#!/usr/bin/perl -w

# "Shepherd"

my $version = '0.2.6';

# A wrapper for various Aussie TV guide data grabbers
#
# Use --help for command-line options.
# See shepherd.txt for details.
#
#  A current version of this script, plus a README file, might be here:
#  http://www.whuffy.com/tv_grab_au/
#
# Changelog:
# 0.1.0   : Basic self-updating and grabber management
# 0.2.0   : --configure
# 0.2.1   : Has a home in ~/.shepherd/
# 0.2.2   : --check
# 0.2.3   : Bugfix: archives correctly
# 0.2.5   : multi-grabber (potentially with partial data)
# 0.2.6   : postprocessor support
#
# ToDo:
# * Make it check compilation after installing by calling --version or
#   --desc or --ready
# * --ready  option that says whether config is required?

BEGIN { *CORE::GLOBAL::die = \&my_die; }
use strict;
use LWP::Simple;
use Sort::Versions;
use Cwd;
use Getopt::Long;
use Data::Dumper;
use XMLTV;
use XMLTV::Ask;
use DateTime::Format::Strptime;
use POSIX qw(strftime);
use Time::HiRes qw(gettimeofday tv_interval);

# ---------------------------------------------------------------------------
# --- Global Variables
# ---------------------------------------------------------------------------

my $progname = 'shepherd';

my $HOME = 'http://www.whuffy.com';

my $invoked = Cwd::realpath($0);

# By default, Shepherd runs from ~/.shepherd/. If it's not run as a user,
# it will try /opt/shepherd/ instead.
my $CWD = ($ENV{HOME} ? $ENV{HOME} . "/." : "/opt/") . $progname;
-d $CWD or mkdir $CWD or die "Cannot create directory $CWD: $!";
chdir($CWD);

my $GRABBER_DIR = "$CWD/grabbers";
my $POSTPROCESSOR_DIR = "$CWD/postprocessors";
my $ARCHIVE_DIR = "$CWD/archive";

my $timeslot_size = (15 * 60); 			# 15 minute slots
my $channel_ok_threshold_percent = 90;		# 90% these may need to be tweaked but look ok for now
my $postprocessor_ok_threshold_percent = 80;	# 80% these may need to be tweaked but look ok for now
my $postprocessor_disable_failure_threshold = 5; # number of times a postprocessor has to fail in a row before it is automatically disabled

my $opt;
my $pref_order;
my $mirror_site;
my $made_changes = 0;
my $debug = 1;
my $grabbers = { };
my $postprocessors = { };
my $preferred; # obsolete but may still exist in shepherd.conf
my $region;
my $channels;
my $config_file =   "$CWD/$progname.conf";
my $channels_file = "$CWD/channels.conf";
my $days;

# postprocessing
my $langs = [ 'en' ];
my $num_timeslots;
my $plugin_data = { };
my $channel_data = { };
my $starttime, my $endtime;
my $input_postprocess_files = "";
my $insufficient_grabber_data = 0;

# ---------------------------------------------------------------------------
# --- Setup
# ---------------------------------------------------------------------------

print ucfirst($progname) . " v$version\n\n";
#print "Cwd: $CWD.\n";

# Any options Shepherd doesn't understand, we'll pass to the grabber(s)
Getopt::Long::Configure(qw/pass_through/);

get_initial_command_line_options();

help() if ($opt->{help});

unless ($opt->{configure})
{
    read_config_file();
    read_channels_file();
}

get_remaining_command_line_options();

if ($opt->{status})
{
    status();
    exit;
}

if ($opt->{show_config})
{
    show_config();
    exit;
}

if ($opt->{enable})
{
    enable($opt->{enable});
}

if ($opt->{disable})
{
    disable($opt->{disable});
}

&set_order(0,$opt->{setorder}) if ($opt->{setorder});
&check() if ($opt->{check});

if ($opt->{enable} or $opt->{disable} or $opt->{setorder} or $opt->{check} or $opt->{mirror})
{
    set_order(1) if $made_changes;
    write_config_file() if $made_changes;
    status();
    exit;
}

# ---------------------------------------------------------------------------
# --- Update
# ---------------------------------------------------------------------------

unless ($opt->{noupdate})
{
    update($progname, $version);
    set_order(1) if $made_changes;
    write_config_file() if (($made_changes) && (! $opt->{configure}))
}

if ($opt->{configure})
{
    configure();
}

# ---------------------------------------------------------------------------
# --- Go!
# ---------------------------------------------------------------------------

unless ($opt->{update})
{
    calc_date_range();
    grab_data();
    postprocess_data();
    output_data();
}

print "Done.\n";

status();
write_config_file();

# ---------------------------------------------------------------------------
# --- Subroutines
# ---------------------------------------------------------------------------

# -----------------------------------------
# Subs: Grabbing
# -----------------------------------------

sub grab_data
{
    my $used_grabbers = 0;
    my $need_more_data = 1;

    printf "\nGrabber stage:\n";

    # iterate across grabbers until we have all our data we want (or need)
    foreach my $grabber (sort { $grabbers->{$a}->{order} <=> $grabbers->{$b}->{order} } keys %$grabbers) {
	next if ($grabbers->{$grabber}->{disabled});
	$used_grabbers++;

