rework initilizaton for cleaner public API.

Gemfile

@@ -2,3 +2,7 @@ source "http://rubygems.org"
 
 # Specify your gem's dependencies in remote_book.gemspec
 gemspec
+
+group :development do
+  gem 'ruby-debug19', :require => 'ruby-debug'
+end

README

@@ -0,0 +1,34 @@
+# RemoteBook
+
+RemoteBook is a gem for searching Amazon & B&N for books.  Returned links have associate information in the links.  
+
+## Installation
+
+It's a gem. Either run `gem install remote_book` at the command line, or add `gem 'remote_book'` to your Gemfile.
+
+## Usage
+
+Get your affiliate digits:
+
+    https://affiliate-program.amazon.com/
+    http://affiliates.barnesandnoble.com/ - sign up with LinkShare
+
+for rails, run the install generator:
+
+    add something like this to an initializer 
+
+    RemoteBook::Amazon.associate_keys = {:associates_id => "me", 
+                                         :key_id        => "digits",
+                                         :secret_key    => "secret_digits"}
+
+Right now it just searches by ISBN, so:
+
+    a = RemoteBook::Amazon.find_by_isbn("somedigits")
+    a.large_image
+    a.medium_image
+    a.small_image
+    a.link
+    a.author
+    a.title
+
+

VERSION

@@ -0,0 +1 @@
+0.0.1

lib/remote_book.rb

@@ -1,7 +1,12 @@
-require "remote_book/version"
-require "remote_book/remote_book"
-require "remote_book/amazon_book"
+require "rubygems"
+require "uri"
+require "openssl"
+require "typhoeus"
+require "nokogiri"
+
+require "remote_book/base"
+require "remote_book/amazon"
 
 module RemoteBook
-  # Your code goes here...
+  VERSION = File.read(File.dirname(__FILE__) + "/../VERSION").chomp
 end

lib/remote_book/amazon.rb

@@ -0,0 +1,87 @@
+module RemoteBook
+  class Amazon < RemoteBook::Base
+    # mac os 10.5 does not ship with SHA256 support built into ruby, 10.6 does. 
+    DIGEST_SUPPORT = ::OpenSSL::Digest.constants.include?('SHA256') || ::OpenSSL::Digest.constants.include?(:SHA256)
+    DIGEST = ::OpenSSL::Digest::Digest.new('sha256') if DIGEST_SUPPORT
+
+    def self.find(options)
+      a = new
+      # unless DIGEST_SUPPORT raise "no digest sup"
+      if options[:isbn]
+        req = build_isbn_lookup_query(options[:isbn])
+        response = Typhoeus::Request.get(req)
+
+        if 200 == response.code
+          xml_doc = Nokogiri.XML(response.body)
+        else 
+          return false 
+        end
+
+        if 1 == xml_doc.xpath("//xmlns:Items").size
+          if xml_doc.xpath("//xmlns:Items/xmlns:Item/xmlns:LargeImage/xmlns:URL")
+            a.large_image  = xml_doc.xpath("//xmlns:Items/xmlns:Item/xmlns:LargeImage/xmlns:URL").inner_text
+          end
+          if xml_doc.xpath("//xmlns:Items/xmlns:Item/xmlns:MediumImage/xmlns:URL")
+            a.medium_image = xml_doc.xpath("//xmlns:Items/xmlns:Item/xmlns:MediumImage/xmlns:URL").inner_text
+          end
+          if xml_doc.xpath("//xmlns:Items/xmlns:Item/xmlns:SmallImage/xmlns:URL")
+            a.small_image  = xml_doc.xpath("//xmlns:Items/xmlns:Item/xmlns:SmallImage/xmlns:URL")
+          end
+          a.title        = xml_doc.xpath("//xmlns:Items/xmlns:Item/xmlns:ItemAttributes/xmlns:Title").inner_text
+          a.authors = []
+          xml_doc.xpath("//xmlns:Items/xmlns:Item/xmlns:ItemAttributes/xmlns:Author").each do |author|
+            a.authors << author.inner_text
+          end
+          # ewww
+          if xml_doc.xpath("//xmlns:Items/xmlns:Item/xmlns:ItemLinks/xmlns:ItemLink/xmlns:Description='Technical Details'")
+            xml_doc.xpath("//xmlns:Items/xmlns:Item/xmlns:ItemLinks/xmlns:ItemLink").each do |item_link|
+              if "Technical Details" == item_link.xpath("xmlns:Description").inner_text
+                a.link = item_link.xpath("xmlns:URL").inner_text
+              end
+            end
+          end
+        end
+      end  
+      return a
+    end
+
+  private 
+    def self.build_isbn_lookup_query(item_id)
+      base = "http://ecs.amazonaws.com/onca/xml" 
+      query = "Service=AWSECommerceService&"
+      query << "AWSAccessKeyId=#{associate_keys[:key_id]}&"
+      query << "AssociateTag=#{associate_keys[:associates_id]}&"
+      query << "Operation=ItemLookup&"
+      query << "ItemId=#{item_id}&"
+      query << "ResponseGroup=ItemAttributes,Offers,Images&"
+      # query << "ResponseGroup=ItemAttributes&"
+      query << "Version=2009-07-01"
+      sig_query = sign_query base, query, associate_keys[:secret_key]
+      base + "?" + sig_query
+    end
+    # most of this is from http://www.justinball.com/2009/09/02/amazon-ruby-and-signing_authenticating-your-requests/ 
+    #  which is actually from the ruby-aaws gem 
+    def self.sign_query(uri, query, amazon_secret_access_key = "", locale = :us)
+      uri = URI.parse(uri)
+      # only add current timestamp if it's not in the query, a timestamp passed in via query takes precedence 
+      # I'm only doing this so the checksum comes out correctly with the example from the amazon documentation
+      query << "&Timestamp=#{Time.now.utc.strftime('%Y-%m-%dT%H:%M:%SZ')}" unless query.include?("Timestamp")
+      new_query = query.split('&').collect{|param| "#{param.split('=')[0]}=#{url_encode(param.split('=')[1])}"}.sort.join('&')
+      # puts new_query
+      to_sign = "GET\n%s\n%s\n%s" % [uri.host, uri.path, new_query]
+      # step 7 of http://docs.amazonwebservices.com/AWSECommerceService/latest/DG/index.html?rest-signature.html
+      hmac = OpenSSL::HMAC.digest(DIGEST, amazon_secret_access_key, to_sign)
+      base64_hmac = [hmac].pack('m').chomp
+      signature = url_encode(base64_hmac)
+
+      new_query << "&Signature=#{signature}"
+    end
+
+    # Shamelessly plagiarised from Wakou Aoyama's cgi.rb, but then altered slightly to please AWS.
+    def self.url_encode(str)
+      str.gsub( /([^a-zA-Z0-9_.~-]+)/ ) do
+        '%' + $1.unpack( 'H2' * $1.bytesize ).join( '%' ).upcase
+      end
+    end
+  end
+end

