use warnings;
use strict;
use Win32::Process;
use File::Find;
use File::Path;
use Tk;

my $cvs = '"C:\Program Files\GNU\WinCvs 1.3\CVSNT\cvs"';

my $diffTool;
my $confictFile;
my $listOnly = 0;

while ($_ = shift)
    {
    ShowHelp (-3, "Too many parameters provided.\n\n") if defined $confictFile;
    $confictFile = $_ if defined $diffTool;
    $diffTool = $_ if ! defined $diffTool;
    }
 
ShowHelp () if ! $diffTool;
ErrorBox ("Missing Conflict File", "Can't find $confictFile\n\n") if ! -e $confictFile;

(my $path = $confictFile) =~ s/^(.*)[\/\\](.*?)$/$1/;
my $fileName = $2;
find (\&setHeadFile, ($path));

my $headFile; # Set in setHeadFile

@ARGV = ($confictFile);
while (<>)
  {
  next if ! />>>>>>>\s+((?:\d+\.){2})/;
  
  my $commonRev = substr $1, 0, -1 + length $1;
  my $commonRevSrc = `$cvs update -P -p -r $commonRev $confictFile`;
  
  ErrorBox ("cvs failed", $commonRevSrc) if $?;
  
  my $tempFileName = "${confictFile}.$commonRev";
  open tempFile, ">", $tempFileName;
  print tempFile $commonRevSrc;
  close tempFile;

  my $proc2;
  Win32::Process::Create
    (
    $proc2, "$diffTool",  "\"$diffTool\" $headFile $confictFile",
    0,
    NORMAL_PRIORITY_CLASS,
    "."
    ) || ErrorBox ("Create failed", Win32::FormatMessage (Win32::GetLastError ()));

  my $proc1;
  Win32::Process::Create
    (
    $proc1, "$diffTool", "\"$diffTool\" $tempFileName $headFile",
    0,
    NORMAL_PRIORITY_CLASS,
    "."
    ) || ErrorBox ("Create failed", Win32::FormatMessage (Win32::GetLastError ()));
  
  exit (0);
  }

ErrorBox ("No conflicts", "No conficts found in $confictFile");

  
sub ShowHelp
{
my $exitValue = 0;
$exitValue = shift if defined $_[0] and $_[0] =~ /^[-+]?\d+$/;

print $_ while $_ = shift;

print "ConflictCompare opens two diff tool apps to compare the HEAD merged result\n";
print "against the common ancestor and the branch version that was merged.\n";
print "\n";
print "Usage:\n\n";
print "ConflictCompare [-n] <tool cmd line> <.# conflict file>\n";
print "\n";
print "  -n: show progress information.\n";
print "\n";
exit ($exitValue || -1);
}


sub ErrorBox
{
my $main = MainWindow->new ();
my $title = shift;
my $message = shift;

$main->withdraw ();
$main->messageBox(-icon => 'error', -message => $message, -title => $title, -type => 'Ok');
exit (-2);
}


sub setHeadFile
{
return if $File::Find::name =~ /^\.\.?/;
return if $File::Find::name !~ /$fileName(?:\.\d+)+/;

return if $headFile and -M $headFile >= -M $File::Find::name;
$headFile = $File::Find::name;
}