#!/usr/bin/perl

# Copyright (c) 2010 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:

# Mike Kinghan, mikek@symbian.org, for Symbian Foundation Ltd - initial contribution.

# Subroutines to deploy a patch file.

# The required patch files reside in build/{linux-prep|windows-prep}/patch_files.

# A patch file with the path:

#   patch-files/DIR1[/DIR...]/FILE

# will be copied to EPOCROOT/DIR1[/DIR...]/FILE,

# except in the special case where DIR1 begins with '$'.

# In this case, the DIR1 is construed as the name of an environment

# variable whose value VAL will be substituted to obtain the name of the

# destination file as VAL//DIR1[/DIR...]/FILE.

use strict;

use File::Spec;

use File::Copy;

use places;

use check_os;

use get_wordsize;

sub compare_files($$)

{

    my ($flhs,$frhs) = @_;

    my $delim = $/;

    $/ = undef;

    open FH,"<$flhs" or die $!;

    my $slhs = <FH>;

    close FH;

    open FH,"<$frhs" or die $!;

    my $srhs = <FH>;

    close FH;

    $/ = $delim;

    return "$slhs" eq "$srhs"; 

}

sub apply_patch_file($)

{

	my $patched = 0;

    my $patch_file = shift;

    my ($src_file, $dest_file);

    my $epocroot = get_epocroot();

    my $patch_files_dir;

	if (os_is_windows()) {

		$patch_files_dir = File::Spec->catfile(get_pkg_dir(),"cross-plat-dev-utils","patch-files","windows");

	} elsif (os_is_linux()) {

		$patch_files_dir = File::Spec->catfile(get_pkg_dir(),"cross-plat-dev-utils","patch-files","linux");

	} else {

		die "*** Unsupported OS $^O ***";

	} 

    $src_file = File::Spec->catfile($patch_files_dir,$patch_file);

    if (! -f $src_file) {

		my $wordsize = get_host_wordsize();

		$wordsize .= "bit";

		if (-f "$src_file\.$wordsize") {

			print ">>> Using $wordsize variant of \"$src_file\"\n";

			$src_file .= "\.$wordsize";

		} else {

	        die("*** Error: not found \"$src_file\" ***");

		}

    }    

    if ($patch_file =~ /^\$/) {

        my ($vol,$dir,$file) = File::Spec->splitpath($patch_file);

        my @dirs = File::Spec->splitdir($dir);

        my $topdir = shift(@dirs);

        $topdir =~ s/^\$//;

        $topdir = $ENV{$topdir};

        my $destdir = File::Spec->catfile($topdir,@dirs);

        $dest_file = File::Spec->catfile($destdir,$file);

    }

    else {

        $dest_file = File::Spec->catfile($epocroot,$patch_file);

    }

	print "??? Need patch \"$src_file\" -> \"$dest_file\" ??? \n";

	if (! -f $dest_file) { 

		print ">>> Yes. \"$dest_file\" does not exist\n";

		print ">>> Copying \"$src_file\" to \"$dest_file\"n";

		copy($src_file,$dest_file) or die $!;

		$patched = 1;

	}

	else {

		my $dif = !compare_files($src_file,$dest_file);

		print "$dif\n";

		if (!$dif) {

		  print ">>> No. \"$dest_file\" is same as \"$src_file\"\n";	   

		}

		else {

			print ">>> Yes. \"$dest_file\" differs  from \"$src_file\"\n";

			my $backup = $dest_file;

			for (; -f ($backup .= '~');) {};

			print ">>> Backing up \"$dest_file\" as \"$backup\"\n";

			copy($dest_file,$backup) or die $!;

			print ">>> Copying \"$src_file\" to \"$dest_file\"\n";                     

			copy($src_file,$dest_file) or die $!;

			$patched = 1;

		}

    }

	return $patched;

}

1;