#!/usr/bin/perl

use warnings;
use strict;
use File::Spec;
use File::Temp;
use Audio::MPD q{0.19.0};
use MpdToys;
use Encode;

=head1 NAME

vipl - edit mpd playlist

=head1 SYNOPSIS

B<vipl> [host]

=head1 DESCRIPTION

vipl allows editing the mpd playlist using your text editor. The current
playlist will be brought up in the editor. Delete or rearrange songs as
desired using the editor. 

You can also enter the name of a playlist, or part of the name of an
album, artist, or song. Matching items will be added to the playlist.
Streaming urls can also be entered.

(If the perl String::Approx module is available, it will be used to handle
typos, etc in the names you enter.)

The currently playing song is marked with a ">" at the front. To change
which song is playing, just move the ">" to a different song.

If the hostname is omitted, the MPD_HOST environment variable will be used.

=head1 AUTHOR

Copyright 2008 by Joey Hess <joey@kitenet.net>

Licensed under the GNU GPL.

=cut

if (@ARGV) {
	$ENV{MPD_HOST}=shift;
}
my $mpd=Audio::MPD->new(conntype => "reuse");
my $current=$mpd->current;
my $pl=$mpd->playlist;
my %names=map { $_->as_string => $_ } $pl->as_items;
my @origlist=$pl->as_items;

my $tmp=File::Temp->new(TEMPLATE => "plXXXXX", DIR => File::Spec->tmpdir);
open (OUT, ">".$tmp->filename) || die "$0: cannot create ".$tmp->filename.": $!\n";
foreach my $song (@origlist) {
	print OUT ">" if defined $current && $song->id eq $current->id;
	print OUT encode_utf8($song->as_string);
	print OUT "\n";
}
close OUT || die "$0: cannot write ".$tmp->filename.": $!\n";

my @editor="vi";
if (-x "/usr/bin/editor") {
	@editor="/usr/bin/editor";
}
if (exists $ENV{EDITOR}) {
	@editor=split(' ', $ENV{EDITOR});
}
if (exists $ENV{VISUAL}) {
	@editor=split(' ', $ENV{VISUAL});
}
my $ret=system(@editor, $tmp);
if ($ret != 0) {
	die "@editor exited nonzero, aborting\n";
}

my $changed=0;
my @list;
open (IN, "<".$tmp->filename) || die "$0: cannot read ".$tmp->filename.": $!\n";
my $playing;
my $num=0;
while (<IN>) {
	chomp;
	$_=decode_utf8($_);
	
	if (s/^>\s*//) {
		$playing=$num;
	}

	if (exists $names{$_}) {
		push @list, $names{$_};
		if (! $changed && !($origlist[$#list] &&
		    $names{$_}->file eq $origlist[$#list]->file)) {
			$changed=1;
		}
		$num++;
	}
	else {
		next if /^\s*$/;

		my @matches=MpdToys::findmatchingsongs($_, $mpd);
		if (! @matches && MpdToys::canmatch_fuzzy()) {
			@matches=MpdToys::findmatchingsongs_fuzzy($_, $mpd);
		}

		if (! @matches) {
			print STDERR "$0: no matches for \"$_\"\n";
		}
		else {
			foreach (@matches) {
				push @list, $_;
			}
			$changed=1;
			$num+=@matches;
		}
	}
}
close IN;
if ($#list != $#origlist) {
	$changed=1;
}

if (! $changed) {
	# yay for optimisation!
}
elsif ($current && grep { $_->file eq $current->file } @list) {
	# Avoid touching the currently playing song, while changing
	# the playlist around it.
	$pl->crop;
	my $pos=0;
	my $past=0;
	foreach my $song (@list) {
		if (! $past && $song->file eq $current->file) {
			$past=1;
			# move current song into right location
			$pl->move(0, $pos);
		}
		else {
			$pl->add($song->file);
		}
		$pos++;
	}
	$mpd->play if @list;
}
else {
	$pl->clear;
	foreach my $song (@list) {
		$pl->add($song->file);
	}
}

if (defined $playing) {
	if (! defined $mpd->status->song || $playing ne $mpd->status->song ||
	    $mpd->status->state ne 'play') {
		$mpd->play($playing);
	}
}
else {
	$mpd->play(0) if @list;
}