#!/usr/bin/perl -w

use File::Spec;

 sub nice_string {
              join("",
                map { $_ > 255 ?                  # if wide character...
                      sprintf("\\x{%04X}", $_) :  # \x{...}
                      chr($_) =~ /[[:cntrl:]]/ ?  # else if control character ...
                      sprintf("\\x%02X", $_) :    # \x..
                      quotemeta(chr($_))          # else quoted or as themselves
                } unpack("U*", $_[0]));           # unpack Unicode characters
          }


sub debug_unicode_string
{
    join("",
         map { $_ > 128 ?                      # if wide character...
                   sprintf("\\x{%04X}", $_) :  # \x{...}
                   chr($_)          
               } unpack("U*", $_[0]));         # unpack Unicode characters
}


# Returns true (1) if the given string is utf8 and false (0) if it isn't.
# Does not modify the string parameter.
sub check_is_utf8 {
    my $value=shift;

    if (!defined($value)) {
	return 0; # not utf8 because it is undefined
    }

    $value =~ m/^/g; # to set \G
    while ($value =~ m!\G.*?([\x80-\xff]+)!sg) {
	my $highbytes=$1;
	# make sure this block of high bytes is utf-8
	$highbytes =~ /^/g; # set pos()
	while ($highbytes =~
		m!\G (?: [\xc0-\xdf][\x80-\xbf]   | # 2 byte utf-8
			[\xe0-\xef][\x80-\xbf]{2} | # 3 byte
			[\xf0-\xf7][\x80-\xbf]{3} | # 4 byte
			[\xf8-\xfb][\x80-\xbf]{4} | # 5 byte
			[\xfc-\xfd][\x80-\xbf]{5} | # 6 byte
			)*([\x80-\xff])? !xg
		) {
	    my $badbyte=$1;
	    if (defined $badbyte) { # not end of string
		return 0; # non-utf8 found
	    } 
	}
    }
    
    return 1;
}

if (scalar(@ARGV)!=1) {
    my $prog_name = $0;
    $prog_name =~ s/^.*(\\|\/)//;

    print STDERR "Usage: $prog_name dir\n";
    exit(1);
}


my $dir = $ARGV[0];

opendir(DIN,"$dir") 
    || die "Unable to open $dir";

my @files = grep { $_ !~ m/^\./ } readdir(DIN);

close(DIN);

foreach my $f (@files) 
{
    print "\nFilename: $f ";
    if(check_is_utf8($f)) {
	print " - is utf8\n";
    } else {
	print " - is not in utf8\n"; 
    }
    
    
    if ($f !~ m/(txt|xml|html)$/) { 
	print "Skipping file content check for $f\n";
	next;
    }
    
    my $os = $^O;

    if ($os =~ m/mswin/i) {
	$f = "$dir\\$f"; 
    }
    else {
	$f = "$dir/$f"; 	
    }
    

    # slurp the file and then print if its contents are utf8.
    # 1. Read all the contents of the html into a string
    # open the original file for reading
    unless(open(FIN, "<$f")) { 
	print STDERR "Unable to open $f...ERROR: $!\n";
	next;
	#exit(-1);
    }
  
    my $contents;
    {
	local $/ = undef;        # Read entire file at once
	$contents = <FIN>;  # Now file is read in as one single 'line'
    }
    close(FIN); # close the file

    if(check_is_utf8($contents)) {
	print "\tcontents are utf8\n";
    } else {
	print "\tcontents are not utf8\n"; 
    }
}