Basic options for build_playlists

1 files changed, 59 insertions, 2 deletions

diff --git a/build_playlists.plx b/build_playlists.plx
index 433c0a1..dd8ec9d 100755
--- a/build_playlists.plx
+++ b/build_playlists.plx
@@ -9,15 +9,22 @@ require "./shared.pl";
 
 # Variables to be set by the user
 our $dbname = File::HomeDir->my_home . "/Music/library.db";
-our $output_dir; # By default, output in current directory
 our $table_name = "LIBRARY";
+our @tags_of_interest; # Record TAG arguments
+our $output_pattern;   # Record OUTPUT_PATTERN argument
+our $statement_arg;    # Record SQL_STATEMENT argument
+
+# Keep track of options that have been set
+our %options = (
+	sql => 0
+);
 
 my $statement; #Hold statements for sqlite
 
 
 # Write to an m3u file to create a playlist
 # 	@_[0] -> m3u file path
-# 	@_[1] -> array of file paths
+# 	@_[1] -> array of audio file paths
 sub append_to_m3u {
 	open FH, ">> $_[0]" or die $!;
 
@@ -28,6 +35,56 @@ sub append_to_m3u {
 	close FH;
 }
 
+# Print a help message
+sub print_help {
+	print
+"Usage:
+  $0 [OPTION]... TAG [OUTPUT_PATTERN]
+  $0 [OPTION]... --sql SQL_STATEMENT [OUTPUT]
+
+Generate m3u playlist(s) for audio files in a database (by default ~/Music/library.db).
+Playlists can be generated based on columns (TAGs) in the database or based on a SQL statement output.
+Multiple tags can be specified. They must be comma-separated.
+If tags are specified, an output pattern can also be specified (see Examples).
+
+Options:
+  -h, --help			display this help and exit
+      --sql SQL_STATEMENT	generate a single playlist based on output of some SQL statement
+
+Examples:
+  $0 ALBUM,ALBUMARTIST ~/Music/playlists/{ALBUMARTIST}-{ALBUM}.m3u			Generate a playlist for every combination of ALBUM and ALBUMARTIST in the database, with the output file pattern ALBUMARTIST-ALBUM.m3u
+  $0 --sql \"SELECT PATH FROM LIBRARY WHERE ARTIST='Steely Dan';\" steely_dan.m3u	Generate a playlist based on the output of this SQL statement
+  $0 --sql \"ARTIST='Steely Dan';\" steely_dan.m3u					If an incomplete SQL statement is received, the \"SELECT PATH FROM LIBRARY WHERE \" part of the SQL statement is assumed to be implied
+";
+}
+
+
+# parse flags and arguments
+for (my $i = 0; $i <= $#ARGV; $i++){
+	if ($ARGV[$i] =~ /-h|--help/){
+		print_help();
+		exit;
+	}
+
+	elsif ($ARGV[$i] =~ /--sql/){
+		$i++;
+		$statement_arg = "$ARGV[$i]";
+		$options{sql} = 1;
+	}
+
+	elsif ($ARGV[$i] =~ /^[^-]/){
+		# This arg should contain the list of tags
+		if (!$options{sql} and !scalar(@tags_of_interest)){
+			@tags_of_interest = split(',', "$ARGV[$i]");
+		}
+		# This arg should contain the output_pattern
+		else {
+			$output_pattern = "$ARGV[$i]";
+			last;
+		}
+	}
+}
+
 my $dbh = DBI->connect("DBI:SQLite:dbname=$dbname", "", "", { RaiseError => 1}) or die $DBI::errstr;
 # DEBUG
 print "Opened database successfully\n";