PWC 103, Task #2 solution

3 files changed, 251 insertions, 0 deletions

diff --git a/challenge-103/bob-lied/perl/ch-2.pl b/challenge-103/bob-lied/perl/ch-2.pl
new file mode 100755
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+++ b/challenge-103/bob-lied/perl/ch-2.pl
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+#!/usr/bin/env perl
+# vim:set ts=4 sw=4 sts=4 et ai wm=0 nu:
+#=============================================================================
+# ch-2.pl
+#=============================================================================
+# Copyright (c) 2021, Bob Lied
+#=============================================================================
+# Perl Weekly Challeng 103, Task #2, What's playing?
+#
+# Working from home, you decided that on occasion you wanted some background
+# noise while working. You threw together a network streamer to continuously
+# loop through the files and launched it in a tmux (or screen) session, giving
+# it a directory tree of files to play. During the day, you connected an audio
+# player to the stream, listening through the workday, closing it when done.
+#
+# For weeks you connect to the stream daily, slowly noticing a gradual drift
+# of the media. After several weeks, you take vacation. When you return, you
+# are pleasantly surprised to find the streamer still running. Before
+# connecting, however, if you consider the puzzle of determining which track
+# is playing.
+#
+# After looking at a few modules to read info regarding the media, a quick bit
+# of coding gave you a file list. The file list is in a simple CSV format,
+# each line containing two fields: the first the number of milliseconds in
+# length, the latter the media’s title
+#
+# For this script, you can assume to be provided the following information:
+#    * the value of $^T ($BASETIME) of the streamer script,
+#    * the value of time(), and
+#    * a CSV file containing the media to play consisting of the length in
+#      milliseconds and an identifier for the media (title, filename, or other).
+#
+# Write a program to output which file is currently playing. For purposes of
+# this script, you may assume gapless playback, and format the output as you
+# see fit.
+# Optional: Also display the current position in the media as a time-like value.
+#
+# Example: Input starttime   currenttime  filelist.csv
+#                1606134123  1614591276   episode.csv
+# Output:
+# "Les Miserables Episode 1: The Bishop (broadcast date: 1937-07-23)"
+# 00:10:24
+# 
+#=============================================================================
+
+use strict;
+use warnings;
+use v5.32;
+
+use experimental qw/signatures/;
+no warnings qw/experimental::signatures/;
+
+use Getopt::Long;
+my $verbose = 0;
+my $doTest = 0;
+
+use FindBin qw($Bin);
+use lib "$FindBin::Bin";
+use lib "$FindBin::Bin/lib";
+
+# Using this as an excuse to use Moo
+use PlayList;
+
+GetOptions("test" => \$doTest, "verbose" => \$verbose);
+
+exit(!runTest()) if $doTest;
+
+sub Usage() { "Usage: $0 startTS endTS file.csv" }
+
+my $startTS = shift;
+my $endTS   = shift;
+my $file    = shift;
+die Usage() unless defined $startTS && defined $endTS && defined $file;
+die Usage(), " start > end" if $startTS > $endTS;
+
+my $playList = PlayList->new( fileName  => $file );
+use Data::Dumper;
+# say Dumper($playList);
+
+# Because the time is in seconds and track time is in millisconds, there's
+# a possibility that we could switch tracks in that second.  Specifications
+# are ambiguous, so do the simplest that works -- use the start of the second.
+my $playTime = ($endTS - $startTS) * 1000; # In milliseconds
+
+my ($track, $timeIntoTrack, $timeIntoCycle) = $playList->playingAt($playTime);
+# time is in millisconds
+
+# Turn a time in milliseconds into format "HH:MM:SS", dropping fractional seconds.
+sub posFormat($pos)
+{
+    use integer;
+    my ($hours, $minutes, $seconds) = (0, 0, 0);
+    $pos /= 1000; # Now in seconds
+    $hours = $pos / 3600;
+    $pos %= 3600;
+    $minutes = $pos / 60;
+    $seconds = $pos % 60;
+
+    return sprintf("%02d:%02d:%02d", $hours, $minutes, $seconds);
+}
+
+say $track;
+say posFormat($timeIntoTrack), " in episode";
+say posFormat($timeIntoCycle), " in cycle of ", posFormat($playList->length);
+
+sub runTest()
+{
+    use Test::More;
+
+    my $pl = PlayList->new(fileName => "episode.csv");
+    is( $pl->length(), 11910604, "Total length");
+
+    my ($track, $songTime, $cycleTime) = $pl->playingAt(0);
+    is( $track, "Les Miserables Episode 1: The Bishop (broadcast date: 1937-07-23)", , "track at 0 ms");
+    is( posFormat($songTime), "00:00:00", "Time at 0 ms");
+    is( posFormat($cycleTime), "00:00:00", "Cycle at 0 ms");
+
+    ($track, $songTime, $cycleTime) = $pl->playingAt(1);
+    is( $track, "Les Miserables Episode 1: The Bishop (broadcast date: 1937-07-23)", , "track at 1 ms");
+    is( posFormat($songTime), "00:00:00", "Time at 1 ms");
+    is( posFormat($cycleTime), "00:00:00", "Cycle at 1 ms");
+
+    ($track, $songTime, $cycleTime) = $pl->playingAt(1000);
+    is( $track, "Les Miserables Episode 1: The Bishop (broadcast date: 1937-07-23)", , "track at 1 sec");