	$grabbers->{$grabber}->{lastdata} = time;
	$grabbers->{$grabber}->{laststatus} = "unknown";

	printf "\nSHEPHERD: Using grabber: (%d) %s\n",$grabbers->{$grabber}->{order},$grabber;

	my $output = "$GRABBER_DIR/$grabber/output.xmltv";
	$input_postprocess_files .= "$output ";

	my $comm = "$GRABBER_DIR/$grabber/$grabber " .
	           "--region $region " .
	           "--channels_file $channels_file " .
	           "--output $output";

	# NOTE: ideally a grabber could be instructed to fetch partial data through --channel, --starttime & --endtime
	# we don't have that for now so instead whenever there is missing data, ALL 7 days for all channels will be collected
	# FIXME FUTURE: call grabbers just with what we want...
	$comm .= " --days $days" if ($days);
	$comm .= " --offset $opt->{offset}" if ($opt->{offset});
	$comm .= " --debug" if ($debug);
	$comm .= " @ARGV" if (@ARGV);
	print "SHEPHERD: Excuting command: $comm\n";

	chdir "$GRABBER_DIR/$grabber/";
	system($comm);
	chdir $CWD;

	# soak up the data we just collected
	&soak_up_data($grabber, $output, "grabber");
	$grabbers->{$grabber}->{laststatus} = $plugin_data->{$grabber}->{laststatus};

	# check to see if we have all the data we want
	$need_more_data = &analyze_plugin_data($channel_ok_threshold_percent, "AGGREGATE GRABBER");

	last if (!$need_more_data);
    }


    if ($used_grabbers == 0)
    {
	print "No valid grabbers installed/enabled!\n";
	return;
    }

    if ($need_more_data)
    {
	print "SHEPHERD: Ran through ALL grabbers but still missing data!!! :(\n";
	$insufficient_grabber_data = 1;
	return;
    }
}


# interpret xmltv data from this grabber/postprocessor
sub soak_up_data
{
    my ($plugin, $output, $plugintype) = @_;

    if (! -r $output) {
	printf "SHEPHERD: Warning: plugin '%s' output file '%s' does not exist\n",$plugin,$output;
	return;
    }

    my $parse_start_time = [gettimeofday];
    printf STDERR "SHEPHERD: Started parsing XMLTV from '%s' in '%s' .. any errors below are from parser:\n",$plugin,$output;
    eval { $plugin_data->{$plugin}->{xmltv} = XMLTV::parsefiles($output); };
    printf STDERR "SHEPHERD: Completed XMLTV parsing from '%s' in %0.2f seconds\n",$plugin,tv_interval($parse_start_time);

    if (defined $plugin_data->{$plugin}->{xmltv}) {
	$plugin_data->{$plugin}->{valid} = 1;

	my $xmltv = $plugin_data->{$plugin}->{xmltv};
	my ($encoding, $credits, $chan, $progs) = @$xmltv;
	$plugin_data->{$plugin}->{total_duration} = 0;
	$plugin_data->{$plugin}->{programmes} = 0;

	my $strptime = new DateTime::Format::Strptime( pattern => "%Y%m%d%H%M %z");
	my $seen_channels_with_data = 0;

	# iterate thru channels
	foreach my $ch (sort keys %{$channels}) {
	    my $seen_progs_on_this_channel = 0;

	    # iterate thru programmes per channel
	    foreach my $prog (@$progs) {
		next if ($prog->{channel} ne $channels->{$ch});

		my $t1 = $strptime->parse_datetime($prog->{start});
		my $t2 = $strptime->parse_datetime($prog->{stop});
		next if (!$t1 || !$t2); # if we can't parse stop/start then clearly THIS data is bunk!

		# store plugin-specific stats
		$plugin_data->{$plugin}->{programmes}++;
		$plugin_data->{$plugin}->{total_duration} += ($t2->epoch - $t1->epoch);
		$seen_progs_on_this_channel++;
		$plugin_data->{$plugin}->{earliest_data_seen} = $t1->epoch if (!defined $plugin_data->{$plugin}->{earliest_data_seen});
		$plugin_data->{$plugin}->{earliest_data_seen} = $t1->epoch if ($t1->epoch < $plugin_data->{$plugin}->{earliest_data_seen});
		$plugin_data->{$plugin}->{latest_data_seen} = $t2->epoch if (!defined $plugin_data->{$plugin}->{latest_data_seen});
		$plugin_data->{$plugin}->{latest_data_seen} = $t2->epoch if ($t2->epoch > $plugin_data->{$plugin}->{latest_data_seen});

		# store channel-specific stats
		$channel_data->{$ch}->{programmes}++;
		$channel_data->{$ch}->{total_duration} += ($t2->epoch - $t1->epoch);

		# store timeslot info
		next if ($t1->epoch > $endtime);	# programme starts after timeslots we are interested .. nice that we have it ... but we really don't care about it!
		next if ($t2->epoch < $starttime);	# programme ends  before timeslots we are interested .. nice that we have it ... but we really don't care about it!
		my $start_slotnum;
		if ($t1->epoch >= $starttime) {
		    $start_slotnum = int(($t1->epoch - $starttime) / $timeslot_size);
		} else {
		    $start_slotnum = 0;
		}
		my $end_slotnum;
		if ($t2->epoch < $endtime) {
		    $end_slotnum = int(($t2->epoch - $starttime) / $timeslot_size);
		} else {
		    $end_slotnum = ($num_timeslots-1);
		}

