#!/usr/bin/perl -w
# hierarchy-comparison                                            -*- Perl -*-
#   Possible bug: only -type f and -type d are checked
# Copyright (C) 2001, 2002, 2003, 2004, 2008 Bradley M. Kuhn <bkuhn@ebb.org>
# Copyright (C) 2011 Denver Gingerich <denver@ossguy.com>
#
# This software's license gives you freedom; you can copy, convey,
# propogate, redistribute and/or modify this program under the terms of
# the GNU  General Public License (GPL) as published by the Free
# Software Foundation (FSF), either version 3 of the License, or (at your
# option) any later version of the GPL published by the FSF.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program in a file in the toplevel directory called
# "GPLv3".  If not, see <http://www.gnu.org/licenses/>.
#

use strict;

use POSIX qw(tmpnam);
use Cwd;

my $VERSION = '1.1';
my $DO_DIFF = 1;

######################################################################
sub FindAndSortOutput {
  use File::Find;

  my($type, $dir, $output, $ignoreRegex, $filterRewrite) = @_;
  my @files;

  my $buildList = sub {
    my $val = $_;
    chomp $val;
    $val =~ s/$filterRewrite// if defined $filterRewrite;
    if ($type eq "NON-REGULAR") {
      push(@files, $val) unless -f $_;
    } elsif ($type eq "FILES") {
      push(@files, $val) if -f $_;
    } elsif ($type eq "DIRECTORY") {
      push(@files, $val) if -d $_;
    } else {
      die "Unknown type requested: $type";
    }
  };

  find({ wanted => $buildList, no_chdir => 1},  $dir);

  open(FILE_OUTPUT, ">$output") or
    die "$0: unable to open temporary output file, $output: $!";

  my @sortedChompedFiles;
  foreach my $file (sort {$a cmp $b } @files) {
    chomp $file;
    next if defined $ignoreRegex and $file =~ /$ignoreRegex/;
    push(@sortedChompedFiles, $file);
    print FILE_OUTPUT "$file\n";
  }
  close FILE_OUTPUT;

  return @sortedChompedFiles;
}
######################################################################
sub MD5SumFiles {
  my($dir, $fileListRef, $outputFile) = @_;

  my $curdir = getcwd();

  chdir $dir or die "unable to change to $dir: $0";

#  open(FILE_OUTPUT, "|/usr/bin/xargs /usr/bin/md5sum >$outputFile 2>&1")
  open(FILE_OUTPUT, "|/usr/bin/xargs -0 /usr/bin/sha1sum >$outputFile")
    or die "unable to write to $outputFile: $!";

  foreach my $file (@{$fileListRef}) {
    print FILE_OUTPUT "$file\000";
  }
  close FILE_OUTPUT;
  die "$0: error running xargs to md5sum command; $!" unless ($? == 0);

  open(FILE_INPUT, "<", $outputFile) or die "unable to read back in $outputFile: $!";
  my %files2sha1;
  while (my $line = <FILE_INPUT>) {
    chomp $line;
    die "$outputFile has a strange line, \"$line\""
      unless $line =~ /^(\S+)\s+(.+)$/;
    $files2sha1{$2} = $1;
  }
  close FILE_INPUT;

  chdir $curdir or die "$0: cannot go back into $curdir: $!";
  return \%files2sha1;
}
######################################################################

if (@ARGV != 3 and @ARGV != 4) {
  print "usage: $0 <ORIG_DIRECTORY> ",
        "<COMPARED_DIRECTORY> <DIFF_OUTPUT_FILE> [<IGNORED_FILES_REGEX>]\n";
  exit 2;
}

my($origDir, $comparedDir, $diffOutputFile, $ignoreRegex) = @ARGV;

$origDir =~ s%/\s*$%%;
$comparedDir =~ s%/\s*$%%;

my $origTempFile = POSIX::tmpnam();
my $comparedTempFile = POSIX::tmpnam();

