#
# AUTHOR:
#  KesieV <http://www.kesiev.com>
#
# WHAT IT DOES:
#  Use mpg123 as backend. Is quite complex, as custom backend, because mpg123
#  seems to be tricky to be remote controlled and pls support is coded.
#  You can reuse some pieces of code for your frontend but I suggest you to
#  start copying the default Mplayer object, which is simplier and cleaner.
#  Obviuosly can be MORE complex (mp3 streaming from STDIN) since the plugin
#  system is raw but flexible.
#

# New player backends are implemented overlapping the Mplayer objects method
class Mplayer
  # NOTE: put @@LASTFM=nil to disable LastFM features. LastFM stations are plain
  # MP3 streams and, since mpg123 supports them, LastFM works out of the box.

  # mpg123 features only the mp3 format, so will be indexed only mp3s
  alias mpg123_initialize initialize
  def initialize(lastfmuser="",lastfmpassword="")
  	mpg123_initialize(lastfmuser,lastfmpassword)
  	@features={:formats=>[".mp3"]}
  end
 
 	# I/O of mpg123 is quite a mess. Have to be manually synced each
 	# line. Implementig a "tell" function, which syncs pipe with
 	# mpg123 each call. Seems working. 
    def tell(string)
      # Since we're using the "sequence" structure, is safe to check the pipe
      # before sending commands - if user hits stop when skipping from a
      # sequence item to another
      begin
      	@pipe.flush
      	@pipe.puts(string)
      	@pipe.flush
      rescue =>error; end
    end
  
	def play(file,metadata={},indexonly=false)

	  # Player object startup, LastFM login etc.
    startup(file,metadata,indexonly)

    # mpg123 do not supports pls playlists when in interactive mode. We attemp
    # to parse it for him, so some Shoutcasts should work. You can reuse this
    # structure for any tiny media player which do not support playlists.
    # The trick is to reset the sequence array with the played filename and
    # substitute with the array of items you want to play when needed.
    # Then, into the player's thread, we will call the player multiple times
    # and quit the sequence fetching when user stops the playback by hand.

    sequence=[file];

    if (file[-3..-1]=="pls") then
      sequence=[]
      open(file,"r") { |f|
        f.each { |line|
          if line[0..3]=="File" then
            sequence << line[line.index("=")+1..-1]
          end
        }
      }
    end

  	@thread=Thread.new {
    
      # Usually is needed to execute this just once per file. We're trying to
      # simulate a "single item playlist" so pls are fetched until one of them
      # works.
      sequence.each { |file|
      
        # Opening a pipe to mpg123 in interactive mode
    	  @pipe=IO.popen("mpg123 -R",'r+')
    	  
    	  # As I said, we have to sync manually with mpg123. Disabling
    	  # automatic sync.
    	  @pipe.sync=false
    	
          # With mpg123, sizes of the media are served once so we will store them
          # and served each time. 
    		  sz=[-1,-1]
    		  @pipe.each { |line|
    		      		  
    		  # Waiting for mpg123 to be ready.
    		  if line[0..1]=="@R" then
    		    # If is ready, it starts playback
    		  	tell((indexonly ? "LP" : "L")+" "+(@meta[:file][0..5]=="lastfm" && @lastfmdata[:session] && @meta[:title]!=$opt[:unknown] ? @lastfmdata[:url] : file) );
            # Playback starts here
    	      setmeta(nil,[:play,nil])
    		  end
    
          # call this sometime (i.e. each stdout line) for updating LastFM meta
          # and doing other stuff.
          backgroundupdate
                    
          # Update meta. Seems that mpg123 ID3 doesn't tell the track number :(
          # ID3 tags are formatted using string chunks 30 characters long.
    		  if line[0..6]=="@I ID3:" then
    		    [:title,:artist,:album].each_with_index { |id,i| setmeta(id,line[7+(30*i)..36+(30*i)].rstrip) if line[7+(30*i)..36+(30*i)].rstrip.length>0 }
          end
          
          # ID3 Track number ships alone...
    		 if line[0..12]=="@I ID3.track:" then
    		  setmeta(:trackno,line[13..-1].rstrip)
    		 end
    
          # Since latest versions of mpg123 supports ID3v2 tags, we will also use
          # them. Track number is supported :)
    		  if line[0..8]=="@I ID3v2." then
    		  	[
    		  		{ :label=>"title:", :id=>:title },
    		  		{ :label=>"artist:", :id=>:artist },
    		  		{ :label=>"album:", :id=>:album },
    		  		{ :label=>"track:", :id=>:trackno },
    		  		{ :label=>"year:", :id=>:year }
    		  	].each { |i|
    		  		if line[9..8+i[:label].length]==i[:label] && line[9+i[:label].length..-1].rstrip.length>0 then 
    		  			setmeta(i[:id],line[9+i[:label].length..-1].rstrip)
    		  		end
    		  	}
    		  end
    		  	
          # Icecast tags
          if line[0..11]=="@I ICY-META:" then
            title=line[/StreamTitle='([^']*)'/,1]
            if title.to_s.length>0 then setmeta(:title,title) end
          end
          
    	      
    		    if indexonly then
    		    
    		      # if this object was called for indexing music, quit ASAP
              if line[0..1]=="@P"  then 
              		tell("quit")
              	end
              
            else
            
              # else update player status
              
              # If playback ended, quits the mpg123 player (is not automatic)
              if line[0..3]=="@P 0" then tell("quit") end
              
              # Updates playback position
      		    if line[0..1]=="@F" then
      		      data=line.split(" ");
      		      if sz[0]==-1 then
                  sz[0]=data[4]
      		        sz[1]=data[2].to_f
                end
                @runtime.call(data[3],sz[0],data[1].to_f,sz[1])
              end
              
            end
          }
          
          # if playback was ended by user, stops the sequence fetching. Else
          # the player quitted for end of stream (i.e. stream error) or end
          # of single MP3 (but should be alone into the sequence array)
          if @state[0]==:stop && @state[1]==:byhand then break end
                    
    		}

        # If thread exited, puts the player in stop state. (end of song)
  		  setmeta(nil,[:stop,@state[1]])
    		
  	}
	end


  # This is called by the GUI for changing the playback status.
	def control(action,attr)
		setmeta(nil,[:stop,attr]) if action == :stop
		setmeta(nil,[(@state[0] == :play ? :pause : :play),attr]) if action==:pause && @state[0]!=:stop
		#fullscreen is not supported
		tell({:stop=>"quit",:pause=>"pause",:forward=>"J +10seconds",:rewind=>"J -10seconds"}[action]) if @thread && @thread.alive?
		@thread.join if @state[0] == :stop && @thread && @thread.alive?
	end

end