		# add this programme into the global timeslots table for this channel
		foreach my $slotnum ($start_slotnum..$end_slotnum) {
		    $channel_data->{$ch}->{timeslots}[$slotnum]++;
		}
	    }

	    $seen_channels_with_data++ if ($seen_progs_on_this_channel > 0);
	}

	# print some stats about what we saw!
	printf "SHEPHERD: %s '%s' returned data for %d channels, %d programmes, %dd%02dh%02dm%02ds duration, %s%s\n",
	    ucfirst($plugintype), $plugin, $seen_channels_with_data, $plugin_data->{$plugin}->{programmes},
	    int($plugin_data->{$plugin}->{total_duration} / 86400),		# days
	    int(($plugin_data->{$plugin}->{total_duration} % 86400) / 3600),	# hours
	    int(($plugin_data->{$plugin}->{total_duration} % 3600) / 60),	# mins
	    int($plugin_data->{$plugin}->{total_duration} % 60),		# sec
	    (defined $plugin_data->{$plugin}->{earliest_data_seen} ? (strftime "%a %e %b %H:%M - ", localtime($plugin_data->{$plugin}->{earliest_data_seen})) : 'no data'),
	    (defined $plugin_data->{$plugin}->{latest_data_seen} ? (strftime "%a %e %b %H:%M", localtime($plugin_data->{$plugin}->{latest_data_seen})) : '');
	$plugin_data->{$plugin}->{laststatus} = sprintf "%dch/%dpr/%dhrs %s-%s",
	    $seen_channels_with_data, $plugin_data->{$plugin}->{programmes},
	    int($plugin_data->{$plugin}->{total_duration} / 3600),
	    (defined $plugin_data->{$plugin}->{earliest_data_seen} ? (strftime "%a%d%b%H:%M", localtime($plugin_data->{$plugin}->{earliest_data_seen})) : 'no'),
	    (defined $plugin_data->{$plugin}->{latest_data_seen} ? (strftime "%a%d%b%H:%M", localtime($plugin_data->{$plugin}->{latest_data_seen})) : 'data');

    } else {
	printf "WARNING: Plugin %s didn't seem to return any valid XMLTV!\n",$plugin;
	delete $plugin_data->{$plugin}->{valid};
    }
}


# analyze grabber data - do we have all the data we want?
# returns 1 if we need more data, 0 if we have all we want
sub analyze_plugin_data
{
    my ($threshold,$analysistype) = @_;
    my $retval = 0; # until proven otherwise
    my $total_data_percent = 0, my $total_channels = 0;
    my $statusstring = "";

    # iterate across each channel
    foreach my $ch (sort keys %{$channels}) {
	$total_channels++;
	if (defined $channel_data->{$ch}) {
	    my $data_in_channel = 0;
	    for my $slotnum (0..($num_timeslots-1)) {
		$data_in_channel++ if ((defined $channel_data->{$ch}->{timeslots}[$slotnum]) && ($channel_data->{$ch}->{timeslots}[$slotnum] > 0));
	    }

	    # do we have enough data for this channel?
	    my $data_in_channel_percent = $data_in_channel / ($num_timeslots-1) * 100;
	    if ($data_in_channel_percent >= $threshold) {
		$statusstring .= sprintf "%s: %0.1f%% [complete], ",$ch,$data_in_channel_percent;
	    } else {
		$statusstring .= sprintf "%s: %0.1f%% [hungry], ",$ch,$data_in_channel_percent;
		$retval = 1;
	    }
	    $total_data_percent += $data_in_channel_percent;
	} else {
	    $statusstring .= sprintf "%s: 0%% [starving], ",$ch;
	    $retval = 1;
	}
    }

    if ($total_channels > 0) {
	$total_data_percent = $total_data_percent / $total_channels;
    } else {
	$total_data_percent = 0;
    }

    # print some stats about what our analysis says!
    printf "SHEPHERD: %s ANALYSIS: %sTOTAL %0.2f%% %s %0.2f%%: %s\n",
	uc($analysistype), $statusstring, $total_data_percent,
	($total_data_percent >= $channel_ok_threshold_percent ? ">" : "<"), $channel_ok_threshold_percent,
	($retval ? "WANT MORE DATA" : "COMPLETE");
    return $retval;
}


# work out date range we are expecting data to be in
sub calc_date_range
{
    # normalize starttime to beginning of hour
    my $now = time;
    my ($sec,$min,@rest) = localtime($now);

    $starttime = $now - ((60 * $min) + $sec);

    if ($days) {
	$endtime = $starttime + ($days * 86400);
    } else {
	$endtime = $starttime + (7*86400);
    }
    $starttime += (86400 * $opt->{offset}) if ($opt->{offset});

    $num_timeslots = ($endtime - $starttime) / $timeslot_size;
}

# -----------------------------------------
# Subs: Postprocessing
# -----------------------------------------

sub postprocess_data
{
    # for our first postprocessor, we feed it ALL of the XMLTV files we have
    # as each postprocessor runs, we feed in the output from the previous one
    # Shepherd checks the "completeness" of the data that comes out of a postprocessor & automatically
    # reverts back to the previous postprocessor if it was shown to be bad