lib/remote_book/base.rb

@@ -0,0 +1,31 @@
+module RemoteBook
+  class Base
+    attr_accessor :large_image, :medium_image, :small_image, :link, :authors, :title, :isbn, :digital_link
+
+    def author
+      @authors.join(", ")
+    end
+
+    class << self
+      def associate_keys
+        @@associate_keys ||= {}
+      end
+
+      def associate_keys=(obj)
+        @@associate_keys = obj
+      end
+
+      def setup
+        yield self
+      end
+
+      def find_by_isbn(isbn)
+        self.find(:isbn => isbn)
+      end
+
+      def find(options)
+
+      end
+    end
+  end
+end

remote_book.gemspec

@@ -1,20 +1,35 @@
 # -*- encoding: utf-8 -*-
 $:.push File.expand_path("../lib", __FILE__)
-require "remote_book/version"
+require "remote_book"
 
 Gem::Specification.new do |s|
   s.name        = "remote_book"
   s.version     = RemoteBook::VERSION
   s.authors     = ["Seth Faxon"]
   s.email       = ["seth.faxon@gmail.com"]
   s.homepage    = ""
-  s.summary     = %q{TODO: Write a gem summary}
-  s.description = %q{TODO: Write a gem description}
+  s.summary     = %q{Pull book affiliate links and images from Amazon, Barns & Noble}
+  s.description = %q{Pull book affiliate links and images from Amazon, Barns & Noble}
 
   s.rubyforge_project = "remote_book"
 
   s.files         = `git ls-files`.split("\n")
   s.test_files    = `git ls-files -- {test,spec,features}/*`.split("\n")
   s.executables   = `git ls-files -- bin/*`.split("\n").map{ |f| File.basename(f) }
   s.require_paths = ["lib"]
+
+  if s.respond_to? :specification_version then
+    s.specification_version = 3
+
+    if Gem::Version.new(Gem::VERSION) >= Gem::Version.new('1.2.0') then
+      s.add_runtime_dependency(%q<typhoeus>)
+      s.add_runtime_dependency(%q<nokogiri>)
+    else
+      s.add_dependency(%q<typhoeus>)
+      s.add_dependency(%q<nokogiri>)
+    end
+  else
+    s.add_dependency(%q<typhoeus>)
+    s.add_dependency(%q<nokogiri>)
+  end
 end