#! /usr/bin/perl -w
use strict;

=head1 Notices

Originally developed for Perforce by VIZIM (www.vizim.com)

Copyright (c) 2014 Perforce Software, Inc. and VIZIM Worldwide, Inc.
All rights reserved.

Please see LICENSE.txt in top-level folder of this distribution for
license information

=cut

use Digest::MD5;

use v5.14.0;   # Earliest version testing was performed against

my $APPNAME = 'FileDetails.pl';
my $APPWHAT = 'Generate file details; version 1.01';
my $APPNOTICES = "Copyright (c) 2014 Perforce Software, Inc. and VIZIM Worldwide, Inc.
All rights reserved.
See LICENSE.txt for license information.";

=head1 File details

Tool that generates details for a file using the same technology as the
import coordination and profile tools.
Details include BOM information and MD5 signature.

=cut

  my $file = $ARGV[0];
  if( ! defined $file || $ARGV[0] =~ m!\-+(h|\?)! ) {
    print "$APPWHAT
$APPNOTICES

Usage:

  $APPNAME -V
  $APPNAME [-h|-?]
  $APPNAME file\n";
    exit 1;
  }

  if( $ARGV[0] =~ m!\-+V! ) {
    print "$APPWHAT\n";
    exit 0;
  }

  if( ! -e $file ) {
    print "Does not exist: $file\n";
    exit 1;
  }

  if( ! -f $file ) {
    print "Not a file: $file\n";
    exit 1;
  }

  if( -z $file ) {
    print "EMPTY\n";
    exit 0;
  }
 
  my $hLocal;
  if( ! open( $hLocal, '<:bytes', $file ) ) {
    print "Can't open $file $!\n";
    exit 1;
  }
  
  my $header = '';
  read $hLocal, $header, 3, 0;
  if( $header =~ m!^\xEF\xBB\xBF! ) {
    print "UTF8 ";
  } elsif( $header =~ m!^\xFE\xFF! ) {
    print "UTF16BE ";
  } elsif( $header =~ m!^\xFF\xFE! ) {
    print "UTF16LE ";
  } else {
    print "NOBOM ";
  }
  seek $hLocal, 0, 0;

  my $ctx = Digest::MD5->new;

  $ctx->reset();
  $ctx->addfile( $hLocal );
  close( $hLocal );

  print uc $ctx->hexdigest();
  print "\n";

  exit 0;