    # first time around: feed in $input_postprocess_files
    my $need_more_data;

    printf "\nPostprocessing stage:\n";

    foreach my $postprocessor (sort { $postprocessors->{$a} <=> $postprocessors->{$b} } keys %$postprocessors) {
	next if ($postprocessors->{$postprocessor}->{disabled});

	$postprocessors->{$postprocessor}->{lastdata} = time;
	$postprocessors->{$postprocessor}->{laststatus} = "unknown";

	printf "\nSHEPHERD: Using postprocessor: %s\n",$postprocessor;

	my $output = "$POSTPROCESSOR_DIR/$postprocessor/output.xmltv";
	my $comm = "$POSTPROCESSOR_DIR/$postprocessor/$postprocessor " .
	           "--region $region " .
	           "--channels_file $channels_file " .
	           "--output $output";
	$comm .= " --days $days" if ($days);
	$comm .= " --offset $opt->{offset}" if ($opt->{offset});
	$comm .= " --debug" if ($debug);
	$comm .= " @ARGV" if (@ARGV);
	$comm .= " $input_postprocess_files";
	print "SHEPHERD: Excuting command: $comm\n";

	chdir "$POSTPROCESSOR_DIR/$postprocessor/";
	system($comm);
	chdir $CWD;

	#
	# soak up the data we just collected and check it
	# YES - these are the SAME routines we used in the previous 'grabber' phase
	# but the difference here is that we clear out our 'channel_data' beforehand
	# so we can independently analyze the impact of this postprocessor.
	# if it clearly returns bad data, don't use that data (go back one step) and
	# flag the postprocessor as having failed.  after 3 consecutive failures, disable it
	#

	# clear out channel_data
	foreach my $ch (keys %{$channels}) {
	    delete $channel_data->{$ch};
	}

	# process and analyze it!
	&soak_up_data($postprocessor, $output, "postprocessor");
	$need_more_data = &analyze_plugin_data($postprocessor_ok_threshold_percent, "POSTPROCESSOR");

	$postprocessors->{$postprocessor}->{laststatus} = $plugin_data->{$postprocessor}->{laststatus};

	if (($need_more_data) && (!$insufficient_grabber_data)) {
	    # urgh.  this postprocessor did a bad bad thing ...
	    printf "SHEPHERD: XML data from postprocessor %s rejected, using XML from previous stage\n",$postprocessor;

	    if (defined $postprocessors->{$postprocessor}->{conescutive_failures}) {
		$postprocessors->{$postprocessor}->{conescutive_failures}++;
	    } else {
		$postprocessors->{$postprocessor}->{conescutive_failures} = 1;
	    }
	    printf "SHEPHERD: Postprocessor \"%s\" has now failed %d times in a row.  %d more and it will be automatically disabled.\n",
		$postprocessor,
		$postprocessors->{$postprocessor}->{conescutive_failures},
		($postprocessor_disable_failure_threshold - $postprocessors->{$postprocessor}->{conescutive_failures});

	    if ($postprocessors->{$postprocessor}->{conescutive_failures} >= $postprocessor_disable_failure_threshold) {
		printf "SHEPHERD: Disabling Postprocessor \"%s\".\n",$postprocessor;
		$postprocessors->{$postprocessor}->{disabled} = 1;
	    }
	} else {
	    # accept what this postprocessor did to our output ...
	    printf "SHEPHERD: accepting output from postprocessor %s, feeding it into next stage\n",$postprocessor;
	    $input_postprocess_files = $output;
	    delete $postprocessors->{$postprocessor}->{conescutive_failures} if (defined $postprocessors->{$postprocessor}->{conescutive_failures});
	}
    }
}


sub output_data
{
    # $input_postprocess_files (hopefully just one file now) contains our final output
    # send it to whereever --output told us to!

    my $output_filename = "$CWD/output.xmltv";
    $output_filename = $opt->{output} if ($opt->{output});

    open(F,">$output_filename") || die "could not open output file $output_filename for writing: $!\n";

    foreach my $infile (split(/ /,$input_postprocess_files)) {
	if (!(open(INFILE,"<$infile"))) {
	    printf "WARNING: could not open input file \"%s\": %s\n", $infile, $!;
	    printf "Output XMLTV data may be damanged as a result!\n";
	} else {
	    while (<INFILE>) {
		print F $_ if ($opt->{output});
	    }
	    close(INFILE);
	}
    }
    close(F);

    printf "Final output stored in $output_filename.\n";
}

# -----------------------------------------
# Subs: Updates & Installations
# -----------------------------------------

sub update
{
    printf "\nChecking for updates:\n\n";

    my $data;
    my $sites = "";
    $sites = "$mirror_site," if ($mirror_site);
    $sites .= $HOME;

    foreach my $site (split(/,/,$sites)) {
	my $url = $site . "/status";
	print "Fetching status file: $url.\n";
	$data = LWP::Simple::get($url);
	last if $data;

	print "Failed to retrieve status file from $url.\n";
    }
    return if (!$data);

    my %glist = %$grabbers;
    my %plist = %$postprocessors;
    while ($data =~ /(.*):(.*):(.*)/g)
    {
	my ($proggy, $latestversion, $progtype) = ($1,$2,$3);
	update_component($proggy, $latestversion, $progtype);
	delete $glist{$proggy} if ($progtype eq "grabber");
	delete $plist{$proggy} if ($progtype eq "postprocessor");
    }

