#!/usr/bin/perl

##############################################################################
# Winfred van Kuijk - http://winfred.vankuijk.net
# 
# Parse the metadata of a .hmt file coming from a Humax 5050C
# The layout is described in the excellent document from Peter:
# http://www.patrn.nl/Projects/5050c/5050c.html
#
# syntax: hmt_meta <filename.hmt>
#
# v1.0, 2009/12/31, initial release
##############################################################################

use Encode;

####################################################################################
# subroutine: read specific bytes from the file
# - offset, length: where to start and how many bytes
# - type: 1 for numbers, 0 for string
# - desc: optional, if provided: will be used as label to display the debugging details

sub myseek {
	my($offset, $length, $type, $desc) = @_;
	my($buf, $result, $hexstring) = "";
	my($values,$bytes) = "";
	
	seek(FILE, $offset, 0);
	read(FILE, $buf, $length);
		
	if ($type == 1) {
		$result = hex(unpack("H*",$buf));
	} else {
		#$result = unpack("Z*",$buf); # only keep the chars, remove the \0
		$result = $buf;
		# fast conversion from iso-8859-1 to utf-8 (not pretty, but hey...)
		$result =~ s/([\x80-\xFF])/chr(0xC0|ord($1)>>6).chr(0x80|ord($1)&0x3F)/eg;
		#sometimes the event name starts one character later, too lazy to find out why
		$result =~ s/[\x00-\x05]//g; #if one later then the first char is 05, take them out
		$length = length($result);
	}

	if ($desc) {
	#for debugging, remove next comment
	#printf ("%5d/%05x, %3d/%03x - %12s: %s %s %s\n",$offset,$offset,$length,$length,$desc,$result, $bytes);
	}

	return $result;
}

####################################################################################
# the main loop

sub process_hmt {
	open(FILE, $ARGV[0]) or die("Error reading file, stopped");
	binmode FILE;

	#print "###################################################\n";
	$timestamp = myseek(25,4,1); # timestamp - localtime(...) (0x19)
	$name = myseek(288,255,0,"name"); #name of what we wanted to record (0x120)
	$channel_nr = myseek(hex(11),2,1,"channel nr"); # Humax channel nr, not used
	$channel_name = myseek(hex(220),33,0,"channel name"); #name of the channel (RTL etc.)
	
	#----------------------------------------------------------------

	# the file can contain multiple events
	# the event we recorded is not necessarily the first one
	# e.g.: recorded "yes", event list "no, yes, no, no" or "yes, no, no", or ...

	$count = myseek(hex(1000),4,1,"events"); #how many events are there? (0x1000)
	$start = hex(1004); # start of the first event (0x1004)
	
	for ($loop = 1; $loop <= $count; $loop++) {
		##print "---- event #".$loop."/".$count." ------------------------\n";
		
		$event_id[$loop] = myseek($start,2,1,"event id"); # unique nr for event, not used (+ 0x2)
		$event_name[$loop] = myseek($start+21,40,0,"event name"); # name of the event (+ 0x15)
		$event_size[$loop] = myseek($start+540,4,1,"event size"); # nr of bytes for event (+ 0x21)
		$event_desc[$loop] = "";

		# the description of each event is broken up in blocks		
		$block_cnt = myseek($start+548,4,1,"blocks"); # number of description blocks (+ 0x224)
		$desc_start = $start + 564; # where does first block start (+ 0x234)
		
		for ($desc = 0; $desc < $block_cnt; $desc++) {
			$len = myseek($desc_start,2,1); # length of this block of the description
			$event_desc[$loop] .= myseek($desc_start+3,$len-1,0); # add (next part of) the description
			$event_lang[$loop] = myseek($desc_start+$len+2,3,0); # lang of description, not used
						
			$desc_start += 14 + $len; #get ready for the next block
		}
		# for debugging remove next comment (shows each description)
		##print $event_desc[$loop]."\n";

		$start += 540+4 + $event_size[$loop]; #get ready for the next event

		##print ">".$name."< >".$event_name[$loop]."<\n";
		##print ">".length($name)."< >".length($event_name[$loop])."<\n";
		if ($event_name[$loop] eq $name) {
			$description = $event_desc[$loop];
		}
	}
	
	#print "$name ($channel_name: ".gmtime($timestamp).")\n";
	print "$name\n";
	print "$channel_name\n";
	print gmtime($timestamp)."\n";
	print "$description\n";
	
	close(FILE);
}

#------------------------------------------------------------------------------

	# to do: combine the transfer_transcode shell script and this one
	
	# step 0: parse the arguments
	# define the variables: url, url_hmt, output filename
	# wget the url_hmt
	# if fails: Humax not online -> exit
	# process hmt to get metadata
	process_hmt();
	# wget the url + transcode
	# add the metadata
	# use iFlicks to add additional metadata and add to iTunes