thodg/mpd_client

diff --git a/.travis.yml b/.travis.yml
index f1a5a8f..d0ab184 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,9 +1,9 @@
 language: ruby
 
 rvm:
-  - 3.0.0
-  - 2.7.2
-  - 2.6.6
+  - 3.1.2
+  - 3.0.4
+  - 2.7.6
 
 script:
   - rspec
diff --git a/CHANGELOG.md b/CHANGELOG.md
index bea2963..d2614a1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # MPD::Client CHANGELOG
 
+## 0.2.0
+
+* Tested with Ruby 3.1
+* Add `albumart` command
+* Add `readpicture` command
+* Remove `playlist` command. Use `playlistinfo` instead
+
 ## 0.1.0
 
 * Rename `MPDClient` to `MPD::Client`
diff --git a/Gemfile b/Gemfile
index 12e41e1..0f11a4b 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,6 +8,7 @@ gemspec
 group :development, :test do
   gem 'pry'
   gem 'rubocop'
+  gem 'solargraph'
 end
 
 group :test do
diff --git a/LICENSE b/LICENSE
index 49a7f85..e46750d 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,4 @@
-Copyright (c) 2012 Anton Maminov
+Copyright (c) 2012-2022 Anton Maminov
 
 MIT License
 
@@ -19,4 +19,4 @@ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
-WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
\ No newline at end of file
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/MPD_COMMANDS.md b/MPD_COMMANDS.md
index 5d7eb38..ac108ce 100644
--- a/MPD_COMMANDS.md
+++ b/MPD_COMMANDS.md
@@ -102,7 +102,7 @@ If the optional `SUBSYSTEMS` argument is used, MPD will only send notifications 
 ---
 `mixrampdb {deciBels} => fetch_nothing`
 
-> Sets the threshold at which songs will be overlapped. Like crossfading but doesn't fade the track volume, just overlaps. The songs need to have MixRamp tags added by an external tool. 0dB is the normalized maximum volume so use negative values, I prefer -17dB. In the absence of mixramp tags crossfading will be used. See [mixramp](https://sourceforge.net/projects/mixramp/)
+> Sets the threshold at which songs will be overlapped. Like crossfading but doesn't fade the track volume, just overlaps. The songs need to have MixRamp tags added by an external tool. 0dB is the normalized maximum volume so use negative values, I prefer -17dB. In the absence of mixramp tags crossfading will be used. See [mixramp](https://mpd.readthedocs.io/en/latest/user.html?highlight=mixramp#mixramp)
 
 ---
 `mixrampdelay {SECONDS} => fetch_nothing`
diff --git a/README.md b/README.md
index bfd5ed9..8c64fdd 100644
--- a/README.md
+++ b/README.md
@@ -31,6 +31,8 @@ gem install mpd_client
 All functionality is contained in the `MPD::Client` class. Creating an instance of this class is as simple as:
 
 ```ruby
+require 'mpd_client'
+
 client = MPD::Client.new
 ```
 
@@ -64,6 +66,26 @@ client.status                # insert the status command into the list
 client.command_list_end      # result will be a Array with the results
 ```
 
+### Binary responses
+
+Some commands can return binary data.
+
+```ruby
+require 'mpd_client'
+
+client = MPD::Client.new
+client.connect('localhost', 6600)
+
+if (current_song = client.currentsong)
+  data, io = client.readpicture(current_song['file'])
+  io # StringIO
+  data # => {"size"=>"322860", "type"=>"image/jpeg", "binary"=>"3372"}
+  File.write('cover.jpg', io.string)
+end
+```
+
+The above will locate album art for the current song and save image to `cover.jpg` file.
+
 ### Ranges
 
 Some commands(e.g. `move`, `delete`, `load`, `shuffle`, `playlistinfo`) support integer ranges(`[START:END]`) as argument. This is done in `mpd_client` by using two element array:
@@ -103,7 +125,7 @@ client = MPD::Client.new
 client.log = Logger.new($stderr)
 ```
 
-For more information about logging configuration, see [Logger](https://ruby-doc.org/stdlib-2.5.1/libdoc/logger/rdoc/Logger.html)
+For more information about logging configuration, see [Logger](https://ruby-doc.org/stdlib/libdoc/logger/rdoc/Logger.html)
 
 ## Development
 
@@ -121,6 +143,6 @@ To install this gem onto your local machine, run `bundle exec rake install`. To 
 
 ## License and Author
 
-Copyright (c) 2013-2018 by Anton Maminov
+Copyright (c) 2012-2022 by Anton Maminov
 
