#!perl -w
# (C) 2003-2007 Willem Jan Hengeveld <itsme@xs4all.nl>
# Web: http://www.xs4all.nl/~itsme/
#      http://wiki.xda-developers.com/
#
# $Id: map.pl 1502 2007-04-15 07:54:20Z itsme $
#
use strict;

my $cfgfile=shift;

my $cfg= ReadConfig($cfgfile);


my $data= ReadFiles($cfg->{input});

WriteFiles($cfg->{output}, $data);

exit(0);

sub ReadConfig {
	my ($filename)= @_;

	my $fh= IO::File->new($filename, "r");

	my $section;
	my $info= {};
	while(<$fh>) {
		s/\s+$//;

		if (/\[(\w+)\]/) {
			$section= [];
			$info->{$1}= $section;
		}
		elsif (/^([^:]+):(\w+)=(\w+)\s+l=(\w+)$/) {
			push @$section, {
				filename=>$1,
				fileoffset=>hex($2),
				virtualoffset=>hex($3),
				length=>hex($4),
			};
		}
		elsif (/^([^:]+):(\w+)\s+(\w+)$/) {
			push @$section, {
				filename=>$1,
				virtualoffset=>hex($2),
				length=>hex($3),
			};
		}
	}

	return $info;
}

sub ReadFiles {
	my ($inputfiles)= @_;

	my $datamap= {};

	for my $input (@$inputfiles) {
		ReadFile($input, $datamap);
	}

	return $data;
}

sub ReadFile {
	my ($input, $datamap)= @_;

	if ( hasOverlapWithAnyRange($datamap, $input->{virtualoffset}, $input->{length})) {
		die sprintf("range overlapping %08lx-%08lx\n", 
			$input->{virtualoffset},
			$input->{virtualoffset}+$input->{length});
	}

	my $fh= IO::File->open($input->{filename}, "r");
	binmode $fh;

	$fh->seek($input->{fileoffset}, SEEK_SET);

	my $data;
	$fh->read($data, $input->{length});

	$fh->close();

	$datamap->{$input->{virtualoffset}}= {
		start=>$input->{virtualoffset},
		length=>$input->{length},
		data=>$data,
	};
}
sub hasOverlapWithAnyRange {
	my ($data, $start, $length)= @_;

	for (values $data) {
		return 1 if hasOverlapWithRange($_, $start, $length);
	}
	return 0;
}
sub hasOverlapWithRange {
	my ($range, $start, $length)= @_;

	return ($range->{start}+$range->{length} > $start
		&& $start+$length > $range->{start});
}
sub WriteFiles {
	my ($outputdef, $datamap)= @_;
	for my $output (@$outputdef) {
		WriteFile($datamap, $output);
	}
}

sub WriteFile {
	my ($datamap, $output)= @_;

	my $fh= IO::File->new($output->{filename}, "w+");
	binmode $fh;

	my $offset= $output->{virtualoffset};
	my $length= $output->{length};

	for my $start (sort keys %$datamap) {
		my $data= $datamap->{$start};
		if (hasOverlapWithRange($data)) {
			if ($offset<$start) {
				WritePadding($fh, min($offset-$start, $length));
				$length -= $offset-$start;
				$offset= $start;
			}
			my $dataofs= $data->{virtualoffset}-$offset;
			my $datalen= min($length, $data->{length}-$dataofs);
			$fh->syswrite($data->{data}, $datalen, $dataofs);
			$length -= $datalen;
			$offset += $datalen;
		}
	}

	if ($length) {
		WritePadding($fh, $length);
		$offset += $length;
		$length= 0;
	}

	$fh->close();
}

sub WritePadding {
	my ($fh, $size) = @_;

	$fh->sysseek($size, SEEK_CUR);
}