+    is( posFormat($songTime), "00:00:01", "Time at 1 sec");
+    is( posFormat($cycleTime), "00:00:01", "Cycle at 1 sec");
+
+    ($track, $songTime, $cycleTime) = $pl->playingAt(1709000);
+    is( $track, "Les Miserables Episode 1: The Bishop (broadcast date: 1937-07-23)", , "track at 1709 sec");
+    is( posFormat($songTime), "00:28:29", "Time at 1709 sec");
+    is( posFormat($cycleTime), "00:28:29", "Cycle at 1 sec");
+
+    ($track, $songTime, $cycleTime) = $pl->playingAt(1709362);
+    is( $track, "Les Miserables Episode 1: The Bishop (broadcast date: 1937-07-23)", , "track at 1709.362 sec");
+    is( posFormat($songTime), "00:28:29", "Time at 1709.362 sec");
+
+    ($track, $songTime, $cycleTime) = $pl->playingAt(1709363);
+    is( $track, "Les Miserables Episode 2: Javert (broadcast date: 1937-07-30)", , "track at 1709.363 sec");
+    is( posFormat($songTime), "00:00:00", "Time at 1710 sec");
+
+    ($track, $songTime, $cycleTime) = $pl->playingAt(1709363);
+    is( $track, "Les Miserables Episode 2: Javert (broadcast date: 1937-07-30)", , "track at 1709.363 sec");
+    is( posFormat($songTime), "00:00:00", "Time at 1709.363 sec");
+
+    ($track, $songTime, $cycleTime) = $pl->playingAt(1800000);
+    is( $track, "Les Miserables Episode 2: Javert (broadcast date: 1937-07-30)", , "track at 1800 sec");
+    is( posFormat($songTime), "00:01:30", "Time at 1800 sec");
+
+    ($track, $songTime, $cycleTime) = $pl->playingAt(24*3600*1000);
+    is( $track, "Les Miserables Episode 2: Javert (broadcast date: 1937-07-30)", , "track at 1 day");
+    is( posFormat($songTime), "00:21:56", "Time at 1 day");
+    is( posFormat($cycleTime), "00:50:25", "Cycle at 1 day");
+
+    ($track, $songTime, $cycleTime) = $pl->playingAt(30*24*3600*1000);
+    is( $track, "Les Miserables Episode 5: The Grave (broadcast date: 1937-08-20)", , "track at 30 day");
+    is( posFormat($songTime), "00:09:23", "Time at 30 day");
+    is( posFormat($cycleTime), "02:03:18", "Cycle at 30 day");
+
+    done_testing;
+}
diff --git a/challenge-103/bob-lied/perl/episode.csv b/challenge-103/bob-lied/perl/episode.csv
new file mode 100644
index 0000000000..9428b93004
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+++ b/challenge-103/bob-lied/perl/episode.csv
@@ -0,0 +1,7 @@
+1709363,"Les Miserables Episode 1: The Bishop (broadcast date: 1937-07-23)"
+1723781,"Les Miserables Episode 2: Javert (broadcast date: 1937-07-30)"
+1723781,"Les Miserables Episode 3: The Trial (broadcast date: 1937-08-06)"
+1678356,"Les Miserables Episode 4: Cosette (broadcast date: 1937-08-13)"
+1646043,"Les Miserables Episode 5: The Grave (broadcast date: 1937-08-20)"
+1714640,"Les Miserables Episode 6: The Barricade (broadcast date: 1937-08-27)"
+1714640,"Les Miserables Episode 7: Conclusion (broadcast date: 1937-09-03)"
diff --git a/challenge-103/bob-lied/perl/lib/PlayList.pm b/challenge-103/bob-lied/perl/lib/PlayList.pm
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index 0000000000..3ee27cb770
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+++ b/challenge-103/bob-lied/perl/lib/PlayList.pm
@@ -0,0 +1,84 @@
+# vim:set ts=4 sw=4 sts=4 et ai wm=0 nu:
+#=============================================================================
+# PlayList.pm
+#=============================================================================
+# Copyright (c) 2021, Bob Lied
+#=============================================================================
+
+use strict;
+use warnings;
+use v5.32;
+
+no warnings qw/experimental::signatures/;
+use feature qw/signatures/;
+
+
+package PlayList;
+{
+    use Moo;
+    use Carp qw/confess/;
+    use Data::Dumper;
+
+    has fileName => (
+        is  => 'ro',
+        required => 1,
+        isa => sub { my $f = shift;
+            -r $f || confess "Can't read file $f: $!" },
+    );
+
+    has list => (
+        is => 'rw',
+        default => sub { [] },
+    );
+
+    has length => (
+        is => 'rw',
+        default => 0,
+    );
+
+no warnings qw/experimental::signatures/;
+    sub BUILD($self, $args)
+    {
+        $self->_loadFile();
+        $self->_calcLength();
+    }
+
+no warnings qw/experimental::signatures/;
+    sub _loadFile($self)
+    {
+        use Text::CSV qw/csv/;
+
+        $self->list( csv(in => $self->fileName, headers => [ qw(time title) ]) );
+
+    }
+
+    no warnings qw/experimental::signatures/;
+    sub _calcLength($self)
+    {
+        my $len = 0;
+        for my $track ( $self->list->@* )
+        {
+            $len += $track->{time};
+        }
+        $self->length($len);
+    }
+
+    sub playingAt($self, $cycleTime)
+    {
+        my $len = 0;
+        $cycleTime %= $self->length;
+        for my $track ( $self->list->@* )
+        {
+            if ( $cycleTime >= $len && $cycleTime < $len + $track->{time} )
+            {
+                my $trackTitle = $track->{title};
+                my $intoTrack = $cycleTime - $len;
+
+                return ( $trackTitle, $intoTrack, $cycleTime);
+            }
+            $len += $track->{time};
+        }
+    }
+}
+
+1;