#!perl -w

# Copyright (c) 2009 Symbian Foundation Ltd

# This component and the accompanying materials are made available

# under the terms of the License "Eclipse Public License v1.0"

# which accompanies this distribution, and is available

# at the URL "http://www.eclipse.org/legal/epl-v10.html".

#

# Initial Contributors:

# Symbian Foundation Ltd - initial contribution.

# 

# Contributors:

#

# Description:

# Merge a set of XML files

use strict;

use XML::Parser;

use Getopt::Long;

# Read option arguments

my $howtoString;

my $xslLink;

my $help;

GetOptions((

	'xsl=s' => \$xslLink,

	'merge=s' => \$howtoString,

	'help!' => \$help,

));

my $wrongArgs = 0;

unless ($help)

{

	$wrongArgs += warn "No merge string specified to indicate how the files should be merged\n" unless defined $howtoString;

	$wrongArgs += warn "No files to be merged\n" unless scalar @ARGV;

}

if ($help || $wrongArgs)

{

	print <<"EOT";

mergeXML.pl --xsl=brag.xsl --merge=SystemDefinition,systemModel,layer(name),block(name),package(name) sysModel1.xml [model*.xml ...] > output.xml

EOT

	exit(0 + !$help);

}

# Hash of tags that should be merged, with optional attribute consideration

my $mergeTags;

foreach my $term (split m{\s*,\s*}, $howtoString)

{

	my ($tag, $attribute) = $term =~ m{(\w+)\((\w+)\)};

	$tag ||= $term;

	$mergeTags->{$tag} = $attribute;

}

# Expand wildcards

@ARGV = map { glob $_ } @ARGV;

# Merge all the trees together

my $outTree = mergeMultipleTrees($mergeTags, @ARGV);

# Output total tree

print "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n";

print "<?xml-stylesheet type=\"text/xsl\" href=\"$xslLink\"?>\n" if $xslLink;

print "\n";

exit(0);

sub mergeMultipleTrees

{

	my $mergeTags = shift or die;

	# Create an XML parser

	my $parser = new XML::Parser(Style => "Objects") or die;

	my $outTree;

	# For each XML file to merge...

	foreach my $xmlFile (@_)

	{

		my $tree = eval { $parser->parsefile($xmlFile) } or die "Failed to parse $xmlFile : $@";

		if (!$outTree)

		{

			# The first file is taken verbatim

			$outTree = $tree;

		}

		else

		{

			# Merge into output Tree

			mergeTwoTrees($outTree->[0], $tree->[0], $mergeTags);

		}

	}

	return $outTree;

}

sub mergeTwoTrees

{

	my $baseTree = shift or die;

	my $extrasTree = shift or die;

	my $mergeTags = shift or die;

	die ("Trees do not match: ".(ref $baseTree)." vs ".(ref $extrasTree)) unless ref $baseTree eq ref $extrasTree;

	return if ref $baseTree eq "main::Characters";

	foreach my $extraChild (@{$extrasTree->{Kids}})

	{

		# Work out whether this child should be merged with a namesake, or appended

		my $mergeIt;

		my $extraChildTag = ref $extraChild;

		$extraChildTag =~ s{^main::}{};

		if (exists $mergeTags->{$extraChildTag})

		{

			# Should be merged if there's already one there

			# Look for a namesake in the base

			$mergeIt = matchTag($baseTree->{Kids}, $extraChild, $mergeTags->{$extraChildTag});

		}

		if ($mergeIt)

		{

			# Merge children

			mergeTwoTrees($mergeIt, $extraChild, $mergeTags);

		}

		else

		{

			# Add this child

			push @{$baseTree->{Kids}}, $extraChild;

		}

	}

}

sub matchTag

{

	my $peers = shift;

	my $outsider = shift;

	my $attr = shift;

	foreach my $peer (@$peers)

	{

		if (ref $peer eq ref $outsider && (!defined $attr || $peer->{$attr} eq $outsider->{$attr}))

		{

			return $peer;

		}

	}

	return undef;

}