    # work out what grabbers disappeared (if any)
    foreach (keys %glist) {
	unless ($grabbers->{$_}->{disabled}) {
	    print "\nDeleted grabber: $_.\n";
	    disable($_,"grabber");
	    $made_changes = 1;
	}
    }

    # work out what postprocessors disappeared (if any)
    foreach (keys %plist) {
	unless ($postprocessors->{$_}->{disabled}) {
	    print "\nDeleted Postprocessor: $_.\n";
	    disable($_,"postprocessor");
	    $made_changes = 1;
	}
    }
}

sub update_component
{
    my ($proggy, $latestversion, $progtype) = @_;

    # handle new installs..
    if (($proggy eq $progname) && ($progtype eq "shepherd")) {
	# shepherd itself..
	if(! -e "$CWD/$progname") {
	    print "Missing: $CWD/$progname\n";
	    install($progname, $latestversion, $progtype);
	    return;
	}
    } elsif ($progtype eq "grabber") {
	if (!defined $grabbers->{$proggy} or ! -e "$GRABBER_DIR/$proggy/$proggy") {
	    print "New grabber: $proggy.\n";
	    install($proggy, $latestversion, $progtype);
	    return;
	}
	print "Warning: grabber $proggy disabled by config file.\n" if ($grabbers->{$proggy}->{disabled});
    } elsif ($progtype eq "postprocessor") {
	if (!defined $postprocessors->{$proggy} or ! -e "$POSTPROCESSOR_DIR/$proggy/$proggy") {
	    print "New postprocessor: $proggy.\n";
	    install($proggy, $latestversion, $progtype);
	    return;
	}
	print "Warning: postprocessor $proggy disabled by config file.\n" if ($postprocessors->{$proggy}->{disabled});
    }

    # upgrade/downgrades
    my $ver;
    if ($progtype eq "grabber") {
	$ver = ($proggy eq $progname ? $version : $grabbers->{$proggy}->{ver});
    } elsif ($progtype eq "postprocessor") {
	$ver = ($proggy eq $progname ? $version : $postprocessors->{$proggy}->{ver});
    } elsif (($proggy eq $progname) && ($progtype eq "shepherd")) {
	$ver = $version;
    } else {
	print "Warning: unknown type of programme: prog '$proggy' progtype '$progtype' not installed.\n";
	return;
    }

    my $result = versioncmp($ver, $latestversion);
    if ($result == -1) {
	print "Upgrading $proggy from v$ver to v$latestversion.\n";
    } elsif ($result == 1) {
	print "Downgrading $proggy from v$ver to v$latestversion.\n";
    } else {
	print "Already have latest version of $proggy: v$ver.\n";
	return;
    }
    install($proggy, $latestversion, $progtype);
}

sub install
{
    my ($proggy, $latestversion, $progtype) = @_;

    print "Downloading $proggy v$latestversion.\n";

    my $sites = "";
    $sites = "$mirror_site," if ($mirror_site);
    $sites .= $HOME;

    my $rdir = "";
    my $ldir = $CWD;
    my $ver = "unknown";

    if (($proggy eq $progname) && ($progtype eq "shepherd")) {
	$ver = $version;
    } elsif ($progtype eq "grabber") {
	$rdir = "grabbers";
	$ldir = "$GRABBER_DIR/$proggy";
	$ver = $grabbers->{$proggy}->{ver} if ((defined $grabbers->{$proggy}) && $grabbers->{$proggy}->{ver});
	-d $GRABBER_DIR or mkdir $GRABBER_DIR or die "Cannot create directory $GRABBER_DIR: $!";
    } elsif ($progtype eq "postprocessor") {
	$rdir = "postprocessors";
	$ldir = "$POSTPROCESSOR_DIR/$proggy";
	$ver = $postprocessors->{$proggy}->{ver} if ((defined $postprocessors->{$proggy}) && $postprocessors->{$proggy}->{ver});
	-d $POSTPROCESSOR_DIR or mkdir $POSTPROCESSOR_DIR or die "Cannot create directory $POSTPROCESSOR_DIR: $!";
    } else {
	print "Warning: unknown type of programme: prog '$proggy' progtype '$progtype' not installed.\n";
	return;
    }
    -d $ldir or mkdir $ldir or die "Cannot create directory $ldir: $!";

    my $newfile = "$ldir/$proggy-$latestversion";
    my $rc;

    foreach my $site (split(/,/,$sites)) {
	printf "Fetching $site/$rdir/$proggy-$latestversion.\n";
	$rc = LWP::Simple::getstore("$site/$rdir/$proggy-$latestversion", $newfile);
	last if (is_success($rc));

	print "Failed to retrieve $site/$rdir/$proggy-$latestversion.\n";
    }
    return if (!is_success($rc));

    # Make it executable
    system('chmod u+x ' . $newfile);

    -d $ARCHIVE_DIR or mkdir $ARCHIVE_DIR or die "Cannot create directory $ARCHIVE_DIR: $!";

    if (-e "$ldir/$proggy")
    {
	rename("$ldir/$proggy", "$ARCHIVE_DIR/$proggy-$ver");
    }
    rename($newfile, "$ldir/$proggy");
    
    print "Installed $proggy v$latestversion.\n" if ($debug);