# First, look for directory differences

print "Doing directory comparision: ";

my(@orgNonRegular) = FindAndSortOutput("NON-REGULAR", $origDir, $origTempFile,
                                 $ignoreRegex, "^/?($origDir|$comparedDir)/?");
my(@comparedNonRegular) = FindAndSortOutput("NON-REGULAR", $comparedDir,
                                      $comparedTempFile, $ignoreRegex,
                                            "^/?($origDir|$comparedDir)/?");

# TODO: use the right Perl mechanism instead of /bin/echo (ossguy)
system("/bin/echo Directory comparison: >> $diffOutputFile 2>&1");
system(
     "/usr/bin/diff -u $origTempFile $comparedTempFile >> $diffOutputFile 2>&1");

my $diffExitCode = $?;
unlink($origTempFile, $comparedTempFile);

if ($diffExitCode == 2) {
  print "\n";
  die "$0: error trying to diff files: $!";
} elsif ($diffExitCode == 0) {
  print "directory structures match.\n";
} else {
  print "differences found in directory structures.\n",
    "See $diffOutputFile for more information.\n";
}

# Now, see if the files are all the same

print "Doing file hierarchy comparision: ";

my(@orgFiles) = FindAndSortOutput("FILES", $origDir, $origTempFile,
                                 $ignoreRegex, "^/?($origDir|$comparedDir)/?");
my(@comparedFiles) = FindAndSortOutput("FILES", $comparedDir,
                                       $comparedTempFile, $ignoreRegex, "^/?($origDir|$comparedDir)/?");

# TODO: use the right Perl mechanism instead of /bin/echo (ossguy)
system("/bin/echo >> $diffOutputFile 2>&1");
system("/bin/echo File hierarchy comparison: >> $diffOutputFile 2>&1");

system(
     "/usr/bin/diff -u $origTempFile $comparedTempFile >> $diffOutputFile 2>&1");

$diffExitCode = $?;

if ($diffExitCode == 2) {
  print "\n";
  die "$0: error trying to diff files: $!";
} elsif ($diffExitCode == 0) {
  print "both contain the same list of files.\n";
} else {
  print "differences found in file hierarchies.\n",
    "See $diffOutputFile for more information.\n";
}

# Now, diff the md5sums of the files.

print "Doing file contents comparisons: ";

# Assume that the two lists were the same, and come down to the list of
# shared files.

my(%origH, %comparedH);

@origH{@orgFiles} = @orgFiles;
@comparedH{@comparedFiles} = @comparedFiles;

my %final;

foreach my $ii (@orgFiles, @comparedFiles) {
  $final{$ii} = $ii
    if defined $origH{$ii} and defined $comparedH{$ii};
}
my(@o, @c);
@o = keys %final;
@c = keys %final;

my $origFiles2sha1 =  MD5SumFiles($origDir, \@o, $origTempFile);
my $comparedFiles2sha1 = MD5SumFiles($comparedDir, \@c, $comparedTempFile);

# TODO: use the right Perl mechanism instead of /bin/echo (ossguy)
system("/bin/echo >> $diffOutputFile 2>&1");
system("/bin/echo 'File contents comparisons (MD5):' >> $diffOutputFile 2>&1");

system(
     "/usr/bin/diff -u $origTempFile $comparedTempFile >> $diffOutputFile 2>&1");

$diffExitCode = $?;
unlink($origTempFile, $comparedTempFile);

# TODO: use the right Perl mechanism instead of /bin/echo (ossguy)
system("/bin/echo >> $diffOutputFile 2>&1");
system("/bin/echo 'File contents comparisons (diff):' >> $diffOutputFile 2>&1");

if ($DO_DIFF) {
  foreach my $file (keys %final) {
    if ($origFiles2sha1->{$file} ne $comparedFiles2sha1->{$file}) {
      system(
             "/usr/bin/diff -u \"$origDir/$file\" \"$comparedDir/$file\" >> $diffOutputFile 2>&1");
    }
  }
}
if ($diffExitCode == 2) {
  print "\n";
  die "$0: error trying to diff files: $!";
} elsif ($diffExitCode == 0) {
  print "all files match.\n";
} else {
  print "differences found in some files.\n",
    "See $diffOutputFile for more information.\n";
  exit 1;
}

exit 0;

#
# Local variables:
# compile-command: "perl -c hierarchy-comparison"
# End: