X-Git-Url: https://git.draconx.ca/gitweb/mpdhacks.git/blobdiff_plain/b0f5f5741b234174958ade58a6e884df8b6b00e4..f0e74c3a1fc44153fe80961ff7de3b4a0786e5ea:/mpdreload.pl

diff --git a/mpdreload.pl b/mpdreload.pl
index ba822ae..66bb39d 100755
--- a/mpdreload.pl
+++ b/mpdreload.pl
@@ -1,6 +1,6 @@
 #!/usr/bin/env perl
 #
-# Copyright © 2019-2020 Nick Bowler
+# Copyright © 2019-2021 Nick Bowler
 #
 # Replace the current MPD play queue with a saved playlist, by rearranging
 # existing queue entries when possible.  This avoids losing the current
@@ -26,44 +26,29 @@ use MPDHacks;
 
 my $sock;
 
-# Submit a command to the MPD server; each argument to this function
-# is quoted and sent as a single argument to MPD.
-sub mpd_exec {
-	my $cmd = join(' ', map { MPD::escape } @_);
-
-	print $sock "$cmd\n";
-}
-
-# Returns a hash reference containing all tracks in the current play queue.
-# The hash keys are filenames.
+# Returns a hash reference mapping filenames to an array reference listing
+# the queue IDs for that file in the current play queue.
 sub get_tracks_in_play_queue {
-	my %matches;
-	my $entry;
+	my (%matches, %idmap, $entry);
+	my $pos = -1;
 
-	mpd_exec("playlistinfo");
+	MPD::exec("playlistinfo");
 	while (<$sock>) {
 		last if /^OK/;
 		die($_) if /^ACK/;
 
 		if (/^(\w+): (.*)$/) {
 			if ($1 eq "file") {
-				if (exists($matches{$2})) {
-					$entry = $matches{$2};
-				} else {
-					$entry = {};
-					$matches{$2} = $entry;
-				}
-			}
-
-			if (exists($entry->{$1})) {
-				$entry->{$1}->{$2} = 1;
-			} else {
-				$entry->{$1} = { $2 => 1 }
+				$entry = $matches{$2} //= [];
+				$pos++;
+			} elsif ($1 eq "Id") {
+				push @$entry, $2;
+				$idmap{$2} = $pos;
 			}
 		}
 	}
 
-	return \%matches;
+	return (\%matches, \%idmap);
 }
 
 # Given an MPD playlist name, returns a reference to an array containing
@@ -72,7 +57,7 @@ sub get_playlist_files {
 	my ($plname) = @_;
 	my @files;
 
-	mpd_exec("listplaylist", $plname);
+	MPD::exec("listplaylist", $plname);
 	while (<$sock>) {
 		last if /^OK/;
 		die($_) if /^ACK/;
@@ -98,10 +83,10 @@ EOF
 }
 
 sub print_usage {
-	my $fh = $_[1] // *STDERR;
+	my ($fh) = (@_, *STDERR);
 
 	print $fh "Usage: $0 [options] playlist\n";
-	print "Try $0 --help for more information.\n" unless (@_ > 0);
+	print $fh "Try $0 --help for more information.\n" unless (@_ > 0);
 }
 
 sub print_help {
@@ -137,37 +122,50 @@ if (@ARGV != 1) {
 $sock = MPD::connect();
 
 # Retrieve the current play queue and target play queue.
-my $current = get_tracks_in_play_queue();
+MPD::run("tagtypes", "clear");
+my ($current, $idmap) = get_tracks_in_play_queue();
 my $target = get_playlist_files($ARGV[0]);
 
-mpd_exec("command_list_begin");
+my $end_position = (keys %$current);
+my $num_added = 0;
+my $add_start;
+
+sub load_tracks($) {
+	my ($seq) = @_;
+
+	my $start = $add_start // $seq;
+	my $end = $seq+1;
+
+	my $add_position = $end_position;
+	MPD::exec("load", $ARGV[0], "$start:$end");
+	$end_position += $end - $start;
+	MPD::exec("move", "$add_position:$end_position", "$start")
+		if ($add_position != $start);
+
+	undef $add_start;
+}
+
+MPD::exec("command_list_begin");
 for (my $i = 0; $i < @$target; $i++) {
 	my $f = $target->[$i];
-	my $ids = $current->{$f}->{Id};
-
-	my $id = (keys %$ids)[0];
-	delete $ids->{$id};
+	my $id = shift @{ $current->{$f} };
 
-	# Remove tracks with no unused queue IDs
-	delete $current->{$f} unless (keys %$ids > 0);
+	load_tracks($i - 1) if (defined $id and defined $add_start);
 
 	if (defined $id) {
-		mpd_exec("moveid", $id, $i);
+		# Try not to move tracks already in the right place.
+		MPD::exec("moveid", $id, $i)
+			if ($i != $idmap->{$id} + $num_added);
 	} else {
-		mpd_exec("addid", $f, $i);
+		$add_start //= $i;
+		$num_added++;
 	}
 }
 
-# Remove any tracks left from the old play queue.
-foreach (keys %$current) {
-	my $ids = $current->{$_}->{Id};
-	foreach (keys %$ids) {
-		mpd_exec("deleteid", $_);
-	}
-}
+# Now all unwanted tracks from the original playqueue have been moved to the
+# end and can be deleted all at once.
 
-mpd_exec("command_list_end");
-while (<$sock>) {
-	last if /^OK$/;
-	die($_) if /^ACK/;
-}
+my $pos = $add_start // @$target;
+MPD::exec("delete", $pos . ":") if map { @$_ } values %$current;
+MPD::exec("load", $ARGV[0], "$add_start:") if defined $add_start;
+MPD::run("command_list_end");