    # if the update was for shepherd itself, restart it
    if (($proggy eq $progname) && ($progtype eq "shepherd")) {
	print "\n*** Restarting ***\n\n";
	exec("$ldir/$proggy");
	# This exits.
    }

    print "Testing $proggy...\n" if ($debug);
    my $result = test_proggy($ldir,"$ldir/$proggy");

    if ($progtype eq "grabber") {
	$grabbers->{$proggy}->{ver} = $latestversion;
	$grabbers->{$proggy}->{ready} = $result;
	$grabbers->{$proggy}->{laststatus} = sprintf "updated to %s on %s", $latestversion, (strftime "%a%d%b%y",localtime(time));
    } elsif ($progtype eq "postprocessor") {
	$postprocessors->{$proggy}->{ver} = $latestversion;
	$postprocessors->{$proggy}->{ready} = $result;
	$postprocessors->{$proggy}->{laststatus} = sprintf "updated to %s on %s", $latestversion, (strftime "%a%d%b%y",localtime(time));
    }

    $made_changes = 1;
}

sub test_proggy
{
    my ($testdir,$proggyexec) = @_;

    chdir($testdir);
    system("$proggyexec --ready");
    chdir ($CWD);

    my $result = $?;
    print "Return value: $result\n" if ($debug);

    print "\nprogramme $proggyexec did not exit cleanly!\n" .
	 "It may require configuration.\n\n" if ($result);
    return !$result;
}

sub enable
{
    my $proggy = shift;

    # confirm it exists first
    if ((!$grabbers->{$proggy}) && (!$postprocessors->{$proggy})) {
	printf "No such grabber/postprocessor: \"%s\".\n",$proggy;
	return;
    }
    print "Enabling $proggy.\n";

    if ($grabbers->{$proggy}) {
	delete $grabbers->{$proggy}->{disabled};
	$grabbers->{$proggy}->{laststatus} = sprintf "enabled on %s, not run yet",(strftime "%a%d%b%y", localtime(time));
    } elsif ($postprocessors->{$proggy}) {
	delete $postprocessors->{$proggy}->{disabled};
	$postprocessors->{$proggy}->{laststatus} = sprintf "enabled on %s, not run yet",(strftime "%a%d%b%y", localtime(time));
    }
    $made_changes = 1;
}

sub disable
{
    my $proggy = shift;

    # confirm it exists first
    if ((!$grabbers->{$proggy}) && (!$postprocessors->{$proggy})) {
	printf "No such grabber/postprocessor: \"%s\".\n",$proggy;
	return;
    }
    print "Disabling $proggy.\n";

    if ($grabbers->{$proggy}) {
	$grabbers->{$proggy}->{disabled} = 1;
	$grabbers->{$proggy}->{laststatus} = sprintf "manually disabled on %s",(strftime "%a%d%b%y", localtime(time));
    } elsif ($postprocessors->{$proggy}) {
	$postprocessors->{$proggy}->{disabled} = 1;
	$postprocessors->{$proggy}->{laststatus} = sprintf "manually disabled on %s",(strftime "%a%d%b%y", localtime(time));
    }
    $made_changes = 1;
}

sub set_order
{
    my ($quiet,$order) = @_;
    $pref_order = $order if ($order);

    # reset current order to zero
    foreach my $proggy (keys %$grabbers) {
	$grabbers->{$proggy}->{order} = 0;
    }

    # and now set order
    my $order_num = 1;
    if ($pref_order) {
	foreach my $proggy (split(/,/,$pref_order)) {
	    if (defined $grabbers->{$proggy}) {
		$grabbers->{$proggy}->{order} = $order_num;
		$order_num++;
	    }
	}
    }

    # set order of any grabbers not specified in a random manner
    foreach my $proggy (sort keys %$grabbers) {
        if ((!defined $grabbers->{$proggy}->{order}) || ($grabbers->{$proggy}->{order} == 0)) {
	    $grabbers->{$proggy}->{order} = $order_num+int(rand(1000));
	}
    }

    # .. and finally normalize the order (& show the user the order we chose)
    print "Grabber order set as follows:\n" unless $quiet;
    $order_num = 0;
    foreach my $proggy (sort { $grabbers->{$a}->{order} <=> $grabbers->{$b}->{order} } keys %$grabbers) {
	$order_num++;
	$grabbers->{$proggy}->{order} = $order_num;
	printf " #%d. %s%s\n",$grabbers->{$proggy}->{order},$proggy,($grabbers->{$proggy}->{disabled} ? " [disabled]" : "") unless $quiet;
    }

    $made_changes = 1;
}

sub check
{
    my $result;
    foreach my $proggy (keys %$grabbers) {
	$result = test_proggy("$GRABBER_DIR/$proggy","$GRABBER_DIR/$proggy/$proggy");
	printf "Grabber %s: %s\n",$proggy,($result ? "OK" : "Failed");
	if (!$result ne !$grabbers->{$proggy}->{ready}) {
	    $grabbers->{$proggy}->{ready} = $result;
	    $made_changes = 1;
	}
    }

    foreach my $proggy (keys %$postprocessors) {
	$result = test_proggy("$POSTPROCESSOR_DIR/$proggy","$POSTPROCESSOR_DIR/$proggy/$proggy");
	printf "Postprocessor %s: %s\n",$proggy,($result ? "OK" : "Failed");
	if (!$result ne !$postprocessors->{$proggy}->{ready}) {
	    $postprocessors->{$proggy}->{ready} = $result;
	    $made_changes = 1;
	}
    }
}