 This library is distributed under the MIT license.  Please see the LICENSE file.
diff --git a/examples/albumart.rb b/examples/albumart.rb
new file mode 100644
index 0000000..6e81635
--- /dev/null
+++ b/examples/albumart.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+require 'bundler'
+Bundler.setup :default
+
+require 'logger'
+require 'mpd_client'
+
+# MPD::Client.log = Logger.new($stderr)
+
+client = MPD::Client.new
+client.connect('localhost', 6600)
+
+if (current_song = client.currentsong)
+  data, io = client.readpicture(current_song['file'])
+  puts data
+  File.write('cover.jpg', io.string)
+end
diff --git a/examples/client.rb b/examples/client.rb
new file mode 100644
index 0000000..a5bb0d5
--- /dev/null
+++ b/examples/client.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+require 'bundler'
+Bundler.setup :default
+
+require 'logger'
+require 'mpd_client'
+
+MPD::Client.log = Logger.new($stderr)
+
+client = MPD::Client.new
+client.connect('localhost', 6600)
+
+puts client.stats
+puts client.status
+puts client.currentsong
+puts client.playlistinfo
diff --git a/examples/stickers.rb b/examples/stickers.rb
index 6908f08..653e245 100644
--- a/examples/stickers.rb
+++ b/examples/stickers.rb
@@ -9,7 +9,7 @@ require 'mpd_client'
 MPD::Client.log = Logger.new($stderr)
 
 # Stickers
-# http://www.musicpd.org/doc/protocol/ch03s07.html
+# https://mpd.readthedocs.io/en/latest/protocol.html#stickers
 
 client = MPD::Client.new
 
diff --git a/lib/mpd_client.rb b/lib/mpd_client.rb
index 82b9655..6c2c82d 100644
--- a/lib/mpd_client.rb
+++ b/lib/mpd_client.rb
@@ -1,17 +1,17 @@
 # frozen_string_literal: true
 
 require 'socket'
+require 'stringio'
 require 'mpd_client/version'
 
 module MPD
   HELLO_PREFIX = 'OK MPD '
   ERROR_PREFIX = 'ACK '
-  SUCCESS = 'OK'
-  NEXT = 'list_OK'
+  SUCCESS = "OK\n"
+  NEXT = "list_OK\n"
 
-  # MPD changelog: http://git.musicpd.org/cgit/master/mpd.git/plain/NEWS
-  # http://www.musicpd.org/doc/protocol/command_reference.html
-  # http://git.musicpd.org/cgit/cirrus/mpd.git/plain/doc/protocol.xml
+  # MPD changelog: https://github.com/MusicPlayerDaemon/MPD/blob/master/NEWS
+  # Protocol: https://mpd.readthedocs.io/en/latest/protocol.html
   COMMANDS = {
     # Status Commands
     'clearerror' => 'fetch_nothing',
@@ -52,7 +52,6 @@ module MPD
     'deleteid' => 'fetch_nothing',
     'move' => 'fetch_nothing',
     'moveid' => 'fetch_nothing',
-    'playlist' => 'fetch_playlist',
     'playlistfind' => 'fetch_songs',
     'playlistid' => 'fetch_songs',
     'playlistinfo' => 'fetch_songs',
@@ -160,6 +159,7 @@ module MPD
 
       def add_command(name, retval)
         escaped_name = name.tr(' ', '_')
+
         define_method escaped_name.to_sym do |*args|
           ensure_connected
 
@@ -189,11 +189,12 @@ module MPD
     def reconnect
       log&.info("MPD (re)connect #{@host}, #{@port}")
 
-      @socket = if @host.start_with?('/')
-                  UNIXSocket.new(@host)
-                else
-                  TCPSocket.new(@host, @port)
-                end
+      @socket =
+        if @host.start_with?('/')
+          UNIXSocket.new(@host)
+        else
+          TCPSocket.new(@host, @port)
+        end
 
       hello
       @connected = true
@@ -222,6 +223,7 @@ module MPD
       raise 'Already in command list' unless @command_list.nil?
 
       write_command('command_list_ok_begin')
+
       @command_list = []
     end
 
@@ -241,6 +243,14 @@ module MPD
     # Sets the +logger+ used by this instance of MPD::Client
     attr_writer :log
 
+    def albumart(uri)
+      fetch_binary(StringIO.new, 0, 'albumart', uri)
+    end
+
+    def readpicture(uri)
+      fetch_binary(StringIO.new, 0, 'readpicture', uri)
+    end
+
     private
 
     def ensure_connected
@@ -266,30 +276,34 @@ module MPD
         reconnect
         @socket.puts line
       end
+
       @socket.flush
     end
 
     def write_command(command, *args)
       parts = [command]
+
       args.each do |arg|
-        line = if arg.is_a?(Array)
-                 arg.size == 1 ? "\"#{arg[0].to_i}:\"" : "\"#{arg[0].to_i}:#{arg[1].to_i}\""
-               else
-                 "\"#{escape(arg)}\""
-               end
+        line =
+          if arg.is_a?(Array)
+            arg.size == 1 ? "\"#{arg[0].to_i}:\"" : "\"#{arg[0].to_i}:#{arg[1].to_i}\""
+          else
+            "\"#{escape(arg)}\""
+          end
 
         parts << line
       end
+
       # log.debug("Calling MPD: #{command}#{args}") if log
       log&.debug("Calling MPD: #{parts.join(' ')}")
       write_line(parts.join(' '))
     end
 
     def read_line
-      line = @socket.gets.force_encoding('utf-8')
+      line = @socket.gets
+
       raise 'Connection lost while reading line' unless line.end_with?("\n")
 
-      line.chomp!
       if line.start_with?(ERROR_PREFIX)
         error = line[/#{ERROR_PREFIX}(.*)/, 1].strip
         raise error
@@ -305,22 +319,22 @@ module MPD
       line
     end
 
-    def read_pair(separator)
+    def read_pair
       line = read_line
-      return if line.nil?
 
