://webservices.amazon.de/onca/xml?Service=AWSECommerceService",
  jp: "http://webservices.amazon.co.jp/onca/xml?Service=AWSECommerceService",
  fr: "http://webservices.amazon.fr/onca/xml?Service=AWSECommerceService"
}.freeze
@@options = 
{}
@@debug = 
false
@@secret_access_key = 
""

Class Method Summary collapse

Methods included from Logging

included, #log

Class Method Details

.camelize(string) ⇒ Object 



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# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 184

def self.camelize(string)
  string.to_s
    .gsub(%r{/(.?)}) { "::" + Regexp.last_match[1].upcase }
    .gsub(/(^|_)(.)/) { Regexp.last_match[2].upcase }
end

.configure {|@@options| ... } ⇒ Object

Yields:



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# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 58

def self.configure(&_proc)
  yield @@options
end

.debug ⇒ Object

Get debug flag.



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# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 49

def self.debug
  @@debug
end

.debug=(dbg) ⇒ Object

Set debug flag to true or false.



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# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 54

def self.debug=(dbg)
  @@debug = dbg
end

.hmac_sha256(message, key) ⇒ Object 



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# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 190

def self.hmac_sha256(message, key)
  block_size = 64
  ipad = "\x36" * block_size
  opad = "\x5c" * block_size
  if key.size > block_size
    d = Digest::SHA256.new
    key = d.digest(key)
  end

  ipad_bytes = ipad.bytes.map { |b| b }
  opad_bytes = opad.bytes.map { |b| b }
  key_bytes = key.bytes.map { |b| b }
  ipad_xor = ""
  opad_xor = ""
  (0..key.size - 1).each do |i|
    ipad_xor << (ipad_bytes[i] ^ key_bytes[i])
    opad_xor << (opad_bytes[i] ^ key_bytes[i])
  end

  ipad = ipad_xor + ipad[key.size..-1]
  opad = opad_xor + opad[key.size..-1]

  # inner hash
  d1 = Digest::SHA256.new
  d1.update(ipad)
  d1.update(message)
  msg_hash = d1.digest

  # outer hash
  d2 = Digest::SHA256.new
  d2.update(opad)
  d2.update(msg_hash)
  d2.digest
end

.item_lookup(item_id, opts = {}) ⇒ Object

Search an item by ASIN no.



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# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 80

def self.item_lookup(item_id, opts = {})
  opts[:operation] = "ItemLookup"
  opts[:item_id] = item_id

  send_request(opts)
end

.item_search(terms, opts = {}) ⇒ Object

Search amazon items with search terms. Default search index option is ‘Books’. For other search type other than keywords, please specify :type => [search type param name].



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# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 65

def self.item_search(terms, opts = {})
  opts[:operation] = "ItemSearch"
  opts[:search_index] = opts[:search_index] || "Books"

  type = opts.delete(:type)
  if type
    opts[type.to_sym] = terms
  else
    opts[:keywords] = terms
  end

  send_request(opts)
end

.options ⇒ Object

Default search options



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# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 35

def self.options
  @@options
end

.options=(opts) ⇒ Object

Set default search options



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# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 44

def self.options=(opts)
  @@options = opts
end

.prepare_url(opts) ⇒ Object 



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# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 164

def self.prepare_url(opts)
  country = opts.delete(:country)
  country = country.nil? ? "us" : country
  request_url = SERVICE_URLS[country.to_sym]
  unless request_url
    raise Amazon::RequestError,
          format(_("Invalid country '%<country>s'"), country: country)
  end

  qs = ""
  opts.each do |k, v|
    next unless v

    v = v.join(",") if v.is_a? Array
    qs << "&#{camelize(k.to_s)}=#{CGI.escape(v.to_s)}"
  end
  url = "#{request_url}#{qs}"
  sign_request(url)
end

.secret_access_key=(key) ⇒ Object 



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# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 39

def self.secret_access_key=(key)
  @@secret_access_key = key
end

.send_request(opts) ⇒ Object

Generic send request to ECS REST service. You have to specify the :operation parameter.



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# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 95

def self.send_request(opts)
  opts = options.merge(opts) if options
  request_url = prepare_url(opts)
  log.debug { "Request URL: #{request_url}" }

  res = transport.get_response(URI.parse(request_url))
  unless res.is_a? Net::HTTPSuccess
    raise Amazon::RequestError, format(_("HTTP Response: %<code>s %<message>s"),
                                       code: res.code, message: res.message)
  end

  Response.new(res.body)
end

.sign_request(request) ⇒ Object

Raises:

  • (AmazonNotConfiguredError) 


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# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 225

def self.sign_request(request)
  raise AmazonNotConfiguredError unless @@secret_access_key

  # Step 0 : Split apart request string
  url_pattern = %r{http://([^/]+)(/[^?]+)\?(.*$)}
  url_pattern =~ request
  host = Regexp.last_match[1]
  path = Regexp.last_match[2]
  param_string = Regexp.last_match[3]

  # Step 1: enter the timestamp
  t = Time.now.getutc # MUST be in UTC
  stamp = t.strftime("%Y-%m-%dT%H:%M:%SZ")
  param_string += "&Timestamp=#{stamp}"

  # Step 2 : URL-encode
  param_string = param_string.gsub(",", "%2C").gsub(":", "%3A")
  #   NOTE : take care not to double-encode

  # Step 3 : Split the parameter/value pairs
  params = param_string.split("&")

  # Step 4 : Sort params
  params.sort!

  # Step 5 : Rejoin the param string
  canonical_param_string = params.join("&")

  # Steps 6 & 7: Prepend HTTP request info
  string_to_sign = "GET\n#{host}\n#{path}\n#{canonical_param_string}"

  # Step 8 : Calculate RFC 2104-compliant HMAC with SHA256 hash algorithm
  sig = hmac_sha256(string_to_sign, @@secret_access_key)
  base64_sig = [sig].pack("m").strip

  # Step 9 : URL-encode + and = in sig
  base64_sig = CGI.escape(base64_sig)

  # Step 10 : Add the URL encoded signature to your request
  "http://#{host}#{path}?#{param_string}&Signature=#{base64_sig}"
end

.transport ⇒ Object

HACK : copied from book_providers.rb



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# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 88

def self.transport
  config = Alexandria::Preferences.instance.http_proxy_config
  config ? Net::HTTP.Proxy(*config) : Net::HTTP
end