# -----------------------------------------
# Subs: Setup
# -----------------------------------------

sub read_config_file
{
    read_file($config_file, 'configuration');

    # if we are updating from a previous rev of shepherd.conf we may not
    # have any 'order' fields set .. check here
    my $found_order = 1;
    foreach (keys %$grabbers)
    {
	$found_order = 0 if (!defined $grabbers->{$_}->{order});
    }
    if (($found_order == 0) && (!$opt->{setorder}))
    {
	# at least one 'order' was missing .. we need to put it in!
	printf "Legacy shepherd.conf file didn't contain any grabber order! Automatically updating using a random order, use --setorder to manually set this if you care.\n";
	&set_order(1);
    }

    # if a mirror has been specified, add it into our config
    if ($opt->{mirror}) {
	$mirror_site = $opt->{mirror};
	$made_changes = 1;
	print "Adding mirror: $mirror_site\n";
    }
}

sub read_channels_file
{
    read_file($channels_file, 'channels');
}

sub read_file
{
    my $fn = shift;
    my $name = shift;

    print "Reading $name file: $fn\n";
    unless (-r $fn)
    {
	unless ($opt->{configure})
	{
	    print "\nNo $name file found.\n" .
		  ucfirst($progname) . " must be configured: " .
		  "configuring now.\n\n";
	    $opt->{'configure'} = 1;
	}
	return;
    }
    local (@ARGV, $/) = ($fn);
    no warnings 'all';
    eval <>;
    if ($@ and !$opt->{configure})
    {
	die "\nError in $name file!\nDetails:\n$@";
    }
}

sub write_config_file
{
    open(CONF, ">$config_file") or die "cannot write to $config_file: $!";
    print CONF Data::Dumper->Dump(
	[$region,  $pref_order,  $mirror_site,  $grabbers, $postprocessors  ],
	["region", "pref_order", "mirror_site", "grabbers", "postprocessors" ]);
    close CONF;
    print "\nUpdated configuration file $config_file.\n" if ($debug);
}

sub write_channels_file
{
    open(CHAN, ">$channels_file") or die "cannot write to $channels_file: $!";
    print CHAN Data::Dumper->Dump([$channels], ["channels"]);
    close CHAN;
    print "Updated channels file $channels_file.\n" if ($debug);
}

sub get_initial_command_line_options
{
  GetOptions( 'config-file=s'   => \$opt->{configfile},
              'help'            => \$opt->{help},
	      'configure'	=> \$opt->{configure},
	      'mirror=s'	=> \$opt->{mirror},
              'debug'           => \$debug);
}

sub get_remaining_command_line_options
{
    GetOptions(
              'version'         => \$opt->{status},
	      'status'		=> \$opt->{status},
	      'list'		=> \$opt->{list},
	      'show-config'	=> \$opt->{show_config},

	      'update'		=> \$opt->{update},
	      'noupdate'        => \$opt->{noupdate},

	      'disable=s'       => \$opt->{disable},
	      'enable=s'        => \$opt->{enable},
	      'setorder=s'	=> \$opt->{setorder},

	      'days=i'          => \$days,
              'offset=i'        => \$opt->{offset},
              'show-channels'   => \$opt->{show_channels},
              'output=s'        => \$opt->{output},
	      'check'		=> \$opt->{check}
	    );
}


# -----------------------------------------
# Subs: Configuration
# -----------------------------------------

sub configure
{
    my $REGIONS = {
	"ACT" => 126,
	"NSW: Sydney" => 73,
        "NSW: Newcastle" => 184,
        "NSW: Central Coast" => 66,
        "NSW: Griffith" => 67,
        "NSW: Broken Hill" => 63,
        "NSW: Northern NSW" => 69,
        "NSW: Southern NSW" => 71,
        "NSW: Remote and Central" => 106,
        "NT: Darwin" => 74,
        "NT: Remote & Central" => 108,
        "QLD: Brisbane" => 75,
        "QLD: Gold Coast" => 78,
        "QLD: Regional" => 79,
        "QLD: Remote & Central" => 114,
        "SA: Adelaide" => 81,
        "SA: Renmark" => 82,
        "SA: Riverland" => 83,
        "SA: South East SA" => 85,
        "SA: Spencer Gulf" => 86,
        "SA: Remote & Central" => 107,
        "Tasmania" => 88,
        "VIC: Melbourne" => 94,
        "VIC: Geelong" => 93,
        "VIC: Eastern Victoria" => 90,
        "VIC: Mildura/Sunraysia" => 95,
        "VIC: Western Victoria" => 98,
        "WA: Perth" => 101,
        "WA: Regional" => 102
    };

    print "\nConfiguring.\n\n" .
	  "Select your region:\n";
    foreach (sort keys %$REGIONS)
    {
	printf(" (%3d) %s\n", $REGIONS->{$_}, $_);
    }
    $region = ask_choice("Enter region code:", "94", values %$REGIONS);

    print "\nFetching channel information... ";

    my @channellist = get_channels();

    print "done.\n\n" .
	  "For each channel you want guide data for, enter an XMLTV id\n" .
    	  "of your choice (e.g. \"seven.free.au\"). If you don't need\n" .
	  "guide data for this channel, just press Enter.\n\n" .
	  "Please don't subscribe to unneeded channels.\n\nChannels:\n";
    $channels = {};
    my $line;
    foreach (@channellist)
    {
	$line = ask(" \"$_\"? ");
	$channels->{$_} = $line if ($line);
    }