-      pair = line.split(separator, 2)
-      raise "Could now parse pair: '#{line}'" if pair.size < 2
+      return if line.nil?
 
-      pair # Array
+      line.split(': ', 2)
     end
 
-    def read_pairs(separator = ': ')
+    def read_pairs
       result = []
-      pair = read_pair(separator)
+
+      pair = read_pair
+
       while pair
         result << pair
-        pair = read_pair(separator)
+        pair = read_pair
       end
 
       result
@@ -328,6 +342,7 @@ module MPD
 
     def fetch_item
       pairs = read_pairs
+
       return nil if pairs.size != 1
 
       pairs[0][1]
@@ -335,6 +350,7 @@ module MPD
 
     def fetch_nothing
       line = read_line
+
       raise "Got unexpected value: #{line}" unless line.nil?
     end
 
@@ -343,6 +359,8 @@ module MPD
       seen = nil
 
       read_pairs.each do |key, value|
+        value = value.chomp.force_encoding('utf-8')
+
         if key != seen
           raise "Expected key '#{seen}', got '#{key}'" unless seen.nil?
 
@@ -358,14 +376,18 @@ module MPD
     def fetch_objects(delimeters = [])
       result = []
       obj = {}
+
       read_pairs.each do |key, value|
         key = key.downcase
+        value = value.chomp.force_encoding('utf-8')
+
         if delimeters.include?(key)
           result << obj unless obj.empty?
           obj = {}
         elsif obj.include?(key)
           obj[key] << value
         end
+
         obj[key] = value
       end
 
@@ -380,6 +402,41 @@ module MPD
       objs ? objs[0] : {}
     end
 
+    def fetch_binary(io = StringIO.new, offset = 0, *args)
+      data = {}
+
+      @mutex.synchronize do
+        write_command(*args, offset)
+
+        binary = false
+
+        read_pairs.each do |item|
+          if binary
+            io << item.join(': ')
+            next
+          end
+
+          key = item[0]
+          value = item[1].chomp
+
+          binary = (key == 'binary')
+
+          data[key] = value
+        end
+      end
+
+      size = data['size'].to_i
+      binary = data['binary'].to_i
+
+      next_offset = offset + binary
+
+      return [data, io] if next_offset >= size
+
+      io.seek(-1, IO::SEEK_CUR)
+
+      fetch_binary(io, next_offset, *args)
+    end
+
     def fetch_changes
       fetch_objects(['cpos'])
     end
@@ -416,17 +473,9 @@ module MPD
       fetch_objects(['playlist'])
     end
 
-    def fetch_playlist
-      result = []
-      read_pairs(':').each do |_key, value|
-        result << value
-      end
-
-      result
-    end
-
     def fetch_stickers
       result = []
+
       read_pairs.each do |_key, sticker|
         value = sticker.split('=', 2)
         raise "Could now parse sticker: #{sticker}" if value.size < 2
@@ -443,6 +492,7 @@ module MPD
 
     def fetch_command_list
       result = []
+
       begin
         @command_list.each do |retval|
           result << (eval retval)
@@ -456,9 +506,11 @@ module MPD
 
     def hello
       line = @socket.gets
+
       raise 'Connection lost while reading MPD hello' unless line.end_with?("\n")
 
       line.chomp!
+
       raise "Got invalid MPD hello: #{line}" unless line.start_with?(HELLO_PREFIX)
 
       @mpd_version = line[/#{HELLO_PREFIX}(.*)/, 1]
diff --git a/lib/mpd_client/version.rb b/lib/mpd_client/version.rb
index dd7e7b5..ce99ef8 100644
--- a/lib/mpd_client/version.rb
+++ b/lib/mpd_client/version.rb
@@ -2,6 +2,6 @@
 
 module MPD
   class Client
-    VERSION = '0.1.1'
+    VERSION = '0.2.0'
   end
 end
diff --git a/mpd_client.gemspec b/mpd_client.gemspec
index 195c492..ccc7320 100644
--- a/mpd_client.gemspec
+++ b/mpd_client.gemspec
@@ -21,4 +21,5 @@ Gem::Specification.new do |gem|
   gem.license       = 'MIT'
 
   gem.add_development_dependency 'bundler'
+  gem.metadata['rubygems_mfa_required'] = 'true'
 end