Allow custom User-Agent

lib/musicbrainz.rb

@@ -19,6 +19,7 @@ require "musicbrainz/release_group"
 require "musicbrainz/release"
 require "musicbrainz/track"
 
+require "tools/configuration"
 require "tools/cache"
 require "tools/proxy"
 

lib/tools/configuration.rb

@@ -0,0 +1,54 @@
+# -*- encoding: utf-8 -*-
+
+module MusicBrainz
+
+  def self.configure
+    yield @config ||= MusicBrainz::Tools::Configuration.new
+  end
+
+  def self.config
+    @config
+  end
+
+  module Tools
+    class Configuration
+      def self.add_config name, value=nil
+        self.instance_variable_set "@#{name}", value
+
+        class_eval <<-RUBY
+          def #{name}=(value)
+            @#{name} = value
+          end
+
+          def #{name}
+            @#{name} || self.class.instance_variable_get('@#{name}')
+          end
+        RUBY
+      end
+
+      DEFAULT_USER_AGENT = "gem musicbrainz (https://github.com/magnolia-fan/musicbrainz) @ " + Socket.gethostname
+
+      add_config :application
+      add_config :version
+      add_config :contact
+
+      add_config :query_interval, 1.5
+      add_config :tries_limit, 5
+
+      add_config :web_service_url, "http://musicbrainz.org/ws/2/"
+
+      def user_agent
+        return @user_agent if @user_agent
+
+        if application
+          @user_agent = application
+          @user_agent << "/#{version}" if version
+          @user_agent << " (#{contact})" if contact
+          @user_agent << ' via '
+        end
+
+        @user_agent = "#{@user_agent}#{DEFAULT_USER_AGENT}"
+      end
+    end
+  end
+end

lib/tools/proxy.rb

@@ -5,26 +5,21 @@ module MusicBrainz
     class Proxy
       class << self
         @@last_query_time = 0
-        @@query_interval = 1.5 # Min: 1.0 Safe: 1.5
-        @@tries_limit = 5
 
-        WEB_SERVICE_URL = 'http://musicbrainz.org/ws/2/'
-        USER_AGENT = "gem musicbrainz (https://github.com/magnolia-fan/musicbrainz) @ " + Socket.gethostname
-
-        def query_interval=(sec)
-          @@query_interval = sec.to_f
+        def config
+          MusicBrainz.config
         end
 
-        def query_interval
-          @@query_interval
+        def query_interval=(sec)
+          config.query_interval = sec.to_f
         end
 
         def tries_limit=(num)
-          @@tries_limit = num.to_i
+          config.tries_limit = num.to_i
         end
 
         def query(params = {})
-          url = WEB_SERVICE_URL + params[:resource].to_s.gsub('_', '-') + '/' + (params[:id].to_s || '')
+          url = config.web_service_url + params[:resource].to_s.gsub('_', '-') + '/' + (params[:id].to_s || '')
           params.delete(:resource)
           params.delete(:id) unless params[:id].nil?
           url << '?' + params.map{ |k, v|
@@ -40,12 +35,12 @@ module MusicBrainz
         def get_contents(url)
           response = nil
 
-          @@tries_limit.times {
+          config.tries_limit.times {
             time_passed = Time.now.to_f - @@last_query_time
-            sleep(@@query_interval - time_passed) if time_passed < @@query_interval
+            sleep(config.query_interval - time_passed) if time_passed < config.query_interval
 
             begin
-              response = open(url, "User-Agent" => USER_AGENT)
+              response = open(url, "User-Agent" => config.user_agent)
               @@last_query_time = Time.now.to_f
             rescue => e
               response = nil if e.io.status[0].to_i == 404