    print "\nRandomly selecting grabber order.\n\n";
    set_order(0);

    show_channels();
    unless(ask_boolean("\nCreate configuration file?"))
    {
	print "Aborting configuration.\n";
	exit 0;
    }

    write_config_file();
    write_channels_file();

    print "Finished configuring.\n\n" .
          "Shepherd is installed into $CWD.\n\n";
    
    if ($invoked ne "$CWD/$progname" and $invoked =~ /$progname/)
    {
	print "Warning: you invoked this program as $invoked.\n" .
	    "In the future, it should be run as $CWD/$progname,\n" .
	    "to avoid constantly re-downloading the latest version.\n\n" .
	    "MythTV users may wish to create the following symlink, by " .
	    "doing this (as root):\n" .
	    "\"ln -s $CWD/$progname /usr/bin/tv_grab_au\".\n\n" .
	    "You may safely delete $invoked.\n\n";
    }

    status();

    unless (ask_boolean("\nGrab data now?"))
    {
	exit 0;
    }
}

sub get_channels
{
    my @date = localtime;
    my $page = LWP::Simple::get(
	"http://au.tv.yahoo.com/results.html?rg=$region&dt=" .
	($date[5] + 1900) . "-$date[4]-$date[3]");
    my @channellist;
    while ($page =~ /<tr class=rtb><td class=rth><a .*?>(.*?)<\/a>/g)
    {
	push @channellist, $1;
    }
    return @channellist;
}

# -----------------------------------------
# Subs: Status & Help
# -----------------------------------------

sub show_config
{
    print "\nConfiguration\n".
	  "-------------\n" .
          "Config file: $config_file\n" .
	  "Debug mode : " . is_set($debug) . "\n" .
          "Output file: " . ($opt->{output} ? $opt->{output} : "None") . "\n" .
          "Region ID  : $region\n";
  show_channels();
  print "\n";
  status();
  print "\n";
}

sub show_channels
{
  print "Subscribed channels:\n";
  print "    $_ -> $channels->{$_}\n" for sort keys %$channels;
}

sub is_set
{
    my $arg = shift;
    return $arg ? "Yes" : "No";
}

sub status
{
    print " Grabber           Version Enabled Ready Last Run   Status\n" .
	  " ----------------- ------- ------- ----- ---------- ---------------------------\n";
    foreach (sort { $grabbers->{$a}->{order} <=> $grabbers->{$b}->{order} } keys %$grabbers) {
	my $h = $grabbers->{$_};
	printf  " %-16s %8s %4s %6s  %11s %s\n",
	        "$h->{order}. $_",
	        ($h->{ver} ? $h->{ver} : "unknown"),
	        $h->{disabled} ? '' : 'Y',
		$h->{ready} ? 'Y' : '',
		$h->{lastdata} ? (strftime "%a%d%b%y", localtime($h->{lastdata})) : 'never',
		$h->{laststatus} ? $h->{laststatus} : '';
    }
    printf "Grabbers shown in order of preference.\n\n";

    print " Postprocessor     Version Enabled Ready Last Run   Status\n" .
	  " ----------------- ------- ------- ----- ---------- ---------------------------\n";
    foreach (sort { $postprocessors->{$a} <=> $postprocessors->{$b} } keys %$postprocessors) {
	my $h = $postprocessors->{$_};
	printf  " %-16s %8s %4s %6s  %11s %s\n",
		$_,
		($h->{ver} ? $h->{ver} : "unknown"),
		$h->{disabled} ? '' : 'Y',
		$h->{ready} ? 'Y' : '',
		$h->{lastdata} ? (strftime "%a%d%b%y", localtime($h->{lastdata})) : 'never',
		$h->{laststatus} ? $h->{laststatus} : '';
    }
    printf "Postprocessors shown in order of execution.\n\n";
}

sub help
{
    print q{
Command-line options:
    --help                Print this message

    --status              Print a list of grabbers maintained
    --list                Print a detailed list of grabbers
    --mirror <s>          Set URL <s> as primary location to check for updates

    --configure           Setup
    --show-config         Print setup details

    --setorder <s>        Set order of grabbers to <s> (comma-seperated list of grabbers)

    --disable <s>         Don't ever use grabber/postprocessor <s>
    --enable <s>          Okay, maybe use it again then
    --uninstall <s>       Remove a disabled grabber/postprocessor

    --noupdate            Do not attempt to update before running
    --update              Update only; do not grab data

    --check               Check status of all grabbers and postprocessors
};
    exit 0;
}

# -----------------------------------------
# Subs: override handlers for standard perl.
# -----------------------------------------

# ugly hack. please don't try this at home kids!
sub my_die {
    my ($arg,@rest) = @_;
    my ($pack,$file,$line,$sub) = caller(1);

    # check if we are in an eval()
    if ($^S) {
	printf STDERR "  shepherd caught a die() within eval{} from file $file line $line\n";
    } else {
	if (!ref($arg)) {
	    CORE::die((sprintf "DIE at line %d in file %s: %s\n",$line,$file,(join("",($arg,@rest)))));
	} else {
	    CORE::die($arg,@rest);
	}
    }
}